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P O S I V A O Y

O l k i l u o t o

F I -27160 EURAJOKI , F INLAND

Te l +358-2-8372 31

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Janne Pekkanen

Juha Vä i säsvaara

January 2010

Work ing Repor t 2010 -02

Flow Measurements in ONKALO at OlkiluotoProbe Holes, ONK-PVA3 and ONK-PVA5

January 2010

Working Reports contain information on work in progress

or pending completion.

The conclusions and viewpoints presented in the report

are those of author(s) and do not necessarily

coincide with those of Posiva.

Janne Pekkanen

Juha Vä i säsvaara

PRG-Tec Oy

Work ing Report 2010 -02

Flow Measurements in ONKALO at OlkiluotoProbe Holes, ONK-PVA3 and ONK-PVA5

FLOW MEASUREMENTS IN ONKALO AT OLKILUOTO, PROBE HOLES, ONK-PVA3 AND ONK-PVA5

ABSTRACT

The Posiva Flow Log, Difference Flow Method (PFL DIFF) uses a flowmeter that

incorporates a flow guide and can be used for relatively quick determinations of

hydraulic conductivity and hydraulic head in fractures/fractured zones in cored

drillholes. This report presents the principles of the methods that were used as well as

the results of the measurements carried out during the excavation of the underground

access tunnel ONKALO at Olkiluoto.

Phase 1 and phase 2 of the probe hole measurements in the access tunnel started when

the tunnel was 15 m long and finished at the tunnel length of 2917 m. The results of

phases 1 and 2 are presented in reports 2006-65 (Phase 1) /Reiman, M., Väisäsvaara, J

& Pöllänen, J. 2006/ and 2008-37 (Phase 2) /Pekkanen, J., 2008/. Probe hole

measurements were continued normally in phase 3. The phase 3 results are presented in

this report. Flow measurements started again on May 5, 2008 when tunnel length was

3009 m and ended on December 16, 2008, tunnel length 3288 m. Probe hole

measurements will continue normally below 3288 m.

In addition to normal probe holes, core-drilled drillholes were also measured in

ONKALO. The drillholes discussed in this report are ONK-PVA3 and ONK-PVA5.

ONK-PVA5 was measured on November 16, 2008 and ONK-PVA3 on January 29,

2009.

The PFL DIFF probe was used to detect flow within single fractures in the drillhole or

probe hole. The method utilizes rubber disks to isolate the flow in a test section from

that in the rest of the probe hole or to measure the flow along the probe hole. Probe

holes from ONK-TR3009 to ONK-TR3121 were measured using a 0.5 m section length

(the distance isolated with the rubber disks) with a 0.1 m point interval. The flow along

the probe hole was measured in ONK-TR3140 and subsequent probe holes.

The device used includes a sensor for single point resistance (SPR). SPR was measured

in connection with flow measurements. The flow measurement and the single point

resistance measurement were used to locate flowing fractures and evaluate their

transmissivity.

Electrical conductivity (EC) and temperature of water were registered during automatic

flow logging. The conductivity values are temperature corrected to 25 C.

Keywords: Groundwater, flow, measurement, bedrock, probe hole, drillhole, electrical

conductivity, Posiva Flow Log, flow logging.

VIRTAUSMITTAUKSET ONKALOSSA OLKILUODON ALUEELLA, TUNNUSTELUREIÄT, ONK-PVA3 JA ONK-PVA5

TIIVISTELMÄ Posiva Flow Log virtauseromittausmenetelmää (PFL DIFF) voidaan käyttää suhteel-

lisen nopeaan vedenjohtavuuksien ja virtauspaineiden määrittämiseen raoista tai rako-

vyöhykkeistä kairanrei’issä. Menetelmässä käytetään virtausanturia, johon mitattavan

syvyysvälin virtaus johdetaan virtausohjaimella. Tässä raportissa esitetään mittauksen

periaatteet ja tulokset mittauksista, jotka tehtiin tunnustelurei’istä ONKALOn

ajotunnelin louhinnan aikana.

Tunnustelureikien mittaukset aloitettiin tunneliurakka 1:n osalta paaluluvulta 15, ja

päätettiin tunneliurakka 2:n osalta paalulukuun 2917. Tunneliurakoiden 1 ja 2 aikana

tehdyt mittaukset on esitetty raporteissa 2006-65 (Tunneliurakka 1) /Reiman, M.,

Väisäsvaara, J & Pöllänen, J. 2006/ ja 2008-37 (Tunneliurakka 2) /Pekkanen, J., 2008/.

Tunnustelureikien mittaukset jatkuivat normaalisti myös tunneliurakka 3:ssa, jonka

mittaukset on esitetty tässä raportissa. Tämän raportin mittaukset alkoivat 5.5.2008

tunnelin pituuden ollessa 3009 m ja päättyivät 16.12.2008 tunnelin pituuden ollessa

3288 m. Tunnustelureikien mittaukset jatkuvat normaalisti 3288 m:stä eteenpäin.

Tunnustelureikien lisäksi ONKALOssa mitattiin myös muita kaira- tai porareikiä. Tässä

raportissa on esitetty mittaukset kairarei’iltä ONK-PVA3 ja ONK-PVA5. ONK-PVA5

mitattiin 16.11.2008 ja ONK-PVA3 29.1.2009

PFL DIFF mittauskalustolla paikallistetaan virtaukset yksittäisistä raoista kaira- tai

tunnustelurei’issä. Menetelmässä hyödynnetään kumikiekkoja joilla rakovirtaus rajataan

muusta reiästä testisektoriin. Vaihtoehtoisesti voidaan mitata reiän suuntaista virtausta.

Tunnustelureiät välillä ONK-TR3009 – ONK-TR3121 mitattiin 0.5 m sektorilla (sekto-

rin pituus joka on erotettu muusta reiästä kumikiekoilla), 0.1 m:n välein. Reiän

suuntaista virtausta mitattiin tunnustelureiästä ONK-TR3140 alkaen.

Mittauskalustossa on myös elektrodi yksipistemaadoitusvastus-mittaukseen (SPR). SPR

mitattiin aina virtausmittausten yhteydessä. Virtausmittausta ja maadoitusvastusmit-

tausta käytettiin vettä johtavien rakojen paikallistamiseen ja näiden transmissiviteetin

määrittämiseen.

Reikäveden sähkönjohtavuutta (EC) ja lämpötilaa mitattiin virtausmittausten yhtey-

dessä. Sähkönjohtavuus arvot korjattiin vastaamaan 25 C:n lämpötilan arvoja.

Avainsanat: Pohjavesi, virtaus, mittaus, peruskallio, tunnustelureikä, kairanreikä,

sähkönjohtavuus, Posiva Flow Log, virtausmittaus.

1

TABLE OF CONTENTS

1 INTRODUCTION ................................................................................................. 5

2 PRINCIPLES OF MEASUREMENT AND INTERPRETATION ............................. 9

2.1 Measurements ............................................................................................ 9

2.2 Interpretation ............................................................................................ 13

3 EQUIPMENT SPECIFICATIONS ....................................................................... 17

4 DESCRIPTION OF THE DATA SET .................................................................. 19

4.1 Field work ................................................................................................. 19

4.2 Results ..................................................................................................... 20

4.2.1 General comments

4.2.2 Transmissivity and hydraulic aperture of fractures during flow

logging

4.2.3 Electrical conductivity and temperature of probe hole water

4.3 Results of the individual probe- and drillholes ........................................... 23

4.3.1 ONK-TR3009, 5.5.2008 – 6.5.2008

4.3.2 ONK-TR3020, 19.5.2008

4.3.3 ONK-TR3040, 20.5.2008 – 21.5.2008

4.3.4 ONK-TR3116, 8.8.2008 – 9.8.2008

4.3.5 ONK-TR3121, 20.8.2008 – 21.8.2008

4.3.6 ONK-TR3140, 4.9.2008 – 5.9.2008

4.3.7 ONK-TR3145, 12.9.2008

4.3.8 ONK-TR3170, 14.10.2008

4.3.9 ONK-PVA5, 16.11.2008

4.3.10 ONK-TR3263, 25.11.2008

4.3.11 ONK-TR3273, 3.12.2008

4.3.12 ONK-TR3288, 16.12.2008

4.3.13 ONK-PVA3, 29.1.2009

5 SUMMARY AND DISCUSSION ......................................................................... 39

REFERENCES ........................................................................................................... 41

3

Appendix 1.1 Probe hole ONK-TR3009B, Flow rate and single point resistance

Appendix 1.2 Probe hole ONK-TR3009B, Transmissivity and hydraulic aperture of detected fractures

Appendix 1.3 Probe hole ONK-TR3009B, Tabulated results of detected fractures

Appendix 1.4 Probe hole ONK-TR3009B, Electrical conductivity of probe hole water

Appendix 1.5 Probe hole ONK-TR3009B, Temperature of probe hole water

Appendix 2.1 Probe hole ONK-TR3020A, Flow rate and single point resistance

Appendix 2.2 Probe hole ONK-TR3020A, Electrical conductivity of probe hole water

Appendix 2.3 Probe hole ONK-TR3020A, Temperature of probe hole water





Appendix 3.5 Probe hole ONK-TR3116C, Flow rate and single point resistance

Appendix 3.6 Probe hole ONK-TR3116C, Transmissivity and hydraulic aperture of detected fractures

Appendix 3.7 Probe hole ONK-TR3116C, Electrical conductivity of probe hole water

Appendix 3.8 Probe hole ONK-TR3116C, Temperature of probe hole water

Appendix 3.9 Probe hole ONK-TR3116D, Flow rate and single point resistance

Appendix 3.10 Probe hole ONK-TR3116D, Electrical conductivity of probe hole water

Appendix 3.11 Probe hole ONK-TR3116D, Temperature of probe hole water

Appendix 3.12 Probe holes ONK-TR3116B and ONK-TR3116C, Tabulated results of detected fractures









Appendix 4.9 Probe hole ONK-TR3121C, Transmissivity and hydraulic aperture of

detected fractures




Appendix 4.13 Probe hole ONK-TR3121D, Transmissivity and hydraulic aperture of detected fractures



Appendix 4.16 Probe holes ONK-TR3121B, ONK-TR3121C and ONK-TR3121D, Tabulated results of detected fractures


Appendix 5.2 Probe hole ONK-TR3140A, Transmissivity and hydraulic aperture of

detected fractures




4




Appendix 5.9 Probe hole ONK-TR3140D, Transmissivity and hydraulic aperture of

detected fractures



Appendix 5.12 Probe holes ONK-TR3140A and ONK-TR3140D, Tabulated results of detected fractures




Appendices 7.1 – 7.2

Drillhole ONK-PVA5, Flow rate and single point resistance

Appendix 7.3 Drillhole ONK-PVA5, Transmissivity and hydraulic aperture of detected

fractures

Appendix 7.4 Drillhole ONK-PVA5, Tabulated results of detected fractures

Appendix 7.5 Drillhole ONK-PVA5, Electrical conductivity of drillhole water

Appendix 7.6 Drillhole ONK-PVA5, Temperature of drillhole water


Appendix 8.2 Probe hole ONK-TR3263D, Transmissivity and hydraulic aperture of

detected fractures

Appendix 8.3 Probe hole ONK-TR3263D, Tabulated results of detected fractures




Appendix 9.2 Probe hole ONK-TR3288A, Transmissivity and hydraulic aperture of

detected fractures

Appendix 9.3 Probe hole ONK-TR3288A, Tabulated results of detected fractures



Appendix 10.1 Drillhole ONK-PVA3, Flow rate and single point resistance

Appendix 10.2 Drillhole ONK-PVA3, Transmissivity and hydraulic aperture of detected

fractures

Appendix 10.3 Drillhole ONK-PVA3, Tabulated results of detected fractures

Appendix 10.4 Drillhole ONK-PVA3, Electrical conductivity of drillhole water

Appendix 10.5 Drillhole ONK-PVA3, Temperature of drillhole water

5

The construction of Posiva’s underground facility, ONKALO, has progressed to a state

where the length of the underground access tunnel is over 3300 m. The location of

ONKALO at Olkiluoto is presented in Figure 1-2. The profile of ONKALO is presented

in Figure 1-3. During the excavation ca. 20 m – 29 m long probe holes were drilled

before the next blasting rounds were exploded. These probe holes were measured by the

Posiva Flow Log, Difference flow method (PFL DIFF). The PFL DIFF probe has been

developed by PRG-Tec Oy for the use of Posiva Oy. The Location of the probe holes

was always at the end of the excavation, i.e., at the back wall of the excavation tunnel.

The amount of probe holes that were drilled was usually four. Probe hole locations and

naming (on the back wall of the tunnel) are presented in Figure 1-1.

This report present measurements of the probe holes that begun with hole ONK-

TR3009B (pile number). The 3009 in the name means that the back wall of the tunnel

was at 3009 m, i.e., the tunnel was 3009 m long. In the illustrations in the appendices

the depth axis starts from 0 m. The reason for this difference is that the zero coordinate

in the depth axis is always the location of the back wall of the tunnel. This is true for all

the holes that were measured. The depth axis always starts from 0 m in every Appendix.

The direction of the depth axis is along the drillhole, i.e., it is not directed towards the

centre of the Earth. The letter B in the name corresponds to the letter B in Figure 1-1.

The naming protocol in probe holes is based on the form ONK-TRxxxxA, where xxxx

is the number of the hole and it is also the length of the tunnel. The last letter shows the

location on the back wall of the tunnel.

The probe holes from ONK-TR3009 to ONK-TR3121 were measured using a 0.5 m

section length (the distance isolated with rubber disks in the probe) and a 0.1 m point

interval. The probe holes starting at ONK-TR3140 were measured without the lower

rubber disks of the probe using a 0.2 m point interval. This device setup measures flow

along the probe hole.

Throughout the measurements the basic rule was that there has to be flow out from the

probe hole before even trying to do any measurements. If there was no flow out from

the probe hole at all, then measurements were not even started.

Overall there were 11 blasting rounds to be measured (one blasting round contains 2 – 4

probe holes), the rest of the probe holes either did not have any outflow (i.e. they were

“dry”) or there were other blockages that prevented the hole from being measured (i.e.

hole was partially collapsed or damaged in some other way). There were no measurable

flows between blasting rounds TR3170 – TR3263.

Core-drilled drillholes were also measured in addition to normal probe holes. The

measured core-drilled holes discussed in this report are ONK-PVA3 and ONK-PVA5.

This report presents the main principles of the methods that were used as well as the

results of the measurements carried out in the probe holes and drillholes. The field work

and the subsequent interpretation were conducted by PRG-Tec Oy.

6

Figure 1-1. Location and naming of the probe holes in ONKALO.

7

Figure 1-2. The Location of Posiva’s underground facility, ONKALO in relation to the drillholes at Olkiluoto.

Figure 1-3. The Profile of Posiva’s underground facility, ONKALO.

9

2 PRINCIPLES OF MEASUREMENT AND INTERPRETATION

2.1 Measurements

Unlike conventional drillhole flowmeters which measure the total cumulative flow rate

along a drillhole, the PFL DIFF probe measures the flow rate into or out of defined

drillhole sections. The advantage that follows from measuring the flow rate in isolated

sections is improved detection of incremental changes of flow along the drillhole. As

these are generally very small, they can easily be missed when using conventional

flowmeters.

Rubber sealing disks located at the top and bottom of the probe are used to isolate the

flow of water in the test section from the flow in the rest of the drillhole, see Figure 2-1.

Flow inside the test section is directed through the flow sensor. Flow along the drillhole

is directed around the test section by means of a bypass pipe and is discharged at either

the upper or lower end of the probe. The entire structure is called the flow guide.

Generally two separate measurements with two different section lengths (e.g. 2 m and

0.5 m) are used. The 2 m setup is usually used first to obtain a general picture of the

flow anomalies. It is also good for measuring larger (less than 2 m in length) fractured

zones. The 0.5 m section setup can separate anomalies which are close to each other.

Different section lengths are also used to confirm that a flow anomaly is real and not

caused for instance by a leak at the rubber disks. Mostly in ONKALO quick

determinations of hydraulic conductivity and hydraulic head in fractures/fractured zones

are needed and only section setup (generally 0.5 m) is used.

Flow rates into or out of the test section are monitored using thermistors, which track

both the dilution (cooling) of a thermal pulse and its transfer by the moving water. The

thermal dilution method is used in measuring flow rates because it is faster than the

thermal pulse method, and the latter is used only to determine flow direction within a

given time frame. Both methods are used simultaneously at each measurement location.

In addition to incremental changes in flow, the PFL DIFF probe can also be used to

measure:

The electrical conductivity (EC) of both drillhole water and fracture-specific water.

The electrode used in EC measurements is located at the top of the flow sensor, see

Figure 2-1.

The single point resistance (SPR) of the drillhole wall (grounding resistance). The

electrode used for SPR measurements is located between the uppermost rubber

sealing disks, see Figure 2-1, and is used for the high-resolution depth determination

of fractures and geological structures.

The prevailing water pressure profile in the drillhole. Located inside the watertight

electronics assembly, the pressure sensor transducer is connected to the drillhole

water through a tube, see Figure 2-2.

The temperature of the water in the drillhole. The temperature sensor is part of the

flow sensor, see Figure 2-1.

10

WinchPumpComputer

Flow along the borehole

Rubberdisks

Flow sensor-Temperature sensor is located in the flow sensor

Single point resistance electrode

EC electrode

Measured flow

Figure 2-1. Schematic of the probe used in the PFL DIFF.

FLOW TO BE MEASURED

FLOW ALONG THE BOREHOLE

RUBBERDISKS

FLOW SENSOR

PRESSURE SENSOR (INSIDE THE ELECTRONICSTUBE)

CABLE

Figure 2-2. The absolute pressure sensor is located inside the electronics assembly and

connected to the drillhole water through a tube.

Flow along the drillhole

PRESSURE SENSOR (INSIDE THE ELECTRONICS ASSEMBLY)

FLOW ALONG

THE DRILLHOLE

RUBBER SEALING

DISKS

Rubber sealing

disks

11

The principles behind PFL DIFF flow measurements are shown in Figure 2-3. The flow

sensor consists of three thermistors (Figure 2-3 a). The central thermistor, A, is used

both as a heating element and to register temperature changes (Figures 2-3 b and c). The

side thermistors, B1 and B2, serve as detectors of the moving thermal pulse caused by

the heating of A.

Flow rate is measured by monitoring heat transients after constant power heating in

thermistor A. The measurement begins by constant power (P1) heating. After the power

is cut off the flow rate is measured by monitoring transient thermal dilution

(Figure 2-3 c). If the measured flow rate exceeds a certain limit, another constant power

heating (P2) period is started after which the flow rate is re-measured from the following

heat transient.

Flows are measured when the probe is at rest. After transferring the probe to a new

position, a waiting period (which can be adjusted according to the prevailing

circumstances) is allowed to elapse before the heat pulse (Figure 2-3 b) is applied. The

measurement period after the constant-power thermal pulse (normally 100 s each time

the probe has moved a distance equal to the test section length and 10 s in every other

location) can also be adjusted. The longer (100 s) measurement time is used to allow the

direction of even the smallest measurable flows to be visible.

The flow rate measurement range is 30 mL/h – 300 000 mL/h. Depending on conditions

in the drillhole, these limits may not always prevail. Examples of possible disturbances

are drilling debris entrained in the drillhole water, bubbles of gas in the water and high

flow rates (some 30 L/min, i.e., 1 800 000 mL/h or more) along the drillhole. If the

disturbances encountered are significant, limits on practical measurements are

calculated for each set of data.

It is also possible to setup the probe so that it measures flow along the hole. This setup

should be less sensitive to roughness of the hole wall and loose rock material. In

addition, with this setup it is possible to measure much higher flow rates, flows

originating from the bottom of the hole and check the results at the site when the probe

is on the top of the hole (if the hole is pumped or if it is an open underground hole). A

drawback is that the accuracy even in good hole conditions is about 20% of current flow

value. Another limitation of the method is that small flow rates above a larger flow may

remain undetected. The method was still in test use during this measurement campaign.

12

-5 0 5 10 15

0

50

100

150

200

Po

we

r (m

W)

AB1 B2

Flow sensor

Constant power in A

-5 0 5 10 15Time (s)

0

10

20

30

40

dT

(C)

Flow rate (mL/h)

1020

3060

6090

13300

27700

57200

135000

297000

Thermal dilution method

Temperature change in A

P1

P2

a)

b)

c)

Figure 2-3. Flow rate measurement.

The device depth reference point in the PFL DIFF is situated at the upper end of the test

section. When assessing the location of anomalies in the measured hole there are always

some errors. They can be caused by the following reasons:

1. If the point interval is x, an error of ± x/2 can potentially occur.

2. The length of the test section is not exact. The specified section length denotes the distance between the nearest upper and lower rubber sealing disks. Effectively, the section length can be larger. At both ends of the test section there are four rubber sealing disks. The distance between them is 5 cm. This will

13

cause rounded flow anomalies: a flow may be detected already when a fracture is situated between the four rubber sealing disks. These phenomena can cause an error of ± 0.05 m when the short step length (0.1 m) is used. A similar error can occur when the flow along the hole is measured.

3. The cable stretches under tension. When the probe is lifted upwards at c. 1000 m the tension can be c. 175 kg. When it is lowered at the same depth, the tension can be c. 75 kg. This difference could cause a depth difference of c. 3 m between the measurements at depth of c. 1000 m. The tension values here are estimates and can vary greatly depending on the device setup and hole properties.

The total error in the worst case can be estimated. With a 0.1 m point interval the error would be:

E = 0.05 m + 0.05 m + d·0.002

where E is the total estimated error and d is the depth of the probe shown by the cable counter of the winch. Note that this is only a rough estimate and it is subject to change. It should also be noted that this is only one way of estimating the error. Experience has shown that when holes with length marks have been measured the error has been approximately 1 m at the depth of c. 1000 m.

Fractures nearly parallel with the hole may also be problematic. Fracture location may be difficult to define accurately in such cases.

2.2 Interpretation

The interpretation of data is based on Thiem’s or Dupuit’s formula that describes a

steady state and a two dimensional radial flow into the drillhole /Marsily, G., 1986/:

hs – h = Q/(T·a) 2-1

where h is the hydraulic head in the vicinity of the drillhole and h = hs at the radius of

influence (R),

Q is the flow rate into the drillhole,

T is the transmissivity of the test section,

a is a constant depending on the assumed flow geometry. For cylindrical flow, the

constant a is:

a = 2· /ln(R/r0) 2-2

14

where

r0 is the radius of the well and

R is the radius of influence, i.e., the zone inside which the effect of pumping is felt.

If measurements of flow rate are carried out using two levels of hydraulic head in the

drillhole, i.e., natural and pump-induced heads, then the undisturbed (natural) hydraulic

head and the transmissivity of the drillhole sections tested can be calculated. Equation

3-2 can be reformulated in the following two ways:

Qs0 = Ts·a·(hs- h0) 2-3

Qs1 = Ts·a·(hs- h1) 2-4

where

h0 and h1 are the hydraulic heads in the drillhole at the test levels,

Qs0 and Qs1 are the measured flow rates in the test section,

Ts is the transmissivity of the test section and

hs is the undisturbed hydraulic head in the tested zone far from the drillhole.

In general, since very little is known about the flow geometry, cylindrical flow without

skin zones is assumed. Cylindrical flow geometry is also justified because the drillhole

is at a constant head, and no strong pressure gradients along the drillhole exist except at

its ends.

The radial distance R to the undisturbed hydraulic head hs is not known and must

therefore be assumed. In this case, a value of 500 for the quotient R/r0 is selected.

The hydraulic head and the transmissivity in the test section can be deduced from the

two measurements:

hs = (h0-b·h1)/(1-b) 2-5

Ts = (1/a) (Qs0-Qs1)/(h1-h0) 2-6

where

b = Qs0-Qs1

15

The transmissivity (Tf) and hydraulic head (hf) of individual fractures can be calculated

provided that the flow rates at the individual fractures are known. Similar assumptions

to those employed above must be used (a steady-state cylindrical flow regime without

skin zones).

hf = (h0-b·h1)/(1-b) 2-7

Tf = (1/a) (Qf0-Qf1)/( h1-h0) 2-8

where

Qf0 and Qf1 are the flow rates at a fracture and hf and Tf are the hydraulic head (far from

the drillhole) and transmissivity of a fracture, respectively.

Since the actual flow geometry and any skin effects are unknown, transmissivity values

should only be considered as an indication of the prevailing orders of magnitude. As the

calculated hydraulic heads do not depend on geometrical properties but only on the ratio

of the flows measured at different heads in the drillhole, they should be less sensitive to

unknown fracture geometry. A discussion of potential uncertainties in the calculation of

transmissivity and hydraulic head can be found in /Ludvigson et al., 2002/.

The hydraulic aperture of fractures can be calculated from /Marsily, G, 1986/:

T = e3·g·ρ/(12·μ·C) 2-9

e = (12·T·μ·C/(g·ρ))1/3

2-10

where

T = transmissivity of the fracture (m2/s)

e = hydraulic aperture (m)

μ = viscosity of water, 0.00139 (kg/(ms))

g = acceleration due to gravity, 9.81 (m/s2)

ρ = density of water, 999 (kg/m3)

C = experimental constant for fracture roughness, here chosen to be 1.

17

In the PFL DIFF method, the flow of groundwater into or out of a drillhole section is

monitored using a flow guide which employs rubber sealing disks to isolate any such

flow from the flow of water along the drillhole. This flow guide defines the test section

being measured without altering the hydraulic head. Groundwater flowing into or out of

the test section is guided to the flow sensor, and flow is measured using the thermal

pulse and thermal dilution methods. Measured values are transferred to a computer in

digital form.

Type of instrument: PFL DIFF probe

Drillhole diameters: 56 mm, 66 mm and 76 mm (or larger)

Length of test section: The flow guide length can be varied

Method of flow measurement: Thermal pulse and thermal dilution

Range and accuracy of measurement: See Table 3-1.

Additional measurements: Temperature, Single point resistance,

Electrical conductivity of water, Water

pressure

Winch: Mount Sopris Wna 10, 0.55 kW,

conductors, Gerhard-Owen cable head

Depth determination: Based on a digital distance counter

Logging computer: PC (Windows XP)

Software: Based on MS Visual Basic

Total power consumption: 1.5 - 2.5 kW depending on the type of

pump employed

Table 3-1. Range and accuracy of sensors.

Sensor Range Accuracy

Flow 30 – 300 000 mL/h ± 10% curr.value

Temperature (central thermistor) 0 – 50 C 0.1 C

Temperature difference (between outer thermistors) -2 – + 2 C 0.0001 C

Electric conductivity of water (EC) 0.02 – 11 S/m ± 5% curr.value

Single point resistance 5 – 500 000 ± 10% curr.value

Groundwater level sensor 0 – 0.1 MPa ± 1% fullscale

Air pressure sensor 800 – 1060 hPa 5 hPa

Absolute pressure sensor 0 - 20 MPa ± 0.01% fullscale

19

The probe holes were measured between May 2008, ONK-TR3009 and December

2008, ONK-TR3288. All measurements were made using the PFL DIFF probe. Core-

drilled drillholes ONK-PVA3 and ONK-PVA5 were also measured in ONKALO. All

measurements were made during natural outflow from an open hole. The activity

schedule is presented in Table 4-1.

Table 4-1. Activity schedule.

Started Finished Activity

5.5.2008 16:00 6.5.2008 1:25 Probe holes at ONK-TR3009. Flow logging (L = 0.5 m, dL = 0.1 m)





4.9.2008 11:30 5.9.2008 0:30 Probe holes at ONK-TR3140. Flow logging. Flow along the probe hole, dL = 0.2 m.



16.11.2008 11:00 16.11.2008 19:00 Drillhole ONK-PVA5. Flow logging (L = 0.5 m, dL = 0.1 m)




29.1.2009 12:00 29.1.2009 17:00 Drillhole ONK-PVA3. Flow logging (L = 0.5 m, dL = 0.1 m)

20

The measurement schedule consisted of several probe hole measurements. However not

all the probe holes could be measured or they could only be measured partially (in these

cases the distance from the back wall of the tunnel to the upper end of the section has

been given). Altogether, there were 11 blasting rounds to be measured (one blasting

round contained 2 - 4 probe holes). All the probe hole measurements where at least one

probe hole had a measurable outflow are presented in Table 4-2. Before each

measurement the probe was pushed to the bottom of the hole with push rods, i.e., the

measurement direction was from the bottom to the top of the hole.

Table 4-2. Probe hole measurements in ONKALO and related appendices.

Probe hole

Flow out from the hole

Successful measurement Comments Appendices

ONK-TR3009A yes not measured *

ONK-TR3009B yes yes Drilling debris in the hole 1.1 – 1.5

ONK-TR3009C yes no ****

ONK-TR3009D yes no *

ONK-TR3020A yes (7.0 m) **, No flows 2.1 – 2.3

ONK-TR3020B no not measured

ONK-TR3020C no not measured

ONK-TR3020D no not measured

ONK-TR3040A no not measured


ONK-TR3040C yes not measured ****, Flow decreased before the measurements


ONK-TR3116A yes not measured **, Drilling rods were stuck at the hole

ONK-TR3116B yes yes Drilling debris in the hole 3.1 – 3.4, 3.12

ONK-TR3116C yes yes Drilling debris in the hole 3.5 – 3.8, 3.12

ONK-TR3116D yes (23.6 m) ** 3.9 – 3.11

ONK-TR3121A yes (20.4 m) **, No flows were detected

4.1 – 4.3

ONK-TR3121B yes yes 4.4 – 4.7, 4.16

ONK-TR3121C yes yes 4.8 – 4.11, 4.16

ONK-TR3121D yes yes 4.12 – 4.16

ONK-TR3140A yes (23.8 m) ** 5.1 – 5.4, 5.12

ONK-TR3140B yes not measured Decided to measure only holes A, C and D

ONK-TR3140C yes (7.0 m) **, Flows below 8.5 m 5.5 – 5.7

ONK-TR3140D yes (12.0 m) ** 5.8 – 5.12

21

Probe hole

Flow out from the hole

Successful measurement Comments Appendices

ONK-TR3145A yes probe stopped at 2.0 m

**, Not measured (5 m minimum length)

ONK-TR3145B yes probe stopped at 2.0 m


ONK-TR3145C yes (13.2m) ** 6.1 – 6.3

ONK-TR3145D yes dummy stopped at 2.0 m


ONK-TR3170A no not measured

ONK-TR3170B yes dummy stopped at 2.25 m




ONK-TR3263A yes dummy stopped at 2.0 m




ONK-TR3263D yes (26.0 m) ** 8.1 – 8.5

ONK-TR3273A yes The probe stopped at 4.0 m

**, Not measured (5 m minimum length), Drilling debris in the hole

ONK-TR3273B yes dummy stopped at 3.0 m

**, Not measured (5 m minimum length), Drilling debris in the hole

ONK-TR3273C yes no Probe hole had collapsed before the measurements

ONK-TR3273D yes dummy stopped at 17 m

**, Not measured. Lots of drilling debris in the hole

ONK-TR3288A yes (8.7 m – 5.0 m) **, The probe got stuck and could not be released

9.1 – 9.5

ONK-TR3288B yes not measured ***

ONK-TR3288C yes not measured ***


* Lack of time for measurements.

** The probe did not go into the probe hole due to pieces of rock or some other

obstacle.

*** Upwards slanted probe hole, not measurable.

**** Probe hole’s outflow below measurement limit.

In some cases the probe hole outflow has been marked zero, even though there was a

small outflow from the hole. In these cases the probe hole outflow was smaller than the

measurement limit of the manual device (30 mL/min [1 800 mL/h] or 500 mL/min

[30 000 mL/h] in upwards slanted holes). Such a hole is considered “dry” for

measurement purposes.

22

The probe holes measured with the PFL DIFF probe produced flow rate and single point

resistance data. They are illustrated side by side (with a common depth axis) in the

appendices. Single point resistance is usually low on a fracture where a flow is detected.

There are also many other resistance anomalies originating from other fractures and

geological features. As the electrode of the SPR tool is located within the upper rubber

sealing disks of the probe, the locations of resistance anomalies associated with leaky

fractures coincide with the lower end of the flow anomalies. EC (electrical conductivity)

and the temperature of the probe hole water were also measured with the PFL DIFF

probe, see Appendices 1.4, 1.5, 2.2, 2.3, 3.3, 3.4, 3.7, 3.8, 3.10, 3.11, 4.2, 4.3, 4.6, 4.7,

4.10, 4.11, 4.14, 4.15, 5.3, 5.4, 5.6, 5.7, 5.10, 5.11, 6.2, 6.3, 7.5, 7.6, 8.4, 8.5, 9.4, 9.5,

10.4 and 10.5.

The flow loggings were performed with a 0.5 m section length and with 0.1 m length

decrements when flow from the measurement section was measured or with 0.2 m

length decrements when flow along the probe hole was measured, see Appendices 1.1,

2.1, 3.1, 3.5, 3.9, 4.1, 4.4, 4.8, 4.12, 5.1, 5.5, 5.8, 6.1, 7.1, 7.2, 8.1, 9.1 and 10.1. All the

measurements were carried out under such conditions that the probe hole was open. The

PFL DIFF method (overlapping flow logging) gives the length and thickness of

conductive zones with a length resolution of 0.1 m (flow from the measured section) or

0.2 m (flow along the probe hole).

The length of the test section, when flow from the measurement section is measured,

determines the resolution of the detection of a flow anomaly. If the distance between

flow yielding fractures is less than the section length, the anomalies will overlap,

resulting in a stepwise flow data plot. If the flow along the hole is measured, the flow

anomaly detection resolution is equal to the point interval.

In the flow logging measurement result images, the detected fractures are illustrated

between the flow and the single point resistance curves. They are interpreted on the

basis of the flow curves and therefore represent only the fractures that have a detectable

flow. A long line represents the location of a leaky fracture; a short line denotes that the

existence of a leaky fracture is uncertain. A short line is used if the flow anomalies are

overlapping or if they are unclear because of noise.

The results of the fractures that were detected are also presented in a tabulated form for

each probe hole, e.g., see Appendix 1.3.

An attempt was also made to evaluate the magnitude of fracture-specific flow rates in

measurements. After that, their flow rates were evaluated.

When flow from the measurement section is analyzed, it is not a problem to evaluate the

flow rate when the distance between flowing fractures is larger than 0.5 m. On the other

hand, the evaluation may be problematic when the distance between fractures is less

than 0.5 m. In these cases a stepwise increase or decrease in the flow data plot equals

the flow rate of a specific fracture. If the flow for a specific fracture cannot be

23

determined conclusively, the flow rate is marked with “-“ and a zero flow value is used

in transmissivity calculation. The flow direction is always into the hole by default. The

results of the evaluation are presented in tabulated form in association with the plotted

results of each drillhole, under the header “Tabulated results of detected fractures…”,

e.g., Appendix 1.3.

Some fracture-specific results were classified as “uncertain”, e.g. Appendix 3.1, short

line. The criterion “uncertain” was in most cases given if a minor flow rate in relation to

the noise level was detected.

The hydraulic aperture of the fractures was evaluated based on transmissivity, as

described in Chapter 2.

The electrical conductivity (EC) and the temperature of the probe hole water were also

measured during the flow measurements, e.g., see Appendices 1.4, 1.5, 2.2, 2.3, 3.3, 3.4,

3.7, 3.8, 3.10, 3.11, 4.2, 4.3, 4.6, 4.7, 4.10, 4.11, 4.14, 4.15, 5.3, 5.4, 5.6, 5.7, 5.10, 5.11,

6.2, 6.3, 7.5, 7.6, 8.4, 8.5, 9.4, 9.5, 10.4 and 10.5).

The temperature of the probe hole water was measured simultaneously with the

electrical conductivity. The EC-values are temperature corrected to 25 C to make them

comparable with other EC measurements /Heikkonen et. al, 2002/.

The EC and temperature results may not fully represent the actual conditions in the

drillhole. When the flow is measured with the 0.5 m test section, the measurement is

conducted using both the upper and lower rubber sealing disks. In this case the flow

guide carries water with it and good flushing at the EC electrode and at the temperature

sensor cannot be guaranteed.

At blasting round ONK-TR3009 four probe holes were drilled and three probe holes had

a measurable outflow. The three measurable probe holes were ONK-TR3009A, ONK-

TR3009B and ONK-TR3009D. Due to lack of time it was decided that only the biggest

outflow would be measured (probe hole ONK-TR3009B). The probe hole was measured

with a section length of 0.5 m and a measurement was performed every 0.1 m.

Preparations for measurements at 16:00 – 18:30.

Notes for ONK-TR3009B:

- The preparations at the site started at 18:30.

- The outflow from the probe hole before the flow measurements, at 19:30, was

8 400 mL/h.

24

- Dummy measurement at 20:00 – 20:20.

- Moving the probe with push rods at 20:20 – 20:35.

- Starting the measurements at 20:43.

- Measurements ready at 23:25.

- Flow out from the probe hole after the measurement at 23:50, 0 mL/h.

- Measurements ready.

- Moving out from ONKALO at 00:00.

Packing, maintenance of measurement equipment and data processing at 00:00 – 01:25.

Comments on ONK-TR3009B results:

Drilling debris was found in the probe hole and in the probe. It probably caused

unreliable flow measurement results.

ONK-TR3009B flow out from the probe hole before measurements = 8 400 mL/h

ONK-TR3009B flow out from the probe hole after measurements = 0 mL/h

ONK-TR3009B measured sum of flows with the PFL DIFF probe = 258 mL/h

- The flow out from the probe hole decreased to zero during the measurements.

This makes it difficult to compare the sum of the measured flows and the

outflow of the probe hole.

The results are presented in Appendices 1.1 – 1.5.

At blasting round ONK-TR3020 four probe holes were drilled and one probe hole had a

measurable outflow. The measurable probe hole was ONK-TR3020A. The probe hole

was measured with a section length of 0.5 m and a measurement was performed every

0.1 m.

Preparations for measurements at 7:00 – 12:00.

Notes for ONK-TR3020A:

- The preparations at the site and measurements started at 12:00.


732 000 mL/h.

- Dummy measurement at 12:30 –12:50.

o The dummy stopped at the length of 7.0 m.

- Moving the probe with push rods at 12:50 –13:07.

o The probe stopped at the length of 7.0 m.



- Flow out from the probe hole after the measurement at 14:10, 606 000 mL/h.

- Measurements ready.

- Moving out from ONKALO at 14:20.

25


Comments on ONK-TR3020A results:

Flushing of the probe hole had been quite successful. A small amount of drilling debris

was found.

ONK-TR3020A flow out from probe hole before measurements = 732 000 mL/h

ONK-TR3020A flow out from probe hole after measurements = 606 000 mL/h

ONK-TR3020A measured sum of flows with the PFL DIFF probe = 0 mL/h

- The entire probe hole could not be measured and it is possible that there were

flowing fractures deeper within the hole.

- It is also possible that some flowing fractures were not detected due to the high

noise level in the upper end of the probe hole (i.e. flows were hidden by the

noise) or because the rubber disks of the PFL DIFF probe were leaking (i.e.

flows bypassed the flow meter).


At blasting round ONK-TR3040 four probe holes were drilled and one probe hole had a

measurable outflow. The measurable probe hole was ONK-TR3040C. The probe hole

was measured with a section length of 0.5 m and a measurement was performed every

0.1 m, but the measurements were unsuccessful.

Preparations before measurements at 9:00 – 11:00.

Notes for ONK-TR3040C, 20.5.2008:

- The outflow from the probe hole before the flow measurements was

190 mL/min.

- Dummy measurement at 11:40 – 11:55


- Moving the probe with push rods 11:55 – 12:33.



- Measurements stopped at 14:22. The probe was not working properly.

Comments on ONK-TR3040C results, 20.5.2008:

- The PFL DIFF probe was not working properly and the measurements were not

continued. Solving the problem at 14:22 – 16:00.

- Due to constructions at ONKALO, the next possible measurement opportunity

was on the following morning.

Packing, maintenance of measurement equipments at 16:00 – 16:30.

26


- Preparations etc. including waiting time to get into the measurement position at

5:30 – 8:00.

- Measurement trailer in the ONKALO at about 8:00.

- Preparations at the site at 8:00 – 10:00.

- Flow out from the probe hole only 15 mL/min at 10:00.

o Flow rate below measurement limit (30 mL/min), aborting flow logging

measurements.

Moving out from ONKALO at 10:40.

At blasting round ONK-TR3116 four probe holes were drilled and all the probe holes

had a measurable outflow. Probe hole ONK-TR3116A could not be measured, because

drilling rods were stuck in it. The other probe holes were measured with a section length

of 0.5 m and a measurement was performed every 0.1 m.

Preparations for the measurements at 10:00 – 15:00.

Notes for ONK-TR3116D, 8.8.2008:


186 000 mL/h.

- Dummy measurement at 15:15 –15:30









11 400 mL/h.




o The probe reached the bottom of the hole (29 m).

- Starting the measurements at19:17.


- Flow out from the probe hole after the measurement at 22:50, 16 800 mL/h

Notes for ONK-TR3116B, 8.8.2008 – 9.8.2008:


18 000 mL/h.

- Dummy measurement was made during ONK-TR3166C measurements.

27

o The dummy reached the bottom of the hole (29 m)


o The probe reached the bottom of the hole (29 m).





Comments on ONK-TR3116 results:

ONK-TR3116D flow out from probe hole before measurements = 186 000 mL/h

ONK- TR3116D flow out from probe hole after measurements = 333 000 mL/h

ONK- TR3116D measured sum of flows with PFL DIFF probe = 0 mL/h

- No certain fracture areas were found. The reason that there is a difference in

flow out from the probe hole and the sum of the measured flows could be due to

the high noise level in the probe hole (i.e. flows are hidden by the noise) or the

rubber disks of the PFL DIFF probe could be leaking (i.e. flows bypass the flow

meter). These leaks can be caused by crushed rock material in the probe hole,

rough probe hole wall or if the wall of the probe hole was more curved/ovoid

than expected.

- The main fracture area is probably below 23.5 m (the probe stopped at the depth

of 23.5 m). High flow rates should probably have been detected above the noise

level.

ONK-TR3116C flow out from probe hole before measurements = 11 400 mL/h

ONK- TR3116C flow out from probe hole after measurements = 16 800 mL/h

ONK- TR3116C measured sum of flows with PFL DIFF probe = 7 800 mL/h

- The reason that there is a difference in the flow out from the probe hole and the

sum of the measured flows could be because the rubber disks of the PFL DIFF

probe could have been leaking (i.e. flows bypassed the flow meter). These leaks

can be caused by crushed rock material in the probe hole, rough probe hole wall

or if the wall of the probe hole is more curved/ovoid than expected.

- The main fracture zone is probably between 7 m – 11 m where all of the

measured flows were located.

- Some drilling debris was found in the probe. It probably caused some inaccuracy

in measured flow rates.

ONK-TR3116B flow out from probe hole before measurements = 18 000 mL/h

ONK- TR3116B flow out from probe hole after measurements = 16 800 mL/h

ONK- TR3116B measured sum of flows with the PFL DIFF probe = 7 920 mL/h


sum of the measured flows could be because the rubber disks of the PFL DIFF




- Some drilling debris was found in the probe. It probably caused some inaccuracy

in measured flow rates.

28


At blasting round ONK-TR3121 four probe holes were drilled and all the probe holes

had a measurable outflow. The probe holes were measured with a section length of

0.5 m and a measurement was performed every 0.1 m.


Notes for ONK-TR3121D, 20.8.2008:


1.20 · 106 mL/h.



o The probe and dummy reached the bottom of the hole (29 m).



- Flow out from the probe hole after the measurement at 18:40, 1.632 · 106 mL/h.



19 200 mL/h.

- Dummy measurement was made during ONK-TR3121D flow logging.


o The probe and dummy reached the bottom of the hole (29 m).




Notes for ONK-TR3121B, 20.8.2008 – 21.8.2008:


36 000 mL/h.



o The probe reached the bottom of the hole (29 m). The dummy had

stopped at the depth of 12.5 m.




Notes for ONK-TR3121A, 21.8.2008:


432 000 mL/h.



29

o The probe and dummy stopped at the length of 20.4 m.






ONK-TR3121D flow out from probe hole before measurements = 1.20 · 106 mL/h

ONK-TR3121D flow out from probe hole after measurements = 1.632 · 106 mL/h

ONK-TR3121D measured sum of flows with the PFL DIFF probe = 150 000 mL/h

- No certain fracture zones were found. The reason was most likely that the probe

hole’s high flow rate caused a high noise level in the probe hole (i.e. flows are

hidden by the noise) and the rubber disks of the probe could have been leaking

(i.e. flows bypassed the flow meter). Rubber disk leaks can be caused by crushed

rock material in the probe hole, rough probe hole wall or if the wall of the probe

hole is more curved/ovoid than expected.

- The main fracture zone is probably between 23.0 m – 26.5 m.


ONK- TR3121C flow out from probe hole after measurements = 13 500 mL/h

ONK- TR3121C measured sum of flows with the PFL DIFF probe = 9 600 mL/h


sum of the measured flows could be because rubber disks of the PFL DIFF




- The main fracture zone is at the bottom of the probe hole (26 m – 29 m).

ONK-TR3121B flow out from probe hole before measurements = 36 000 mL/h

ONK- TR3121B flow out from probe hole after measurements = 36 900 mL/h

ONK- TR3121B measured sum of flows with the PFL DIFF probe = 9 540 mL/h






ONK-TR3121A flow out from probe hole before measurements = 432 000 mL/h

ONK- TR3121A flow out from probe hole after measurements = 492 000 mL/h

ONK- TR3121A measured sum of flows with the PFL DIFF probe = 0 mL/h

- No certain fracture areas were found. The reason that there is a difference in the

flow out from the probe hole and the sum of the measured flows could be due to

30

the high noise level in the probe hole (i.e. flows are hidden by the noise) or the

rubber disks of the PFL DIFF probe could have been leaking (i.e. flows

bypassed the flow meter). These leaks can be caused by crushed rock material in

the probe hole, rough probe hole wall or if the wall of the probe hole is more

curved/ovoid than expected.

- The main fracture area is probably below 21.0 m (the probe stopped at the depth

of 21.0 m). High flow rates probably should have been detected above the noise

level.


At blasting round ONK-TR3140 four probe holes were drilled and all probe holes had a

measurable outflow. It was decided that only probe holes A, C and D would be

measured. The flow along the probe hole was measured in 0.2 m steps.



- Preparations at the site at 15:30 – 16:30

- The outflow from the probe hole before the flow measurements was about

9·106 mL/h – 9.6·10

6 mL/h.






- Flow out from the probe hole after the measurement at 19:15 was about

9·106 mL/h – 9.6·10

6 mL/h.

Notes for ONK-TR3140D:


1.02·106 mL/h.

- Dummy measurement was made during ONK-TR3140A flow logging.






Notes for ONK-TR3140C:


30 000 mL/h.

- Dummy measurement was made during ONK-TR3140A flow logging.


31







ONK-TR3140A flow out from probe hole before measurements = about 9·106 mL/h –

9.6·106 mL/h

ONK-TR3140A flow out from probe hole after measurements = about 9·106 mL/h –

9.6·106 mL/h

ONK-TR3140A sum of measured flows with the PFL DIFF probe = 8.82·106 mL/h

- Main fracture area is probably between 13 m – 15 m.

ONK-TR3140D flow out from probe hole before measurements = 1.02·106 mL/h

ONK-TR3140D flow out from probe hole after measurements = 930 000 mL/h

ONK-TR3140D sum of measured flows with the PFL DIFF probe = 249 000 mL/h

- The reason that there is a difference in flow out from the probe hole and the sum

of the measured flows could be caused by the new measurement system’s

incomplete calibration (measurement without lower rubber disks). The new

measurement system (flow along the hole) was still in test use.

- Detected fractures at 11.7 m and 2.4 m.

- The probe stopped at the depth of 12.5m. There could be more fractures below

12.5 m.


ONK-TR3140C flow out from probe hole after measurements = 30 000 mL/h

ONK-TR3140C sum of measured flows with PFL DIFF probe = 0 mL/h

- The probe stopped at the depth of 8.5m. No fractures were detected. There are

probably fractures below 8.5 m.


At blasting round ONK-TR3145 four probe holes were drilled and all probe holes had a

measurable outflow. The flow along the probe hole was measured in 0.2 m steps. The

probe holes were 29 m deep.




- The outflow from the probe hole before the flow measurements was 6 L/min.


32

o The dummy stopped at the length of 10 m.


o The probe stopped at the length of 2 m.

- Second dummy measurement after an extra flushing of the probe hole at 7:17 –

7:20


- Measurements at ONK-TR3145 stopped because the minimum measurement

length of a probe hole is 5 m.


- The outflow from the probe hole before the flow measurements was 0.5 L/min.





- Not measured, minimum measurement length is 5m.



60 000 mL/h.



- Second dummy measurement after an extra flushing of the probe hole at 7:08 –

7:15






- Flow out from the probe hole after the measurement was 51 600 mL/h.


- The outflow from the probe hole before the flow measurements was 0.5 L/min.



- The hole was not measured because the minimum measurement length is 5m.



All probe holes had some drilling debris. It was decided to flush the probe holes again

(SK-Kaivin). Second measurement attempts were made in probe holes B and C.


ONK-TR3145C flow out from probe hole after measurements = 51 600 mL/h

ONK-TR3145C sum of measured flows with PFL DIFF probe = 112 200 mL/h

33


sum of the measured flows could be caused by the new measurement system’s

(flow along the probe hole) incomplete calibration. The new measurement

system was still in test use. Therefore, no fractures table is presented in the

results.

- The main fracture zone is probably at the depth of 12.2 m.

Probe holes A, B and D were not measured. The probe did not pass the minimum

measurement length, 5 m.


At blasting round ONK-TR3170 four probe holes were drilled. ONK-TR3170B had a

measurable outflow. The rest of the probe holes were dry. The flow along the probe

hole was measured in 0.2 m steps. The probe hole’s depth was 29 m.





100 mL/min.



- Not measured, minimum measurement length is 5m.


Comments on ONK-TR3170B results:

ONK-TR3170B flow out from probe hole before measurements

(measured by SK-Kaivin) = 100 mL/min

ONK-TR3170B flow out from probe hole 16:30 = 80 mL/min

ONK-TR3170B flow out from probe hole 17:25 = 80 mL/min

Probe hole B was not measured. The dummy did not pass the minimum measurement

length, 5 m.

ONK-PVA5 measurements were conducted using the PFL DIFF probe. The drillhole was measured with a section length of 0.5 m and a measurement was conducted every 0.1 m. The outflow of the drillhole before the measurements was 9000 mL/h. The depth of the drillhole was 40.1 m.

34

Notes for ONK-PVA5:


- The outflow from the drillhole before the flow measurements, at 12:55, was

9 000 mL/h.


o The probe reached the bottom of the drillhole.

o 39.2 m – 40.1 m could not be measured due the structure of the probe.



- Flow out from the probe hole after the measurement at 17:20, 150 mL/min.


Comments on ONK-PVA5 results:

ONK-PVA5 flow out from drillhole before measurements = 9 000 mL/h

ONK-PVA5 flow out from drillhole after measurements = 9 000 mL/min

ONK-PVA5 measured sum of flows with the PFL DIFF probe = 7 510 mL/min

- The rubber disks of the probe could have been leaking (i.e. flows bypassed the

flow meter) causing a small difference between the flow out from the drillhole

and the sum of the measured flows.

- The detected main fracture zones are at depth interval 27.7 m – 34.4 m. No

fractures were found below 34.4 m.


At blasting round ONK-TR3263 four probe holes were drilled. Two probe holes (ONK-

TR3263A and ONK-TR3263D) had a measurable outflow. The rest of the probe holes

were dry. The flow along the probe hole was measured in 0.2 m steps. The probe holes

were 29 m deep.





600 000 mL/h.



- Second dummy after an extra flushing of the probe hole at 18:20 – 18:35.


- The probe hole was not measured because minimum measurement length is 5 m.

35



28 800 mL/h.

- Dummy measurement at 16:00 – 16:15. The dummy reached the bottom of the

hole.

- There was a delay at 16:20 – 17:40.

o Pumping failure at the end of ONKALO, water level increased.

o Blasting at depth level -90 m.




- The probe got stuck at the length of 16.4 m.

o Releasing the probe at 18:50 – 19:19.

- Continuing the measurements at 19:19.




Comments on ONK-TR3263D results:

ONK-TR3263D flow out from probe hole before measurements = 28 800 mL/h

ONK-TR3263D flow out from probe hole after measurements = 27 000 mL/h

ONK-TR3263D measured sum of flows with the PFL DIFF probe = 18 000 mL/h






- The detected main fracture zones are at depth intervals 18 m – 19 m and 14 m –

15 m.


At blasting round ONK-TR3273 four probe holes were drilled. All four probe holes had measurable flows before measurements. Probe hole A was leaking 5 L/min, probe hole B was leaking 300 mL/min, probe hole C was leaking 1.5 L/min and probe hole D was leaking 1.9 L/min. The flow along the probe hole was measured in 0.2 m steps. The probe holes were 29 m deep.

Preparations at 12:00 – 13:10.


- Preparations at the site at 13:10 – 13:40

- The flow out from the probe hole before the measurement was 5 L/min.

36


o The dummy reached the bottom of the hole.



- The probe hole was not measured because the minimum measurement length is

5 m.


- The flow out from the probe hole before the measurement was 1.9 L/min.

- Dummy measurement at 15:07 –15:43.

o The dummy was first stuck at the length of 3 m.

o Finally the dummy could be pushed up to 17 m.

- Lots of drilling debris came out from the probe hole with the dummy.

- The probe hole could not be measured.


- The flow out from the probe hole before the measurement was 300 mL/min.



- The probe hole was not measured because the minimum measurement length is

5 m.


- The flow out from the probe hole before measurement was 1.5 L/min.

- The dummy measurement was not performed.

o The top of the probe hole had collapsed.

- The probe hole could not be measured.

Moving out from ONKALO at 16:30.

Maintenance of equipment and data processing at 16:30 – 19:05.


Flushing of the probe holes had been unsuccessful and lots of drilling debris was found.

None of the probe holes could be measured.

At blasting round ONK-TR3288 four probe holes were drilled and three probe holes had

a measurable outflow. Probe hole A was leaking 550 mL/min, probe hole B was leaking

500 mL/min and probe hole C was leaking 2.8 L/min. Probe hole D was dry. The flow

along the probe hole was measured in 0.2 m steps. The probe holes were 29 m deep.

Probe holes B and C were upwards slanted and could not be measured.

37




- The flow out from the probe hole before the measurement was 550 mL/min.


o The dummy reached the bottom of the hole.




- The probe got stuck at the length of at 5 m.

o Trying to release the probe at 5:35 – 6:35.

- Unsuccessful attempts to release the probe. Measurements could not be

continued.

- PFL DIFF probe number 3 was left in the probe hole.


ONK-TR3288A flow out from probe hole before measurements = 550 mL/min

ONK-TR3288B flow out from probe hole before measurements = 500 mL/min

ONK-TR3288C flow out from probe hole before measurements = 2.8 L/min

The first measured probe hole was ONK-TR3288A. The PFL DIFF probe got stuck in

the probe hole at the length of 5 m. PFL DIFF probe number 3 was left in the probe hole

after unsuccessful release attempts and was blasted up later at the next blasting round. It

was not possible to measure any of the other probe holes due to lack of time.


ONK-PVA3 measurements were conducted using the PFL DIFF probe. The drillhole was measured with a section length of 0.5 m and a measurement was conducted every 0.1 m. Drillhole outflow was measured by Posiva after the PFL DIFF loggings. The outflow from the hole was 2 880 mL/h, 3.2.2009. Flow logging was performed once earlier in this drillhole, 25.9.2006. The results of the earlier measurements are combined with the new results.


Notes for ONK-PVA3:



o The probe stopped at the depth of 22.6 m.

o 22.6 m – 23.2 m could not be measured due the structure of the probe.



38


Comments on ONK-PVA3 results:

ONK-PVA3 measured sum of flows with the PFL DIFF probe = 1 340 mL/h

ONK-PVA3 flow out from the drillhole after the measurements, 3.2.2009 = 2 880 mL/h

- The rubber disks of the probe could have been leaking (i.e. flows bypassed the

flow meter) causing a small difference in the flow out from the drillhole and the

sum of the measured flows.

ONK-PVA3 was re-measured because outflow from the drillhole had decreased after

first flow logging measurements in 2006. After the new measurements in January 2009

the PFL DIFF probe was covered by small amount of cement, which was probably used

for rock injection. That could be one reason for the decreased drillhole outflow. A

new, uncertain fracture was found at the depth of 20.3 m. The fractures at the depths of

11.6 m, 12.4 m and 17.7 m were not found during these measurements.


39

In this study the Posiva Flow Log, Difference Flow Method was used in the probe holes

from ONK-TR3009 to ONK-TR3288 in ONKALO, Olkiluoto. The probe holes were

drilled before the tunnel blasting within the tunnel profile. Core-drilled drillholes were

also measured in addition to normal probe holes. The measured core-drilled holes were

ONK-PVA3 and ONK-PVA5.

The first measured probe holes at blasting round TR3009 were logged on May 5, 2008

when the tunnel was 3009 m long. The last reported probe holes, at blasting round

TR3288, were measured on December 16, 2008 when the tunnel was 3288 m long.

Probe holes from ONK-TR3009 to ONK-TR3121 were measured using a 0.5 m section

length (the distance isolated with the rubber disks) with a 0.1 m step. Probe holes

starting at ONK-TR3140 were measured without lower rubber disks. This setup is used

to measure the flow along the probe hole in 0.2 m steps. There were no measurable

flows between blasting rounds TR3170 – TR3263.

The main results for all drillholes and probe holes are the distribution of flowing

fractures and their transmissivity. The hydraulic aperture of fractures was also

evaluated.

The use of the flow meter in the probe holes was experimental and there were

performance problems:

The probe did not go into the probe hole (or did not reach the bottom of the

hole) because the diameter of the probe hole was less than expected, it was more

curved than expected or there was crushed rock, drilling debris or some other

obstacle in the probe hole.

Unreliable results we obtained mainly because of leaks at the rubber disks.

These leaks can be caused by crushed rock material in the probe hole, rough

probe hole wall, air / gas bubbles in the water or if the cross section of the hole

is, for example, ovoid. The probe does not perform well whenever there is loose

material in the probe hole or if the cross section of the drillhole is far from

circular. For these reasons the summed flow measured in the probe holes was

usually less than the yield of the probe holes.

At blasting round TR3288 the PFL DIFF probe got stuck in the probe hole

ONK-TR3288A at the depth of 5 m. PFL DIFF probe number 3 was left in the

probe hole after several unsuccessful release attempts. The probe was destroyed

later at the next blasting round.

Higher flow rates than PFL DIFF can measure.

To obtain better results from probe hole measurements the probe hole flushing must be

well managed. Crushed rock in the probe holes was one of the main reasons when

measurements were unsuccessful.

40

The tested measuring setup for flow along the probe hole seemed to be more suitable for

the probe holes. This setup should be less sensitive to roughness of the hole wall and

loose rock material. In addition, with this setup it is possible to measure much higher

flow rates, flows originating from the bottom of the hole and check the results at the site

when the probe is on the top of the hole (if the hole is pumped or if it is an open

underground hole). A drawback is that the accuracy even in good hole conditions is

about 20% of current flow value. Another limitation of the method is that small flow

rates above a larger flow may remain undetected.

In most cases the probe holes that had an outflow could not be measured or were

measured only partially because of structural problems: The dummy tool or the probe

did not go into the probe hole, there was a lot of drilling debris etc. In cases where

measurements could be performed flowing fracture zones were located or, based on the

results, the location of flowing fracture zones could be approximated.

41

Heikkonen, J., Heikkinen, E. & Mäntynen, M. 2002. Mathematical modelling of

temperature adjustment algorithm for groundwater electrical conductivity on basis of

synthetic water sample analysis. Helsinki, Posiva Oy. Working report 2002-10 (in

Finnish).

Ludvigson, J.-E., Hansson, K. and Rouhiainen, P. 2002. Methodology study of Posiva

difference flow metre in borehole KLX02 at Laxemar. SKB Rapport R-01-52.

Marsily, G. 1986. Quantitative Hydrogeology, Groundwater Hydrology for Engineers.

Academic Press, Inc. ISBN 0-12-208915-4.

Pekkanen, J. 2008. Flow measurements in ONKALO at Olkiluoto. Probe holes and

ONK-PR2 – ONK-PR5, ONK-PP114 and ONK-PVA4. Posiva Oy. Working Report

2008-37.

Reiman, M., Väisäsvaara, J & Pöllänen, J. 2006. Flow measurements in ONKALO at

Olkiluoto. Probe holes and ONK-KR1 – ONK-KR4, ONK-PVA1 and ONK-YPPL18.

Posiva Oy. Working Report 2006-65.

43

Appendix 1.1

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104

Single point resistance (ohm)

Flow from the measured section (L = 0.5 m, dL = 0.1 m), 2008-05-05

Interpreted fracture specific flow into the hole

7.4

25.8

ONKALO, Probe hole ONK-TR3009BFlow rate and single point resistance

Flow rate out of the probe hole:Before flow logging = 8 400 mL/hAfter flow logging = 0 mL/h

PFL DIFF flow rate:Sum of measured flows = 258 mL/h

44

Appendix 1.2

0 0.02 0.04 0.06 0.08 0.1

Hydraulic aperture of fracture (mm)

30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6

Transmissivity (m2/s)


ONKALO, Probe hole ONK-TR3009BTransmissivity and hydraulic aperture of detected fractures2008-05-05

Transmissivity of fracture

45

Appendix 1.3

Tabulated results of detected fractures in probe hole ONK-TR3009B

Probe hole ONK-TR3009B

Elevation of the top of the

hole (masl.): -288.66

Inclination: -5.7o

Depth of fracture along the

probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

7.4 160 -289.4 294.66 1.49E-10 0.006

25.8 99 -291.2 294.66 9.23E-11 0.005

46

Appendix 1.4

0.01 0.1 1 10

Electrical conductivity (S/m, 25 oC)

30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (L = 0.5 m, dL = 0.1 m), 2008-05-05

ONKALO, Probe hole ONK-TR3009BElectrical conductivity of probe hole water

47

Appendix 1.5

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3009BTemperature of probe hole water

48

Appendix 2.1

100

101

102

103

104

105

106

Flow rate (mL/h)

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




ONKALO, Probe hole ONK-TR3020AFlow rate and single point resistance

Flow rate out of the probe hole:Before flow logging = 732 000 mL/hAfter flow logging = 606 000 mL/h

PFL DIFF flow rate:Sum of measured flows = 0 mL/h(PFL DIFF probe stopped at the depth of 7 m)

49

Appendix 2.2

0.01 0.1 1 10


20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3020AElectrical conductivity of probe hole water

50

Appendix 2.3

8.5 9 9.5

Temperature (oC)

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3020ATemperature of probe hole water

51

Appendix 3.1

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104


Flow from the measured section (L = 0.5 m, dL = 0.1 m), 2008-08-08 - 2008-08-09


16.7

21.0

26.1

10.4

17.5

19.5

24.5

25.6

10.9

18.0

26.7



PFL DIFF flow rate:Sum of measured flows = 7 920 mL/h

52

Appendix 3.2

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3116BTransmissivity and hydraulic aperture of detected fractures2008-08-08 - 2008-08-09


53

Appendix 3.3

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (L = 0.5 m, dL = 0.1 m), 2008-08-08 - 2008-08-09


54

Appendix 3.4

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



55

Appendix 3.5

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




10.2

8.2

9.7

ONKALO, Probe hole ONK-TR3116CFlow rate and single point resistance



56

Appendix 3.6

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3116CTransmissivity and hydraulic aperture of detected fractures2008-08-08


57

Appendix 3.7

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3116CElectrical conductivity of probe hole water

58

Appendix 3.8

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3116CTemperature of probe hole water

59

Appendix 3.9

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




ONKALO, Probe hole ONK-TR3116DFlow rate and single point resistance


PFL DIFF flow rate:Sum of measured flows = 0 mL/h(PFL DIFF probe stopped at the depth of 23.6 m)

60

Appendix 3.10

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3116DElectrical conductivity probe hole water

61

Appendix 3.11

9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3116DTemperature of probe hole water

62

Appendix 3.12

Tabulated results of detected fractures in probe holes ONK-TR3116B and ONK-TR3116C



hole (masl.): -293.0

Inclination: -5.7o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

10.4 359 -294.0 299.0 3.30E-10 0.008 *

10.9 164 -294.1 299.0 1.51E-10 0.006 *

16.7 6530 -294.7 299.0 6.00E-09 0.022

17.5 68 -294.7 299.0 6.25E-11 0.005 *

18.0 65 -294.8 299.0 5.97E-11 0.005 *

19.5 12 -294.9 299.0 1.10E-11 0.003 *

21.0 53 -295.1 299.0 4.87E-11 0.004

24.5 13 -295.4 299.0 1.19E-11 0.003 *

25.6 25 -295.5 299.0 2.30E-11 0.003 *

26.1 606 -295.6 299.0 5.57E-10 0.010

26.7 17 -295.7 299.0 1.56E-11 0.003 *

Probe hole ONK-TR3116C



Inclination: -5.7o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

8.2 131 -293.8 299.0 1.20E-10 0.006 *

9.7 558 -294.0 299.0 5.13E-10 0.010 *

10.2 7190 -294.0 299.0 6.61E-09 0.022

* Uncertain fracture. The flow rate is less than 30 mL/h or the flow anomalies are overlapping or they are unclear

because of noise.

63

Appendix 4.1

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104






PFL DIFF flow rate:Sum of measured flows = 0 mL/h(PFL DIFF probe stopped at the depth of 20.4 m)

64

Appendix 4.2

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (L = 0.5 m, dL = 0.1 m),2008-08-21


65

Appendix 4.3

9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



66

Appendix 4.4

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104


Flow from the measured section (L = 0.5 m, dL = 0.1 m), 2008-08-20 - 2008-08-21


9.9

12.6

13.5

8.2

11.1

26.0




67

Appendix 4.5

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3121BTransmissivity and hydraulic aperture of detected fractures2008-08-20 - 2008-08-21


68

Appendix 4.6

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (L = 0.5 m, dL = 0.1 m),2008-08-20 - 2008-08-21


69

Appendix 4.7

9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



70

Appendix 4.8

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




5.9

26.9

27.8



PFL DIFF flow rate:Sum of measured flows = 9 600 mL/h(PFL DIFF probe stopped at the depth of 28.2 m)

71

Appendix 4.9

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3121CTransmissivity and hydraulic aperture of detected fractures2008-08-20


72

Appendix 4.10

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



73

Appendix 4.11

9 9.5 10 10.5

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



74

Appendix 4.12

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




26.4

23.7

24.4

25.6


Flow rate out of the probe hole:Before flow logging = 1.2·106 mL/h

After flow logging = 1.632·106 mL/h


75

Appendix 4.13

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3121DTransmissivity and hydraulic aperture of detected fractures2008-08-20


76

Appendix 4.14

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Probe hole ONK-TR3121DElectrical conductivity of probe hole water

77

Appendix 4.15

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



78

Appendix 4.16

Tabulated results of detected fractures in probe holes ONK-TR3121B, ONK-TR3121C and ONK-TR3121D




Inclination: -5.7o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

8.2 510 -292.8 298.0 4.70E-10 0.009 *

9.9 1320 -293.0 298.0 1.22E-09 0.013

11.1 624 -293.1 298.0 5.75E-10 0.010 *

12.6 2150 -293.3 298.0 1.98E-09 0.015

13.5 4850 -293.3 298.0 4.47E-09 0.020

26.0 85 -294.6 298.0 7.84E-11 0.005 *

Probe hole ONK-TR3121C



Inclination: -5.7o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

5.9 376 -292.6 298.0 3.47E-10 0.008

26.9 6630 -294.7 298.0 6.11E-09 0.022

27.8 2400 -294.8 298.0 2.21E-09 0.016

Probe hole ONK-TR3121D



Inclination: -19.2o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

23.7 49400 -302.8 301.0 4.51E-08 0.042 *

24.4 20100 -303.0 301.0 1.83E-08 0.031 *

25.6 23400 -303.4 301.0 2.14E-08 0.033 *

26.4 60500 -303.7 301.0 5.52E-08 0.045


because of noise.

79

Appendix 5.1

100

101

102

103

104

105

106

107

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104


Flow along the probe hole (without lower rubber disks, dL = 0.2 m), 2008-09-04


13.0

14.2


Flow rate out of the probe hole:Before and after flow logging =

about 9·106 mL/h - 9.6·106 mL/h

PFL DIFF flow rate:Sum of measured flows = 8.82·106 mL/h

(PFL DIFF probe stopped at the depth of 23.8 m)

80

Appendix 5.2

0 0.05 0.1 0.15 0.2 0.25 0.3


30

25

20

15

10

5

0

De

pth

(m

)

10-9

10-8

10-7

10-6

10-5

10-4



ONKALO, Probe hole ONK-TR3140ATransmissivity and hydraulic aperture of detected fractures2008-09-04


81

Appendix 5.3

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (dL = 0.2 m),2008-09-04


82

Appendix 5.4

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)

During flow logging, upwards (dL = 0.2 m), 2008-09-04


83

Appendix 5.5

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104





Flow rate out of the probe hole:Before and afterflow logging = 30 000 mL/h

PFL DIFF flow rate:Sum of measured flows = 0 mL/h(PFL DIFF probe stopped at the depth of 7 m)

84

Appendix 5.6

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



85

Appendix 5.7

9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



86

Appendix 5.8

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




2.4

11.7


Flow rate out of the probe hole:Before flow logging = 1.02·106 mL/hAfter flow logging = 930 000 mL/h

PFL DIFF flow rate:Sum of measured flows = 249 000 mL/h(PFL DIFF probe stopped at the depth of 10 m)

87

Appendix 5.9

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-9

10-8

10-7

10-6

10-5

10-4





88

Appendix 5.10

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



89

Appendix 5.11

9 9.5 10

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



90

Appendix 5.12

Tabulated results of detected fractures in probe holes ONK-TR3140A and ONK-TR3140D

Probe hole ONK-TR3140A



Inclination: -15.8o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

13.0 1092000 -300.0 302.5 9.92E-07 0.119 **

14.2 7700440 -300.4 302.5 6.99E-06 0.228 **




Inclination: -19.2o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

2.4 46000 -297.3 302.5 4.18E-08 0.041 **

11.7 203000 -300.3 302.5 1.84E-07 0.068 **

** Fixed flow rate values were used in fracture table results. A fixed value is based on PFL DIFF probe flow rate and probe hole outflow.

91

Appendix 6.1

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




12.2




92

Appendix 6.2

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



93

Appendix 6.3

10 10.5 11

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



94

Appendix 7.1

100

101

102

103

104

105

106

Flow rate (mL/h)

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104

105




6.1

ONKALO, Drillhole ONK-PVA5Flow rate and single point resistance



95

Appendix 7.2

100

101

102

103

104

105

106

Flow rate (mL/h)

40

39

38

37

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

De

pth

(m

)

101

102

103

104

105




29.4

30.6

34.4

31.1

22.4

27.7




96

Appendix 7.3

0 0.02 0.04 0.06 0.08 0.1


40

35

30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Drillhole ONK-PVA5Transmissivity and hydraulic aperture of detected fractures2008-11-16


97

Appendix 7.4

Tabulated results of detected fractures in drillhole ONK-PVA5

Drillhole ONK-PVA5



Inclination: -20.0o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

6.1 43 -230.7 234.6 5.04E-11 0.004 *

22.4 45 -236.3 234.6 5.27E-11 0.004 *

27.7 63 -238.1 234.6 7.38E-11 0.005 *

29.4 129 -238.7 234.6 1.51E-10 0.006

30.6 6710 -239.1 234.6 7.86E-09 0.024

31.1 233 -239.3 234.6 2.73E-10 0.008

34.4 283 -240.4 234.6 3.31E-10 0.008


because of noise.

98

Appendix 7.5

0.01 0.1 1 10


40

35

30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Drillhole ONK-PVA5Electrical conductivity of drillhole water

99

Appendix 7.6

8 8.4 8.8 9.2 9.6 10

Temperature (oC)

40

35

30

25

20

15

10

5

0

De

pth

(m

)


ONKALO, Drillhole ONK-PVA5Temperature of drillhole water

100

Appendix 8.1

100

101

102

103

104

105

106

Flow rate (mL/h)

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




14.4

18.3

14.8

18.9



PFL DIFF flow rate:Sum of measured flows = 18 000 mL/h(PFL DIFF probe stopped at the depth of 26 m)

101

Appendix 8.2

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6





102

Appendix 8.3

Tabulated results of detected fractures in probe hole ONK-TR3263D




Inclination: -19.2o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

14.4 5500 -313.4 314.7 4.80E-09 0.020

14.8 10200 -313.6 314.7 8.91E-09 0.025

18.3 1500 -314.7 314.7 1.31E-09 0.013

18.9 75 -314.9 314.7 6.55E-11 0.005 *


because of noise.

103

Appendix 8.4

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



104

Appendix 8.5

9.5 10 10.5

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



105

Appendix 9.1

100

101

102

103

104

105

106

Flow rate (mL/h)

10

9

8

7

6

5

4

3

2

1

0

De

pth

(m

)

101

102

103

104




5.5

6.7

7.1

6.0

6.5


Flow rate out of the probe hole:Before flow logging = 33 000 mL/h

PFL DIFF flow rate:Sum of measured flows = 9 080 mL/h(PFL DIFF probe stopped at the depth of 8.7 mand got stuck at the depth of 5.0 m)

106

Appendix 9.2

0 0.02 0.04 0.06 0.08 0.1


30

25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6



ONKALO, Probe hole ONK-TR3288ATransmissivity and hydraulic aperture of detected fractures2008-12-16


107

Appendix 9.3

Tabulated results of detected fractures in probe hole ONK-TR3288A

Probe hole ONK-TR3288A



Inclination: -5.7o


probe hole (m)

Flow

(mL/h)

Fracture

elevation

(masl.)

Drawdown

(m) T (m

2/s)

Hydraulic

aperture of

fracture (mm)

Comments

5.5 4580 -311.5 317.0 3.97E-09 0.019

6.0 3340 -311.6 317.0 2.89E-09 0.017 *

6.5 319 -311.6 317.0 2.76E-10 0.008 *

6.7 694 -311.7 317.0 6.01E-10 0.010

7.1 149 -311.7 317.0 1.29E-10 0.006


because of noise.

108

Appendix 9.4

0.01 0.1 1 10


30

25

20

15

10

5

0

De

pth

(m

)



109

Appendix 9.5

10 10.5 11

Temperature (oC)

30

25

20

15

10

5

0

De

pth

(m

)



110

Appendix 10.1

100

101

102

103

104

105

106

Flow rate (mL/h)

24

23

22

21

20

19

18

17

16

15

14

13

12

11

10

9

8

7

6

5

4

3

2

De

pth

(m

)

101

102

103

104


Flow 1 from the measured section (L = 0.5 m, dL = 0.1 m), 2006-09-25

Flow 1, Interpreted fracture specific flow into the drillhole, 2006-09-25

Flow 2 from the measured section (L = 0.5 m, dL = 0.1 m), 2009-01-29

Flow 2, Interpreted fracture-specific flow into the drillhole, 2009-01-29

6.0

11.4

14.1

16.6

17.7

18.2

5.5

8.2

20.3

21.6

11.6

12.4


111

Appendix 10.2

0 0.02 0.04 0.06 0.08 0.1


25

20

15

10

5

0

De

pth

(m

)

10-11

10-10

10-9

10-8

10-7

10-6


Hydraulic aperture of fracture 1 (mm),2006-09-25

Hydraulic aperture of fracture 2 (mm),2009-01-29

ONKALO, Drillhole ONK-PVA3Transmissivity and hydraulic aperture of detected fractures

Transmissivity of fracture 1,2006-09-25

Transmissivity of fracture 2,2009-01-29

112

Appendix 10.3 Tabulated results of detected fractures in drillhole ONK-PVA3

Drillhole: ONK-PVA3

Elevation of the top of the hole

(masl.): -78.535

Inclination: -9.76o


drillhole (m)

Fracture

elevation

(masl.)

Drawdown

(m)

Flow 1

(mL/h)

T 1

(m2/s)

Hydraulic

aperture of

fracture 1

(mm)

Flow 2

(mL/h)

T 2

(m2/s)

Hydraulic

aperture of

fracture 2

(mm)

Comments

5.5 -79.47 84.535 34 1.11E-10 0.006 25 8.13E-11 0.005 *

6.0 -79.55 84.535 354 1.15E-09 0.013 30 9.75E-11 0.005

8.2 -79.93 84.535 29 9.43E-11 0.005 32 1.04E-10 0.006 *

11.4 -80.47 84.535 122 3.97E-10 0.009 47 1.53E-10 0.006

11.6 -80.50 84.535 56 1.82E-10 0.007 - - - *, **

12.4 -80.64 84.535 37 1.20E-10 0.006 - - - *, **

14.1 -80.93 84.535 410 1.33E-09 0.013 98 3.19E-10 0.008

16.6 -81.35 84.535 68 2.21E-10 0.007 57 1.85E-10 0.007

17.7 -81.54 84.535 2250 7.31E-09 0.023 - - - **

18.2 -81.62 84.535 2990 9.72E-09 0.025 444 1.44E-09 0.013

20.3 -81.98 84.535 576 1.87E-09 0.015 300 9.75E-10 0.012 *

21.6 -82.20 84.535 - - - 310 1.01E-09 0.012 *, ***

* Uncertain fracture. The flow rate is less than 30 mL/h or the flow anomalies are overlapping or they are unclear because of noise.

* * Fracture was not found, Flow 2 (2009-01-25 measurements).

*** New fracture found, Flow 2 (2009-01-25 measurements).

112

113

Appendix 10.4

0.01 0.1 1 10


25

20

15

10

5

0

De

pth

(m

)



ONKALO, Drillhole ONK-PVA3Electrical conductivity of drillhole water

114

Appendix 10.5

6 6.5 7 7.5 8 8.5

Temperature (oC)

25

20

15

10

5

0

De

pth

(m

)



ONKALO, Drillhole ONK-PVA3Temperature of drillhole water

flow measurements in onkalo at olkiluoto probe holes, … · flow measurements in onkalo at...

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