05 eoog mcgt inspection technology

Diagnostic Package-Assisted Trunk

Pipeline Inspection Technology

Multi-channel Geometry Tool

EOOG-032-MCGT-10 March 11’ 2010

2

Name: Diagnostic Package-Assisted Trunk Pipeline Inspection Technology Multi-channel Geometry Tool (MCGT) Number: EOOG-032-MCGT-10 Date: March 11’ 2010


3

TABLE OF CONTEXT:

1. INTRODUCTION...........................................................4

2. ENTRY OF MULTI-CHANNEL GEOMETRY TOOL (MCGT).......6

3. LAUNCHING OF MCGT..................................................8

4. TRACKING OF MCGT ALONG THE PIPELINE.....................10

5. RECEIVING OF MCGT................................................16

6. REMOVAL OF MCGT FROM SCRAPER RECEIVER..............19

7. CLEANING OF MCGT.................................................20

8. PECULIARITIES OF RUNNING CALIPER BY AIR...................21

9. IDENTIFYING CALIPER RUNNING CONDITIONS..................25

10. TERMS AND DEFINITIONS.........................................27


4

1. INTRODUCTION

The present Technology has been elaborated by specialists of EOOG

(Energy Overseas Oil and Gas) based on the existing requirements of

standard-technical documentation (including POF Specification)

During construction or rehabilitation of a trunk pipeline, it is mandatory to

examine a pipe wall and seam welds for defects by in-line inspection at the

stage of commissioning.

In-line geometry inspection of a long distance oil transmission pipeline section

is conducted by means of a Multi-channel Geometry Tool with the aim to

identify controllability of a pipeline section by detecting of defects of geometry

and manifestation of the pipeline features (dents, buckles, out-of-roundness

and projecting of valve components into a pipeline).

Operations of geometry inspection include:

- cleaning scraper run to clean the internal surface of a pipeline from dirt and

sand as well as to remove foreign matters and construction wastes;

- geometry tool launch to verify a pipeline bore and to define pipeline

positioning coordinates.

The package configuration includes the following in-line MCGTs:

- cleaning scrapers,

- Multi-channel Geometry Tool with Navigation System;

and surface auxiliary equipment:

- GPS receiver HiPer+ or its equivalent – 3 items (stationary receiver – 1 item,

portable receiver – 2 items);

- portable PC – 1 item,

- data processing station – 1 item,

- tray,

- acoustic locators,


5

- locators,

- reference marker transmitters,

- route seekers.

The following operations are to be accomplished to run each in-line tool:

- entry into a scraper launcher,

- launching,

- tracking along the pipeline,

- receiving in a scraper receiver,

- removal from a scraper receiver.

2. ENTRY OF MULTI-CHANNEL GEOMETRY TOOL (MCGT)

Initial Position:

All scraper launcher pipeline valves shall be closed and a product shall be

released.

2.1. Prior to shipping of the Multi-channel Geometry Tool (MCGT) to a scraper

launcher, the MCGT shall be prepared for operation, in accordance with the

appropriate operating documents.

2.2. MCGT run shall be scheduled beyond the explosive area with a scraper launcher

closed.

Using a hoist, lift the MCGT tray from a transport facility and put it near

the scraper launcher.

Connect ground cable between the scraper launcher and the tray, install

cable clamps on coating-free areas.

Caution! It is prohibited to connect or disconnect a cable with the open cap of

the scraper launcher!

2.3. Open a cap of the scraper launcher and let air in at least 15 minutes. If

necessary (under the Operator norms and engineering documents), purge the scraper

launcher by inert gas.


6

2.4. Using a hoist, lift the tray with the MCGT and position it in such a way that its

forefront would be against the open scraper receiver and the tray bottom and the

lower end of the scraper receiver will be at the same level. MCGT nose shall be toward

the scraper launcher.

2.5. While the tray is slung, lower its feet to the ground and secure them on the tray

by lock pins. Install the tray on the ground. Disconnect slings and take aside the

crane jib.

2.6. Pull the MCGT slowly and gradually into the scraper launcher using entry bars

till the first sleeve comes into the nominal size scraper launcher section. The back of

the sensor carrier shall be positioned out of a product flow, when a product will be

supplied to the scraper launcher (refer to Fig. 1).

Fig. 1: Entry of MCGT into a Scraper Launcher


7

Warning!

MCGT shall be pulled into the scraper launcher in such a way that the front

sleeve of the drive section comes into the nominal size scraper launcher

section. This position of MCGT will ensure its travel from the scraper launcher

to a pipeline by a product flow.

2.7 Using a hoist, remove the tray from the scraper launcher to close the

scraper launcher cap.

2.8 Close the scraper launcher cap.

2.9 Disconnect the ground cable from the scraper launcher.

2.10 Assemble and load the tray on a vehicle and ship it at the scraper receiver

site.

3. LAUNCHING OF MCGT

3.1 Scraper Launcher Initial Position (refer to Fig. 2):

MCGT is positioned in the scraper launcher in such a way that its front sleeve

comes into the nominal size scraper launcher section.

Gate valve V 1 - open; gate valves V 2, V 3, V 4, T 1, T 2 and Т 3 - close

Fig. 2.


8

3.2 Install a locator receiver (LR) at the scraper launcher outlet gate valve

upstream.

3.3 Open the gate valves of plungers Т 1 and Т 2.

3.4 Supply a product to the scraper launcher gradually by gate valves V 3 and

V4, until a product comes out of plungers Т 1 and Т 2.

3.5. Close the gate valves of plungers Т 1 and Т 2.

3.6. Close gate valves V 3 and V 4.

3.7. Operator shall set the flow (Q1) velocity at a long distance pipeline as approved

by Customer and Contractor (in a range: from 0.2 to 3 m/sec. Stops and travel of

MCGT at the velocity lower than 0.2 m/sec are not allowed) and wait until the flow

velocity becomes steady.

3.8. Equalize pressure between a pipeline (pressure gauge Р1) and the scraper

launcher (pressure gauge Р2) by opening and closing the valve V 3.

3.9. Open the gate valve V 2 fully. The gate valves V 3 and V4 remain closed.

3.10. Open the gate valve V3.

3.11. Start closing the gate valve V1. MCGT will commence to travel from the scraper

launcher to the pipeline. Using the locator, watch the MCGT passage through the

scraper launcher outlet gate valve, the T-piece and SPI Series indicator (Fig. 3.).

Fig. 3.


9

3.12. Open the gate valve V 1 fully as soon as the locator will detect the MCGT at the

first reference marker.

3.13. Isolate the scraper launcher by closing the gate valves V 2 and V 3.

4. TRACKING OF MCGT ALONG THE PIPELINE

4.1 GENERAL REQUIREMENTS

To track MCGT, the following facilities are applied: MCGT transceivers,

antennae of which are fitted under the bumper grate in the forefront and ground

tracking devices that include locators. The MCGT transceivers generate low

frequency electromagnetic signals that are received by the locator receiver

antenna on the ground surface from 3 meters from the transmitter in a pipeline.

The locator receivers designed to track the MCGT during their travel along a

pipeline, they shall be needed to refer inspection data to particular oil pipeline

locations and shall be installed at the reference marker locations. Tracking

teams with the locator receivers shall arrive at the reference marker location not

later than 20 minutes before the expected time of the MCGT passage. To track

the MCGT by the acoustic noise produced during its travel along a pipeline,

acoustic locators may be applied.

The cleaning scraper equipped with remote signal transmitter will travel along a

pipeline and it will be tracked by the acoustic locator or aurally at valves

locations (gate valves and plungers), as well as at exposed pipeline sections.


10

4.2 REFERENCE MARKER WORK PROCEDURE

Fig. 4: General View of Marker Signal Logger (MSL) and its faceplate


11

4.2.1 LOGGING OF A MOVING MCGT

4.2.1.1 Place MSL at a minimum possible distance above the pipeline at the

location where an in-line MCGT or a cleaning scraper is expected to pass

(control point). Longitudinal axis of MSL should be parallel to pipeline axis, see

Fig. 7.2. (a). Efficiency of transmitting device (TD) signal detection depends on

the distance between the axes.

4.2.1.2 When MSL is logged, there is a specific sound signal accompanied by

four or more flashing indicators.

4.2.2 LOGGING OF A STATIONARY MCGT

4.2.2.1 Move MSL along the pipeline as close as possible to its axis. Efficiency of

TD signal detection is maximum when MSL antenna axis is parallel to the

pipeline axis.

4.2.2.2 When MSL is logged, there is a specific periodic sound signal

accompanied by four or more flashing indicators.

4.2.2.3 While approaching to MCGT it is necessary to reduce sensitivity of MSL

gradually and keep the number of flashing indicators between five and six in

order to identify a location with maximum strength of the signal. MSL antenna

axis should be parallel to the pipeline axis. The location where the MSL signal

strength is maximum corresponds to the location of TD antenna, fixed on a flaw

detector.

4.2.2.4 For more exact detection of MCGT it is necessary to find minimum

strength of a signal by putting MSL antenna axis 90° to the pipeline axis, see

Fig. 5 (b). It is acceptable to change sensitivity of MSL during search to watch

the signal alteration.


12

Fig. 5: Variants of MSL antenna positioning over the pipeline axis.

4.2.3 APPLICATION OF MSL FOR LOGGING OF MCGT PASSAGE MOMENT 4.2.3.1 Prior to placement of MSL in a marker point it is essential to

synchronize timers of the MCGT and MSL. This procedure is carried out

immediately before launching of the MCGT.

4.2.3.1 After MSL placement in a marker point and adjustment of due

sensitivity turn“recording enable” on.

4.2.3.3 After passage of MCGT turn the power of MSL or “recording enable” off.

4.2.3.4 Copying of received data and its subsequent processing are made with a

special computer program.

4.2.3.5 In order to increase reliability of marker work it is recommended to take

into account the following rules:


13

4.2.3.5.1 Placement of MSL in marker points during tracking of MCGT

should be made in the following way: antenna (MSL axis) can be placed

vertically, strictly above pipeline axis;

Fig. 6.

4.2.3.5.2 Antenna can be placed horizontally above pipeline, parallel to pipeline

axis.

Fig.7.


14

4.2.3.5.3 Variant of antenna placement is subject to operator’s decision

depending on existing disturbance in a marker point. It is important to choose

optimum type of MSL placement to reduce the influence of disturbance.

Note 1: Vertical placement is preferable, since in this case (during post-

processing of obtained information) the moment of MCGT passage through the

marker point is more exact.

Note 2: In a situation of high disturbance, high speed of MCGT motion or deep

occurrence of the pipeline it is recommended to place two MSLs in every marker

point: one is vertical, the other is horizontal.

5. RECEIVING OF MCGT

5.1 Scraper Receiver Initial Position (refer to Fig. 8):

The gate valve V1 is closed; The gate valves V2 and V3 are opened.

Fig. 8.


15

5.2 Position the locator receiver about 20 m from T-piece of the scraper receiver (refer

to fig. 9).

5.3 Watch the MCGT passes "А" T-piece by the locator receiver.

5.4 Move the locator receiver to the scraper receiver to identify the MCGT position

(transmitter antenna) at the scraper receiver.

5.5 Carrying the locator along the scraper receiver (the antenna shall be

perpendicular to the scraper receiver wall), find the accurate position (± 20 см) of the

transmitter antenna by the minimum signal to make sure that the MCGT entered the

scraper receiver fully and the gate V2 will not obstruct to close it.

5.6 Open the gate valve V1 fully.

5.6 If the MCGT entered the scraper receiver fully, close gate valves V2 and V3

sequentially.

Fig. 9.


16

5.7. Release pressure in the scraper receiver.

6. REMOVAL OF MCGT FROM SCRAPER RECEIVER

6.1 Using a hoist, lift a tray from the transport facility and put it near the closed

scraper receiver.

6.2 Connect a ground cable between the scraper entry facility and the scraper

receiver. Make sure the ground cable runs along both sides.

Warning! Make sure the ground cable is clamped at coating-free sections!

It is prohibited to connect or disconnect the ground cable with the open cap of

the scraper receiver!

6.3 Release a product from the scraper receiver. If necessary, use an inert gas.

6.4 Open the scraper receiver cap and remove remaining product.


17

6.5 Wait 15 minutes to let fumes out of the scraper receiver or purge by inert gas.

6.6 Lift the tray by hoist and position it in front of the scraper receiver opening so as

its rear end is close to the open scraper receiver and the tray bottom is not higher

than the scraper receiver bottom. Adjust the feet and secure them. Secure the MCGT

tray on the scraper receiver to avoid offset.

6.7 Secure a wire in the bumper lug in the front of the MCGT. Using a winch or a

tractor, pull the MCGT smoothly from the scraper receiver, until it is completely

placed on the tray. Secure the MCGT in the tray to avoid offset.

6.8 Remove the tray with the MCGT from the scraper receiver to close the scraper

receiver cap.

6.9 Close the scraper receiver cap.

6.10 Disconnect the ground cable between the scraper receiver and the tray.

6.11 Move the tray with the MCGT beyond the dangerous zone of the scraper receiver

(out of the safety guard).

6.12 According to the MCGT operation guidelines, take the MCGT run-related initial

data and shut down the MCGT.

6.13 Axamine the MCGT visually.

7. CLEANING OF MCGT

1. Remove possible deposits. It is prohibited to apply heavy tool or sharp-

edged tool, since it may damage connection cables and the odometer

wheels.

2. The amount of wax and tar deposits, as well as damages detected during

initial inspection and cleaning shall be indicated in MCGT Acceptance

Report.

3. Clean all MCGT components thoroughly, including cables. Steam and

water jetting will be the most appropriate cleaning technique.

4. If a steam facility is unavailable, diesel fuel-wet rags may clean the MCGT.

Upon cleaning, the MCGT shall be dried by clean rags.


18

5. When the MCGT is cleaned to a degree that allows to ship it to the

operation facility, examine the external condition of the MCGT and execute

the appropriate "MCGT Acceptance Report".

8. PECULIARITIES OF RUNNING CALIPER BY AIR

Essentials Major issues related to running caliper with the help of air:

- increased wear of cup-type seals;

- non-uniform movement of caliper with stops and brisk accelerations (in excess

of maximum allowable 8 m/s);

- difficulties in choosing compressor duty.

As distinct from running with the help of liquid, pressure drop contributing to

in-line inspection tool movement heavily depends on the force of the tool friction

against pipeline wall. Such force heavily depends on deposits covering pipeline

inner wall.

Increased wear of cup-type seals in large-diameter pipelines could be handled

using support wheels for the caliper body. The wheels serve as an additional

support for the body and reduce cup-type seals pressure. Base of the wheels

contains instrument transducers capable of measuring all pipeline geometrics.

Service life of the support wheels is no less than 250 km. They assist in

reducing wear of cup-type seals.

Components of the Caliper

The product mainly consists of the body (Figure 10, 11). The body holds cup-

type seals, support wheels, with rate-of-turn sensors. Head of the product

carries a bumper, and low-frequency transmitter. Rear part of the product

contains odometers.

Cup-type seals align the product within the pipeline and enable its movement

through the pipeline with the medium. The wheels roll over the pipeline inner

surface tracking all its irregularities. Data from rate-of-turn sensors enter


19

electronics unit to undergo further processing. Data related to traveled distance,

speed and acceleration will be transmitted from odometers to the same

electronics unit.

Bumper, contains an eye used to insert the product into the launcher (when

pulling it in), while its rear part contains a ringbolt used to withdraw the

product from the pipeline receiver and handling operations.

Fig. 10. Version 48-PM


20

Fig. 11. Version 38-PM


21

9. IDENTIFYING CALIPER RUNNING CONDITIONS

Pipelines vary in terms of design (according to terrain peculiarities, laying

conditions and elevation differences; application of T-joints, gate valves etc.),

steel grades and equipment used for in-line operations (compressors etc.).

Therefore, caliper running conditions would be identified based on cleaning pig

running results.

Caliper run should without fail be preceded with cleaning pig run. In the course

of the run, technical personnel will not only assess pipeline cleaning degree, but

identify service conditions adequate for ensuring allowable caliper travel speed.

Equipment service conditions shall correspond to the pre-set parameters:

speed from 0.5 to 4 m/s (for short periods: no less than 0.2 m/s and no more

than 8 m/s)

the caliper shall move continuously for XYZ Mapping,

At particularly heavy route sections, where the caliper may stick, the Customer’s

technical personnel should run a foam pig behind the caliper. Joint application

of the caliper and foam pig will enable to negotiate the heaviest pipeline sections

changing no compressor duty.

Personnel accompanying the caliper along the pipeline route will make rapid

calculation of its travel speed using obtained results to adjust compressor duty.

Peculiarities of running caliper during dewatering:

Running caliper to displace water left after hydrotesting almost does not differ

from its run with the help of liquid (crude or water).


22

A peculiarity:

Prior to running a caliper, technical personnel operating the pipeline will

calculate water displacement conditions depending on air feed flow rate and

potential water flow rate.

Motion mode could be adjusted by reducing / increasing liquid outflow from the

pipeline.

Caliper motion mode will be controlled by technical personnel operating the

pipeline at the run start as soon as the caliper leaves checkpoint I behind.


23

10. TERMS AND DEFINITIONS

The following acronyms and terms with appropriate definitions shall be used in

the Technology:

Pipeline A system of pipes and other components used for the transportationof products between (but excluding ) plants. A pipeline extends from pig trap to pig trap (including the pig traps), or, if no pig trap is fitted, to the first isolation valve within the plant boundaries or a more inward valve if so nominated.

LDOTP means a long distance oil transmission pipeline. Customer means an owner of an oil pipeline that enters into

agreement with the Contractor to execute LDOTP inspection-related operations.

Contractor means a Customer-contracted dedicated company

conducting cross-country pipeline diagnostics. Flaw Detection means detection of defects and anomalies in a

pipeline by means of in-line inspection tool. Cleaning Scraper means an in-line intpection tool designed to clean

a pipe and a pipe wall from wax and tar deposits as well as from foreign matters.

Multi-channel Geometry Tool (MCGT) Equipped with Navigation System means an in-line inspection tool designed to

detect such features as dents, buckles, ovality, bend radius and angle and in some cases considerable areas of internal corrosion during in-line geometry inspection and also to define pipeline positioning coordinates.

Transmitting Device or Transmitter means a device generating low frequency

electromagnetic pulses and emitting them through a dedicated aerial. It is mounted on an in-line inspection tool to detect its location from the ground surface.


24

Locator or Marker Signal Logger means a surface hand-held device designed to

detect low frequency transmitters-fitted in-line inspection tools in a pipeline by means of signals to be produced.

Acoustic Locator means a surface hand-held device designed to

detect in-line inspection tool passage through a location of a pipeline by the acoustic noise

Buckle means a partial collapse of the pipe due to excessive bending or compression associated with soil instability, land slides, washouts, frost heaves, earthquakes, etc

Dent means a distortion of the pipe wall resulting in a

change of the internal diameter but not necessarily resulting in localized of wall thickness

Launching/Receiving Trap means an ancilliary item of pipeline equipment,

with associated pipeworks and valves, for introducing and removing MCGT from a pipeline.

05 eoog mcgt inspection technology

Documents