NEAR SURFACE MONITORING IN THE ENOS(ENABLING ONSHORE CO2 STORAGE) PROJECT

01.08.2017

Dave Jones, Stan Beaubien, Sabini Bigi, Tanya Goldberg, Ingo Möller, Stefan Schloemer, Michela Vellico and

colleagues

BGS, URS, TNO, BGR and OGS

01.08.2017 2

LateraAilano

Near surface monitoring aspects

Continuous monitoring stations Rapid survey systems (wide area coverage)Ground based (ground mapper and mobile laser)Airborne (UAV gas monitoring, thermal imaging)

Leakage associated with faults and abandoned wellsControls on leakage Is low-level diffuse leakage important?

Source attributionQuantification (scanning laser and other methods)

01.08.2017 3

c. 80 cm

backfill with removed soil

GasProCO2 sensor

Box with antenna and batteries

Pressure sensor

Humidity and temperature sensor

to base station

to server • Sensors buried at 80 cm depth

include:• CO2 and temperature• Optional humidity and pressure

• Sensors connected to surface box that contains batteries and antenna

• Unit communicates wirelessly to a base station, which in turn uploads data to a central university server

• For ENOS a total of 25-50 of these low cost units will deployed above the CO2 injection point at the SulcisFault Lab site in Sardinia

GasPro CO2 monitoring system

Page 5

Main aim is to progress the TRL (at least to TRL 6) of custom‐made: Permanent monitoring stations [1] that 

record continuously soil gas concentrations and other relevant environmental data (Hontomin)

Permanent vertical profiling devices [2] for measuring CO2 concentrations at near surface atmospheric levels (boundary layer; GTB)

Additionally, Eddy Covariance systems [3] and CO2 accumulation chambers [4] will be used for cross‐evaluations and interpretation of data against environmental parameters

Experience has already been obtained at non‐leaking test sites in Germany, incl. the CCS pilot site Ketzin, in the Ardennes (B) and at naturally leaking sites in the Eger Rift valley (Cz) 

BGR’s near surface gas monitoring in ENOS

12

3

44

Page 6

Integration of systems as principle of approach

vado

se  zon

e

1. Permanent gas monitoring stations:Soil gas concentrations

3. Atmospheric concentration and flux computations

2. Mobile and continousnear surface gas flux measurements

near

surface

atmosph

ere

Page 7

Example of a time series obtained by vertical CO2 profiling (atmospheric concentration recording). 

Test results as motivation for advancing the vertical CO2 profiling method

Concentration levels where CO2 influences human health and the environment may emerge in surface situations like hollows in combination with calm air. Here, continuous wind speed measurements plus air CO2 concentration show good potential as basic monitoring technique.

Wind speed (green) vs. CO2 concentration (brown)

Page 8

Installation of permanent soil CO2monitoring stations at Hontomin

Three soil gas monitoring stations installed at the Hontomin pilot site

Fully operational since March 22, 2017  Besides the CO2 data environmental and 

technical parameters are recorded to:‐ check instrument function‐ interpret the CO2 data

Data are stored locally and then transferred via GSM protocol to BGR’s base in Hanover

Initial data show soil CO2 concentrations 10 to 20 times the mean atmospheric value but in the range of values from comparable sites

Oldenburg and Unger, 2004

GasPro CO2 ground mapper• Wind velocity has a log distribution that

approaches zero near the ground surface

• CO2 leaking from the soil may accumulate in this interval (z0)

• This interval, which is only 1-2 cm, is the monitoring target

• Goal is develop a low cost system that can map large areas rapidly

• Requirements are high sensitivity, high signal stability, and very rapid response

• Early development promising. Within ENOS it will be tested at natural leak sites and Sulcis CO2 injection site

200 m

UAV activities in Sulcis

Use of a drone to monitor possible leakages escaping from the Sulcis fault after CO2injection

Innovative sensors mounted on board, self developed by OGS (Arduino systems), measuring CO2 concentration, humidity, pressure and temperature

Monitoring campaigns before and after the injection

Data integration and comparison with the other monitoring techniques/tools tested on site

Temperature-humidity sensor

Barometric Pressure Sensor

CO2sensor

• Some horizontal profiles will be acquired, in order to spatially detect possible leakages

• Some vertical profiles will be acquired in correspondence of leakage points, in order to measure CO2 concentration variation with height.

Horizontal and vertical profilesCO2

Hei

ght

Gas migration styles• In ENOS we will use a number of

natural sites where CO2 is leaking at the surface to study migration styles, especially along faults. Sites include:

• Ailano, Latera, San Vittorino Italy• In addition we will inject CO2 at a

depth of about 150 m into a fault in volcanic rocks, located in SW Sardinia (Sulcis)

• Work will include flow modelling and surface monitoring

• Detailed work will be performed to better understand leakage along faults and shallow overburden, to assist in monitoring strategies

CO2 source identification in the vadose zone

local production (oxidation, respiration, dissolution) 

Gas sampling at natural leakage site(s)• CO2, δ13C, O2, N2, δ15N• CH4 and higher hydrocarbons (C2‐C5) ratios 

and δ13C and δD• D47 “clumped isotopes” = C‐O isotopologues

CO2 sources 

seepage of deep natural CO2seepage of deep injected CO2

combined geochemical approach  processes behind soil CO2

CO2 source identification in the vadose zone

Shallow CO2 source = low temperature

D47 “clumped isotopes”

Deep CO2 source = high temperature 

Preferential “clumping” of heavy isotopes (18O, 13C) at low temperature = high D47

At high temperature movement towards stochastic distribution = low D47

Determination of C‐O isotopologues

Ailano

Fiumicino

San Vittorino

Latera

Natural gas sampling  Natural gas escape areas: San Vittorino, Latera, Ailano, Fiumicino~90% CO2, ~0.3 CH4, N2, traces of H2S

Sampling setup

Quantification Scanning open path lasers (c.f. Shell Quest

monitoring) New laser development (RAL) Comparison with other approaches (Automated flux

chambers, eddy covariance, soil gas stations)

01.08.2017 18

Integration

Technical guidelines for integrated onshore monitoring and developed tools to detect and quantify leakage Upscaling from experimental sites to large scale storage sites Leakage simulation alliance (GTB, Sulcis, Field Research Station, Otway shallow injection, S Korea (e.g. K-COSEM sites), Brazil field site, CO2 Field Lab)

01.08.2017 19