Download - Online Gas Monitoring of Drilling Mud

Online Gas Monitoring of Drilling Mud

[1] Erzinger, J., Wiersberg, T. and Zimmer M.(2006) Real-time mud gas logging and sampling during drilling, Geofluids 6, 225-233

[2] Wiersberg, T., Erzinger, J., Zimmer, M., Schicks, J., and Dahms, E. (2004) Real-time gas analysis at the Mallik 2002 Gas Hydrate Production Research Well; in Scientific Results from Mallik 2002 Gas Hydrate Production Research Well Program, Mackenzie Delta, Northwest Territories, Canada, (ed.) S.R. Dallimore and T.S. Collett; Geological Survey of Canada, Bulletin 585 pp. 15. [3] Erzinger J., Wiersberg T. and Dahms E. (2004) Real-time mud gas logging during drilling of the SAFOD Pilot Hole in Parkfield, CA, Geophys. Res. Lett. 31, L15S18, doi:10.1029/2003GL019395

OverviewOnline monitoring of gas from circulating drilling mud has been proven being a

reliable and inexpensive technique to obtain information on the composition

and spatial distribution of gases at depth-in real time [1]. The method had

been successfully applied on several ICDP drilling projects and IODP Exp. 319.

For more information please contactThomas WiersbergScientific DrillingGFZ German Research Centre for GeosciencePhone +49 331 288 1081Fax +49 331 288 [email protected]

Outcome·Online drilling mud gas monitoring is suitable

to detect fluid-bearing horizons, shear zones, open

fractures, sections of enhanced permeability and

methane hydrate occurrences in the subsurface of

fault zones [3, 4, 6], volcanoes [5], geothermal

and permafrost areas [2], and others.

·Off-site isotope studies on mud gas samples

help reveal the origin, evolution, and migration

mechanisms of deep-seated fluids [4].

·It also has important application to aiding

decisions if and at what depth rock or fluid samples

should be taken or formation testing should be

performed.

1 2 3

0 2 4 6 8

H2 (vol%)

1800

1900

2000

2100

2200

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2400

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3100

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Depth (m) 0 2000 4000

222Rn (Bq/m3)

200 600

0 0.4 0.8 1.2

CO2 (vol%)

2 3 42 4 6 8 10

0 0.5 1 1.5 2CH4 (vol%)

0 4 8 12 16

Formation gas (CH4+CO2+H2)

1

0 500 1000 1500 2000 2500 3000 3500 40000.0

0.2

0.4

0.6

0.8

1.0

1.2

Pacific Plate Transition zone North American Plate

borehole depth (m)

SAF

3 He/

4 He

[Ra]

air-

corr

ecte

d

Experimental Setup

For online drilling mud gas analysis, the dissolved gas is

1 continuously extracted from returning drilling mud in an

airtight gas-water separator located at the “possum belly”,

2 pumped in a field laboratory nearby the shale shakers,

3 automatically analysed for its composition (CO , N , H , O , He, 2 2 2 2

222Ar, CH , C H , C H , i/n-C H , and Rn) in real-time, and 4 2 6 3 8 4 10

4 automatically sampled for further studies (stable isotopes,

noble gases).

[4] Wiersberg T. and Erzinger J. (2007) A helium isotope cross-section study through the San Andreas Fault at seismogenic depths, G-cubed 8, No. 1, doi: 10.1029/2006GC001388

[5] Tretner, A., Zimmer, M., Erzinger, J., Nakada, S., Saito, M. (2008) Real-time drill mud gas logging at the USDP-4 drilling, Unzen volcano, Japan. Journal of Volcanology and Geothermal Research, 175(1-2):28-34

[6] Wiersberg T. and Erzinger J. (2008) On the origin and spatial distribution of gas at seismogenic depths of the San Andreas Fault from drill-mud gas analysis, Applied Geochemistry 23, 1675-1690, doi:10.1016/j.apgeochem.2008.01.012

References

CH , C H , C H , 4 2 6 3 8

n-C H , i-C H 4 10 4 10

gas massspectrometer

gaschromatograph

H2

FID

column

field laboratory

Ar, CO , H , He, 2 2

N , O , CH 2 2 4

dataprocessing unit

autosampler

bypa

ss

pump

222

Rn detector

flowmeter

2 4

3

mud tank

cuttings

shaker

screen

mud pump

“possum belly”

gas pipelinepHcond.temp.

separator

9.0

mo

tor

axix shaftwith impeller

1