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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
2300
2400
2500
2600
2700
2800
2900
3000
3100
3200
3300
3400
3500
3600
3700
3800
3900
4000
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
