Modeling of gas generation from the Cameo coal zone in the Piceance Basin, Colorado

Zhang, Etuan; Hill, Ronald J.; Katz, Barry J.; Tang, Yongchun

doi:10.1306/04020806015

Cited by 40 publications

(28 citation statements)

References 36 publications

(33 reference statements)

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“…In coal, the lower boundary of the thermogenic gas window corresponds approximately with a vitrinite reflectance (R o ) of 0.8% ( Jüntgen and Klein, 1975). Closed system pyrolysis experiments suggest that coal can generate 4 to 10 times more methane than can be retained in coal matrix (Zhang et al, 2008). The excess gas will be expelled through adjacent strata if coal is poorly confined, will migrate along bedding if coal is well confined, and will contribute to overpressuring and cleating if the coal is confined and has low permeability.…”

Section: Geothermicsmentioning

confidence: 99%

Geology of North American Coalbed Methane Reservoirs

Pashin

2014

Coal Bed Methane

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Section: Geothermicsmentioning

confidence: 99%

Geology of North American Coalbed Methane Reservoirs

Pashin

2014

Coal Bed Methane

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“…Coal can generate 3 to 20 times more thermogenic gas than can be retained by adsorption, which can lead to significant updip migration and expulsion (Zhang et al, 2008), and the very low permeability of the strata bounding coal seams in the Pottsville Formation probably favored updip migration within coal over direct expulsion. However, the adsorption capacity of coal increases during regional uplift and cooling, and so it is widely thought that coal can be substantially undersaturated with thermogenic gas if not augmented by hydrocarbon migration or late-stage bacterial methanogenesis (Yang and Saunders, 1985;Scott, et al, 1994).…”

Section: Burial History and Gas Generationmentioning

confidence: 99%

Variable gas saturation in coalbed methane reservoirs of the Black Warrior Basin: Implications for exploration and production

Pashin

2010

International Journal of Coal Geology

109

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“…The Cameo coal zone varies in thickness from 400 to 500 feet and is comprised of interbedded sandstones, shales, and coals. The Cameo zone is thought to be a source for the Williams Fork gas (Zhang et al 2008). In the basin center of this study area, Williams Fork gas saturations can extend over 1,700 feet above the Rollins Sandstone.…”

Section: Production Profiling -Challenging Factorsmentioning

confidence: 99%

Enhanced Production Profiling of Gas Wells Using a New Method to Model the Geothermal Temperature Gradient

et al. 2010

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Quantitative gas and water production profiling is very useful in completion and production performance evaluation. Production profile analysis that incorporates mass rate modeling of the flowing temperature has dramatically increased confidence in profiling results. Accurate mass rate modeling requires an accurate estimate of the geothermal temperature gradient. The conventional technique of estimating a linear geothermal gradient is not reasonable in producing regions with long completion intervals and complex lithologies. This paper will detail a new method of simulating the geothermal temperature gradient and advances in quantitative production profiling.A multi-well study was conducted in the Piceance Basin in Northwestern Colorado because of the unique effect of lithology on the geothermal gradient. Coal, sand and shale sequences which impact the geothermal gradient must be taken into consideration. The study includes open and cased hole log data to define lithology and shut-in temperature data to characterize the geothermal gradient. An analytical simulator was developed to model the geothermal gradient. Research in rock, mineral and fluid thermal conductivities is utilized to qualify the field data and analytical model.Results demonstrate that higher shale volume and coal beds increase the geothermal gradient above clean sand layer gradients. Measured geothermal gradients across coal bearing intervals are an order of magnitude higher than clean sand intervals. Geothermal gradients from the simulator were used as constraints in production profile analyses. The analyses will illustrate the identification and quantification of zonal gas and water production, even when some of the wells were flowing under adverse conditions of low gas rate, severe slug flow and high water production.Enhanced production profiling has enabled the operator to enhance their reservoir characterization, completion strategies and production performance of future offset wells. Other applications for the technology include: 1) production profiling in similar regions with complex lithology and non-linear geothermal gradient, and 2) distributed temperature sensing used for continuous temperature and production profile monitoring.

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Modeling of gas generation from the Cameo coal zone in the Piceance Basin, Colorado

Cited by 40 publications

References 36 publications

Geology of North American Coalbed Methane Reservoirs

Geology of North American Coalbed Methane Reservoirs

Variable gas saturation in coalbed methane reservoirs of the Black Warrior Basin: Implications for exploration and production

Enhanced Production Profiling of Gas Wells Using a New Method to Model the Geothermal Temperature Gradient

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