Quantitative Prediction of Coalbed Gas Content Based on Seismic Multiple-Attribute Analyses

Renfang Pan; Huanhuan Gao; Kehui Lei; Zhengping Zhu

doi:10.5614/j.eng.technol.sci.2015.47.4.7

Authors

Renfang Pan College of Earth Science, Yangtze University, Hubei Wuhan 430100
Huanhuan Gao College of Earth Science, Yangtze University, Hubei Wuhan 430100
Kehui Lei PST Service Company, Beijing 100001, China
Zhengping Zhu College of Earth Science, Yangtze University, Hubei Wuhan 430100

DOI:

https://doi.org/10.5614/j.eng.technol.sci.2015.47.4.7

Abstract

Accurate prediction of gas planar distribution is crucial to selection and development of new CBM exploration areas. Based on seismic attributes, well logging and testing data we found that seismic absorption attenuation, after eliminating the effects of burial depth, shows an evident correlation with CBM gas content; (positive) structure curvature has a negative correlation with gas content; and density has a negative correlation with gas content. It is feasible to use the hydrocarbon index (P*G) and pseudo-Poisson ratio attributes for detection of gas enrichment zones. Based on seismic multiple-attribute analyses, a multiple linear regression equation was established between the seismic attributes and gas content at the drilling wells. Application of this equation to the seismic attributes at locations other than the drilling wells yielded a quantitative prediction of planar gas distribution. Prediction calculations were performed for two different models, one using pre-stack inversion and the other one disregarding pre-stack inversion. A comparison of the results indicates that both models predicted a similar trend for gas content distribution, except that the model using pre-stack inversion yielded a prediction result with considerably higher precision than the other model.

Downloads

Download data is not yet available.

References

Yee D., Seidle, J.P. & Hanson, W.B., Gas Sorption on Coal and Measurement of Gas Content, Hydrocarbons from Coal: AAPG Studies in Geology, pp. 203-218, 1993.

Fu, X., Qin, Y., Wang, G.G.X. & Rudolph, V., Evaluation of Gas Content of Coalbed Methane Reservoirs with the Aid of Geophysical Logging Technology, Fuel, 88(11), pp. 2269-2277, 2009.

Li, B., Wei, J.P., Li, P., Wang, K. & Borisyuk, Y.A., Nonlinear Motion Law of Coalbed Gas Seepage under the Combined Effects of Stress and Temperature, Journal of Power Technologies, 94(2), pp. 106-113, 2014.

Diamond, W.P. & Schatzel, S.J., Measuring the Gas Content of Coal: A Review, International Journal of Coal Geology, 35(1), pp.311-331, 1998.

Pen, S.P., Gao, Y.F., Yang, R.Z., Chen, H.J. & Chen, X.P., Theory and Application of AVO for Detection of Coalbed Methane-A Case from the Huainan Coalfield, Chinese Journal of Geophysics, 48(6), pp. 1475-1486, 2005.

Sun, B.Yang, M.F., Sun, X. & Sun, F.J., Coalbed Methane Enrichment Area Prediction Based On Seismic AVO Attributes, Natural Gas Industry, 30(6), pp. 15-18, 2010.

Pan, R.F., Chen, S.L., Zhang, L.P. & Ai, J.F., Semi-Quantitative Analysis of AVO Forward of Gas-Containing Sands, Geophysical Prospecting for Petroleum, pp. 103-108, 2013.

Shuck, E.L, Davis, T.L. & Benson, R.D., Multicomponent 3-D Characterization of a Coalbed Methane Reservoir, Geophysics, 61(2), pp. 315-330, 1996.

Marroqun, I.D. & Hart, B.S., Seismic Attribute-based Characterization of Coalbed Methane Reservoirs: An Example from the Fruitland Formation, San Juan basin, New Mexico, AAPG Bulletin, 88(11), pp. 1603-1621, 2004.

Su, X., Lin, X., Zhao, M., Song, Y. & Liu, S., The Upper Paleozoic Coalbed Methane System in the Qinshui Basin, China, AAPG Bulletin, 89(1), pp. 81-100, 2005.

Long, S.X., Chen, C.F., Li, X.Z., Ye, X. & Liang, Y., SINOPEC's Coalbed Methane Development Potential, Oil & Gas Geology, 32(3), pp.481-488, 2011.

Meng, G.X., He, X.H., Zhao, J.H., Zhou, G.W., Yang, Y.Y. & Zhang,R.R., Distribution Characteristics and Control Factors of Gas Content of No. 15 Coal Seam in Heshun Block, China Coalbed Methane, 10(1), pp.6-9,2013.

Spencer, T.W., Edwards, C.M. & Sonnad, J.R., Seismic Wave Attenuation in Nonresolvable Cyclic Stratification, Geophysics, 42(5), pp. 939-949, 1977.

Johnston, D.H., Toksz, M.N. & Timur, A., Attenuation of Seismic Waves in Dry and Saturated Rocks: II. Mechanisms, Geophysics, 44(4), pp. 691-711, 1979.

Xin, K.F., Li, Z.C., Wang, Y.G., Tu, S.J. & Ma, Z.T., Formation Equivalent Absorption Coefficient Inversion, Geophysical Prospecting for Petroleum, 40(4), pp. 14-20, 2001.

Liu, S.G., An, L.Q., Xue, R. & Zhang, X.L., Application of Gaussian Curvature Method in Forecasting Natural Fracture Zones in Coal Seam, Journal of China University of Mining & Technology, 33(5), pp. 573-577, 2004.

Shen, J., Qin, Y., Fu, X., Wang, B., Yang, S. & Zhao, L., Application of Structural Curvature of Coalbed Floor on CBM Development in the Zaoyuan Block of the Southern Qinshui Basin, Mining Science and Technology (China), 20(6), pp. 886-890, 2010.

Chen, X.P., Huo, Q., Lin, J., Wang, Y., Sun, F., Li, W. & Li, G., Theory of CBM AVO: I. Characteristics of Anomaly and Why It Is So, Geophysics, 79(2), pp. 55-65, 2014.

Shuey, R.T., A Simplification of the Zoeppritz Equations, Geophysics, 50(4), pp. 609-614, 1985.