Geologically controlling factors on coal bed methane (CBM) productivity in Liulin
Tóm tắt
It is of great significance to forecast high yield of CBM wells and analyze dynamic production by having an overall study on the characteristics of the produced CBM and determining the main factors influencing the productivity of CBM. With the test report and the related geological parameters of a single well, methods of combining the productivity data and typical production curves were used to analyze different geological factors and how to influence the capacity of a single layer. Then, the paper proposed a new understanding about capacity characteristics of the study area and geological control factors: First, the Shanxi formation production capacity characteristics was divided into two-stages, showing signs of gas and gas breakthrough for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were better than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well production. Finally, comprehensive analysis concluded that the ratio of critical desorption pressure to reservoir pressure has greater influence on the production of vertical CBM wells. Besides, the potential of gas production capacity has greater impact at stage of showing gas signs; the coal reservoir pressure and gas production capacity have greater impact at stage of gas breakthrough for 100 days. Thus, to seek the coal bed methane with high ratio of critical desorption pressure to reservoir pressure and high yield of gas will be important guarantee to the success of the coal bed methane exploration and development.
Tài liệu tham khảo
Chen Z H, Wang Y B, Yang J S, Wang X H, Chen Y P, Zhao Q B, 2009. Influencing factors on coal-bed methane production of single well: a case of Fanzhuang Block in the south part of Qinshui Basin. Acta Petrolei Sinica, 30(3): 409–402.
Fu X H, Qin Y, Wei C T, 2003. The coal-bed gas geology. Xuzhou: China University of Mining and Technology Press.
Huang X M, Lin L, Wang Z W, Zhang W Z, Cai X L, 2010. Correlation features of the coal measure in Liulin block, Shanxi. China Coal Bed Methane, 7(3): 3–7.
Lin L, Yao Y, Huang X M, 2011. The porosity and permeability characteristics of the Liulin Coalbed Methane Block, Shanxi Province. //Proceedings of 2011 Coalbed Methane Symposium. Beijing: Geological Publishing House, 182–186.
Liu R H, Liu F, Zhen W, Li J M, Wang H Y, Wang B, Liu H L, Zhao Q, 2008. Characteristies and favorable area prediction of coal reservoirs in Qinshui Basin. Petroleum Geology and Recovery Efficieney, 15(4): 16–19.
Lou J Q, 2004. Factors of influencing production of coalbed gas wells. Natural Gas Industry, 24(4): 62–64.
Makee C R, 1986. Using permeability vs depth correlations to assess the potential for producing gas from coal seams. Quarterly Reviews of Methane from Coal Seams Technology, 4(1): 15–26.
Ni X M, Chen P, Zhu M Y, 2010. Analysis on main controlled geological factors of production capacity of coal bed methane vertical drilling well. Coal Science and Technology, 38(7): 109–113.
Si S P, Li W F, Ma J M, 2001. Influence factors of production capacity and strategy on coalbed gas wells. Fault-Block Oil & Gas Field, 8(5): 50–53.
Su F Y, Cai Y F, 2004. Application of numeral simulation in Liulin test zone of coal-bed gas. Natural Gas Industry, 24(5): 95–96.
Su X B, Chen J F, Sun J M, 2001. Coalbed gas geology and exploration and development. Beijing: Science Press.
Su X B, Lin X Y, 2009. The coal-bed gas geology. Beijing: China Coal Industry Publishing House.
Sun M Y, Huang S C, 1998. Hand book of coal bed methane development and utilization. Beijing: China Coal Industry Publishing House.
Wu S G, Hu A M, Li X M, 2011. The theoretical calculation study of flow rate and pressure drop in coalbed for a CBM well. //2010 Chinese Unconventional Gas Exploration and Development Progress. Beijing: Petroleum Industry Press.
Xu H, Tang D Z, Tang S H, Lü R M, Li S, 2011. Several key pressure control factors on coalbed gas well productivity.//Coal Seam Gas Exploration and Development of Theory and Technology of Coal Bed Gas-2010 National Symposium. Beijing: China Academic Electronic Journal Press, 53–58.
Yao H F, Yin C Z, 2006. Features of coalbed methane reservoir in Yangjiaping area, Liulin County, Hedong Coalfield, Shanxi Province. China Petroleum Exploration, (3): 68–72.
Zhang W Z, Zhou S Z, Meng S Z, Zhao J, Mo R H, 2011. Hydrogeologic conditions and its influence on coalbed methane accumulation in Liulin Block, Shanxi Province. //Proceedings of 2011 Coalbed Methane Symposium. Beijing: Geological Publishing House, 90–97.