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 pro...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 break- through for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were bet- ter than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well pro- duction. 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.展开更多
The enriched characters of methane content in the main coal seam of Yunnan＇s Laochang coal mine was analyzed through combined with the geologic conditions of the research area： structure type, hydrogeology condition...The enriched characters of methane content in the main coal seam of Yunnan＇s Laochang coal mine was analyzed through combined with the geologic conditions of the research area： structure type, hydrogeology condition, coal reservoir＇s macerals, ash, water content, and so on. The geology factors of controlling gas in Laochang coal mine were illustrated; and the different geology models of controlling gas of geologic condition coupling were posed. Research shows that, in the region, the methane contents of the main coal seams decrease gradually from middle to all around it; the northeast and southeast is higher than the west. In the local area, the methane content of anticline axis is higher, and the gas content is reduced to both wings and plunging crown. On macroscopic view, the distribution of methane content in coal-beds was controlled by structural type. On microscopic view, the methane content in coal-beds is mainly involved in coal reservoir＇s macerals, ash content, and water content. The enriched characters of CBM in the research area are mainly the result of structure-hydrogeology-petrophysics coupling controls of CBM. On the basis of above analysis, according to the distribution character of methane content in coalbeds, the research area was divided into low gas area, middle gas area, and high gas area.展开更多
文摘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 break- through for 100 days. Second, two parameters, which include potential of gas production and gas production capacity, were bet- ter than the single parameter, such as gas content, coal thickness, and penetration to analyze affecting factors of single well pro- duction. 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.
基金Supported by the National Major Special Projects of Science and Technology of China （2011ZX05034） the National Basic Research Program of China （2009CB219605） the National Natural Science Foundation of China （41272178）
文摘The enriched characters of methane content in the main coal seam of Yunnan＇s Laochang coal mine was analyzed through combined with the geologic conditions of the research area： structure type, hydrogeology condition, coal reservoir＇s macerals, ash, water content, and so on. The geology factors of controlling gas in Laochang coal mine were illustrated; and the different geology models of controlling gas of geologic condition coupling were posed. Research shows that, in the region, the methane contents of the main coal seams decrease gradually from middle to all around it; the northeast and southeast is higher than the west. In the local area, the methane content of anticline axis is higher, and the gas content is reduced to both wings and plunging crown. On macroscopic view, the distribution of methane content in coal-beds was controlled by structural type. On microscopic view, the methane content in coal-beds is mainly involved in coal reservoir＇s macerals, ash content, and water content. The enriched characters of CBM in the research area are mainly the result of structure-hydrogeology-petrophysics coupling controls of CBM. On the basis of above analysis, according to the distribution character of methane content in coalbeds, the research area was divided into low gas area, middle gas area, and high gas area.
