Geologically controlling factors on coal bed methane （CBM） productivity in Liulin

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.

防喷泄油一体化工艺技术研究

针对大庆油田不能明确二次作业压力的采油井,因无法确定应使用防喷工具还是泄油工具,开展了防喷泄油一体化工艺技术研究。在防喷泄油一体化工具底部设计安装了压力滑套,将阀球压紧于阀座上,可实现二次作业防喷;在防喷泄油一体化工具上部设计安装了泄油销钉,通过井口投撞击杆的方式,可以实现泄油功能。现场应用8口井,其中有5口井进行了二次施工作业,防喷及泄油成功率都为100%。防喷泄油一体化工艺技术的研究与应用,为井下作业井筒流体控制提供了技术支持,实现了压力临界状态下采油井井筒无溢流施工作业。