鄂尔多斯盆地东缘三区块煤层气井产能主控因素及开发策略

发布时间：2019-07-21 16:49

【摘要】：根据鄂尔多斯盆地东缘三区块煤层气田83口排采井的资料,系统分析了地质条件、工程技术和排采制度等因素对煤层气井产能的影响,并在此基础上提出了相应的开发策略。结果表明:煤层厚度、地下水流体势、含气量、渗透率和临储比是影响研究区煤层气井产能的主要地质因素;井距、压裂液量和加砂量是影响煤层气井产能的主要工程技术因素;井底压力下降速度、动液面下降速度、套压直接影响煤层气井产能。在此基础上,采用灰色关联分析法得出研究区煤层气井产能影响因素的大小次序,并从有利区优选、井网部署、压裂设计和排采制度4个方面,提出了适合于研究区煤层气地质特征的开发策略:在有利区优选方面,构建了煤层气开发有利区评价指标,将研究区划分为I—Ⅳ类单元;在井网部署方面,I类和Ⅱ类单元井距应控制在335~370 m;Ⅲ类和Ⅳ类单元井距应控制在370~400 m;在压裂施工设计方面,I类和Ⅱ类单元煤层气井的压裂液量应控制在800~1 200 m3;加砂量应控制在35~60 m3;Ⅲ类和Ⅳ类单元煤储层地质条件相对较差,对于不同地质条件,提出了不同的压裂措施;排采制度方面,将煤层气排采产气过程划分为5个阶段,并针对不同排采阶段,提出了具体的排采控制方法。
[Abstract]:According to the data of 83 wells in the three-block coal-bed gas field in the eastern margin of the Ordos Basin, the effect of geological conditions, engineering technology and drainage system on the productivity of the coal seam gas well is systematically analyzed, and the corresponding development strategy is put forward. The results show that the coal seam thickness, the groundwater fluid potential, the gas content, the permeability and the temporary storage ratio are the main geological factors that affect the gas well productivity in the research area; the well distance, the amount of the fracturing fluid and the amount of sand addition are the main technical factors that affect the productivity of the coal seam gas well, and the bottom hole pressure drop speed, The falling speed of the moving liquid surface and the casing pressure directly affect the gas well productivity of the coal seam. On the basis of this, the paper puts forward the development strategy suitable for the geological characteristics of the coal-bed gas in the research area by using the grey correlation analysis method to obtain the influence factors of the gas well productivity in the research area, and from the four aspects of the favorable zone, the well network deployment, the fracturing design and the drainage system. in that prefer aspect of the favorable area, the evaluation index of the favorable area for the development of the coal bed gas is constructed, and the study area is divide into I-class IV units; in the aspect of the well network deployment, the well distance of the class I and the class II unit should be controlled to be 335-370m; the well distance of the class III and the class IV unit should be controlled to be 370-400m; and in the aspect of the design of the fracturing construction, The amount of fracturing fluid in the coal-bed gas well of Class I and Type II units shall be controlled at 800 ~ 1,200m3; the amount of sand added shall be controlled to be between 35 and 60m3; the geological conditions of the coal reservoirs of Class III and Class IV units are relatively poor, and different fracturing measures are proposed for different geological conditions; in terms of the drainage and production system, The gas production process of the coal bed gas is divided into five stages, and the specific drainage control method is put forward for different production stages.
【作者单位】：中国煤炭地质总局勘查研究总院;中国矿业大学资源与地球科学学院;中石油煤层气有限责任公司陕北项目经理部;
【基金】：国家重大科技专项“煤层气储层工程及动态评价技术”(2011ZX05034) 中国煤炭地质总局勘查研究总院青年科技创新基金资助
【分类号】：TE37

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