柳林煤层气区块不同井型产能分析研究

对鄂尔多斯盆地柳林煤层气区块压裂直井与多分支水平井的生产状况进行了分析。多年的排采生产历史表明，该区块内大多数压裂直井的产量低于预期，特别是生产1~2 a后的产量，只有预期的30%左右；而投产的多口多分支水平井的产气量较高和稳定，与预期的结果相当。根据柳林区块的地质特征、生产历史和煤层气开采的数值模拟模型，对不同井产能进行了分析，并与现场生产数据进行对比，研究不同井型的产气机理、产能大小及其影响因素。研究结果表明，压裂裂缝的支撑效果差及裂缝的先期闭合是导致压裂直井后期生产效果差的主要原因，而该区块的综合地质特征更适合于采用多分支水平井技术。结合数模，分析了水平井的排采控制范围以及煤层厚度、储层系数、分支水平井结构参数等对煤层气产能的影响。

Productivity analysis of different types wells in Liulin coalbed methane block

The production data from fractured vertical wells and multi-branch wells in Ordos Basin Liulin block were analyzed.Production history show that vertical wells’ performance is significantly poorer than expected,especially after 1-2 years of production,only about 30% as expected,while multi-branch horizontal wells’ high gas production rate is basically identical with the results of numerical simulation.According to the geological characteristics of Liulin blocks,the production history and numerical simulation model,the productivity of different types of wells were analyzed,and compared with the field production data.The mechanism of different well types,productivity and its influencing factors were studied.Results show that the damage of fracturing fluid to reservoir and the closure of induced fracture are the main reasons for the poor production of fractured vertical wells.The multi-branch horizontal well is more appropriate for the exploitation of CBM in the Liulin block.Through numerical simulation,the control area of multi-branch horizontal well and the influence of coal thickness,reservoir coefficient and the structure parameters on yield were analyzed.