School of Resources and Geosciences,China University of Mining and Technology Key Laboratory of Coalbed
Methane Resource and Reservoir Formation Process,Ministry of Education,China University of Mining and Technology

为给煤层气U型井排采制度的制定和优化提供依据,在分析柿庄南区块煤层气U型井排采典型阶段指标的基础上,提出研究区U型井排采过程可以划分为单一排水阶段、波动上升阶段和高产稳定阶段。在排采过程中,分阶段选取初始见气时间、初始累计产水量、初始降液幅度、初始降液速率、初始排水速率、波动上升时间、套压波动范围、液顶平均距离、典型高产日产气量、典型高产日产水量、典型高产套压、底液平均距离作为典型指标。根据以上分析结果,建议第1阶段应控制初始降液速率在5 m/d以下;第2阶段应控制套压在0~0.45 MPa波动,同时控制动液面维持在煤层顶板以上10 m之内;第3阶段应控制典型高产套压稳定在0.01~0.03 MPa,动液面稳定在煤层底板附近。

In order to provide the references for coalbed methane U-shaped well drainage system establishment and optimization, based on the reasonable analysis of the typical periods indexes for coalbed methane U-shaped wells drainage in Southern Shizhuang Block,the authors put forward that the drainage process could be divided i nto single drainage phase,wavelike rising phase and high production and steady phase.In the whole drainage process,some typical indexes were selected,including initial g as breakthrough time, initial cumulative water production,initial water level descending amplitude,initial water level descending rate, initial drainage rate,wavelike rising time, variation range of gas pressure,average distance from working fluid level to coal seam roof,typical high gas production,typical water production,typical gas pressure,averag e distance from coal seam floor to working fluid level.The analysis of drainage typical indexes showed that the initial water level descending rate should be controlled belo W5 m/ d in the first phase ,the casing pressure should be stabilized in 0 ~0.45 MPa while the working fluid level was kept below 10 m from the coal seam roof in the secon d phase,and the typical gas pressure should be stabilized in 0.01 ~ 0.03 MPa while the working fluid level was kept around the coal seam floor in the third phase.

国家科技重大专项资助项目(2011ZX05034)；国家自然科学基金重点资助项目(41272178)；江苏省“青蓝工程”及江苏高校优势学科建设工程资助项目(PAPD)；