摘要
L区块位于鄂尔多斯盆地东南缘,目前处于大井组试采评价阶段,有排采井100余口,其中部分煤层气井排采产水量高,造成液面下降困难、修井作业频繁,导致了排采产气效果不理想。本文深入分析了影响煤层产水的主要因素,5#煤层及顶底板含水性弱,产水量低,8~#煤层顶板存在局部高含水灰岩,通过压裂进一步沟通后是形成高产水井的主要原因。在对8~#煤层顶底板含水性识别分析的基础上,采取了差异性的地质选层和压裂工艺等措施。这些认识和措施应用在试采井组生产中,排采实践证实高产水井的数量得到了有效控制,单井平均产水量大幅降低,取到了较好的效果。
Pressure reduction by CBM well water drainage is the key to achieve output of CBM desorption.High yield water will cause the difficulty of liquid level and frequent repair,which leads to the difficulty of CBM production,and thereby decreases in the productivity of CBM wells.With the data of well logging,drainage and fracturing data,the CBM geological conditions,fracturing construction and the production characteristics in the L block of the Ordos Basin were systematically analyzed and studied,and the reasons for the formation of high yield water characteristics of CBM wells in L block were found out.The water content of 5~# coal seam and the top floor is weak,and the local water content of 8~# coal seam roof is strong.By fracturing effect,communication the Permian system Taiyuan Group limestone fractureddissolution pore water aquifer,become the main contribution of high yielding water layer.8~# coal seam roof limestone water identification method is obtained,and according to the prediction results,the plane distribution characteristics of coal seam water content in the study area were divided,which determined that the control measures of high water production wells with different perforation layer and the targeted fracturing technology.The methods and measures used in testing well group drainage application,confirmed that the number of high yielding wells has been effectively controlled,single well average water yield substantially reduced,which shows that good effect were obtained.
出处
《中国矿业》
北大核心
2017年第S1期393-398,共6页
China Mining Magazine
关键词
鄂尔多斯盆地
煤层气
高产水井
影响因素
预防措施
Ordos basin
CBM(coal bed methane)
high production water well
influence factor
preventive measures
