煤层气井酸化压裂增产机理及施工程序优化  

Optimization of Stimulation Mechanism and Construction Scheme of Acidizing Fracturing in Coalbed Gas Wells

作　　者：王镜惠 梅明华[3] 刘娟[2] 王华军[3] WANG Jing-hui;MEI Ming-hua;LIU Juan;WANG Hua-jun(School of Chemistry and Chemical Engineering,Yulin University,Yulin 719000,China;School of Life Science Engineering,Yulin University,Yulin 719000,China;No.2 Gas Production Plant of PetroChina Changqing Oilfield Branch Company,Yulin 719000,China)

机构地区：[1]榆林学院化学与化工学院,榆林719000 [2]榆林学院生命科学学院,榆林719000 [3]中国石油长庆油田分公司第二采气厂,榆林719000

出　　处：《当代化工》2020年第9期1892-1895,共4页Contemporary Chemical Industry

基　　金：榆林市科技计划项目(项目编号:2018-2-53)

摘　　要：为了明确酸化压裂对煤储层增产改造的适应性,通过煤样碳酸岩质量分数测试和酸液浸泡前后渗透率实验,得到了酸液对煤样渗透率的影响规律,将研究成果应用于酸化压裂工艺选井和现场实施。结果表明,碳酸盐质量分数较高且填充在割理、裂缝中是研究区储层渗透率较低的重要原因;酸化压裂能够有效提高煤样渗透率,但碳酸盐矿物质量分数大于1%,黏土矿物质量分数低于2%,储层渗透率低于0.2m D时效果较好;酸化压裂工艺应该包括小型预压裂、酸化处理、注替液和焖井4个环节,其中小型预压裂应逐级提排量,控制前置液量小于总液量的17%,最大排量小于6m3·min-1,砂比小于15%;酸化处理分为注前置酸、处理酸和后置酸,排量和液量逐级降低;最后需要注入顶替液,并焖井24 h以上。研究内容对煤层气井酸化压裂增产工艺实施具有指导意义。In order to clarify the adaptability of acidizing fracturing to coalbed gas reservoirs,the stimulation mechanism of acidizing fracturing was studied through the content test of carbonate rock incoal samples and the permeability change experiment after acid soaking,and then a reasonable construction planwas put forward.The results showed that the content of carbonate was high in some areas,and the permeability of fractures was greatly reduced when carbonate minerals were filled in the cleavage and fractures.The permeability of 6 coal samples was increased perfectly after soaking them in acid solution.When the content of carbonate minerals was more than 1%,clay mineral content was less than 2%,and the permeability was less than 0.2 m D,the performance of acidizing fracturing was perfect.The acidizing fracturing process should include four steps:small pre-fracturing,acidizing treatment,fluid injection and confining well.In the small pre-fracturing,the displacement should be increased step by step,andthe pre-flush volume should be less than 17%of the total fluid volume,the maximum displacement should be less than 6 m3·min-1,and the sand ratio should be less than 15%.The acidification treatment was divided into pre-acid injection,treatment acid and post-acid injection.Finally,displacement fluid should be injected and the well should be confined for more than 24 h.Field test showed that the well selection principle and construction technology effectively improved the output of a single well.

关 键 词：煤层气井 酸化 增产措施 碳酸盐矿物 施工方案 

分 类 号：TE377[石油与天然气工程—油气田开发工程]