贵州织金地区煤层气合采开发实践与认识  

Practice and understanding of coalbed methane co-production in Zhijin area,Guizhou

作　　者：李佳欣 陈贞龙[3] 郭涛[3] LI Jiaxin;CHEN Zhenlong;GUO Tao(Hubei Key Laboratory of Petroleum Geochemistry and Environment(Yangtze University),Wuhan 430100,China;SINOPEC Chongqing Shale Gas Co.,Ltd.,Chongqing 408400,China;SINOPEC East China Oil&Gas Company,Nanjing 210000,China)

机构地区：[1]油气地球化学与环境湖北省重点实验室(长江大学资源与环境学院),湖北武汉430100 [2]中石化重庆页岩气有限公司,重庆408400 [3]中国石化华东油气分公司,江苏南京210000

出　　处：《煤田地质与勘探》2022年第9期163-170,共8页Coal Geology & Exploration

基　　金：中国石化科技项目(P19019-4,P20074-1,P21086-5)。

摘　　要：贵州省是薄至中厚煤层群发育的典型地区,煤层数量多、厚度薄、渗透率低、地应力高、压力系统多层叠置等资源禀赋特征导致国内外主流煤层气开发工艺技术本土化困难,煤层气资源难以动用。多、薄煤层煤层气地质特征的特殊性决定了煤层气开发技术的明显选择性,多煤层合采成为该地区煤层气资源高效开发利用的必由之路。2009年至今,中石化华东油气分公司在贵州织金区块陆续完成23口合采煤层气井的部署工作,实现了单井最大日产气量达5000 m^(3)、试验井组(10口直井)单井平均日产气量超1000 m^(3)的突破。对此,基于织金区块多煤层煤层气的勘探开发实践,系统分析了该地区多、薄煤层煤层气成藏地质条件,归纳总结了开发关键工艺的地质适用性,从地质选层、开发模式及排采管控等方面取得以下认识:(1)建立了合采产层优化判别方法,明确了以珠藏次向斜Ⅲ煤组20、23、27、30号煤层为主的最优层位组合关系;(2)形成了定向井多层分压合采、水平井分段压裂体积改造相结合的特色开发模式;(3)制定了以“平衡排采、阶段降压”为理念、以“面积降压”为目的的精细化排采管控制度。研究成果有助于促进该区域的多煤层煤层气开发,对贵州省煤层气高效开发具有重要的参考价值。Guizhou Province is a typical area where thin-to-medium thick coalbeds are developed,where the resource endowment characteristics,including multiple coalbeds,small thickness,low permeability,high in-situ stress and multilayer superposition of pressure system,lead to the difficulties in localization of the mainstream technologies at home and abroad for the development of coalbed methane(CBM)and the utilization of CBM resources.The particularity of these geological characteristics of the multiple and thin CBM determines the obvious selectivity of technologies for its development,and thus the co-production of multiple coalbeds becomes the essential method for effective development and utilization of CBM resources in the area.Since 2009,23 coalbed methane wells have been successively deployed in Zhijin area by SINOPEC East China Oil&Gas Company,realizing the maximum daily single-well output of 5000 m^(3)and the average daily single-well output over 1000 m^(3)in the test well group(10 vertical wells).Therefore,the geological conditions for accumulation of coalbed methane in multiple thin layers in this area were systematically analyzed based on the exploration and development practice of coalbed methane in multiple layers in Zhijin area,and the geological applicability of the key development technologies was summarized.Finally,the following understandings were obtained from the aspects of geological layer selection,development mode and drainage control method:(1)The discrimination method for optimization of co-production layers was established,the optimal horizon combination dominated by No.20,No.23,No.27 and No.30 coalbeds in coal formationⅢin Zhuzang subsyncline was defined for co-production.(2)The featured development mode combining the separate pressure co-production in directional wells and the volume stimulation by staged fracturing in horizontal wells was formed.(3)The refined drainage and production control system was formulated based on the concept of“balanced drainage and gradient pressure reduction”fo

关 键 词：织金地区 多、薄煤层 多层合采 地质选层 压裂方式 排采制度 

分 类 号：TE12[石油与天然气工程—油气勘探]