沁南煤层气田开发区块内煤层气生产接替研究  

Production replacement of coalbed methane in developing block of southern Qinshui

作　　者：刘会虎[1] 桑树勋[1] 李仰民 李梦溪 张建国 安士凯[1] 李军军[1] 

机构地区：[1]中国矿业大学资源与地球科学学院煤层气资源与成藏过程教育部重点实验室,江苏徐州221116 [2]中国石油华北油田煤层气勘探开发分公司,山西晋城048000

出　　处：《中国矿业大学学报》2011年第3期410-416,共7页Journal of China University of Mining & Technology

基　　金：国家高新技术研究发展计划(863)项目(2007AA06Z220);教育部科学技术研究重大项目(307014);华北油田公司科技项目

摘　　要：通过对煤层富气高渗地质规律及煤层气井排采主控因素的研究,结合对开发区块煤层气井工程数据与测试资料的分析,提出了沁南煤层气田开发区块内煤层气生产接替方法,依据煤层富气高渗等级和地解压差等级将开发区划分为5类煤层气开发单元.研究表明:Ⅰ类至Ⅴ类开发单元面积分别占研究区面积的1.10%,20.86%,47.44%,28.96%,1.64%;开发单元的分布受地质构造的影响最为显著,开发单元展布与煤层含气性、渗透性的区域性变化及煤层压差吻合程度较高;区块内煤储层压力四周高、中心低且变化梯度大的部位,地解压差小,有利于压降扩展,开发单元类型级别高;开发区内地形较为平缓,开发单元多位于煤层埋深1 000 m以浅地区,对煤层气开发施工较为有利.开发区内产能接替工艺开发技术表明:后期井网部署应以现有井网为中心,以埋深1 000 m为界,在Ⅲ类以上开发单元区域向四周布井,布井时考虑地形落差可采用分层次(多层次)布井;现有井网内煤层气井产能低下区域采用二次压裂或补充小井距井以提高煤层气井产能;在地层稳定、构造简单的地形和缓区可考虑水平井生产工艺.Combined with the analysis of engineering data of coalbed methane wells and testing data,a method for production replacement of coalbed methane in developing block of southern Qinshui was put forward by the study on the geological law of enrichment and high-permeability of coal bed and drainage governing factors.The developing blocks were divided into five types of developing units of coalbed methane based on the grade of enrichment and permeability of the coal bed and differential pressure between the formation pressures and the critical desorption pressure.The results suggest that the proportions of different types of developing units in developing blocks are 1.10%,20.86%,47.44%,28.96%,and 1.64%,respectively.The distribution of developing units is affected by the tectonic setting,and accord with coalbed methane gas content of coal seam,coal permeability,and differential pressure between the formation pressures and the critical desorption pressure.The region where the coal reservoir pressure increase from center to around has a small differential pressure between the formation pressure and the critical desorption pressure;the grades of developing units are relatively high.Most regions of study area are flat,and most developing units are located in the regions where the burial depth of coal seam is lower than 1 000 m,which is favorable for construction engineering of coalbed methane.Analysis of development technology on production replacement in developing block show that,the later well pattern arrangement should be conducted in the third type of development unit or above and spread around the original multiple well system with a bound of 1 000 m burial depth,well pattern can use a layered method based on topographic relief.Secondary,the fracturing and arrangement of small space well pattern should be adopted in the areas where coalbed methane wells have low production,where as the horizontal well technology should be conducted in the smooth region with stable formation and simple structure.

关 键 词：生产接替 煤层气产能 开发单元 沁南煤层气田 

分 类 号：P618.11[天文地球—矿床学]