煤层气开采定向羽状水平井井身结构优化  

Optimization of Well Profile for Pinnate Horizontal and Multilateral Wells of Coalbed Gas Recovery

作　　者：王新海[1] 张冬丽[2] 方海飞[3] 孙吉军[4] 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学),湖北荆州434023 [2]中国石化石油勘探开发研究院油藏所,北京100083 [3]长江大学地球科学学院,湖北荆州434023 [4]塔里木油田分公司开发事业部,新疆库尔勒841000

出　　处：《石油天然气学报》2007年第4期124-128,共5页Journal of Oil and Gas Technology

基　　金：国家重点基础研究发展规划项目(2002CB211709)

摘　　要：井的总长度相同,不同方式的主支、分支排列会得到不同的开采效果,一般说来,在同样区域范围内,呈对称、发散状均匀分布的多个主支比单一主支开采的效果要好。当主支和分支排列方式相同时,考虑分支间距的影响,若从哪种井网井距方案能获得最高平均日产量或总产量来衡量,存在最佳的分支间距。对纵向非均质韵律性地层,羽状水平井垂向上的位置会影响开采的效果。对正韵律地层井的垂向位置在整个煤层的下部效果更好,对反韵律地层井的垂向位置在上部效果更好。A mathematical model was established for describing coalbed gas recovery in heterogeneous anisotropic dual medium of pinnate horizontal multilateral wells.The factors including heterogeneity and anisotropy of stratum,sensitivity of permeability to pressure,friction and acceleration loss in wellbore and start-up pressure gradient in low-permeability coalbed were considered in this model.The numerical simulation method was presented and used to simulate the production of coalbed gas in the pinnate horizontal multilateral wells.The effect of start-up pressure gradient on the simulated gas production was analyzed.The result shows that the gas production in low-permeability coalbed could be raised greatly by drilling pinnate horizontal multilateral wells.For vertical heterogeneous rhythmic strata,the vertical position of pinnate horizontal well will influence production effect.For positive rhythmic strata,its vertical position produces better production effect on the low position of coalbed,for reversed rhythmic strata,its up vertical position results in better production effect.

关 键 词：煤成气 开采 水平井 定向羽状水平井 井身结构 优化 

分 类 号：TD842[矿业工程—煤矿开采]