考虑薄煤层影响的致密砂岩气藏地质工程双甜点评价方法——以鄂尔多斯盆地神府区块为例  

A method for evaluating geology-engineering sweet spots of tight sandstone gas reservoirs considering the influence of thin coal seams:A case study on Shenfu Block of the Ordos Basin

作　　者：张兵[1] 周展 米洪刚 朱海燕 张兆鹏 魏超 徐伟 龚丁 王泽宇 贺甲元[5] ZHANG Bing;ZHOU Zhan;MI Honggang;ZHU Haiyan;ZHANG Zhaopeng;WEI Chao;XU Wei;GONG Ding;WANG Zeyu;HE Jiayuan(China United Coalbed Methane Co.,Ltd.,Beijing 100011,China;College of Energy/College of Modern Shale Gas Industry,Chengdu University of Technology,Chengdu,Sichuan 610059,China;COSL-EXPRO Testing ServicesCo.,Ltd.,Tianjin 300450,China;School of Petroleum Engineering,Southwest Petroleum University,Chengdu.Sichuan 610500,China;Sinopec Petroleum Exploration and Production Research Institute,Beijing 102206,China)

机构地区：[1]中联煤层气有限责任公司,北京市033000 [2]成都理工大学能源学院(页岩气现代产业学院),四川省成都市610059 [3]中海艾普油气测试(天津)有限公司 [4]西南石油大学石油与天然气工程学院 [5]中国石化石油勘探开发研究院

出　　处：《天然气工业》2024年第10期170-181,共12页Natural Gas Industry

基　　金：国家自然科学基金重大项目“开采过程多场时空演变规律与流动调控方法”(编号:52192622);国家自然科学基金面上项目“页岩气立体加密井组压裂复杂裂缝扩展与井间干扰机理研究”(编号:52374004);国家重点研发计划“大型油气藏CO_(2)压裂埋存全流程关键技术指标体系及标准化”(编号:2023YFF0614102);“CO_(2)地质封存协同枯竭页岩储层增渗开采技术”(编号:2023YFE0110900);中国海洋石油有限公司“十四五”重大科技专项“陆上非常规天然气勘探开发关键技术”(编号:KJGG-2021-1000)。

摘　　要：在薄煤层发育的致密砂岩气藏,由于薄煤层割理发育且塑性较强,容易限制水力压裂裂缝的缝高扩展,进而导致遴选的地质、工程双甜点区域的实际产能无法达到预期效果。为获得更加准确的双甜点评价结果,以鄂尔多斯盆地神府南区致密砂岩气藏为研究对象,首先构建了多属性融合的地质、工程双甜点评价模型,然后开展了双甜点三维分布的初次预测,进而采用Abaqus软件分析了煤层厚度、起裂点距煤层垂直距离对水力压裂裂缝穿煤层扩展的影响规律,最后形成了穿煤层双甜点二次优选评价技术。研究结果表明:①当煤层厚度大于等于4 m或起裂点距煤层垂直距离大于等于4 m时,水力压裂裂缝难以纵向穿过煤层扩展,可压性降低;②研究区双甜点指数划分标准为,Ⅰ类双甜点≥0.46,0.37≤Ⅱ类双甜点<0.46,0.30≤Ⅲ类双甜点<0.37。结论认为:①考虑薄煤层影响的致密砂岩气二次甜点评价技术能够准确筛选出优质的地质、工程双甜点,且优选结果与实际高产区域的匹配度较高;②建立的评价方法对于砂泥岩互层非常规储层的开发和多气合采中甜点的同步动用具有较好的理论与实际意义。Speaking of the tight sandstone gas reservoirs developed in thin coal seams,the cleats in thin coal seams are developed with strong plasticity,which tend to restrict the height propagation of hydraulic fractures,thus hindering the actual productivity in the selected geology-engineering sweet spot area to reach the expected value.In order to evaluate geology-engineering sweet spots more accurately,this paper takes the tight sandstone gas reservoir in southern Shenfu Block of the Ordos Basin as the research object to establish a geology-engineering sweet spot evaluation model integrating multiple attributes.Then,the 3D distribution of a geology-engineering sweet spot is predicted primarily,and the influence patterns of coal seam thickness and vertical distance of fracture initiation point to coal seam on the through coal seam propagation of hydraulic fractures are analyzed by using Abaqus software.Finally,the two-stage selection and evaluation technology for geology-engineering sweet spots through coal seams is formed.The following results are obtained.First,when the coal seam thickness is equal or more than 4 m or the vertical distance of fracture initiation point to coal seam is equal or more than 4 m,hydraulic fractures can hardly run through coal seams to propagate vertically,leading to the reduction of fracability.Second,the geology-engineering sweet spot index classification standards of the study area are typeⅠ≥0.46,0.37≤typeⅡ<0.46,and 0.30≤typeⅢ<0.37.In conclusion,the two-stage sweet spot evaluation technology of tight sandstone gas considering the influence of thin coal seams can accurately screen out the excellent geology-engineering sweet spot,and its selection results are in line with the actual high yield areas.What's more,the evaluation method established in this paper is of better theoretical and practical significance to the development of unconventional reservoirs of sandstone interbedded with mudstone and the simultaneous utilization of sweet spots in multi-gas commingled production.

关 键 词：神府区块 致密砂岩气 薄煤层 地质工程双甜点 裂缝扩展 

分 类 号：TE375[石油与天然气工程—油气田开发工程]