基于综合可压指数的煤层气水平井压裂分段参数优化  

Optimization of segmented fracturing parameters for coalbed methane horizontal wells based on comprehensive fracability index

作　　者：孔祥伟[1,2] 谢昕 王存武 KONG Xiangwei;XIE Xin;WANG Cunwu(School of Petroleum Engineering,Yangtze University,Wuhan,Hubei 430100,China;Hubei Key Laboratory of Drilling and Production Engineering for Oiland Gas,Yangtze University,Wuhan,Hubei 430100,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]长江大学石油工程学院,湖北武汉430100 [2]长江大学油气钻采工程湖北省重点实验室,湖北武汉430100 [3]中海油研究总院有限责任公司,北京100028

出　　处：《油气藏评价与开发》2024年第6期925-932,941,共9页Petroleum Reservoir Evaluation and Development

基　　金：中国海油“十四五”重大科技项目“煤层气地质工程关键参数表征及‘甜点’区评价技术”(KJGG2022-1001);中国海油“十四五”规划重大项目“差异化大型压裂物模实验及可压性研究”(CCL2022RCPS0471RSN);中国海油“十四五”规划重大项目“柿庄区块煤层气水平井高效压裂优化研究及应用”(CCL2022RCPS0038ESN)。

摘　　要：沁水盆地柿庄区块煤层具有割理发育、低渗、煤体结构软、非均质性强等特点,前期采用水平井分段压裂后单井产气量差异较大,且气井产能与压裂参数关系尚不清楚,导致区块煤层气开发经济效益较差,水平井分段压裂设计参数有待进一步优化。基于煤层脆性指数、地应力和储渗特征评价,建立了煤层综合可压指数评价模型;考虑水平井分段压裂应力阴影影响,绘制形成不同煤层结构的压裂应力阴影及裂缝干扰图版,明确了不同净压力、裂缝长度、裂缝间距和簇数对诱导应力的影响。根据煤层气开发经济性要求,考虑单井投资内部收益率(IRR)与日产气量关系,优化了煤层不同综合可压指数的水平井压裂位置和段数设计参数,建立了煤层气水平井高效压裂技术图版,有助于提高沁水盆地柿庄区块煤层气水平井分段压裂改造效果,助力煤层气勘探开发提质增效。The coal seams in the Shizhuang block of the Qinshui Basin are characterized by developed cleats,low permeability,soft coal structures,and strong heterogeneity.In earlier development stages,hydraulic segmented fracturing of horizontal wells resulted in significant variations in gas production per well,with unclear relationships between gas well productivity and fracturing parameters.This led to poor economic performance in coalbed methane(CBM)development,highlighting the need for optimization of horizontal well fracturing parameters.This study established a comprehensive fracability index(CFI)evaluation model based on coal seam brittleness,in-situ stress,and reservoir-seepage characteristics.Considering the impact of stress shadows during horizontal well fracturing,stress shadow and fracture interference charts were generated for different coal seam structures,clarifying the effects of net pressure,fracture length,spacing,and cluster number on induced stress.Based on the economic requirements for CBM development,the fracturing positions and segment design parameters of horizontal wells with different CFI values were optimized by considering the relationship between the internal rate of return(IRR)of single-well investment and daily gas production.A high-efficiency fracturing technology chart for horizontal wells was developed,aimed at improving the fracturing effectiveness in the Shizhuang block of Qinshui Basin and enhancing the quality and efficiency of CBM exploration and development.

关 键 词：煤层气 水平井 压裂 可压指数 压裂位置 内部收益率 

分 类 号：TE133[石油与天然气工程—油气勘探]