薄互层低渗透油藏水平井压裂产能模型  

Productivity Equation of Multi-fractured Horizontal Well in Thin Inter-bedded Low Permeability Reservoirs

作　　者：朱维耀[1] 高英[1] 岳明[1] 宋洪庆[1] 邓佳[1] 

机构地区：[1]北京科技大学土木与环境工程学院,北京100083

出　　处：《应用基础与工程科学学报》2014年第6期1140-1149,共10页Journal of Basic Science and Engineering

基　　金：国家科技重大专项(2011ZX05051)

摘　　要：薄互层具有砂泥交互、储层平面各向同性、纵向非均质严重的特点,压裂裂缝在纵向上扩展呈非平面特征.考虑薄互层净总厚度比、纵向非均质性及压裂裂缝非平面特征,将压裂裸眼水平井周围流场划分为两个渗流区域,建立裸眼水平井多级压裂开发薄互层的稳态渗流数学模型,并推导出解析解.通过模型计算分析了净总厚度比、非平面系数、裂缝半长、启动压力梯度、应力敏感系数等因素对裸眼水平井多级压裂产能的影响.研究结果表明,薄互层的储层特性对产能有很大的影响,考虑薄互层特性计算的产能要明显小于不考虑薄互层特性的产能;净总厚度比越小、纵向非均质性越强、裂缝非平面性越强,多级压裂水平井产能越小;应力敏感系数越大,多级压裂水平井产能越小;启动压力梯度越大,多级压裂水平井产能越小.Thin inter-bedded low permeability reservoir is sand layer alternating with mud layer,areal isotropic formation and seriously longitudinal heterogeneous. Induced hydraulic fractures are non-planar fractures in thin inter-bedded reservoirs because of these characteristics. The flow field was divided into two regions with different flow mechanisms for multi-fractured open-hole horizontal well. A mathematical model was established for multi-fractured horizontal well in thin inter-bedded low permeability reservoirs,considering factors such as ratio of thickness of sand layers to total reservoir thickness,longitudinal heterogeneity and non-planar artificial fractures.According to the analytical solutions derived,productivity equation was presented. Numerical analysis was carried out to investigate influence of thickness ratio of sand layer,non-planar coefficient,fracture half-lengths,threshold pressure gradient and deformation coefficient. The results show that productivity considering characteristics of thin inter-bedded reservoirs is smaller than that without considering characteristics. Smaller thickness ratio of sand layer and thin inter-bed,more serious longitudinal heterogeneity and more serious non-planarity of fractures lead to smaller productivity of multi-fractured horizontal well. Productivity decreases with increasing deformation coefficient. The larger the threshold pressure gradient,the smaller productivity.

关 键 词：薄互层 多级压裂 多裂缝干扰 非线性渗流 非平面裂缝 净总厚度比 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]