特低渗透油藏压裂水平井裂缝间距计算方法  

Computational Method for Hydraulic Fractures Spacing of Multi-Fractured Horizontal Well in Ultra Low Permeability Reservoirs

作　　者：陈福有[1] 郝明强[2] 陈美瑾 张玉[1] 于占梅 

机构地区：[1]华北油田分公司开发部,河北任丘062552 [2]中国石油勘探开发研究院,北京100083 [3]华北油田分公司第三采油厂,河北河间062450 [4]华北油田分公司勘探开发研究院,河北任丘062552

出　　处：《油气井测试》2016年第3期18-22,76,共5页Well Testing

摘　　要：基于非达西渗流理论,采用椭圆渗流方法和平均质量守恒定律,以水平井两条相邻人工裂缝中点处流体刚好发生流动为极值条件,建立了确定水平井人工裂缝间距的数学模型和计算方法。定量分析了油藏渗透率、油层厚度、人工裂缝半长和导流能力,以及生产压差等对压裂缝间距的影响规律。结果表明,随着油藏渗透率的增加,人工裂缝间距增大,二者具有较好的双对数直线关系;油层厚度越大,人工裂缝越长,裂缝间距越小,且油层厚度和人工裂缝半长对裂缝间距的影响都与裂缝导流能力有关;裂缝导流能力较高时,裂缝间距相对较大,但随着裂缝导流能力的增大,裂缝间距增长幅度逐渐变缓;生产压差与人工裂缝间距呈近似线性增长关系,生产压差越大,人工裂缝间距也越大。Hydraulic fractures spacing of horizontal well is an extreme important item for the optimization of fractured horizontal well in ultra-low permeability reservoir. By adopting the maximum condition that fluid on the midpoint of the two hydraulic fractures just be able to flow,the mathematical model and computational method to define the hydraulic fractures spacing of horizontal well were established based on the non-Darcy flow theory,the elliptical seepage theory and average mass conservation law. Then the law of the influences of the reservoir permeability,thickness,hydraulic fracture half length and conductivity,producing pressure drop on hydraulic fractures spacing of horizontal well was studied quantitatively. The results show that hydraulic fractures spacing increases as the permeability increases and they have a preferable double log linear relationship; the interspacing decreases as the reservoir thickness and half fracture length increases,and the influences of the reservoir thickness and half fracture length on the interspacing are related to the hydraulic fracture conductivity; When the fracture conductivity is high,the interspacing is relatively long,but with the fracture conductivity increasing,the interspacing growth gradually slows; The relationship between the producing pressure drop and the interspacing is approximately linear,the larger of the producing pressure drop,the longer of the interspacing of horizontal well.

关 键 词：特低渗透油藏 启动压力梯度 水平井 压裂缝间距 裂缝半长 裂缝导流能力 数学模型 

分 类 号：TE348[石油与天然气工程—油气田开发工程]