高尚堡油田裂缝高度影响参数分析及控制技术

 针对高尚堡油田沙河街组在薄互层的压裂过程中,裂缝极易穿透产层窜通水层的问题,利用多因素正交表对该区块裂缝高度影响因素进行权重分析。结果表明,该区域裂缝高度影响参数按强弱排序为:地应力差、施工规模、施工排量、压裂液黏度。为了防止窜通水层,在施工中采用线性胶和冻胶交替泵注、变排量、段塞式加砂技术改变地应力的方式进行裂缝高度控制。压后通过净压力拟合、返排液矿化度分析,显示裂缝高度得到较好控制,未能沟通水层。

Analysis of fracture height influencing parameter and control in Gaoshangpu Oilfield

Due to the characteristics of thin interbeded layer of the third member of Shahejie formation in Gaoshangpu Oilfield, fracture can easily propagate into water layer. This paper uses multi-factor orthogonal table to conduct a weight analysis about the fracture height impact factor in this area. The results show that the fracture height impact factor in this area follows the pecking order: geostress difference, fluid volume, rate and viscosity. Therefore, to control the fracture height, linear gel and cross-linked gel alternating injection, variable rate and plug sand injection technologies are used to alter the stress between sand and shale layers. Through the net pressure analysis and analysis of fracturing flowback fluid salinity, it is shown that fracture height has been well controlled and the fracture fails to channel the water layer.