A井区梧桐沟组稠油油藏水平井体积压裂开发论证

Demonstration of Horizontal Well Volume Fracturing Technology in Heavy Oil Reservoir in Wutonggou Formation in A Wellblock

A井区梧桐沟组稠油油藏具有埋藏深、中孔、低渗等特点,地层原油具有高黏度、高密度、中等含蜡量等特点,属于难动用储量。由于原油流度低,渗流困难,导致单井自然产能低,衰竭式或注水开发适应性差;由于油藏埋藏深度大,导致热采措施中井筒热损严重,经济效益差。为了改善本区开发效果,在中国类似稠油油藏压裂经验的基础上,结合该区前期直井压裂效果分析,论证了采用水平井体积压裂开发本区的必要性及可行性,采用了有限元压裂数值模拟技术优化了压裂规模、裂缝导流能力等参数,选取典型井组预测水平井体积压裂实际开发效果,单井衰竭开采15a,累产油达23 031t。

The heavy oil reservoir in the A wellblock is characterized by deep burial,middle porosity and low permeability.The crude oil in the formation has high viscosity,high density,high freezing point,high non-hydrocarbon content,medium wax content.Due to low mobility,Wells have low natural production capacity,the effect of using exhaustive development or water injection development method is poor,common thermal recovery technologies are faced with the difficulties of large heat loss in the wellbore due to large burial depth,and can't produce enough economic benefits.In recent years,some domestic heavy oil reservoirs have achieved positive effect in vertical well fracturing,and multi-stage fracturing technology in horizontal well is also gradually develop mature.Referring to the experiences of domestic similar heavy oil reservoir fracturing and the analysis of the fracturing effect of the vertical wells in the early stage of this area,the necessity and feasibility of multi-stage fracturing in horizontal well was firstly demonstrated,and the finite element fracturing numerical simulation technology was further used to optimized the parameters such as fracturing scale,fracture conductivity,etc.Finally,a typical well group was selected to predict the actual development effect of multi-stage fracturing in horizontal well,the single well has been exploited for 15 years with a cumulative oil production of 23 031 t.