基于全缝长压裂模拟技术的致密储层压裂改造效果定量表征

Quantitative characterization of fracturing effect of tight reservoir based on full-length fracturing simulation technology

在考虑压裂液滤失的压裂缝形成机制的基础上,利用石油工程地质一体化的全缝长压裂数值模拟技术,结合储层地质分析及精细油气藏三维建模,对松辽盆地白垩统泉头组扶余油层开展水力压裂的目的储层段压裂改造效果定量表征研究。结果表明研究区储层微观裂缝较为发育,黏土矿物含量较高,自生石英较为发育,对岩石的力学性质影响较大,将不可避免地影响到水力裂缝的张开及导流能力的非均质性;各小层压裂改造效果的“有效导流范围”均可进一步细分为四级导流区,对原油开采将起到不同程度的促进作用;提出的“单砂体产液量极限值”及“微地层单元产液量极限值”概念及计算方法,可为评估单砂体内部产能贡献提供借鉴,有利于开展单砂体“靶向”改造。

In the framework of formation mechanism of the pressure fracture with losing fracturing fluid,the quantitative characterization of the fracturing effect of the target reservoir was studied for hydraulic fracturing in the Fuyu oil layer of Quantou formation of Cretaceous in Songliao Basin.Numerical simulations of full-length fracturing are integrated with petroleum engineering geology,and are combined with geological analysis of reservoir and 3D modeling of fine oil and gas reservoir.The results show that the micro-fracture of reservoir is well developed,the clay mineral content is high,and the authigenic quartz is relatively developed,which has a greater control on the mechanical properties of rock.This inevitably affects the opening of hydraulic fracture and the heterogeneity of conductivity.The"effective diversion range"of the fracturing effect of each small layer can be further divided into four-stage sub-areas,which play different roles in promoting crude oil production.The concept and calculation method of"limit value of liquid production in single sand body"and"limit value of liquid production in micro-formation unit"are put forward,which can applied in evaluating the contribution of internal production capacity of single sand body,and is conducive to the"target"improvement of single sand body.