致密储层水力压裂裂缝几何形态地质影响因素及控制方法

Geological Influencing Factors and Control Methods of Hydraulic Fracturing Fracture Geometry in Tight Reservoir

水力压裂是致密储层有效开发的主要技术之一,在油田开采领域广泛应用。水力压裂裂缝几何形态影响因素研究是致密储层压裂成功的关键,因此,以大庆致密储层为例,采用Abaqus有限元软件进行了模拟计算,研究了油藏储隔层最小水平地应力差、弹性模量差、泊松比差和抗拉强度差对裂缝几何形态的影响。研究结果表明:储隔层最小水平地应力差、弹性模量差和抗拉强度差对裂缝的几何形态和扩展有较大的影响;而泊松比差对裂缝几何形态的影响微乎其微。通过低温冷却和增加人工隔层等方法对裂缝几何形态的控制分析为现场压裂施工提供了基础。

Hydraulic fracturing is one of the main technologies for the effective development of tight reservoirs,and has been widely used in oil fields.The research on the influencing factors of hydraulic fracturing fracture geometry is considered to be the key to the success of tight reservoir fracturing.Therefore,taking the Daqing tight reservoir as an example,the Abaqus finite element software was used for simulation calculation.The effects of the minimum horizontal in-situ stress difference,elastic modulus difference,Poisson s ratio difference and tensile strength difference of the reservoir on the fracture geometry were further studied.The results show that the minimum horizontal in-situ stress difference,elastic modulus difference and tensile strength difference of the reservoir interlayer have great influence on the fracture geometry and expansion.While the Poisson s ratio difference has little effect on the fracture geometry.Additionally,the control analysis of fracture geometry by low temperature cooling and adding artificial interlayer provides a foundation for on-site fracturing construction.