鄂尔多斯盆地延长组页岩气藏裂隙连通条件研究

Research of Fissure Communicating Conditions of Shale Gas Reservoir in the Yanchang Formation of the Ordos Basin

页岩气储层具有低孔隙度、低渗透率的特性,储层基质向裂隙供气的能力较差。裂隙的有效性(即裂隙是否张开)在页岩气井压裂改造以及井位优选方面具有重大意义。在研究鄂尔多斯盆地中生界储层天然裂隙特征、地应力和岩石物理力学性质的基础上,建立了地应力控制裂隙有效性力学模型与判识天然裂隙滑移、错断的力学条件,并研究不同天然裂隙分布模式下的天然裂隙张开及连通的条件。充分利用天然裂隙,形成人工裂隙与天然裂隙交错的网络裂隙系统,从而达到提高单井产量的目的。

The shale gas reservoir has the characteristics of low porosity and low permeability,and the reservoir matrix has a poor ability to supply gas to fractures.The fissure validity(that is,whether the fractures are opened or not)is of great significance in the fracturing transformation and well location optimization of shale gas wells.Based on the research of the characteristics of natural fractures,crustal stress and petrophysical and mechanical rock properties of Mesozoic reservoirs in Ordos Basin,the effective mechanical model of crustal stress controlling fracture is established,and the mechanical conditions of natural fracture slippage and dislocation is identified,the conditions of natural fracture opening and connection under different natural fracture distribution patterns are also studied.Make full use of the natural fractures,forming artificial fractures and natural fractures interlaced network fracture system,so as to achieve the goal of increasing single well production.