论文详情
页岩储层为低孔低渗岩石,须经过大规模的压裂改造才能够获得商业产能,而地应力是进行压裂改造的关键因素,它在油气勘探领域具有重要的作用,不仅是油气运移的驱动力,而且能为井壁稳定性分析和钻井优化设计等提供依据。在油层改造过程中,地层地应力场的状态和岩石的力学性质决定了压裂的裂缝延伸方向、形态和方位,影响着压裂的增产效果。对地应力预测技术进行了归纳总结,分别从地应力测量方法、地应力测井计算方法、地应力数值模拟方法及地应力地震预测方法四个方面介绍了地应力的研究现状。不同的地应力预测方法反映了不同方面的地应力信息,有着不同的适用条件和预期成果。着重介绍了地应力的地震预测方法,该方法可以得到三维地应力剖面,对地应力的地震评价有着重要的意义。最后对地应力地震预测方法的发展前景进行了展望。
Shale has low porosity and low permeability,and requires large-scale hydraulic fracturing to produce shale gas.In-situ stress,which is a key factor for fracturing,can provide a driving force for migration of oil and gas,as well as theoretical guidance for wellbore stability analysis and drilling optimization design.Moreover,during oil horizon reformation the state of in-situ stress fields and mechanical properties of rock determine the propagation direction,shape,and orientation of fracturing fractures,thus affecting the production of fracturing effect.In this paper,we summarize four kinds of in-situ stress prediction methods,i.e.,acquiring in-situ stress by measurement methods,logging data calculation,numerical simulation,and seismic prediction methods.Different in-situ stress prediction methods reveal different stress information with different applicable conditions and expected results.The seismic prediction method is emphasized,as it can help obtain a three-dimensional stress profile that is of great significance to seismic evaluation of stress.Finally,we give outlooks for the development of the stress prediction method.
国家自然科学基金-石油化工基金联合项目(U1562215,U1762103)、国家油气重大专项课题(2016ZX05024004, 2017ZX05009001, 2017ZX05036005, 2017ZX05032003)联合资助。