【作者】 韩培锋；

【导师】 刘建军； 何翔；

【作者基本信息】 武汉工业学院 ， 岩土工程， 2011， 硕士

【摘要】 随着我国经济的快速发展和社会的不断进步,能源问题将会成为制约我国经济和社会快速发展的一个瓶颈,低渗透油藏的开发将会成为我国解决石油危机的一个重要方面。水力压裂技术作为提高低渗透油藏采收效果的一种重要的手段,在低渗透油藏开采中使用非常的广泛。但是这些低渗透油藏大部分是“三低”油藏(储量丰度低、渗透率低、油井产能低),这些油田主要由受岩性因素影响很大的复合性油藏构成,储油砂体多呈比较零散的窄条带状,横向岩性变化很大,渗透率很低,油水关系错综复杂,现有的水力压裂技术在应用过程中出现了各种问题,因此研究低渗透油藏的水力压力过程中出现的各种问题就迫在眉睫。本文基于流-固耦合理论,结合渗流力学、弹塑性力学及岩石断裂、损伤力学研究了射孔参数变化、薄弱层窜层、天然裂纹和断层等几种主要影响低渗透油藏水力压裂效果的因素,通过理论分析和数值模拟计算后发现:(1)水力压裂中射孔方位角度的变化将会影响水力压裂的裂纹开裂的应力和位移;(2)水力压裂水泥环套管与岩层接触处是薄弱面,在该接触处的应力和位移产生应力奇异的现象,导致压裂液的窜层大部分发生在该处;(3)低渗透油藏中原生裂纹会影响水力压裂主裂纹的开裂和扩展,原生裂纹数量越多,则主裂纹的应力和位移将会越小;(4)当多油层同时注水压裂时,各油层裂纹的起裂和扩展将会相互影响,且隔层厚度越小,则影响越大,并且中间裂纹受到两边裂纹的影响十分明显;(5)低渗透油层中断层将会影响水力压裂的效果,断层倾斜角的改变将会影响水力压裂的速度和压力,在断层附近压裂流体的流速急剧变化,倾斜角越小,断层附近的流速也越小,而断层附近的压力梯度变化则越大。根据以上的研究结果,可以为低渗透油层的水力压裂的压裂参数提供理论依据。更多还原

【Abstract】 With China’s rapid economic development and social progress, the energy problem will be restricting our rapid economic and social development of a bottleneck, the development of low permeability reservoir solution will become an important aspect of the oil crisis. Hydraulic fracturing of low permeability reservoirs to improve harvesting as an important means of effective, low-permeability oil reservoir in the very extensive use. But most of these low-permeability reservoirs, "three lows" reservoirs (stocks low abundance, low permeability, low oil production), mainly composed of these fields is strongly influenced by lithology factors constitute a complex of reservoirs, storage Comparison of sand scattered mostly narrow band, large lateral changes in lithology, permeability is low, water relations are complicated, the existing application of hydraulic fracturing technology in a variety of problems arising in the course, so the oil of low permeability Hydraulic pressure reservoir problems arising in the course is urgent.Based on the fluid - solid coupling theory, mechanics, plastic and rock fracture mechanics, damage mechanics, study of the perforation parameters, the weak layer scurrying layer, natural cracks and faults and other effects of several major effect of hydraulic fracturing in low permeability reservoir factors, through theoretical analysis and numerical simulation revealed that: (1) hydraulic fracturing in the perforation orientation angle changes will affect crack initiation of hydraulic fracturing stress and displacement; (2) hydraulic fracturing cement casing contacts with the rock is that the weak side, in the contact stress and displacement generated at the stress singularity phenomenon, resulting in fracturing fluid layer channeling most of them in there; (3) low permeability reservoir of water, the native will beat crack cracking and crack main crack extension, the greater the number of primary cracks, the main crack stress and displacement will be smaller; (4) When water fracturing multiple layers simultaneously, each reservoir crack initiation and expansion of mutual influence will be , and the interlayer thickness are smaller, the greater the impact, and by the middle of the crack is very clear on both sides of the crack; (5) low-permeability reservoirs in the fault will affect the effect of hydraulic fracturing, fault inclination changes will affect the hydraulic fracturing of the velocity and pressure in the fracturing fluid flow near the fault dramatic changes, the smaller the angle, the smaller the velocity near the fault, while the pressure gradient near the fault is greater.Based on the above findings, for hydraulic fracturing in low permeability reservoir fracturing parameters provide a theoretical basis.更多还原