陇东长7致密油储层改造缝网模态探讨

发布时间：2018-06-12 19:00

本文选题：致密油 + 体积压裂　；参考：《西安石油大学》2015年硕士论文

【摘要】：致密油是一种自生自储、连续分布聚集的典型非常规油气资源,具有储层致密、渗透率低,储层基质向裂缝供油能力较差的特点,靠传统的水力压裂很难取得较好的增产效果,必须采用体积压裂对储层进行改造,使裂缝不断扩张和脆性岩石产生剪切滑移,形成天然缝与人工主裂缝相互交错的裂缝网络以增大储层改造波及体积。因此研究致密油体积压裂形成的复杂缝网是非常必要的,目前尚未有对体积压裂形成缝网模态进行系统的讨论。本文采用数值模拟的研究方法,在弹性力学与断裂力学模型基础上,运用边界元法编写程序模拟体积压裂形成的复杂缝网,先对裂缝延伸、裂缝间互作用进行研究,包括水平井单簇以及两簇压裂在不同压力、不同间距、不同角度下的裂缝间互作用,随后根据A、B两个致密油区块的基本数据,研究在不同地应力、不同主裂缝缝内压力、不同天然缝角度下形成的复杂缝网,进而探索得出可能的缝网模态。结果表明:主裂缝在未与天然缝接触前就会诱导天然缝延伸,主裂缝压力越大越容易诱导天然裂缝破裂形成次生裂缝,且这种诱导作用随着主裂缝与天然缝间距增大而减小;两簇压裂时,主裂缝在延伸过程中其延伸走向会发生偏转,当两簇压裂不同步时,先压开的裂缝会抑制后压开裂缝的延伸,且这种抑制作用随着二者之间距离的增大而减小;对致密油体积压裂形成的缝网进行模拟,得出可能的两种缝网模态:水波型、网格型。本研究对体积压裂形成裂缝缝网的机理、评价压后效果具有较重要的意义。
[Abstract]:Compact oil is a typical unconventional oil and gas resource, which is self-generated and self-stored and continuously distributed and accumulated. It has the characteristics of tight reservoir, low permeability, poor oil supply ability to fracture of reservoir matrix, and it is difficult to obtain better effect of increasing production by traditional hydraulic fracturing. The reservoir must be reformed by volume fracturing in order to make the fracture expand continuously and the brittle rock produce shear slip and form a fracture network intertwined between natural fracture and artificial main fracture in order to increase the sweep volume of reservoir reconstruction. Therefore, it is very necessary to study the complex fracture network formed by bulk fracturing of dense oil, and there is no systematic discussion on the fracturing pattern of volume fracturing at present. In this paper, based on the elastic and fracture mechanics models, the numerical simulation method is used to compile a program to simulate the complex fracture network formed by volume fracturing. At first, the fracture extension and the interaction between fractures are studied. It includes single cluster fracturing in horizontal well and the interaction between two fracturing groups under different pressure, different spacing and different angle. Then, according to the basic data of two tight oil blocks, the pressure in different ground stress and main fracture is studied. The complex seams formed at different angles of natural seams, and the possible modes of seams are explored. The results show that the main fracture can induce the extension of the natural crack before contacting with the natural crack, and the higher the pressure of the main crack is, the easier it is to induce the natural fracture to form the secondary fracture, and the effect of this inducement decreases with the increase of the distance between the main crack and the natural crack. When two clusters fracturing, the main fracture will deflect during the extension process. When the two clusters fracturing is out of step, the first fracturing fracture will suppress the extension of the fracture, and the inhibition effect will decrease with the increase of the distance between the two groups. In this paper, the fracture net formed by tight oil volume fracturing is simulated, and two possible fracture network modes are obtained: water wave type and grid type. This study is of great significance to the formation mechanism of fracture network by volume fracturing and the evaluation of post-compression effect.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE357.1

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