致密油藏体积压裂数值模拟研究

发布时间：2019-03-21 11:30

【摘要】：体积压裂技术是在压出主裂缝的同时,在主裂缝的周围压出次生裂缝,并在次生裂缝上继续分支形成二级次生裂缝,重复此步骤,不断的使主裂缝与多级次生裂缝交织并且使天然缝与人工缝进行沟通连接,形成复杂的裂缝网络系统。通过体积压裂增加了裂缝面与油藏基质的接触面积,缩短了油气从基质到裂缝的渗流距离,改善了储层整体渗透能力,提高了储层内油气的动用程度,增加了纵向上可动用小储层的层数,提高了单井产量,从而增加了油藏的可采储量,体积压裂技术最近几年兴起并被广泛应用于非常规油藏的开采中。为了提高致密油藏体积压裂的压裂效果,本文建立了考虑启动压力梯度的有限元数学模型,使用三角形单元描述基质,使用线单元描述裂缝,在自然能量开采的条件下,以单井作为研究对象,对体积压裂中裂缝参数对水平井开发效果的影响进行了研究。借助正交试验设计和分析方法,研究分析了不同水平井段长度(1000m、1300m、1800m)条件下,裂缝半长、裂缝导流能力及压裂级数对水平井日产油量、日产水量、日产液量及累计产油量生产动态参数的影响规律,给出了不同水平井段长度的最优方案,为致密油藏体积压裂技术的现场应用提供了一定的理论指导。
[Abstract]:Volume fracturing technology is to press out the secondary fracture around the main fracture while pressing out the main fracture, and continue to branch on the secondary fracture to form the second secondary fracture, and repeat this step. The main fracture is interlaced with the multi-stage secondary fracture and the natural crack is connected with the artificial crack to form a complex fracture network system. Through volume fracturing, the contact area between fracture surface and reservoir matrix is increased, the seepage distance from matrix to fracture is shortened, the overall permeability of reservoir is improved, and the production degree of oil and gas in reservoir is increased. In recent years, volume fracturing technology has been developed and widely used in the production of unconventional reservoirs by increasing the number of layers of small vertically exploitable reservoirs and increasing the output of single well, thus increasing the recoverable reserves of reservoirs. The technology of volume fracturing has emerged in recent years and has been widely used in the production of unconventional reservoirs. In order to improve the fracturing effect of compact reservoir volume fracturing, a finite element mathematical model considering starting pressure gradient is established in this paper. The triangular element is used to describe the matrix, the linear element is used to describe the fracture, and under the condition of natural energy exploitation, the finite element model is established. Taking single well as the research object, the influence of fracture parameters in volume fracturing on horizontal well development is studied. By means of orthogonal test design and analysis method, the half-length of fracture, the capacity of fracture diversion and the fracturing series of horizontal wells with different horizontal section lengths (1000m, 1300m, 1800m) are studied and analyzed for the daily production and water production of horizontal wells, and the results are as follows: (1 000 m, 1 300 m, 1 800 m). The influence law of dynamic parameters of daily production and cumulative oil production is given, and the optimal scheme of section length for different levels is given, which provides some theoretical guidance for the field application of volume fracturing technology in tight reservoirs.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE357

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