大庆油田采油八厂低渗储层合理流压确定方法研究

发布时间：2018-03-30 14:48

本文选题：低渗透　切入点：应力敏感　出处：《东北石油大学》2017年硕士论文

【摘要】：低渗透油藏储层存在启动压力梯度和应力敏感现象。在衰竭开发过程中,流体压力降低,岩石骨架发生弹塑性变形,孔隙喉道变小,渗透率降低。虽然后期注水开发过程中流体压力升高,但储层渗透率只能部分恢复。因此,分析研究低渗透油藏的渗透规律,确定油田开发初期油井的合理井底流压范围,对于保护储层以及低渗透油田的后续开发有着非常重要的意义。首先通过改进现有的液固耦合测定方法,模拟实际地层液固耦合过程,研究流体压力下降时不同渗透率级别岩石的渗透率损失规律,以及流体压力上升时不同渗透率级别岩石的渗透率恢复规律,根据所得的规律给出了开采初期的最小流压。同时改进应力实验装置和驱替装置,研究岩石弹塑性与渗透率之间的相互影响,并且建立了二者之间的定量关系。通过对低渗透油田孔隙损失程度对流体通过能力的影响进行研究,得出孔隙度的变化对油水两相渗流能力影响不大。然后本文通过分析研究低渗透油藏渗流机理及流体的非达西渗流规律,建立了考虑启动压力梯度和应力敏感性的低渗透油藏三维三相非达西渗流模型,并采用有限差分方法将数学模型离散。在此基础上应用Visual Basic编制了考虑启动压力梯度和应力敏感性的低渗透油藏数值模拟软件,同时还建立了考虑应力敏感性和启动压力梯度的油井产能方程。针对葡萄花油层不同渗透率级别储层,分别应用数值模拟软件进行模拟计算以及产能方程计算的方法,确定不同含水率下的合理流压的取值范围。本文所得研究数据结果主要适用于采油八厂葡萄花油层,对于其他同类油田也具有一定的指导意义。
[Abstract]:In the low permeability reservoir, the initial pressure gradient and stress sensitivity exist. In the process of failure development, the fluid pressure decreases, the rock skeleton is elastic-plastic deformation, and the pore throat becomes smaller. Permeability is reduced. Although fluid pressure increases during the later stage of water injection development, reservoir permeability can only be partially restored. Therefore, the permeability law of low permeability reservoirs is analyzed to determine the reasonable bottom hole flow pressure range of oil wells in the early stage of oilfield development. It is very important to protect reservoir and develop low permeability oilfield. Firstly, by improving the existing method of liquid-solid coupling, we simulate the process of liquid-solid coupling in real formation. The law of permeability loss of rocks with different permeability levels when fluid pressure decreases and the permeability recovery law of rocks with different permeability levels when fluid pressure is rising are studied. According to the obtained rules, the minimum flow pressure in the early stage of mining is given. At the same time, the stress experimental apparatus and displacement device are improved to study the interaction between elastic-plastic and permeability of rock. And the quantitative relationship between them is established. The influence of pore loss degree on fluid flow capacity in low permeability oil field is studied. It is concluded that the change of porosity has little effect on the oil-water two-phase percolation ability. Then, the seepage mechanism of low permeability reservoir and the non-Darcy percolation law of fluid are analyzed and studied in this paper. A three dimensional non Darcy flow model for low permeability reservoirs considering start-up pressure gradient and stress sensitivity is established. The mathematical model is discretized by finite difference method. Based on this, a numerical simulation software for low permeability reservoir considering start-up pressure gradient and stress sensitivity is developed by using Visual Basic. At the same time, the productivity equation of oil well considering stress sensitivity and starting pressure gradient is established. The numerical simulation software is used to simulate and calculate the productivity equation for different permeability reservoirs of Putaohua reservoir. The results obtained in this paper are mainly suitable for the Grape formation of the eighth Oil recovery Plant, and also have certain guiding significance for other similar oilfields.
【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】：TE348

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