关键词: 致密油储层,    , 经验公式,    ,  正交试验,    ,  启动压力梯度,   衰竭开采

Abstract:

      There is usually a starting pressure gradient in the tight oil. This article considers the seepage law of the crude oil flowing from the matrix to the fractures in the formation under the premise of starting the pressure gradient and some assumptions. Through the establishment of numerical model, the relationship between the pressure, permeability, core size and other factors and the degree of failure recovery in the onedimensional space is analyzed, as well as the threedimensional plate is drawn. The results show that when the core scale is very small, the main factors affecting the degree of recovery are the failure pressure difference. At the same time when the scale increases, the relationship between the recovery degree and the core length and permeability is more and more significant. Then, based on the conclusion of the previous the paper put forward the empirical formula considering the degree of calculation and recovery under various factors, and extend the space to three dimensions. On the basis of one dimensional revise the formula, the empirical formula of the failure rate of three dimensional matrix failure is obtained. It provides some reference for production practice.

Key words: Tight oil reservoir,    , Empirical formula,    , Orthogonal test,    , Starting pressure gradient,    , Depletion mining