论文部分内容阅读
为了研究正交裂缝网络模型中单相流体渗流运动特征,利用缝洞介质物理模拟实验装置进行了一系列单相流动实验.根据实验数据拟合得到了临界速度的经验关系式,给出了用临界速度确定破坏油田井壁线性规律时极限产量的方法,基于等效思路用有限元方法对非线性渗流进行了数值模拟.研究表明:低渗流速度下裂缝网络模型中渗流服从线性渗流规律,随着渗流速度不断增大,渗流曲线向压力梯度轴弯曲,呈现非线性渗流特征;渗透率与垂直裂缝密度的对数成线性关系;临界速度随垂直裂缝数增加而增大;非线性渗流的数值模拟结果与实验数据拟合较好,相对误差小于4.93%.流体在井底附近地带运动时能产生使线性渗流规律受到破坏的强惯性阻力.
In order to study the characteristics of single-phase fluid percolation in the orthogonal fracture network model, a series of single-phase flow experiments were carried out by using slit-media physical simulation experimental device. Based on the experimental data, the empirical relationship of critical velocity was obtained, The critical velocity is used to determine the limit output when the wellbore linear rule is destroyed. The nonlinear finite element method is used to simulate the nonlinear seepage based on the equivalent theory. The results show that the percolation in the fractured network model with low seepage velocity obeys the linear seepage law, The seepage velocity is increasing to the pressure gradient axis, showing the nonlinear seepage characteristics; the permeability is linear with the logarithm of the vertical fracture density; the critical velocity increases with the increase of the number of vertical fractures; the numerical value of the nonlinear seepage The simulation results are in good agreement with the experimental data, and the relative error is less than 4.93% .The strong inertial resistance that causes the fluid flow in the vicinity of the bottom of the well to break the law of linear seepage can be produced.