页岩天然裂缝网络渗透率模型研究

发布时间：2018-03-21 21:44

本文选题：页岩　切入点：天然裂缝网络　出处：《天然气地球科学》2017年02期 　论文类型：期刊论文

【摘要】：页岩储层天然裂缝网络气体渗透率模型是页岩气开发的研究重点之一。基于Hagen-Poiseulle方程,采用二叉树分形网络模型模拟储层中天然裂缝分布,得到了气体在二叉树分形网络中球面向心流的渗透率模型。分析了矩形、三角形、椭圆形及圆形等不同裂缝截面以及裂缝分叉角θ、裂缝分形维数D_f、裂缝毛管长度级差系数α、矩形裂缝截面宽与高的比值x_1、椭圆裂缝截面长轴与短轴长度的比值x_3等裂缝结构参数对裂缝分形表观渗透率K_f的影响。在相同裂缝截面积的情况下,裂缝分形表观渗透率K_f从大到小依次为圆管模型、椭圆模型、矩形模型和三角形模型。裂缝分形表观渗透率K_f随着裂缝分形维数D_f的增大而增大;K_f随着裂缝分叉角θ(0°θ100°)的增大先减小后增大,在裂缝分叉角为90°时取得最小值;K_f随着裂缝毛管长度级差系数α的增加而减小;K_f随着矩形裂缝截面宽与高比值x_1的增大先增大后减小,在裂缝宽与高比值x_1值取1时得到最大值;K_f随着椭圆裂缝截面长轴与短轴长度比值x_3的增大而减小。
[Abstract]:The gas permeability model of natural fracture network in shale reservoir is one of the key points in shale gas development. Based on Hagen-Poiseulle equation, a binary tree fractal network model is used to simulate the distribution of natural fractures in the reservoir. The permeability model of spherical concentric flow of gas in binary tree fractal network is obtained. Different crack sections such as ellipse and circle, fracture bifurcation angle 胃, crack fractal dimension D _ f, crack capillary length differential coefficient 伪, ratio x _ 1 of rectangular crack cross-section width to height, ratio x _ 3 of elliptical crack section length to short axis length, etc. The effect of fracture structure parameters on fracture fractal apparent permeability KF. The fracture fractal apparent permeability K _ T _ f from large to small is in turn a circular pipe model, an elliptical model, The fracture fractal apparent permeability K _ f increases with the increase of fracture fractal dimension D _ f and increases with the increase of fracture bifurcation angle 胃 _ 0 掳胃 _ (100 掳), and then increases with the increase of fracture bifurcation angle 胃 ~ (0 掳胃 ~ (100 掳)), the fracture fractal apparent permeability K _ f increases with the increase of fracture fractal dimension D _ f. When the fracture bifurcation angle is 90 掳, the minimum value K _ S _ f decreases with the increase of the crack capillary length differential coefficient 伪, and then decreases with the increase of the ratio of rectangular crack cross-section width to height x _ 1. When the ratio of crack width to height x _ 1 is taken as 1, the maximum value K _ S _ f decreases with the increase of the ratio x _ 3 of the long axis and short axis length of the elliptical crack section.
【作者单位】：常州大学石油工程学院;
【基金】：国家自然科学青年基金“甲烷吸附和碳原子热扩散规律对三维网状石墨烯生长均匀性及其热导率影响的研究”(编号:51506012)资助
【分类号】：TE312

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