低渗气层气体的渗流特征实验研究  

The Experimental Study of Characteristics of Gas Flow in Tight Formation

作　　者：任晓娟[1,2] 阎庆来[1,2] 何秋轩 张敏渝 

机构地区：[1]西安石油学院 [2]长庆石油勘探局

出　　处：《西安石油学院学报》1997年第3期22-25,共4页Journal of Xi'an Petroleum Institute

摘　　要：通过大量的岩心实验，研究了陕甘宁中部低渗气田某储层岩心中存在残余水时气体的渗流规律．研究表明，低渗岩心中气体的流动存大多种渗流形态，这与低渗岩心的渗透率、含水饱和度以及压力梯度的大小有关．当含水饱和度较低时（小于３０％），仅在一定的压力梯度范围内存在达西渗流．当含水饱和度较高时（大于３０％至束缚水饱和度以下），气体的渗流存在非达西渗流的现象．这种非达西流动表现为在较低的压力梯度下为非线性流动，而在较高的压力梯度下为线性流动，即气体的视渗透率随压力梯度的增加而增加，至一定值后，视渗透率基本保持不变，但此时气体的流动规律同达西线性流相比，气体的流动存在附加压力损失．文中还初步分析了低渗岩心中气体流动存在多种渗流形态的原因及其存在的范围．This paper studies the characteristics of gas flow in low permeability cores which were get from the middle district of shaan Gan Ning and in which there exists residual water.A lot of experimental results show that:(1) There exist many froms of gas flow in low permeability cores.This has something to do with the permeability,water saturation and pressure gradient of the cores.(2)When water saturation is lower (<30%),there exists only Darcy flow in certan pressure gradient range.(3)when the water staturation is higher (>30%,but less than irreducible water saturation),there exists non Darcy flow.The non Darcy flow is non linear flow under lower pessure gradient.However,the non Darcy flow is linear flow under higher pressure gradient,i.e,the apparent gas permeability increases as the pressure gradient increases.After the pressure gradient comes up to certain value,the apparent gas permeability does not change with the pressure gradient.Compared with linear Darcy flow,the gas flow exists extra pressure lost.This paper also has preliminarily analyzed the reasens why gas flow in low permeability cores has many forms and the ranges in which the forms exist.

关 键 词：低渗透油气藏 非达西流 渗流 油气田开发 

分 类 号：TE312[石油与天然气工程—油气田开发工程] TE348