考虑科林贝尔效应的低渗、特低渗气藏数学模型

MATHEMATICAL MODEL OF LOW AND VERY LOW PERMEABILITY GAS RESERVOIR CONSIDERING KLINKENBERG EFFECT

科林贝尔在 194 1年提出了气体在不含束缚水多孔介质中渗流时出现的滑脱现象。而且岩石越致密 ,渗透率越低 ,科林贝尔效应越明显。然而 ,到目前为止还没有一套可靠的描述低渗透气藏动态预测的模型和方法 ,对低渗透气藏的研究仍沿用常规气藏模型 ,导致预测开发指标与实际存在较大的差异 ,导致错误的开发决策。为此 ,文章基于对低渗气藏渗流机理分析 ,建立了考虑科林贝尔效应的低渗透气藏非线性渗流数学模型、数值模型和模拟模型。通过对磨溪雷一1气藏磨 75井区的模拟研究表明 ,文章建立的方法、模型能正确地反映低渗气藏的开采动态。该项研究成功实现了对低渗透气藏的定量动态预报 。

In 1941,Klinkenberg proposed that the slippage effect would occur when natural gas flow through porous media in absence of connate water.The tighter the rock is,the less the permeability is,and the more obvious Klinkenberg effect is.Unfortunately, so far there has not been a model or method to characterize the productive performance of low permeability gas reservoirs.The conventional gas reservoir model is usually used to study this kind of gas reservoirs.As a result,there exist great differences between the predicted data and the actual record,which usually lead to wrong development decision in most cases.Based on percolation mechanism analysis of low permeability gas reservoirs,the non linear percolation mathematical model,numeral model,and simulative model taking the Klinkenberg effect into account have been established in this paper.The case study of Lei-1 reservoir of Moxi gas field shows that the models and method presented in this paper can reflect the productive performance of low permeability gas reservoirs properly.The presented models successfully realize the quantitative dynamic prediction of the low permeability gas reservoir,which can provide a strong technical support for the optimization of development plans and recovery schemes.