确定有效储层物性下限的两种新方法及应用——以东营凹陷古近系深部碎屑岩储层为例

试油法和束缚水饱和度法是确定有效储层物性下限的两种新方法。试油法是将有效储层和非有效储层对应的孔隙度、渗透率绘制在同一坐标系内,两者分界处所对应的孔隙度值、渗透率值为有效储层物性下限值。束缚水饱和度法是建立束缚水饱和度与孔隙度之间函数关系,取束缚水饱和度为80%时所对应的孔隙度值作为有效储层的孔隙度下限值。两种方法在东营凹陷古近系深层应用效果较好,求取的3000～3200m有效储层孔隙度下限为9%、渗透率下限为0.8×10-3μm2,与分布函数法、测试法计算结果基本一致,说明试油法和束缚水饱和度法具有推广使用的价值。

苏77山2^3段低阻气层的形成机理与识别方法

通过对研究区块岩心的扫描电镜、X衍射、黏土矿物分析、阳离子交换容量测量、铸体薄片及水分析等资料的研究发现，高束缚水饱和度是造成苏77山2^3段低电阻的根本原因，高矿化度地层水是直接原因，导电矿物影响微弱．由于低阻气层在电性曲线上与气水层、水层差异不明显，应用常规测井技术和解释方法很难有效识别，在解释过程中容易漏掉气层．提出用孔隙度重叠法、阵列感应测井法和束缚水饱和度法进行低阻气层的识别，与常规测井解释方法相比，解释精度大幅度提高，并将上述方法应用到苏里格气田中，取得了显著效果．

The establishment of a new deliverability equation considering threshold pressure gradient

The flowing mechanism of a low permeability gas reservoir is different from a conventional gas reservoir,especially for that with higher irreducible water saturation the threshold pressure gradient exists. At present,in all the deliverability equation,the additional pressure drop caused by the threshold pressure gradient is viewed as constant,but this method has big error in the practical application. Based on the non-Darcy steady flow equation,the limited integral of the additional pressure drop is solved in this paper and it is realized that the additional pressure drop is not a constant but has something to do with production data,and a new deliverability equation is derived,with the relevant processing method for modified isochronal test data. The new deliverability equation turns out to be practical through onsite application.