纵横波速度比在东胜气田致密低渗储层流体识别中的应用

东胜气田锦72井区盒1段储层纵向非均质性强,含气饱和度差异大,气水赋存状态多样,预测有效储层是目前勘探开发的关键问题。笔者结合测井数据,采用统计、对比研究方法,建立盒1段致密低渗储层流体测井响应特征及识别标准。理论证明,含气砂岩随着含气饱和度升高,纵波速度和横波速度都降低,但是纵波速度比横波速度变化大,因此,纵横波速度比降低。在此理论基础上,通过交会图分析,定量化识别出储层流体,同时采用纵横波速度比反演与纵波阻抗反演分析,明确了研究区盒1段气水分布规律及其空间展布特征,为研究区油气勘探提供依据。

v_P/v_S applied to fluid identification of tight sandstone reservoir of Dongsheng gas field

The longitudinal heterogeneity of reservoir and gas saturation in He 1 member of well block Jin 72 of Dongsheng gas field is quite large, and gas and water distribution is diverse.Predicting effective reservoir is a key issue in exploration and development.Combined with well logging data,a statistical and comparative study method was used to establish the logging response characteristics and the criteria of fluid identification in the tight sandstone reservoir of He 1 member.The theory proves that the gas-bearing sandstone decreases with the increase of gas saturation,and the longitudinal wave velocity and the shear wave velocity decrease,but the longitudinal wave velocity changes more than the shear wave velocity.Therefore,the longitudinal and transverse wave velocity ratio decreases.Based on this theory,the reservoir fluid is quantitatively identified through cross-section analysis.At the same time,based on the longitudinal and transverse wave velocity ratio inversion and longitudinal wave impedance inversion analysis,the regularity of gas-water distribution and its spatial distribution characteristics in He 1 member of the study area are clarified,which provides the basis for oil and gas exploration in the study area.