利用阵列声波测井定量评价低渗透砂岩储层含气性

低孔低渗含气砂岩储层的气层识别与饱和度计算受孔隙结构影响显著,阵列声波测井纵、横波信息为解决这一难题提供了非电法手段。从含气砂岩储层的声波测井响应特征模拟研究入手,从理论上建立的波速比-纵波时差交会图与实际井数据分布特征完全一致,表明了理论模拟的可靠性。反之,对于实际测井数据,在已知地层波速比、骨架参数及孔隙度基础上可以估算其含气饱和度,研究结果在歧口凹陷深层及苏里格气田等典型的低孔低渗气层评价中得到很好的应用和验证。

QUANTITATIVE EVALUATION OF GAS BEARING SANDSTONE RESERVOIR OF LOW PERMEABILITY WITH ARRAY ACOUSTIC LOGGING

Pore structure has remarkable effect on gas zone identification and saturation calculation in gas-bearing sand reservoirs with low porosity and permeability.P-wave and S-wave of array acoustic logging provides a non-electrical method to solve the problem.Based on theoretical response characteristic simulation of gas bearing sand reservoirs,the cross-plot of wave speed ratio-p-wave time difference is coincident with the data distribution features of practical wells.Contrarily,gas saturation can be estimated with real logging data when wave speed ratio, matrix parameter and porosity are given.The research has been successfully applied in evaluating the reservoirs of Qikou depression and Sulige gas field.