砂泥岩储层孔隙度和含水饱和度同步反演

Porosity and water saturation simultaneous inversion for sand-mudstone reservoir

基于岩石物理和地震反演理论,提出了一种同步反演储层孔隙度和含水饱和度的方法.以岩石物理为基础,建立了砂泥岩储层物性和弹性参数之间定量的关系—Simon模型,以贝叶斯理论为手段,结合不同类型的砂泥岩储层,建立了多信息联合约束的物性参数反演目标函数,并通过蒙特卡罗和遗传算法相结合的思路求解该目标函数,最终得到孔隙度和含水饱和度的同步反演结果.将该方法应用于河道砂和砂砾岩两种不同的砂泥岩储层中,孔隙度和含水饱和度数据的联合应用,进一步减少了储层预测的多解性,为石油地质综合研究提供了更加丰富准确的基础数据.

The reservoir physical properties estimation from seismic data can be seen as a seismic inversion problem. A joint estimation of porosity and water saturation is proposed that combines rock physics and seismic inversion. A sand-mudstone rock-physics model which named Simon model is established. Simon model provides the link between reservoir properties and seismic velocities. Based on Bayesian theory, a reservoir physical properties inversion objective function is established combining different types of sand-mudstone reservoirs. The objective function is solved by means of Monte Carlo simulation and genetic algorithm, and the porosity and water saturation results are acquired simultaneously. We applied this method to two different types of sand-mudstone reservoir： channel sandstone and sand-conglomerate reservoir. The combined application of porosity and water saturation data further reduces the multiple solutions of reservoir prediction and provides more abundant and accurate basic data for comprehensive research of petroleum geology.