基于岩石物理分析的致密砂岩流体检测方法研究

在致密砂岩气藏的勘探中,利用地震属性检测流体对致密砂岩气藏的高效开发显得尤其重要.由于地震是岩性、孔隙度、流体等地质因素的综合响应,因此优选敏感流体属性至关重要.从苏里格气田西区某区块为例,从基础岩石物理数据出发,优选出了适合致密砂岩岩石物理模拟的岩石物理模型.系统研究了储层弹性参数与岩石岩性、孔隙度、含气饱和度变化的关系;并通过多变量正演模型筛选出对流体敏感的属性.研究表明:采用Brie模型对Xu-White模型进行改进后更适合致密砂岩储层的岩石物理模拟,利用地震数据检测含气饱和度是可行的,应用P+G属性能够较好的预测致密砂岩的含气饱和度.所采用的思路与方法,对其他类型的气藏检测方法优选具有较好的借鉴意义.

Tight gas saturation detection by most sensitive AVO attributes with rock physics analysis

In the process of tight sand prospecting, it is important to detect the fluid by seismic attributes in the efficient exploring. As the seismic attributes were affected by many factors at the same time, such as lithology, porosity, fluid property and so on, and different seismic attributes have different sensitive ability to geology factors. Taking the Sulige gas field as an application example, according to the experimental data, and then prioritize the rock physics model which is fit for tight sand rock physics modeling to assure the relationships between the rock physics parameters and lithology, porosity, gas saturation, and then filter best seismic attribute which is most sensitive to fluid. From the research result, after the Xu-White model was improved by Brie model, it is more suitable for tight gas sand rock physics modeling, and it is feasible to detect the gas saturation in tight sand, the gas saturation can be predicted by the P G attribute. The workflow and method can be widely used by other reservoirs prediction.