根据AVO响应识别不同流体类型的方法

 根据AVO的响应分类进行储层预测是目前油气勘探中最基础有效的油气勘探方法,但在实际应用中依然存在诸多问题,成功和失败的案例很多。主要原因是影响AVO响应的因素较多,例如岩性、物性、流体性质、成岩作用、地层压力、埋深等。本文以西非海域探井实际测得的物性参数为依据,设计了多个可能的岩石物理模型,并进行正演,归纳和总结了不同流体条件下,AVO响应随埋深的变化特征。指出了浅层由含水砂岩造成的“亮点”与含油气砂岩在AVO响应特征的不同,对经典AVO分类在该地区的应用做了补充,并给出了该区AVO分类有效应用的经验深度范围。

Identification Method for Various Fluids Based on AVO Responses

At the present time, AVO responses classification is the basic and most efficient method to predict reservoir. However, there are still many problems in its applications. The number of successful cases is almost equal to number of unsuccessful cases. The main reason is that there are many factors which affect AVO responses, such as lithology, physical property, fluid property, lithogenesis, and burial depth, etc. Considering these factors, it is necessary to analyze specific AVO response for a particular area on the basis of classical AVO classification. Based on the physical property parameters surveyed in the actual drilled wells of western Africa offshore, several possible petrophysical models are designed, and some forward AVO modeling on different fluid substitutions at different depth interval is performed. It is summarized that the characteristics of AVO response changes at different depths on different fluid substitutions. The applications of AVO classification in this area are also improved and some empirically depth ranges in which the AVO classification could be effectively applied to is provided.