4D Feasibility Case Study in a Mature Oilfield

Feasibility study is an essential component for 4D seismic projects. It includes rock physics modelling, seismic forward modelling, 4D difference calculation and feasibility study. Among them, rock physics modelling is very important because it links the attributes of reservoir fluid-flow simulation model with elastic properties such as P-wave and S-wave properties, and the measured data of cores in the laboratory are required. However, these data are lack of for some oilfields. But well logging data are available. We propose a method of rock physics modelling using well logging data, based on which 4D feasibility is carried out. It is applied to a mature oilfield where a seismic survey was shot more than ten years ago, which is different from what we usually do, to an undeveloped oilfield. The subsequent 4D case study proves the proposed method is practical, and it is the first 4D project offshore in China.