Two Azimuth Data Processing for Time Lapse Seismic Residual Fluid Prediction: A Case Study from Huizhou Oilfield in the South China Sea

Time-lapse (TL) seismic is the most direct and effective way to dig the potential of residual fluid in old oilfields. In China, most old oilfields, including Huizhou oilfields in the South China Sea, did not implement repetitive TL seismic acquisition. Oilfield A in Huizhou has entered the later stage of high water-cut and high recovery. The only way to ensure its continuous production is to find out the distribution and movement of oil and water. In the case of only two seismic data with large differences in acquisition parameters in different periods, the mathematical two-azimuth TL seismic processing is helpful to solve the problem of oilfield development and reduce the cost of data acquisition. The two-azimuth TL seismic processing includes simultaneous conventional processing, TL seismic matching and targeted two-azimuth cross equalization processing, which can effectively reduce the difference of seismic inconsistencies caused by acquisition differences. It is proved by drilling that the two-azimuth TL seismic can provide reliable oil-water movement rules and remaining oil distribution forecasting for old oilfields, and can be used for reference in offshore oil fields.