A Case Study of Offshore Time-Lapse Seismic Technology in the South China Sea Oil Field

Abstract

Time-lapse seismic technique is an important method for by-passed oil distribution prediction and reservoir monitoring. However, the complex reservoir conditions and the lack of basic data bring difficulties to the application of time-lapse seismic in Chinese Offshore oilfield. For example, most of offshore oilfields have no second well logging, second 3D seismic data and dynamic test data. Even with second 3D seismic data, due to the change of seismic acquisition conditions (flow, tide, environmental noise, obstacle etc.), the update of acquisition technology and equipment, and the lack of pre-consideration, non-repetitive time-lapse seismic acquisition problems have become increasingly prominent, which brings much more difficult for the processing and interpretation. In addition, the multi-layer commingled injection and production of the reservoir further increases the difficulty for the difference interpretation. In this paper, it studies the offshore non-repetitive time-lapse seismic technology. Based on the combination of high quality second seismic data, drilling dynamic and production dynamic information, the time-lapse seismic technology are studied. It puts forward key technologies such as global optimal acquisition, consistency processing and comprehensive interpretation. The application of this technology has achieved good results in the South China Sea. In an oilfield comprehensive adjustment, 9 wells are optimized, and 4 risk wells are avoided.