Discovery of a new oil field within existing fields, offshore Gabon - An application of voxel technology to the reservoir distribution prediction

摘要

There are many oil fields with the Upper Cretaceous Batanga reservoirs in the northern offshore Gabon, West Africa. Main structural closures, however, have already been drilled and the exploration of the area is considered to have been matured. In 1994, Mitsubishi Petroleum Development Co., Ltd. (MPDC)together with Elf Gabon (operator)onducted a 3D seismic survey to evaluate the remaining potential. We have carried out a sedimentoligicalstudy based on the 3D seismic data utilizing voxel technology. Through this study, the Batanga sandstone reservoirs are revealed to be a complex of many turbidite channels within mud-rich deepsea fan body. These channels are, whilst meanderin and diverging, running basically frm east to west, which indicates that the fluid flow within the reservoirs should have been restricted in the N-S direction. Based on this study and other geological/engineeringdata, we have constructed a geological model, which implied considerable remaining oil reserves(equal to or even larger potential han each of the weisting fields)over the saddle area between the two existing fields. MPDC propoed and Elf Gabon agreed to drill an exploration well to this area. This well was successful and proved that our geological model is correct.