Pore pressure prediction and lateral stress determination for an exploration well, a case studies

Abstract

Pore pressures trend are different in certain areas. This is due to the geological factor that took place over the geological time. Most of the hydrocarbon reservoir are lies beneath the thick sedimentary shale that are not hydrostatic pressure, instead they are an abnormal pressures especially for deep water sedimentary with small margin mud weight window. If the abnormal formation pressure are not accurately predicted prior to drilling, there will be a catastrophic incidents not only asset to the investor but also to the offshore worker life. Occurrences of abnormal pore pressure came from several geological factor that could be cause to various elements either from small scale i.e. minerals to the formed of mega structure or area. At present, more and more energy companies are investing billions of dollars in exploration to the new frontier and challenging harsh areas to find the oil and gas. Exploration becomes more challenging in this new frontier area, still technology are far behind due to natural complexity. This study analyses the outcome of one exploratory well for pore pressure prediction, fracture gradient and overburden gradient by using Drillworks? software. Eaton’s and Bower’s method were used with the integration of all relevance data to understand what are the pore pressure model compaction history and lateral stress determination exist. The method was tested in the Western Australia Field in the Western Australia Sea, where the field possibly dominated by normal faulting stress state (SV> SHmax >Shmin). Results suggest that the Bower’s sonic method with gave better results for the area than the Eaton resistivity method.