Publications

Sustaining field life through continuous production and reserves growth are main focuses in every oil and gas company. To face this situation, there must be addition of reserves especially in undeveloped areas of PHE ONWJ. Since the oil price is unpredictable, the development of gas fields becomes favorable. Interpreting subsurface conditions in a gas field remains challenging. This is because of lack of data, limited reservoir distribution, and the different methods employed by different interpreters. This paper will cover on how to unlock the potential of Pre-Parigi Carbonate reservoirs by considering the geological risk of its development. The Belut structure was discovered by B-exploratory well in 1989 but no production test was performed on the Pre-Parigi Formation. Time Depth conversion analysis was carried out on the Belut structure to provide assurance of carbonate geometry in predicting hydrocarbon volumes in the reservoir and the feasibility of future development. The layer-cake approach reflects the influence of structure on control of velocity. Depending on the velocity characteristics and how the Parigi affects pull velocity up at Pre-Parigi structure, it can generate uncorrected carbonate geometry. To minimize pull up effects, this method creates top – base formation which is most suitable as it accounts for vertically variable velocity and spatially variable thickness. Determination of the geological markers can be defined by using the analogs from surrounding wells and biostratigraphy data from B well. Compared to previous depth carbonate geometry the new approach increases the level of accuracy proven by differences existing BRV and provides optimum depth errors of less than 5 ft. Quality control is provided in velocity seismic section, giving a comparison of time versus depth structure. Overall analysis reveals that the carbonate reservoir in the Belut structure has more volume and gas in place with an average porosity of 30% and Sw 33% hence this structure could be economical to develop.