COMPARATIVE ANALYSIS OF DECLINE CURVE ANALYSIS AND MATERIAL BALANCE ANALYSIS RESERVES ESTIMATION USING MBAL SOFTWARE

The correct estimation of hydrocarbon reserves is still a key factor in petroleum reservoir management and economic planning. This paper made a comparative evaluation of both Decline Curve Analysis (DCA), and Material Balance Analysis (MBA) based on the MBAL software on the model of a single-tank black oil reservoir which fits a model of a field in the Niger Delta. The aim was to assess the consistency, reliability, and prediction power of the two methods in the estimation of reserves as well as predicting the behavior of the reservoir. The DCA technique, which is empirical modeling of history production decline, and the MBA technique, which is the law of conservation of mass, both were practiced in MBAL using real field data. Both of the models were deeply history matched and forecasted to identify an Estimated Ultimate Recovery (EUR), Original Oil in Place (OOIP) and drive mechanisms. Comparative analysis showed MBA had predicted 29.6 MMSTB EUR, field life 46 years and that DCA had predicted 13.6 MMSTB with a field life 26 years which made the variance 117.6%. This difference was ascribed to the fact that a powerful aquifer drive was realized in MBA and this could not be reflected in DCA which is an empirical tool. The analysis confirmed that MBA gives more physically stable and realistic forecasts, particularly the reservoirs that have active pressure support, but DCA is a valuable screening option of early-stage performance forecasting. The findings confirm the complementation of DCA and MBA and show the strength of MBAL as a combined system of analyzing reservoir engineering. The study will assist in a better practice of reserves estimation, teaching, and enhancing the integrated workflow in digital reservoir management.