Exploitation Strategy in the Development of Gas and Oil Mature Fields:Case Study

摘要

This paper presents the results of the exploitation strategy in the development of mature fields such as gas condensate and oilrnfields. For the gas condensate field, the integration of the geology, seismic, production and reservoir had allowed to definernflow zones, and also had identified new opportunities for drilling and then to establishing a strategy for a proper developmentrnof the field under study.rnThe static and dynamic modeling teams have proven that the four studied reservoirs in the gas condensate field could bernunified in a unique hydraulic unit, and then they were created the static model accordingly. However, and due to the scarcityrnof the available information, the official gas reserves were revaluated and re-estimated using analytical methods (such asrnempirical correlations, volumetric analysis and material balance). The empirical correlations (such as Eaton and Jacobi) havernbeen used to provide a rapid estimation of the gas condensate reserves. Both stand-alone and comingled producing intervalsrnhave been also identified in the named hydraulic unit under study.rnAccording to this study results, the oil and gas condensate in place have been increased by 9% and 22% respectivelyrncompared with the official reserves. Material balance calculation had shown an gas condensate in place (GCIP) ofrnapproximately of 1,132 BSCF. The economical sensitivity analyses under various scenarios have confirmed that the bestrnoption is to drill a horizontal well which would be producing at different rates ranging between 600 STB/D and 1,500 STB/D.rnThe results have also shown that a higher profitability could be gained from a horizontal versus an vertical well.rnTherefore, a Field Development Plan (FDP) has been also established during the course of this work in order to definerndifferent forecasting scenarios. For the oil field case study, the strategy of exploitation can be clearly improved. FieldrnDevelopment Plan should incorporate future workover services, ESPs, gas lift optimization, water-flooding, infill drilling,rntwin wells, horizontal wells and appraisal wells which will surly add more recoverable oil that the conventional producingrnactivities cannot achieve. A secondary recovery project using water-flood was recommended through a spot patternrnsimulation model. In exploratory areas, the appraisal wells required the construction of production forecast and reservernestimation under probabilistic scenarios and statistical data by extrapolation from surrounding wells supported by the use ofrn3-D seismic. The good FDP would add an extra 50% of the nowadays production to the daily field production by 2016.