Production Optimization Of Gas Condensate Reservoir

Gas condensate loss is a major problem being faced by the global petroleum industry.Considering the fact that gas condensates is in great demand,methods are being researched to optimize gas condensate production yielding lesser condensate loss and greater economic benefits.Production optimization study plays vital role in enhanced oil recovery during the field development to yield optimum profit.Gas injection,specifically,gas cycling is an effective field development method since gas is effectively miscible with oil and reduces oil viscosity which eventually decreases residual oil saturation and recovers the lost condensate.But such enhanced oil recovery technique is subjected to certain field parametric restrictions to optimize gas condensate reservoirs.In this thesis,a short practical literature review is performed after which simulations are used and explained to highlight production optimization of gas condensate reservoirs.The single layer,heterogeneous–gas condensate reservoir is modeled in a compositional simulator to highlight the characteristics of reservoir and fluid properties.Then production development study of gas cycling and CO₂ injection is analyzed to understand which method is most optimal and economically feasible to recover lost condensate and increase ultimate productivity yield.In contrast with gas and condensate recoveries of 11%and 65.3%and gross profit?annual?of$3444Billion from CO₂ injection,gas cycling yields better recovery of 20%and 78.2%gas and condensate recoveries with$6281Billion annual gross profit.In continuation,the study on injection patterns of five-spot and nine-spot with gas cycling has been carried out with the analysis of impact of injection patterns on enhancing the condensate recovery and project economics.19 years gas cycling with five-spot and nine-spot pattern flooding improve 41%condensate recovery,however five-spot pattern due to lesser drilling cost and lower number of wells generated higher gross profit of$0.231Million than nine-spot pattern?$0.162Million?.Results proved that selection of optimum well spacing can assist to best select flooding pattern in order to optimize field development plan for the gas condensate reservoir.Therefore,production optimization of gas cycling five-spot with optimum well spacing plans?i.e.425ft²-small well spacing and 850ft²-large well spacing?are studied;CapEx for drilling number of injection-production wells is the influencing factor found in this study.Large well spacing of 850ft² between injection-production wells drilled less number of wells;therefore required less CapEx of$1.3Million and hence yielded better NPV after17years of production time.Finally,19 years field development plan of gas cycling five-spot pattern is optimized by studying the field optimum injection pressure and injection flow-rate;project OpEx costs are the influencing variables determined in the development revenue and NPV estimations.From two optimum field injection pressures?above dew point–4000psi and near dew point 3550psi?,lower injection pressure of 3550psi cost less OpEx cost of injection gas?$120Million?with optimum condensate recovery?47.2%?and better NPV yield.From two optimum field injection flow-rates?1.4MMScfD and 0.7MMScfD?,lower injection flow-rate of 0.7MMScfD cost less OpEx of injection gas?$29.2Million?,higher gas sales?$87.5Million?,optimum condensate recovery?18.4%?and best NPV yield.In 19 years production time of NPV and production optimization study,results conclude that recovering lost condensate is improved with optimum gas cycling–field development strategy;a smart production optimization solution for the optimum field development of gas condensate reservoir.