Cyclic Steam Stimulation Designing for Two Horizontal Wells in Sudanese Oil Field - Case Study FNE Oil Field

Abstract

Enhanced oil recovery (EOR) became more important at present time as the conventional resources deplete, EOR have many methods, thermal method is the most method used in EOR. thermal method reduces viscosity of heavy oil and residual oil saturation to improve mobility and achieve an economic recovery. Cyclic Steam Stimulation (CSS)is one of the thermal methods, which has faster production, lower costs and lower pressure operations, it’s of great interest in thermal methods. Fula North East (FNE) Field is one of the Sudan’s heavy oil field with low API of 17.7 and high oil viscosity 3800cP at29oC. CSS have been implemented in this field. This study concerns the simulation of cyclic steam stimulation process of two horizontal wells in FNE reservoirs and find the optimum parameter of this wells. the horizontal area can increase sweep efficiency. optimum Cyclic Steam Stimulation (CSS) parameters and several simulation models for different development scenarios have been built, each scenario with different parameters and condition, all this to compare the feasibility of applying Cyclic Steam Stimulation in horizontal wells, all this is done by using STARS simulator of Computer Modeling Group (CMG) software. the results obtained after the designing models and future prediction till 2030, it has been found that implementation of (CSS) in two horizontal wells with optimum conation will give 8% recovery factor more than to drill 10 CHOPS vertical wells. the optimum Cyclic Steam Stimulation parameters have been determined as follows for (well-1005) injection rate of 250 m3/day and temperature of 330 (0C), steam quality equal 80% injection period 28 days and soaking period 3 days. For (well-1003) injection rate of 200 m3/day and temperature of 200 (0C), steam quality equal 80% injection period 3 days and soaking period 2 days. This work shows that oil recovery could be improved from 24.29% by cold vertical production to 32.18% by CSS in two horizontal wells.