Perpustakaan Digital ITB

Mature fields require artificial lift methods to enhance production. As production declines and watercut increases, wells are often converted from gas lift to ESPs, as ESPs are an attractive alternative for achieving lower bottom hole pressure. This situation is critical when deciding on artificial lift conversion. In this study, gas lift wells will be converted to ESP systems under specific conditions to achieve maximal production. Binary Integer Programming (BIP), alongside nonlinear and linear programming, will be used to facilitate this objective, ensuring enhanced production within existing limitations. Seven wells will be evaluated to determine whether to convert to ESPs or remain in the gas lift system. An inflow performance analysis will assess the potential production increment for each well. Optimizing the existing gas lift system is necessary to ensure that the current system is performing optimally. Nonlinear optimization using Sequential Quadratic Programming (SQP) will be conducted for lift gas allocation optimization. The availability of 3.5 MMSCFD of gas injection serves as a constraint for nonlinear optimization. Additionally, linear programming will be applied for design rate optimization in each well, constrained by surface facility capacity of 9,000 BLPD. Both nonlinear and linear programming prove effective for lift gas allocation and design rate optimization, respectively. The methods result in an increase in total oil production by up to 318.26 BOPD for lift gas allocation optimization and 534.88 BOPD for design rate optimization. Each method respects the constraints, with the total gas injection required being 3.5 MMSCFD and the total liquid production capped at 9,000 BLPD. These results are used to guide artificial lift substitution decisions using BIP. BIP is employed to achieve maximal oil production, constrained by surface facility capacity of 9,000 BLPD and a special condition that a well will only be converted to ESPs if the incremental oil production from design rate optimization exceeds 15 BOPD. This threshold is set to cover the costs of well service, electricity, and pump rental. BIP results indicate that three wells—B-X04, B-X07, and B-X08—will be converted to ESPs, leading to a total oil production increase of up to 490.25 BOPD. BIP proves to be a powerful tool for decision-making, helping to achieve maximal oil production within multiple constraints and conditions.