Perpustakaan Digital ITB

Naturally aging oil fields are now usually on the secondary or even the tertiary recovery phase. However, the primary recovery is still used to boost the production. One of the most effective primary recovery method, artificial lift method, especially the sucker rod pump is widely used in the industry. Over time, the sucker rod pump could be on the condition that it will not be efficient enough to lift the oil due to its pump capability not being suitable for the reservoir performance. Therefore, the reservoir performance will decreases as the reservoir pressure drops, so the reservoir no longer has support to flow as previously. Nonetheless, several parameters on the sucker rod pump could be adjusted to reach its optimum condition, which will be suitable for reservoir performance. Therefore, the pump and reservoir evaluation should be done regularly to look at whether the well is in optimum condition or not. While the pump condition is no longer in accordance with the reservoir performance, the optimization also should be performed, routinely, indeed. A case study in this research is carried out on a mature field, J- Field, in South Sumatra by observing three wells namely J-001, J-042, and J-194. Each well pump deliverability and reservoir performance is evaluated and the optimization design is generated. At well J-001 and J-042, only the current well performance is evaluated as the wells have limited data. Whereas for well J-194, future well performance will also be carried out by generating four scenarios of optimization design. Each scenario proposes a combination of time and sucker rod pump parameters, such as pumping speed, stroke length, rod size, plunger size, and tubing size, which will be designed to predict when and what sucker rod pump parameters ought to be changed or redesigned in the future, so that the pump is always on the optimum condition. The scenarios are generated to find the best scenario that has the most optimum design. Optimum design means the design provides the least power required to lift one barrel of fluid. Resulting in the pumping speed of Well J-001 should have been changed to 9 and 5 SPM on January 18th, 2017, and February 28th, 2017, respectively, Well J-042 should have been changed to 7 SPM on February 28th, 2017, and Well J-194 should have been changed to 5 and 4 SPM on October 26th, 2016, and February 23rd, 2017, respectively, to achieve their optimum condition at that time. Furthermore, at Well J-194, scenario C is chosen as the best scenario as it gives the lowest power required to lift one barrel of fluid. Other than that, scenario C also offers the least optimization effort to be done.