| Abstract |
Geothermal well ULB-1 in Indonesia has been in operation for several years, supplying steam to one of the geothermal plants. The well has a multi-feed zone and has experienced fluctuations in steam and liquid production, which can be attributed to a competing phenomenon between the reservoir and the wellbore. The change in pressure between the reservoir and the wellbore, where the steam feed zone is overlying the brine part, produces a flow mobility between steam and brine that does not produce steam only; rather, it shifts the production of fluid from one to another. The phenomenon caused the well to produce an exceedingly large amount of undesired brine out of the wellbore. This study offers an analysis of the irregularity of the multiphase multi-feed zone wells by simulating the wellbore flow model. With the flow model recreated, chart depths and output curves are utilised to observe the multiphase multi-feed zone well behaviour. In order to assess the irregularity within the wellbore, a sensitivity analysis was additionally applied to the study. The sensitivity tests on the well flow model are done based on several main parameters, such as variation in productivity index and changes in pressure and temperature conditions of each feed zone. The well has a higher mass rate output if the productivity of a feed zone is optimised, whether it is steam or brine-dominated, according to the model. |