The Implementation of Flow Performance Test to Monitor Well Performance in Geothermal Field

Abstract

Reservoir monitoring of a geothermal field has an important role in determining the direction of company policies in managing a geothermal field, one of which needs to be monitored is by looking at changes in the pattern of the deliverability curve so that it can determine changes in the characteristics and performance of production wells. In order to update the deliverability curve, it is necessary to conduct periodic production tests. However, this cannot be done due to limited steam reserves. This research was conducted to determine the performance of production wells using the Flow Performance Test (FPT) method. This method is an alternative solution that can update the production well deliverability curve without leaving the gathering system. The FPT is applied to UBL-DL5 and JL2, UBL-JL3 is shown to validate the equations used. The data obtained were validated with TFT data and production test data where the deviation of the data obtained for UBL-DL5 was 1.42%, UBL-JL2 was 2.7%, and UBL-JL3 was 2.74%. The comparison of the UBL-DL5 and JL3 models based on time shows a significant production decline, and this is possible because the wells have only been operating within a period of 4 months - 1 year where the condition of production wells are still looking for stable condition, while the UBL-JL2 have not been seen there is a change in characteristic. The FPT is reliable enough to be used as an alternative method in monitoring production wells compared to the TFT method and the horizontal lip pressure production test. The FPT program should be conducted periodically and synchronized with the company's operational activities plan. The delivery curve modeling as FPT result is used to monitor production wells' condition as the basis for the company to develop a dynamic five-year work plan.