Operation Modification of X Gathering Station by Utilizing Existing Production Facilities for Pressure Maintenance Activities and Improving Trunkline Investment Cost Efficiency

Abstract

X Structure is operated by PT. PERTAMINA EP and located in north Kalimantan. In 2008, the peak production was around 190 BOPD. Currently, X Structure produce 60 BOPD from 8 wells. The oil is transferred using a reciprocating pump with a capacity of 120 m3/hour. The total production from X gathering station and Y gathering station is transferred to MGS along 11.78 Km. Somehow there are leaks on X trunkline to the MGS which caused production loss and environmental pollution. In 2017 AFE- 922A-736 was made to accommodate the improvement of the trunkline which requires a budget of more than one million USD. The authors see the potential cost reduction from AFE by utilizing existing facilities and adding other benefits such as pressure maintenance for X structure and reduce water level in Y water injection plant. Based on the calculation, the maximum oil thickness in wash tank is 1.6 meters, with a tank height of 6 meters, diameter of 8 meters, and retention time for 63 minutes. X gathering station has a water cut of 95% in wash tank, separation process analysis in actual condition in tank can be set as high as 5.7 meters for the water and 0.3 meters for the oil. The oil stored in the storage tank will be sent by vacuum truck to the storage tank at the MGS.

Based on sonolog data, current X structure pressure is 600 Psi, so it requires pressure maintenance. Modification in operating patterns to carry out pressure maintenance is possible. Previously, this could not be done since there is no WIP in the X structure. Separated water in the wash tank will be injected into the well with a reciprocating pump, along 1 km between the well and the pump, to reduce the water by 2000 BWPD using a pump with capacity of 120 m3 / hour. There will be installed gate valve for
circulation into the well and wash tank. it is expected that water will be injected at 70 bbl / hour which can support Pressure Maintenance activities in X structure. Based on the economics calculation, it could save investment about one million USD.