A progressive cavity pump (PCP) well (S-648) remotely located in Heritage's offshore field was unable to produce since October 2018 due to high flowline pressures. This paper describes the approach that was taken to produce the well and initiatives undertaken to resolve challenges.
Analysis of the fluid properties was conducted for input into a multiphase flow simulation software. The software was utilized to determine flowline restriction and a solution to reducing flowline pressures by viscosity reduction and flowline replacement. Since subsea flowline replacement is a costly and time-consuming exercise, a laboratory viscosity evaluation was done utilizing a chemical viscosity reducer. The results were inputted into the software to determine the percentage reduction in flowline pressure for producing the well.
The chemical solution was applied despite multiple challenges. Infrastructure on the location was a challenge with no pneumatic or 110V electrical supply to operate the chemical injection pump, limited space on the well deck for a chemical tank and no access to refill the chemical tank. Initiatives were taken to resolve these challenges and commission the injection. Upon commissioning of the chemical injection system, the flowline pressure reduced by approximately 70% and the well was able to restart and sustain production until this day. The initial chemical injection rate was optimized downwards for reducing the operating costs for the well without increase in the flowline pressure.
Testing facilities were not available for this well at start up to quantify production, however pump functionality checks were being done to assure that fluid was moving through the system. The pump is capable of a flowrate of 200 barrels per day. Assuming 80% pump efficiency, the initial estimate of production gain from this initiative was approximately 70 barrels of oil per day. When testing facilities became available in February 2020, the well tested production was 172 barrels of oil per day.
This approach can be utilized to start up and produce wells with high flowline pressures in an offshore environment within a short timeframe, where restrictions are present and modifying/replacing flowlines is not possible or cost effective.