The Energy demand in Pakistan is increasing day by day. In this challenging environment, operators have shifted their focus to optimizing the production from their existing assets i.e. mature fields. Rather than discovering the new fields, they have realized the importance of advance techniques of Artificial Lift System (ALS) for maximizing their production through the years.
One of the most effective ALS technologies is jet pumping which has been applied domestically in Pakistan for more than 20 years. Jet pump technology possesses a very unique advantage of no moving parts while operating in the well. It has numerous designs and methods of deployment, which depend upon the operating parameters of the wells. However, if the operating conditions and parameters are not continuously monitored, the dynamics of the wells can compromise jet pump performance. In some cases the venture can turn out to be uneconomical, even to the point of abandonment, irrespective of the recovery factor achieved.
In this study jet pumps were optimized for one of the mature oil fields in Pakistan. The analysis approach was based on a variety of operational conditions of the wells such as vessel pressures, injection parameters, flow restrictions, surface pumping unit power, and nozzle throat combinations of jet pump to realize the true potential of the reservoir. The designs were also evaluated with different scenarios of the producing wells such as matching the Productivity Index (PI) and Inflow Performance Relationship (IPR) of the well with extended jet pump performance curves. The analysis and design of these jets was performed using Jet Pump Evaluation and Modelling Software (JEMS).
This paper demonstrates the process and gives the results for optimizing the production from a mature field. It also shows significant improvements attained for optimized input power for each well. Lessons learned are also presented for further improvements of the field. In the end, a comprehensive methodology towards the selection of the most feasible size and operational parameters of jet pumps for a given set of well, reservoir and fluid parameters has been illustrated.
