ESP Water Injector Well with Injection Pressure Available for Real-Time Monitoring Recovered 30% of Production in Low-Producer Wells: Case Study
In Ecuador, the fields are getting more challenging in terms of reservoir depletion. Inchi field is an example of such a field in which production is normally obtained using electric submersible pumps (ESPs), with a fast production decline. The wells start with production rates of 1,000 BOPD, and immediately production and pump intake pressure begin to decrease, requiring a secondary recovery technique, such as water injection. However, the water to inject at required pressure is not always available, and special facilities are required to execute this operation, which increases capital expenditure (capex). Adopting a new approach that used the advantages of ESP sensors and operational flexibility, a production well was selected and converted to an injection well, thus avoiding the high investments in surface facilities and making the secondary recovery a feasible option for low-producing wells.
The Inchi A8 well on the Inchi A pad was converted to a production-injection well because of lack of available water in the field and production facilities. The paper includes an analysis of the completion design, ESP design, sensor installation modification for real-time injection pressure monitoring, ESP performance, injection stimulation, and results, with the performance analysis for production recovery of nearby wells. The experience shared in this paper will help the reader understand the challenges for installation of a production-injection well driven by the specific needs for and the advantages of injection pressure monitoring.
After the installation of the production-injection completion, the decrease in production and reservoir pressure stopped. Production increased by up to 284 BFPD and the flowing bottomhole pressure increased by up to 106 psi in the wells Inchi 01 and Inchi A5, while in the well Inchi B6, the flowing bottomhole pressure is now steady at close to 600 psi (before it was constantly decreasing). The injection pressure monitoring has been useful, especially during the injection pressure tests performed by a testing unit, which allows checking the actual injection index of the reservoir. The savings associated with the installation of the production-injection well include eliminating the need for additional surface facilities, a pipeline to bring water from the main station, and the construction of the water treatment plant in the location.
This paper presents a design guideline for future production-injection well applications, the benefits of having real-time injection pressure monitoring, and the way to use a conventional ESP discharge pressure to monitor the injection pressure and its performance.