Successful Offshore Deployment of the First Bottom Discharge ESP in Saudi Aramco
Presented in this paper is the success story of the offshore deployment
of a Bottom Discharge Electrical Submersible Pump (BD ESP), the first of its
kind in Saudi Aramco. Based on an immediate need for pressure support at low
cost, this pump was selected to provide the required injection volume and
pressure for a water injection system using nonpotable water (NPW). Water from
a shallow depth (4,500 ft) was injected into an oil zone located below (7,400
ft), with no water at the surface, eliminating any need for treatment at the
water injection plant.
The concept of using bottom discharge was considered as part of the
ongoing efforts to evaluate different completion strategies for local and
independent injection. Typically, a centralized water injection plant and
pipeline network stretched over long distances is common practice within Saudi
Aramco. These efforts were driven by the business need of a particular field to
provide sufficient water injection to the producing reservoirs, with the
consideration of low capital investment, and a short implementation time frame.
Water conservation efforts require the Company to use either treated seawater
or NPW (water so non-potable that it would be more expensive to attempt to
treat it than use treated seawater).
Well X, an existing offshore completion suitably located close to
oil-water contact (OWC) of the Arab-D reservoir and within the perimeter of the
aquifer (TDS = 24,700 ppm), was selected for this application. These factors
made the well an excellent candidate to test the BD ESP completion and to
provide 8-12 thousand barrels per day (MBD) of water injection to support the
Arab-D reservoir. The aquifer was perforated and the BD ESP completion was
deployed successfully in tandem with a satellite communication surveillance
system, to validate injectivity, optimize pump performance, and gather
reservoir data for further analysis.