Electrical Submersible Pump is an artificial lift method which consists of lowering a pump system on tubing string during rig workover where the power cable is clamped externally along with the tubing.
Because of the significant rig workover cost, the ESP is usually run until failure.
Wireline Retrievable ESP (WRESP) is a step change in ESP method, where the pump without electrical cable can be retrieved and reinstalled with a wireline method (as a rigless job) at any time of ESP life cycle.
A Wireline Retrievable ESP system consists of two main parts:
Permanent part: Docking station with a male connector, attached to a large bore tubing string with a power cable clamped on it and lowered in the well bore during a rig work-over job
Retrievable part: Standard ESP string with a seal assembly on top and motor connector on the lower end, lowered and retrieved with Wireline inside the large bore tubing.
This technology was implemented as a trial jobs in Oman, Ecuador and Nigeria. Challenges faced during implementation were as follow:
Considerable seals friction of seal assembly, resulting in a serious damage and stuck in tubing wall during pulling out of hole.
Difficulties to retrieve remaining pieces of damaged seals from the docking station.
Swap to CT conveyance.
During the first implementation in Kuwait, similar challenges were faced.
An Innovative Idea was designed, implemented and succeeded to overcome the above challenges. It was about adding a circulating device (operated by a slickline method) to the seal assembly configuration part, which was resulting first time (in Kuwait and worldwide) in completing a trial project smoothly and successfully.
This paper will describe the innovative idea, experience and best practices of the first WRESP application in Kuwait oilfield.