The technologies for rigless electric submersible pump (ESP) deployment were introduced in the oil industry to reduce expenditure during ESP replacement. Most of the technology is used to avoid rig utilization, which will reduce significant cost and safety risk during operations. At the same time, production restoration will be faster since some wellsite job preparation, such as for flowline strip-out and re-manifold, can be eliminated.
The new cable rigless deployed ESP system was successfully deployed and put on stream for the first time worldwide. The system has a unique concept and components, which consist of a specially designed cable hanger and coiled tubing. The cable hanger design offers cable isolation while providing a nonrestricted flow through the flow path built into the body of spool. The coiled tubing was manufactured to have resistance to H2S and CO2 as well as for isolating the cable from any corrosive fluid from the well.
Part of the technology assessment was to ensure the system should be able to retrieve and redeploy riglessly. A rigless job successfully retrieved and reinstalled the ESP after the pump had been on operation for more than 2 years. The most challenging operation is the killing procedure since the operation deals with high fluid losses while the gas from the well can be released at any time. Job preparation is key for success during retrieval activities, which involve a special study to find the proper kill fluid selection to control the well during activities. The kill fluid should be able to pump through the ESP, which is nondamaging for the formation and provides adequate weight to control the pressure and fluid losses.
This paper will share the experience from concept, design, field implementation planning and technical challenges, and lessons learned during preparation and installation.