Published: 08/17/2018
Published: 08/17/2018
In 2015, an operator in Ecuador needed to replace an ESP in one of its wells. At the time, it was common for rigs and hoists to take 7 to 10 days to respond to an ESP failure and an additional 4 days to pull and replace the ESP on jointed tubing. To reduce the time and cost of subsequent replacements, Schlumberger installed the new ESP as part of a ZEiTECS Shuttle system.
After running for 520 days, the ESP failed and required replacement, providing an opportunity to demonstrate the value of the ZEiTECS Shuttle system installed earlier.
The ZEiTECS Shuttle system consists of a downhole docking station and retrievable ESP string. The docking station is attached to the end of the tubing. Inside the docking station are three connectors and landing shoulders that support the weight of the ESP and its reactive forces and prevent the motor from counter-rotating on startup.
The retrievable ESP string is made up of a motor connector, standard ESP assembly, and a bypass valve. The motor connector contains female wet connectors and has corresponding parts to orient and connect the ESP to the docking station, intake and discharge, as well as a bypass valve to allow fluid to drain on system retrieval.
Schlumberger followed a systematic, integrated approach to plan the intervention with a coiled tubing unit instead of a conventional workover rig. The complete rigless solution included a coiled tubing unit, an ESP stinger, and an ESP retrieval tool.
Coiled tubing was rigged up to the well to pull the old ESP string through the tubing without a workover rig. The new ESP was subsequently run into the well using the same tool. When the ESP reached the ZEiTECS Shuttle system’s docking station, the motor connector automatically orientated and connected, providing the electrical source to enable powering up.
The operation was completed in 47 hours with no operational or HSE issues and only 12 people involved rather than the 40 typically required to replace an ESP with a workover rig. In addition to saving approximately USD 95,000 by eliminating a rig, the customer avoided at least 5 days of deferred production.
Challenge: Minimize workover cost, deferred production, and HSE risks when replacing an ESP.
Solution: Use coiled tubing instead of conventional jointed tubing and a workover rig to run the new REDA ESP system into the installed ZEiTECS Shuttle rigless ESP replacement system.
Results:
