Rigless Esp Deployments Saving Deferred Production in Greater Burgan Field

Summary Kuwait Oil Company (KOC) has its biggest and the oldest field "The Greater Burgan" producing for several decades now and providing the biggest contribution to Kuwait's oil production. Greater Burgan is the world's largest sandstone oil field. This was the first oil discovery field of Kuwait and has been a cornerstone of making Kuwait one of the top oil producers in the world. The field being a highly permeable sandstone reservoir, providing easy access to hydrocarbon, was tapped with huge number of wells drilled through it. Over the decades of production from this field, the water table gradually started rising, reaching limits where the water cut became so high that the reservoir pressure was not sufficient to lift the fluid by itself. Majority of the wells since then started requiring artificial lifting to lift the fluids from the reservoirs. Water cut became as high as 50-70% in majority of the wells. As of 2023, approximately 70% of the wells in the Greater Burgan Field are artificially lifted through Electrical Submersible Pumps (ESPs). All conventional ESP installations / maintenance / repair / replacements requires a workover rig. 60-70% of the workover rigs in this field are allocated to ESP related activities including installation of a new ESP in a well which was naturally producing but now ceased to flow due to increase in water cut as well as replacement of existing ESPs in wells which has failed due to mechanical or electrical failure. A typical workover related to ESP operation in this field requires approximately 15-20 days. Rig schedules are planned a few months in advance so if a well has a sudden ESP failure or a natural producer suddenly ceases to produce due to water cut, it takes at least 1-3 months to get the well scheduled on a workover rig causing deferred production from the well. KOC pioneered a novel solution to quickly restore production and minimize deferred oil in these wells. The technique utilizes a slim ESP set inside production tubing without the need of a work over rig. The rigless wireline ESP deployment solved a major bottleneck and wells were put back to production with capacity of producing up to 2200 bbl/day. The efficiency with which the rigless ESP is deployed saves a lot of deferred production until a rig is available for workover or even as a long term solution in certain cases. The first field deployment of the technology was done in 7 days and with improvement in efficiency of deployment the installation and commissioning time of the pump has been reduced to as low as 3 days. Once candidate is selected, certain pre-works are required in the location to get the same ready for rigless ESP installation. Tubing leakage detection is one of the important steps to be done to ensure tubing integrity is good before planning a well for installation. Once tubing integrity is confirmed, Slickline is utilized to set a packer in the tubing. This is a special nipple-less packer which is specially designed to have an inner profile where the pump BHA end latches onto. This packer acts as a docking station for the pump BHA. Once packer assembly is installed in the tubing, a wireline unit is used with a special cable to deploy the pump BHA in the well which latches on the packer. Once pump is latched into the packer, the cable is cut and terminated at surface which is electrically connected to a Variable Frequency Drive (VFD) which provides the power to the downhole BHA through this cable. The entire operation, including pre-works, Slickline packer setting as well as Wireline ESP deployment is done riglessly making it a complete rigless solution to restore the well production. So far KOC has managed to successfully deploy the rigless pump in 6 wells out of which 3 wells pump was retrieved after a short term deployment whereas 3 wells the rigless ESPs are still live contributing to oil production. Till Oct 2023, KOC has gained approximately 500,000 bbls of Oil from the Rigless ESP deployments and the same is expected to cross 700,000 bbls of Oil by end of 2023. The longest running pump in KOC has cross 270 days and is expected to complete 1 year soon which would further strengthen the reliability of the rigless ESP system to potentially use the same to also provide a long term solution in addition to a short term application. The success of rigless ESP deployments has allowed KOC to optimize the utilization of the available rigs by performing other workover operations and increase the overall production of Kuwait. With having such rigless pumping capability, KOC's workover operations strategy will be revisited for better benefit of Kuwait.