Sea Technology

APR 2017

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

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Page 15 of 72 April 2017 / st 15 O perators in challenging offshore locations continually seek to select optimal forms of artificial lift to sus- tain maximum production, and there are a variety of dif- ferent options available for the purpose: electric submers- ible pumps (ESPs), sucker rod pumps, plunger lift, gas lift, chemical lift, progressive cavity pumps (PCPs) and hydrau- lic pumping systems. ESPs are often considered the best artificial lift option in terms of cost-efficiency. However, the optimum potential of ESPs in offshore and remote locations has been constrained by the high cost of intervention as- sociated with rig deployment, the associated loss of production, and an inability to access the reservoir without pulling the production tubing. AccessESP reduces the cost of operating ESP wells with its in- novative ESP deployment system, allowing ESPs to be replaced through tubing using slickline. The company focuses on operating in remote areas, such as the Arctic and offshore, where changing a traditional ESP takes a long time due to rig availability and associated loss of production. The AccessESP system offers significantly lower intervention costs, reduces lost produc- tion and provides full-bore access to the reservoir by elimi- nating the need for a workover rig. Furthermore, the live well intervention saves costs and avoids reservoir damage, as no kill fluid is required. Technology A robust production-tubing landing string is combined with a side-pocket-mounted downhole wet connector and a high-power permanent magnet motor (PMM) to form the "rigless" conveyance system, comprising the permanent completion system and the slickline retrievable ESP assem- bly. The permanent completion system is deployed with the production tubing and comprises two components: the side-pocket-mounted downhole wet connector and the connector orientation and latching system. Electrical power is provided via the ESP cable to the surface. The PMM is compatible with surface electrical equipment (variable- speed drives, step-up transformers, downhole cables and wellhead/packer penetrators) from all major suppliers. The client's surface electrical equipment can, therefore, remain the same. The slickline retrievable assembly integrates the PMM and wet connect system with industry-standard ESP com- ponents (pumps, gas handling equipment, seals, cables) from all major ESP providers, allowing the operator to combine the system with ESP components from vari- ous different suppliers. The light- weight, high power density PMM is only a fifth of the weight and length of conventional ESP induc- tion motors. Following on from the deployment of the permanent completion, it takes a matter of hours to complete the through tubing installation of the slickline assembly. The retrieval of the slickline assembly also only takes a few hours and is essentially the reverse of the instal- lation. The wet connector on the retrievable ESP assembly is aligned with the mating connector on the permanent com- pletion before engagement. The mechanical forces gener- ated by the retrievable ESP system are taken by mechanical supports provided by the permanent completion. The system can be installed and retrieved with a stan- dard slickline operation through tubing in live wells. Most offshore platforms do not have a permanent rig installed, therefore a rig or hydraulic workover unit will have to be mobilized whenever a tubing-deployed ESP requires re- placement. In order to manage costs and efficiency, these units are typically assigned work scopes months in advance. Therefore, it may take months before a workover can be scheduled. It may not be economical to mobilize a rig for a single well workover. Slickline operations, however, are Offshore Rigless Conveyance System AccessESP Enables Efficient Electric Submersible Pump Replacement By John Algeroy • Greg Nutter "The AccessESP system offers significantly lower intervention costs, reduces lost production and provides full-bore access to the reservoir by eliminating the need for a workover rig."

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