This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper OTC 35379, “Road to Well Completions Electrification To Support Sustainable Field Development,” by Martin Le Ménach, Muhammad Sofyan, SPE, and Juliana Padrao, TotalEnergies, et al. The paper has not been peer reviewed.
A collaborative venture aims to introduce an innovative intelligent completion system in the context of multiple wells to replace conventional electrohydraulic systems that have been in use for decades by electrifying the process. The study illustrates that electrification can facilitate the coexistence of sustainable practices and profitability, offering a promising outlook for the future.
All-electric completions aim to replace the entire hydraulic infrastructure downhole, at seabed, and topside with electric systems, thus opening new performance capabilities while simplifying operations.
All-electric downhole tools can be multidropped on a single line as opposed to hydraulically controlled equipment that requires dedicated control lines for each device. The single electric line distributes power and provides bidirectional communication between the topside control system and all downhole tools. All-electric completions open the possibility of controlling conventional equipment such as gas-lift valves or chemical-injection valves with much higher precision with control from topside of any equipment that would otherwise require wellbore or annulus pressure to be actuated.
Electrified completion devices theoretically can be connected to the same electric cable, which is called tubing-encased cable or permanent downhole cable. Where power, risks, or safety aspects require special management, using two electric cables may be desirable for configurations involving a large amount of equipment.
No Limitation on Number of Devices.
Because direct hydraulic control of downhole equipment requires a minimum of one hydraulic control line per device, intelligent completions are practically limited to no more than three hydraulic flow-control valves per well because of the complexities of deployment and installation. Electric systems that are all multidropped on the same line have no practical limitations on the number of devices other than the amount of power that can possibly be sent to the wellhead.
Simplification of Installation.
All-electric completions are deployed from a single electric line and a single wet-mate connector, greatly reducing the number of connections to be made during installation and enabling simple coiling when using contraction joints and fewer penetrations in packers. This simplicity returns significant time savings for running an entire intelligent completion of up to 20% from normal completions when including the thousands of meters of tubing strings that run in hole faster, because clamping a single control line is much faster than clamping half a dozen hydraulic lines altogether.
An all-electric system uses a single wet connector as opposed to multiple wet connectors. The use of an alternating-current power bus also supports replacing downhole electric wet connectors with high-reliability inductive couplers that are contactless devices, immune to fluid effects.
A typical configuration stacks multiple inductive couplers to access the multilateral branches, with each branch equipped with all-electric devices. Such an application would be impossible with hydraulic systems. Fig. 1 shows typical photographs of multizone hydraulic installations compared with all-electric ones.
