Multishell-Core Flexible Self-Healing Nonmetallic Electric Connector Concept and Evaluation

Abstract

Intelligent well completions are complex design integrated packages that includes flow control tools, zonal isolation devices, downhole monitoring systems, control, and emergency shut-in systems. This complete package allows for local automation and optimization of multi-lateral reservoirs or target developments, as well as independent or remote-control operations. As part of the intelligent completion system, the downhole wet connect links the upper and lower completions providing hydraulic, electric or both linkage for power to lower completion equipment. This paper proposes a downhole electric Wetconnect concept that differs from current downhole methods in that it is conformal, nonmetallic, has a multishell-core structure, and self-healing capabilities that allow the structure to be restored once the electric contact is disengaged by removing connecting pin. This paper presents the construction, working principles and assessment of the unique electric connector and describes initial literature review from lab study on synthesis methods. The procedure of developing the multishell-core connector is challenging and comprises selection, synthesis and interlacing of various layers with different properties. Metallic and Nonmetallic conductors, including powders, liquid metal, carbon materials, are anticipated to be employed as the connector’s core, which will be protected by dielectric layers. The material for the dielectric layers will be selected depending on temperature resistance and required thickness. The outer layers or shells can have cleaning and autonomous self-healing characteristics against both mechanical or electrical damage, by including microcapsules or employing the vascular network. Furthermore, self-healing elastomers are being studied for the outer most layer of downhole Wetconnector. Non-Metallics for conducting core are carbon-nanotubes and graphene-based conductors, and like traditional metal wires, now have electrical characteristics of their metallic counterparts, as well as several benefits, such as resilience to severe temperatures. A highly stretchable and heat-resistant material will be chosen as the dielectric layer from a range of commercially available elastomers and other silicone compounds. Due to high cost of constructing a vascular network, microcapsules containing healing agents are preferred in terms of self-healing characteristics of the outer layer. It is possible to create a self-healing elastomer that combines the unique qualities of high stretchability and universally autonomous self-healing. The key to this design is the synergistic interaction of several dynamic bonds, such as disulfide metathesis, strong crosslinking H-bonds, and weak crosslinking H-bonds. The paper introduces concepts and presents preliminary lab study of novel multishell-core flexible self-healing nonmetallic electric connector. The development plan includes electric connection evaluation, along with self-healing characteristics and resistance to water penetration under hydrostatic pressure. It is anticipated that when the tubing is redeployed, the intelligent well completion incorporated with this novel connector will allow for multiple orientation agnostic disconnect/reconnect of the upper completions and lower completions in a multi-lateral well configuration.