Design and Development of All-Electric Surface-Controlled Subsurface Safety Valve System

Summary The subsurface safety valve (SSV) is an essential device of a subsea production system. The hydraulic SSV is widely used, but it has some drawbacks when used in deep water: It needs a long pipeline from platform to wellhead, and brings additional pressure loss. The system needs higher pressure and manufacturing costs, but the response is slower. To solve the problem, a new all-electric surface-controlled SSV (E-SCSSV) system consisting of an E-SCSSV body and a control system is developed. The innovative structural designs include electric-drive mechanisms and a magnetic coupler that can transfer linear motion. The mechanical property of E-SCSSV body is analyzed to determine the ability to resist well pressure. The coupling rule of the magnetic coupler is studied through experiment and finite-element analysis. The dynamics of the failure-safety mechanism is investigated to obtain the optimal performance and combination of structural parameters. Using sensors on the E-SCSSV body, the operation status of the E-SCSSV can be monitored. An E-SCSSV system prototype has been developed to validate the function of the E-SCSSV. Reliability requirements are discussed. Compared with existing SSVs, the biggest advantage of the E-SCSSV is its quick response.