Unique Safety Valve Design Using a Floating Magnetic Coupler and Metal-to-MetalSealing Capability to Provide Step-Change Improvements in Reliability, Safety, andCost

摘要

Although design concepts for tubing retrievable safety valvesrn(TRSV) have improved considerably over the last decade, therndemands imposed by deep-water, high-pressure/hightemperaturern(HP/HT) environments, high-flow-rate gasrnreservoirs and remote subsea applications have also increased.rnIn spite of the use of non-elastomeric and metal-to-metal (M-t-rnM) sealing materials and enhanced validation testing, all ofrnwhich have improved drastically TRSV performance over thernlast decade, equipment has continued to be pushed to itsrnlimits.rnThis paper reviews the unique capabilities of a new TRSVrnconcept that uses a magnetic coupler. The discussion willrnfocus on the targeted applications and specific issues that thisrntechnology addresses. In addition, the paper will cover therndevelopment and preparation of the magnetic coupled TRSVrnfor field installation.rnThe magnetic-coupler concept was developed for deep andrnultra deep completions. As the TRSV is set deeper, it typicallyrnrequires additional operating pressure. By using the magneticrncoupler design, the operating pressure required for the TRSVrnis drastically reduced by removing any interaction between thernhydraulic operating piston and the internal tubing-wellborernpressure. This is especially beneficial for deepwater systemsrnwhere a lower operating pressure simplifies the overallrnoperating system. This simplification is important both forrnsafety and costs since the magnetic coupler design couldrneliminate the need for high-pressure equipment and thernassociated high-pressure umbilicals in subsea systems. Thernbenefits of this new, intrinsically simple design go beyond therninitially targeted deep completions and include:rn1. Increased environmental and personnel safetyrn2. Reduced system costsrn3. Reduced service demands for sealsrn4. An extremely reliable tubing-retrievable safety valvern5. Enhanced well life.