Junction Plate for High Pressure High Temperature System

Abstract

Development of Ultra deepwater wells drilled to greater than 25,000 feet total depth in Gulf of Mexico (GoM) have led to the need for High Pressure (HP) systems. Existing MQC / Junction Plates were designed for maximum 15,000 PSI and needed to be updated to meet the 20,000 PSI system requirements. This paper documents the development of 20,000 PSI (20k) Multi-Quick Connect (MQC) / Junction Plate (J-Plate). This 20k MQC was updated in terms of material strength and qualified per API 17F. All Pressure containing components and the internal MQC drive mechanism had to be updated and verified for a Design Pressure (DP) of 20,000 PSI. Design and Analysis iteration was performed to verify the structural integrity of the MQC/J-Plate under the design operational loads (both internal and external loads) with all couplers pressurized to a design pressure of 20,000 PSI and test pressure (TP) of 30,000 PSI pressure. In qualification (per API 17F) the MQC went through cycle testing for mated and unmated conditions under pressure, unbalanced pressure load, and hyperbaric testing of the MQC with environmental pressure of 4400 psig (equivalent to water depth 10,000 ft / 3,048 m). Higher yield strength materials have been used for components as required to support the loading due to the high-pressure requirement. For higher stress (stress above allowable criteria in linear elastic stress analysis) areas, Elastic-Plastic stress analysis has been performed to check the structural integrity against the plastic collapse. The results of the analyses indicate that the MQC/J-Plate satisfies all the allowable criteria for the analyzed operational load cases. The coupler seal and body have been qualified by the vendor to required pressure and temperature cycles. A completely built MQC has been qualified with lines at 20,000 PSI design and 30,000 PSI test pressure per API 17F. Qualification tests were completed for the cycle testing (Balanced and Unbalanced) and hyperbaric pressure testing and successfully completed all cycle testing. In qualification, both mated and unmated conditions were performed with five cycles. MQC/J-Plate for High Pressure High Temperature (HPHT) has complied with all requirements of TRL 6. The new 20k MQC allows for the ultra deepwater development utilizing the existing 15k reliable, field proven MQC system with minor modifications. New coupling bodies were developed to enable this high pressure MQC to work seamlessly across the production and control systems in the field.