Wet Christmas Tree and Control System Standardization and Interchangeability - More Than 10 years of Lessons Learned

Abstract

Abstract The scope of this work is to present the main results obtained with the interfaces standardization on Wet Christmas Trees (WCTs) and its Electrohydraulic Multiplex (EHMUX) Subsea Control Systems in pre-salt scenario, in Brazil, which completes more than 10 years since their first installation. This work also presents how much the standardization of interfaces reduced the OEM (Original Equipment Supplier) dependance, how it helped to mitigate field operational issues, and how new opportunities of broader applications are being pursued in recent projects. The WCT-interfaces standardization has been developing in Brazil since the beginning of the 90's, where Pre-Salt WCTs is the last generation. A review of the cases where this standardization succeeded was made, allowing the demonstration of its value to mitigate suppliers’ delays, to minimize cost in projects’ implementation, to increase flexibility and to overcome o perational issues faced in the field. Several examples of successful cases were found where standardization helped to mitigate issues in delivery schedule, changes in projects schedule and scope, and equipment failures faced in the field. Statistics have been carried out on this data showing estimated gains obtained. Additionally, for global service-only contracts with tools owned by the operator, to project-oriented services and tools availability contracts, the interchangeability level provided by the standardization became much more relevant, since it opens more alternatives for services’ contracting, from the OEM or other suppliers. Some challenges to become completely independent of OEM were identified and will be presented in this paper, as well as different scenarios where the standardization application is wider or narrower. Some opportunities were identified in recent projects, fostering new equipment suppliers, softening the transition to next equipment generation from the same supplier and enable the use of all-electrical shared actuation systems in subsea manifolds connected to WCTs from a different supplier. Besides, this paper discusses on the main achievements obtained with the philosophy of standardization of the EHMUX-type Subsea Control System (SCS) for WCTs and subsea manifolds, also standardized for applications of the Brazilian pre-salt, which in 2023 completed 10 years since the first installation of the combination of standardized SCS and WCT, in the Sapinhoa field. The use of this standardized SCS allowed full operational interchangeability between SCS equipment and both the Brazilian pre-salt standards of WCTs and subsea manifolds, supplied by the main vendors of subsea equipment. The standardization of the SCS has also been helping to deal with operational problems that arise during the productive life of fields, minimizing the number of failures and their related costs.