Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Deepwater Subsea Test Tree and Intervention Riser System
DTC International, Inc
Stress Engineer Services, Inc.
Det Norske Veritas
DTC International, Inc. (DTC) will develop a Deepwater Subsea Test Tree (SSTT) and Intervention Riser System (IRS) that are capable of conducting Riser–Based (Thru-Drilling Riser and Open Water Riser) intervention operations on subsea completed wells with wellhead shut-in pressures up to 20,000 psi and wellhead flowing temperatures up to 350 °F in water depths up to 12,000 feet. The SSTT and IRS will be developed as part of a fully integrated Subsea Well Intervention System (SWIS) that also includes a Riserless Intervention System (RIS) that is capable of conducting both Wireline and Coiled Tubing (future upgrade) intervention operations without the need for a riser.
The RIS portion of the SWIS is currently being development by DTC under RPSEA Project No. UDW2301. This project will develop the remaining two parts of the SWIS, the SSTT and IRS. Once completed, the SSTT, IRS and RIS will function as a fully integrated subsea well intervention system that shares many common components, including the Well Control Package (WCP), Emergency Disconnect Package (EDP) and Intervention Control System (ICS), and is capable of conducting both riser-based and riserless intervention operations on both Vertical (VXT) and Horizontal (HXT) Christmas Trees.
The objectives of this project are  to complete the development of a fully integrated Subsea Well Intervention System (SWIS) that is capable of conducting both riser based and riserless intervention operations,  to develop a SSTT and IRS that are capable of operating in water depths up to 12,000 feet and at working pressures up to 20,000 psi and working temperatures up to 350 °F;  to progress the design of the SSTT and IRS to the point that that they are certified, ready to fabricate,  to develop cost estimates for manufacturing and qualification testing of the SSTT and IRS, and  to develop a business case for a SWIS “Tool Pool” that includes the SSTT and IRS in addition to the RIS.
The SSTT and IRS Development Project is estimated to require eighteen months to complete. Major Project Deliverables are as follows:
- Project Management Plan
- Technology Status Assessment Report
- Technology Transfer Plan
- Monthly Progress Reports
- Functional Design Specifications for the SSTT/IRS
- SSTT/IRS Design and Analysis Summary Report
- TRAP, HAZOP/HAZID and FMECA Analysis Report
- Design Verification Report
- SSTT/IRS Cost and Schedule Estimate Summary Report
- SWIS Business Case Development Plan
A Final Project Summary Report will be submitted upon completion of the project and Final Project Presentation made to RPSEA.
Expected Impacts and Benefits
The SSTT and IRS proposed by DTC are expected to have the following major impacts and benefits:  provide a means of conducting thru-drilling riser and open water riser intervention operations on subsea wells in water depths up to 12,000 ft. water depths and at working pressures and temperatures up to 20,000 psi 350 °F,  together with the RIS, complete the development of a fully integrated Subsea Well Intervention System capable of conducting both riser-based and riserless intervention operations,  be applicable for use on =80% of the subsea wells in the deepwater and ultra-deepwater areas of the Gulf of Mexico,  reduce the risk of interface problems, equipment damage, loss of well control, or discharge of fluids to the environment; and  reduce the cost of conducting intervention operations on subsea wells by sharing components between multiple applications and forming a SWIS “Tool Pool” that includes the SSTT, IRS and RIS.
DTC will lead a team of personnel who have extensive experience in all of the technical and op-erational areas required to perform this development project. DTC has teamed with several industry-leading companies to provide the necessary personnel and technical expertise support. These include: Stress Engineering Services; a Titanium Engineering/Manufacturing Company; Det Norske Veritas; and several specialty/expert Consultants.
Principal Investigator: Bill Parks