Offshore oil and gas producers know they provide a great service to our country by providing the fuels we need for daily living and commerce. They also know that society depends on them to operate safely and spill-free. In the post-Macondo era, all operators are now working with a heightened sensitivity for safety. The welfare of our nation’s waters, as well as our energy industry, is at stake.
A variety of technologies and equipment types are on the market to assist producers in subsea well surveillance and mitigation of accidents during operations within their offshore infrastructure. One of the needs is to provide enough pressure isolation during well completion and intervention so that serious accidents do not occur. A key piece of equipment needed during many operations is the subsea test tree (SSTT).
Subsea Test Tree
The primary function of the SSTT is to provide pressure barriers to control pressurized fluid flow and to enable well control in the unlikely event of an unplanned disconnection of the rig from the well, without requiring the blow out preventer to kick in. They have been in use since the 1950s.
The SSTT connects to the landing string on the bottom-hole assembly. Its main function is to prevent accidents by ensuring that adverse pressures are isolated downhole and do not manifest at the surface. Here are a few of the features of this equipment:
- It provides a safe interface for both coiled tubing as well as wireline operations
- It is manufactured with high-load-bearing swivels
- It is designed with two pressure-isolation valves, in both the upper and lower parts of the tree
- Pressure rateing are typically standardized to 5,000, 10,000, 15,000 and 20,000 psi
- It is designed to function in temperatures up to 250F.
A subsea control system operates the valves and chokes on the SSTT. A direct hydraulic control system is the simplest remotely operated mode of control.
Safety First Is the Top Priority
The aftermath of the Macondo disaster made clear that safe operations are of paramount importance and that all parties, including operators, contractors, and clients, need to work hand-in-glove to achieve environmental excellence. If not, they will no longer be allowed to operate.
PRT offshore is dedicated to providing impeccable quality and top-level safety as top priorities. They incorporate the best safety training programs in the industry. Their environmental-protection commitment is robust, independently verified, and built into all their operations.