A subsea test tree is an immediate solution for controlling subsea wells. It provides dual-barrier well control and large-bore well access, along with reliable means to disconnect the completion landing string in an emergency.
Material Selection
According to those at companies like PRT Offshore, material selection for a subsea test tree requires a combination of considerations. First, choosing materials compatible with each other and conforming to the design is important. Typically, structural steels are chosen. These steels are commonly welded and should have the appropriate property ratings.
In addition to the type of material, the temperature rating is another factor that determines the cost of a subsea test tree. There are a variety of manufacturers that offer equipment with different temperature ratings. However, temperature ratings do not have a significant influence on cost. Ultimately, the type of material used to make the subsea test tree will be determined by the characteristics of the reservoir.
In addition to its structural integrity, a subsea test tree must be robust and durable. They control hydrocarbon production and flow by monitoring production flow and managing fluid and gas injection at the wellhead. While a subsea test tree can be horizontal or vertical, the design and materials used will depend on each well’s operating conditions and physical environment.
Costs
Subsea test trees are not cheap, and operators need to bear these costs in mind. These trees are unique and require custom engineering solutions, which are expensive and energy-intensive. These solutions also lack the benefits of mass production and standardization. In addition, they harm the carbon footprint of the industry. Subsea test tree procurement costs vary depending on the size of the project and the required tools. These costs can run from $3000 to $6000 per day. Additionally, the cost of EFAT is included in the procurement of individual equipment. Another cost that is accounted for is vessel downtime and standby waiting time.
Operation
The development and operation of a subsea test tree can be a challenging task. Every subsea tree has its design and componentry, making it difficult to match existing models and save on costs. Furthermore, custom subsea trees lack the efficiency benefits of mass production and standardization. In addition, they are expensive and require a great deal of energy. Therefore, using bespoke subsea trees seriously impacts the industry’s carbon footprint. In addition to providing data, an RBI consists of a corrosion and erosion study report, design data, and operational data. The data determines a subsea tree’s PoF and CoF and establishes an optimized inspection plan. These data also provide an evaluation of the risk associated with the subsea equipment. Understanding and assessing the risks associated with subsea equipment is crucial, and ensuring that it meets all engineering specifications is crucial.