The paper highlights the critical importance of the subsea connections in offshore field developments and proposes an integrated approach to reduce the "connection cost" and operational risks involved.
As the subsea industry has progressed into deeper water, the subsea hardware components have increased in size and complexity as a result of the operating conditions and the production requirements. These increased technical requirements have resulted in components being supplied that are difficult to handle and install. We need to recognize this trend and then ensure that these components are designed so that they can be more easily installed.
As an industry, we need to ensure we are "making all the right connections" between the Component Suppliers and the Installation Contractors to ensure we make the right connections at the subsea worksite.
One of the most complicated installation tasks performed subsea is the interconnection of components. Just about every component that is installed subsea needs some form of connection - be it electrical, hydraulic, mechanical or fluid. These can vary in size from small electrical connectors to large export lines.
There are now a number of connection systems on the market. These range from simple shallow water systems to large and expensive deepwater systems. These connections systems can be supplied by either the Subsea Production System (SPS) hardware manufacturers or the installation contractors.
Assuming that a number of different connection systems can meet the operating specification for the process fluid, then how do we decide what type of connection system to adopt for a field development? The selection process is generally based on one or more of the following:
The same type of system that's historically been used before elsewhere.
A system recommended by the FEED Design House.
CAPEX cost considerations.
Existing Frame Agreements or development programs.
Subsea connections are frequently complex and operationally intensive. To be successful the systems should be designed from both a Component Supplier and an Installers point of view. Failure to adopt this joint approach will result in a compromised system design, this will directly result in costly offshore operations.
As the industry has moved into deep water the operating environment for the connection systems has changed in terms of the system loadings, hydrostatic pressure and also the seabed conditions. The production requirement can also be more demanding with issues such as high fluid temperature, high pressure, flow assurance, thermal expansion and specialized fluid requirements.