A flowline is a segment of steel pipe conveying the produced fluids from a single wellhead, through a production manifold as necessary, to a fluid separator of a surface facility.
In a larger well field, multiple flowlines may connect individual wells to a manifold.
Flowlines in offshore operations indicate:
- flowlines transporting oil and/or gas from satellite subsea wells to subsea manifolds,
- flowlines transporting oil and/or gas from subsea manifolds to production facility platforms, to a pre-process stage or to a transportation facility or vessel,
- infield flowlines transporting oil and/or gas from between production facility platforms,
- export pipelines transporting oil and/or gas from production facility platforms to shore.
Flowlines may be in a land or subsea well field and may be buried or at grade on the surface of land or seafloor.
Gathering lines are similar to flowlines but collect the flow from multiple flowlines.
Gathering lines are similar to flowlines but collect the flow from multiple flowlines.
Flowlines are located at the well site tied to a specific well.
It may be a metallic pipe or a hose.
Most flowlines are very short in length but others may be run for kilometers in onshore applications.
In comparison gather lines are used after flowlines have brought the fluid to a manifold or other piece of process equipment, these lines may run for miles or up to a process ship if off shore.
Flowlines are constructed onshore and may be lowered to the seafloor, and have terminal connectors that make installation at the well head easier.
It may be a metallic pipe or a hose.
Most flowlines are very short in length but others may be run for kilometers in onshore applications.
In comparison gather lines are used after flowlines have brought the fluid to a manifold or other piece of process equipment, these lines may run for miles or up to a process ship if off shore.
Flowlines are constructed onshore and may be lowered to the seafloor, and have terminal connectors that make installation at the well head easier.
Flowlines may be single wall pipe or hose and may be insulated or may include an outer pipe known as pipe in pipe (PIP) system to limit heat losses and protect the carrier pipe.
As with any subsea installation, consideration should be given to connection orientation to reduce risks from snagging and to assist with installation.
Helical pipe strakes are often added to the pipe’s surface to reduce pipeline vortex induced vibration that can lead to pipe fatigue.
Flowlines operate as one component of a pumping system. For additional information on energy efficiency opportunities involving pump optimization see the pumps for power topic.
Types of flowlines:
- Single Tubular: Single, simple tube system (onshore or subsea). This is the standard type of flowline for on-shore applications;
- Bundled Line: these systems comprise of several export flowlines, injection and umbilical control lines of varying configurations;
- Coiled Tubing;
- Riser: Flowlines carrying the hydrocarbon flow from the seabed to the surface facility;
- Flexible Catenary Risers (FCR);
- Hybrid Riser: a riser bundle attached to a submerged buoyancy tank;
- Jumper: short flowline connecting a subsea well back to its manifold;
- Piggy-Back: an export line from the field carrying an externally attached import injection flowline to the wellhead;
- Pipe-In-Pipe: An external pipeline carrying an internal flowline. PiP systems are used for protection near the shore and for insulation in deeper waters;
- Steel Catenary Riser (SCR).
