Methods of remotely, selectively controlling the flow rate of fluid moving through a subsea pipeline during dewatering of the pipeline involve a control unit of a subsea valve actuation system selectively, autonomously varying the flow of fluid through a fluid flow conduit of the system fluidly coupled to the pipeline at the pig receiving end thereof based at least partially upon one or more signals emitted by at least one pressure transducer or flow meter fluidly coupled to the fluid flow conduit.

Methods of remotely, selectively controlling the flow rate of fluid moving through a subsea pipeline during dewatering of the pipeline involve a control unit of a subsea valve actuation system selectively, autonomously varying the flow of fluid through a fluid flow conduit of the system fluidly coupled to the pipeline at the pig receiving end thereof based at least partially upon one or more signals emitted by at least one pressure transducer or flow meter fluidly coupled to the fluid flow conduit.

A method for separating two or more different gases that are being transported in a pipeline is described. A slug of inert gas, particularly nitrogen is introduced between the two or more different gases to replace the isolators that have been traditionally used. This slug of inert gas will assist in more efficiently transporting the gas while reducing the problems associated with isolators. There is further disclosed a method for separating and transporting at least two liquid products such as two different crudes or diesel and gasoline in a pipeline.

A method for separating two or more different gases that are being transported in a pipeline is described. A slug of inert gas, particularly nitrogen is introduced between the two or more different gases to replace the isolators that have been traditionally used. This slug of inert gas will assist in more efficiently transporting the gas while reducing the problems associated with isolators. There is further disclosed a method for separating and transporting at least two liquid products such as two different crudes or diesel and gasoline in a pipeline.

Methods of remotely facilitating the transition between flooding and hydrotesting a subsea pipeline include a control unit of a subsea valve actuation system closing off fluid flow out of the pipeline at the receiving end thereof based at least partially upon one or more signals emitted by at least one intelligent pig that has passed through the pipeline during flooding and without the involvement of an external source at the surface, or a UV, at the pig receiving end of the pipeline.

Methods of remotely facilitating the transition between flooding and hydrotesting a subsea pipeline include a control unit of a subsea valve actuation system closing off fluid flow out of the pipeline at the receiving end thereof based at least partially upon one or more signals emitted by at least one intelligent pig that has passed through the pipeline during flooding and without the involvement of an external source at the surface, or a UV, at the pig receiving end of the pipeline.

Compositions and methods for reducing the formation of hydrates within subsea or over-land pipeline systems. The compositions and methods include the use of organic salt solutions, such as an acetate salt solution, to precondition, treat, and/or dewater the pipeline systems, or employ the use of the organic salt solutions during other pre-commissioning operations. An effective concentration of an organic salt solution acts to reduce hydrates and/or inhibit hydrate formation within the pipeline systems.

A method for separating two or more different gases that are being transported in a pipeline is described. A slug of inert gas, particularly nitrogen is introduced between the two or more different gases to replace the isolators that have been traditionally used. This slug of inert gas will assist in more efficiently transporting the gas while reducing the problems associated with isolators. There is further disclosed a method for separating and transporting at least two liquid products such as two different crudes or diesel and gasoline in a pipeline.

A method for separating two or more different gases that are being transported in a pipeline is described. A slug of inert gas, particularly nitrogen is introduced between the two or more different gases to replace the isolators that have been traditionally used. This slug of inert gas will assist in more efficiently transporting the gas while reducing the problems associated with isolators. There is further disclosed a method for separating and transporting at least two liquid products such as two different crudes or diesel and gasoline in a pipeline.

Methods of remotely, selectively controlling the flow rate of fluid moving through a subsea pipeline during dewatering of the pipeline involve a control unit of a subsea valve actuation system selectively, autonomously varying the flow of fluid through a fluid flow conduit of the system fluidly coupled to the pipeline at the pig receiving end thereof based at least partially upon one or more signals emitted by at least one pressure transducer or flow meter fluidly coupled to the fluid flow conduit.