Abstract: An essentially cylindrical deadleg having a first cross sectional area at one end of the deadleg and a second cross sectional area, the first cross sectional area being smaller than the second cross sectional area.

Abstract: Method and system for direct electric heating of a pipeline to contribute to removal or hindrance of plugs of ice and optionally hydrates, distinguished in that heating takes place to a temperature above the ice melting point, but below the hydrate melting point.

Abstract: The present invention provides a method of inhibiting formation of solid hydrates in a conduit used to contain a flowing, water-containing hydrocarbon, which method comprises introducing into said hydrocarbon in said conduit a gas which raises the pressure threshold for hydrate formation for said water-containing hydrocarbon, said gas being introduced in a manner which causes it to travel along at least part of said conduit in the direction of hydrocarbon flow.

Abstract: A method of protecting a hydrocarbon conduit during a period of reduced hydrocarbon flow is disclosed, where nitrogen is introduced into the conduit at a pressure of 1 to 350 bar g and at a rate of (1.5 to 35)A kg/sec (where A is the internal cross sectional area of the conduit in square meters) for a period of t hours where t=(p×d)/n where d is the length in km of the conduit from the nitrogen introduction location and n is 10 to 400.

Abstract: An essentially cylindrical deadleg having a first cross sectional area at one end of the deadleg and a second cross sectional area, the first cross sectional area being smaller than the second cross sectional area.

Abstract: The invention provides a method of protecting a hydrocarbon conduit during a period of reduced hydrocarbon flow, said method comprising introducing nitrogen into said conduit during a said period at a pressure p of 1 to 350 bar g and at a rate of (1.5 to 35). A kg/sec (where A is the internal cross sectional area of the conduit in square metres) for a period of t hours where t=p.d/n where d is the length in km of the conduit from the nitrogen introduction location and n is 10 to 400.

Abstract: A thruster pig for sending through a pipe from an entrance facility to a receiving location, for servicing or monitoring, by pumping a thrusting fluid into the pipe to force the pig forward is disclosed. The thruster pig includes a body having a front end and a back end, where the back end includes a reaction surface to which said the thrusting fluid applies a motive force. The body is slightly smaller in diameter than the inner diameter of the pipe. The pig also includes a seal circumferentially arranged on the pig to seal between said body and said pipe. A desired differential pressure is maintained over the pig to urge said pig forward through the pipe by pumping a fluid into the annulus between the pipe and the return flow line while returning fluid through said return flow line utilizing connected servicing or monitoring equipment. A connector releasably connects a return flow line to the pig.

Abstract: The present invention provides a method of inhibiting formation of solid hydrates in a conduit used to contain a flowing, water-containing hydrocarbon, which method comprises introducing into said hydrocarbon in said conduit a gas which raises the pressure threshold for hydrate formation for said water-containing hydrocarbon, said gas being introduced in a manner which causes it to travel along at least part of said conduit in the direction of hydrocarbon flow.

Abstract: A method for removal of deposits such as hydrate plugs from a pipeline is provided including inserting a thruster pig connected to a return flow line into the pipeline The pig is then advanced forward into the pipeline by pumping a thrusting fluid into an annulus between the pipeline and the return flow line while removing deposits continuously or intermittently and returning flow as appropriate from ahead of the pig through the return flow line. The return flow line is then disconnected from the pig after sufficient deposit removal and retrieved from the return flow line. Next, the pig may then be transported through the pipeline by the pipeline fluid to a pig receiving location once the pipeline flow is resumed.

Abstract: Method and system for direct electric heating of a pipeline to contribute to removal or hindrance of plugs of ice and optionally hydrates, distinguished in that heating takes place to a temperature above the ice melting point, but below the hydrate melting point.

Abstract: A thruster pig for sending through a pipe from an entrance facility to a receiving location, for servicing or monitoring, by pumping a thrusting fluid into the pipe to force the pig forward is disclosed. The thruster pig includes a body having a front end and a back end, where the back end includes a reaction surface to which said the thrusting fluid applies a motive force. The body is slightly smaller in diameter than the inner diameter of the pipe. The pig also includes a seal circumferentially arranged on the pig to seal between said body and said pipe. A desired differential pressure is maintained over the pig to urge said pig forward through the pipe by pumping a fluid into the annulus between the pipe and the return flow line while returning fluid through said return flow line utilizing connected servicing or monitoring equipment. A connector releasably connects a return flow line to the pig.

Abstract: A method for removal of deposits such as hydrate plugs from a pipeline is provided including inserting a thruster pig connected to a return flow line into the pipeline The pig is then advanced forward into the pipeline by pumping a thrusting fluid into an annulus between the pipeline and the return flow line while removing deposits continuously or intermittently and returning flow as appropriate from ahead of the pig through the return flow line. The return flow line is then disconnected from the pig after sufficient deposit removal and retrieved from the return flow line. Next, the pig may then be transported through the pipeline by the pipeline fluid to a pig receiving location once the pipeline flow is resumed.