Method and apparatus for a cold flow subsea hydrocarbon production system
AssigneeShell Oil Company
InventorsSzabolcs Roland Balkanyi, James George Broze, Jose Oscar Esparza, Gregory John Hatton, Ajay Praful Mehta, Chien Kuei Tsai, Moye Wicks, III, George John Zabaras
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Abstract
A system for assuring subsea hydrocarbon production flow in pipelines by chilling the hydrocarbon production flow in a heat exchanger and causing solids to form, periodically removing deposits and placing them in a slurry utilizing a closed loop pig launching and receiving systems.
Claims23
A system for maintaining production flow in a subsea pipeline having a proximate and a distal end, the pipeline being in fluid communication with a host on a distal end, the system comprising:
- a pig handler, having an inlet system in fluid communication with at least one subsea well adapted to receive a hydrocarbon production flow, and an outlet system in fluid communication with the proximate end of the pipeline;
- a subsea heat exchanger, the heat exchanger having an inlet in fluid communication with the pig handler inlet system and an outlet in fluid communication with the pig handler outlet system, adapted so that the temperature of the hydrocarbon production flow may be reduced sufficiently to cause solids to form;
- a pig launching system, adapted so that a pig may be selectively placed into the hydrocarbon production flow through the pig handler inlet system, launching the pig into the heat exchanger to remove deposited solids from the heat exchanger;
- and
- a pig receiving system, adapted so that a pig may be removed from the hydrocarbon production flow through the pig handler outlet system prior to production flow entry into the subsea pipeline;
- wherein the heat exchanger is a forced coolant pipe-in-pipe system, having inner and outer pipes, adapted so that production flows through the inner pipe and coolant flows through the annulus formed between the inner and outer pipes in a direction counter to the production flow direction.
A method for maintaining production flow in a subsea pipeline, comprising:
- producing a hydrocarbon from at least one subsea well;
- transporting the hydrocarbon from the at least one subsea well to a heat exchanger;
- passing the hydrocarbon through the heat exchanger, in order to cool the hydrocarbon and precipitate at least one solid selected from waxes, paraffins, asphaltenes, and/or hydrates;
- passing the hydrocarbon through a pipeline from the heat exchanger to a host;
- and
- pigging the heat exchanger with a pig to produce a slurry of the solids in the hydrocarbon;
- wherein passing the hydrocarbon through the heat exchanger comprises passing the hydrocarbon through an inner pipe in a first direction and passing seawater coolant through an annulus surrounding the inner pipe in a second direction, the second direction opposite the first direction.
Dependencies are inferred from the claim text.