Hydrate Prevention and Methanol Distribution on Canyon Express

摘要

The Canyon Express field in deepwater Gulf of Mexico is adevelopment consisting of multiple subsea gas-condensatewells owned by different companies. Each deepwater well(ranging from 6400 to 7250 foot water depth) flows into oneof two 57 mile, 12” flowlines which tie the subsea wells to ashallow water host platform on the Continental Shelf. Theproduction from each well is predominantly methane gas butalso consists of produced water and condensate. Due to thenature of the production and the combination of high pressures/ low temperatures expected, the potential for hydrateformation is a serious concern to system operability. Toadequately protect the system against hydrate formation anddeposition, injection of hydrate inhibitor (methanol) at eachsubsea well from a common umbilical system is beingemployed. Although wet gas metering is being used at eachwell to measure gas and liquid rate, water content per wellcannot be accurately predicted. Thus, a robust methanolinjection strategy was required to effectively inhibit hydrateformation. This paper presents the design of the methanolinjection system and development of the overall injectionstrategy. Examples from the early field life of the CanyonExpress development will be presented which demonstrate theapplication of this injection strategy to the system operation.