System and method for converting wellhead gas to liquefied petroleum gases (LPG)

摘要

A method of converting natural wellhead gas to liquefied petroleum gases (LPG) may comprise the steps of: separating natural gas from petroleum fluids exiting a wellhead; compressing the natural gas; refrigerating the natural gas, liquefying at least a portion thereof; separating LPG from gas vapors of the refrigerated natural gas; storing the separated LPG in a storage tank with a vapor space therein; and recirculating a portion of the LPG vapors in the storage tank with the natural gas exiting the wellhead to enhance recovery of LPG. A system for performing the method may comprise: a two-stage gas compressor connected to the wellhead; a refrigeration unit downstream of the gas compressor for refrigerating the compressed gases therefrom; at least one product separator downstream of the refrigerator unit for receiving refrigerated and compressed gases discharged from the refrigerator unit and separating LPG therein from gases remaining in vapor form; and a storage tank for receiving and storing the separated LPG therein, the storage tank having a vapor space therein connected upstream of the gas compressor through a pressure regulator allowing recirculation of some LPG vapors with the natural gases through said system.