The Christmas tree is a valve-accessories combination designed to control fluids from oil and gas wells and to provide inlet for production tubing strings,including all components above the tubing head adapter.Christmas tree assemblies can constitute many different kinds of combinations in oeder to meet any special requirement.Based on their different functions.Christmas trees can be classified into such special Christmas trees as oil production (flowing and artificial lift) Christmas trees,gas (natural gas and various sour gas) production Christmas trees,water injection Christmas trees,thermal recovery Christmas tree,fracturing Christmas trees and acidizing Christmas trees.Different pressure ratings serialize Christmas trees. The gas production Christmastree and tubing head are mainly used to produce gas and inject gas.The relative density of natural gas is low and gas column pressure is low,while well head pressure is high and liable to leakage regardless of gas production and gas injection.Sometimes natural gas contains corrosive media such as H2S and CO2.Therefore,the gas production Chrismas tree calls for rigid requirements on both its materials and its sealing characteristics.For the sake of safety,two gate valves are used on the tubing and casing respectively.Some gate valves to be used on high pressure and ultra-high pressure gas wells are integrated valves manufactured from high quality forged steel. The pressurization parts of the Christmas trees and tubing spools manufactured by Yancheng Shenhua Machinery manufacture Co.,Ltd.are made of forged or special smelted forging,so it is high-pressurization safety and so on.
|