Several Classifications Of Christmas Trees 

The Christmas tree is a component at the top opening that leads to the oil well. It includes valves for measurement and maintenance, safety systems, and a series of monitoring devices. The Christmas tree connects the production pipeline and the output pipe from the downhole, and at the same time acts as an important barrier to isolate the top of the oil well from the external environment. It includes many valves that can be used to regulate or prevent the production of crude oil vapor, natural gas and liquids from gushing out of the well. The Christmas tree is connected to the production manifold system through subsea pipelines.

There are many types of Christmas trees. According to the application area, they are divided into water Christmas trees (placed on the platform deck) and underwater Christmas trees (placed on the seabed); according to the installation position, they are divided into vertical (or vertical) Christmas trees and horizontal ( Or horizontal) Christmas tree, plug-in (or caisson) Christmas tree; divided into dry Christmas tree, wet Christmas tree and dry/wet Christmas tree according to the structure; divided into satellite well Christmas tree and chassis well according to the well layout Christmas tree.

The Christmas tree has the following functions:

(1) Connect each layer of casing downhole, seal the annular space of each layer of casing, and bear part of the weight of the casing.

(2) Suspending tubing and downhole tools, supporting the weight of all tubing strings in the well, and sealing the annular space between tubing and casing.

(3) Control and regulate the production of oil wells.

(4) Ensure the construction of various underground operations, facilitate the construction of well killing operations, starting operations and other measures, and conduct daily production management such as pressure measurement and wax removal.

(5) Enroll oil pressure and casing pressure data.

Christmas tree is also called Christmas tree. A wellhead control device for testing oil and gas after the completion of an oil (gas) well, or during oil production such as blowout wells and mechanical production wells. It consists of a tubing hanger and many gates and tees or crosses, and is directly mounted on the casing head. A Christmas tree with a delivery pipe on one side is called a single-wing Christmas tree; a double-wing Christmas tree with a delivery pipe on both sides is called a double-wing Christmas tree. The Christmas tree is equipped with nozzles (stop nozzles), which can control the oil and gas output by replacing nozzles with different inner diameters.