A Christmas tree is an assembly of valves, spools and fittings used for oil, gas, water injection, water disposal, gas injection, condensate and other types of wells. It is named for its resemblance to a decorated tree at Christmas.
A wellhead must be present to utilize a Christmas tree and is used without a Christmas tree during drilling operations. The wellhead is the component at the surface of a well that provides the structural and pressure-containing interface for the drilling and production equipment. Producing surface wells that require pumps (pump jacks, nodding donkeys, etc.) frequently do not use any tree because no pressure containment is required.
The Christmas tree and the wellhead work together to bring oil and gas to the surface.
The trees are frequently manufactured from blocks of steel containing multiple valves rather than made from multiple flanged valves.
The primary function of a tree is to control the flow into or out of the well, usually oil or gas.
A tree often provides numerous additional functions including chemical injection points, well intervention means, pressure relief means (such as annulus vent), tree and well monitoring points (such as pressure, temperature, corrosion, erosion, sand detection, flow rate, flow composition, valve and choke position feedback, connection points for devices such as down-hole pressure and temperature transducer.)
PURPOSE Of Christmas Tree is to:
On producing wells, injecting chemicals or alcohols or oil distillates to prevent and or solve production problems (such as blockages).
Controlling the injection of gas or water on a producing or non-producing well to sustain economic “production” volumes of gas from other wells in the area (in the field).
The control system attached to the tree controls the downhole safety valve (surface controlled subsurface safety valves, downhole safety valve or subsurface safety valve) while the tree acts as an attachment and conduit means for the control system to the downhole safety valve.
Appreciation: Thanks to all who their inputs were part of this article