Functions:

 

The primary function of a Christmas Tree is to control the flow, usually oil or gas, out of the well. (A tree may also be used to control the injection of gas or water into a non-producing well in order to enhance production rates of oil from other wells.) When the well and facilities are ready to produce and receive oil or gas, tree valves are opened and the formation fluids are allowed to go through a flow line.

 

A Christmas Tree often provides numerous additional functions including chemical injection points, well intervention means, pressure relief means, monitoring points (such as pressure, temperature, corrosion, erosion, sand detection, flow rate, flow composition, valve and choke position feedback), and connection points for devices such as down hole pressure and temperature transducers (DHPT). On producing wells, chemicals or alcohols or oil distillates may be injected to preclude production problems (such as blockages).

 

What purpose does a tree serve? 

 

• On producing wells, injection of chemicals or alcohols or oil distillates to prevent and or solve production problems (such as blockages) may be used.

• A tree may also be used to control the injection of gas or water injection application on a producing or non-producing well in order to sustain economic "production" volumes of gas from other well(s) in the area (field).

• The control system attached to the tree controls the downhole safety valve (scssv, dhsv, sssv) while the tree acts as an attachment and conduit means of the control system to the downhole safety valve.

3. Valves:

 

Christmas Tree have a large variety of valve configurations and combinations of manual and/or actuated (hydraulic or pneumatic) valves. Examples are identified in API Specifications 6A and 17D.