Strong corrosion resistance: suitable for complex fracturing conditions with high acid content, oil (gas) and high H2S content and CO2.
The sealing position of the valve in the wellhead is covered with corrosion-resistant material, and the service life is greatly extended.
High fatigue strength, suitable for pressure cycle alternating, multi-stage fracturing construction.
The equipment has a high pressure rating to meet the requirements of deep wells and high pressure fracturing conditions.
The role of the wellhead equipment is to suspend tubing and seal the oil jacket annular space. The most basic parts of the wellhead equipment are the tubing head (casing tee or four-way), tubing tee and sealing box. In addition, there are production valves, return pressure valves, venting sampling valves, oil jacket connection valves, etc., and equipped with oil pipe and casing pressure gauge to observe the oil casing pressure.
First, the role of oil harvesting trees
Wellhead device, commonly known as "oil production tree", is one of the most important and common equipment for oil, gas and water wells, and is the main equipment for controlling and regulating oil well production. Its main functions are:
(1) The weight of all tubing columns in the suspension tubing and supporting well;
(2) Seal the annular space between oil and casing to control casing gas;
(3) control and regulate the production of oil wells;
(4) Daily management of admission oil, set pressure data, testing, wax cleaning, etc.;
(5) Ensure the smooth progress of underground operation construction such as well washing, sand washing, acidification, fracturing, etc.
Figure 1-1 shows the composition of wellhead KY65-21 oil production tree.
Figure 1-1 Schematic diagram of KY65-21 oil production tree
1- Test the valve; 2- Left or right production of valves; 3 - clamps; 4 - tubing tee; 5 - total valve; 6 - upper flange; 7 - casing tee; 8 - lower flange; 9 - left and right casing valves; 10- Tubing topping wire
Second, the type of oil harvesting tree
There are two main categories of oil producing trees, namely old oil producing trees and new oil producing trees. The old-fashioned oil harvesting tree refers to the oil harvesting trees such as Dalong (imitation Great Rome), Rongfeng (imitation Little Rome), and Lianggong (imitation Su) in the 60s of the 20th century. The new oil production tree refers to the Daqing 150, Daqing 160 miniature, Sheng 251, Sheng II type and other oil production trees designed and manufactured by China.
Third, the structure of oil extraction trees
Taking the domestic KY65-21 oil production tree as an example, the parts and components include oil production tree casing tee, left and right casing valve, tubing head, tubing tee, general valve, left and right production valve, test valve or wax cleaning valve (well sealer), tubing top wire, clamp, steel ring and other accessories.
Fourth, the connection method of oil production trees
There are five main ways to connect oil trees:
(1) Clamp connection: The connection between the components of the oil production tree is mainly clamped, such as Daqing 150II, Sheng 261 micro, Sheng 254 and other oil production trees;
(2) Thread connection: the connection between the components of the oil production tree is mainly threaded, such as Daqing 150, Sheng 251 and other oil production trees;
(3) Iron hoop connection: the connection between the components of the oil production tree is mainly iron hoop, such as Sheng I, Sheng II and other oil production trees;
(4) Flange connection: the connection between the components of the oil production tree is mainly flange, such as Shanghai Dalong, Rongfeng, Lianggong and other oil production trees;
(5) Clamp flange connection: The connection between the components of the oil production tree is mainly clamp and flange, such as the original CY250 and other oil production trees.
Basic parameters
Size specifications |
4-1/16"~7-1/16" |
Pressure level |
10000psi~20000psi |
Material level |
AA~HH |
Temperature level |
KU |
Specification level |
PSL1~PSL4 |
Performance level |
PR1~PR2 |