Casing head hanger

The casing head hanger (also known as a casing hanger) is the core pressure-bearing and sealing component of the casing head. Compliant with API 6A and GB/T 22513 standards, it is installed inside the casing head four-way connector. Its main function is to suspend the entire weight of the downhole casing string and seal the annulus of multiple casing layers. It is a key device for ensuring wellbore integrity and wellhead pressure sealing. It is divided into two main categories: slip type and mandrel type, and is widely used in drilling and completion operations for various oil and gas wells both onshore and offshore. Core functions:
1. Bearing the load of the suspended casing string: Transferring the weight of the technical casing and production casing to the casing head body, while also bearing the load of upper wellhead equipment such as the blowout preventer and Christmas tree, preventing the casing from being pulled out or deformed due to its own weight.
2. Sealing the annulus to isolate formation pressure: Through BT composite sealing and metal sealing structures, the annular space between the outer wall of the casing and the inner cavity of the casing head prevents oil, gas, drilling fluid, and formation fluids from leaking upwards along the annulus, mitigating well control safety risks. The sealing area can be greased, pressure tested, depressurized, and pressure balanced via the side outlet.
3. Positioning and fixing the casing to correct wellhead deviation: Constraining the radial displacement of the casing reduces wellhead casing tilt, ensuring the coaxial installation accuracy of the upper wellhead equipment.
4. Multi-stage wellbore barrier: Working in conjunction with multi-stage casing heads, multiple layers of casing are suspended and sealed step-by-step, forming a multi-layered pressure protection barrier, suitable for deep wells, high-pressure wells, and acidic oil and gas wells.