Casing hangers can be sorted into thread (mandrel) type and slip type. Slip casing hanger includes G type, W type, WD type, WE type and etc.  WD type casing hanger is used to connect casing head and surface casing, and the slip jaw can hold the casing tightly by external force. W type casing hanger realizes seal function by self-weight of casing. WE type and G type realize seal function by manual operation.

Casing hanger design

The main problems to be overcome in designing a reasonable well casing hanger are as follows:
1. The tendency of the hanger slips to crush
2. The tendency of the hanger gasket to crush the top section
3. The tendency of pressure-squeezed top section in annular space

Each of these forces tends to narrow down the inner diameter of the tube, which is not serious. But combined, they can cause damage. Excellent casing hanger design can avoid the collapsing forces concentrating on the same part of the top section. 

The limited circular workspace causes a big problem to the design of the casing hanger. A larger height and diameter will enable the manufacturer to produce a larger load hanger. The equipment designed in the deep well must be in accordance with the size before the the drilling. Under the existing restriction conditions, put the heavier on the hanger.

Casing hanger load capacity

The strength of the outer casing and the load capacity of the casing head and hanger must be taken into account. When the casing string is relaxed, the possibility of other string bending should be taken into account. On the other hand, if additional work to appear on the casing pressure, casing tensile strength should be considered, casing string were seated, the casing string must also be taken into account in the tensile state of casing collapsing and the influence of internal pressure strength. When cementing, the casing in the wellhead is subjected to additional tension and tends to elongate due to its weight. Special production environments require special technical analysis and processing.  

The necessary design features of deep well casing hanger are:
1. Wrap design should be used
2. The slip should be able to withstand loads greater than the strength of the connection and not collapse the casing
3. The sealing element shall be designed to isolate the annular space and provide an effective seal without collapsing the casing
4. The location of the plant of the bee garden should make the experimental pressure not reach the hanger slip
5. The design of the hanger shall make the experimental pressure not push the sealing element and the slip to play the role of piston along the casing head