The Liner Hanger is located below the Liner Top Packer or the Setting Sleeve/Pack off Nipple. The purpose of the Liner Hanger is to provide an anchoring function for the liner in the casing. In order to meet every downhole condition DEW is able to provide a comprehensive product line of Liner Hanger systems. The product line allows a choice between mechanical and hydraulic setting and further between rotating and non-rotating systems.
To minimize proper casing damage the outer slips are specially designed according to the total weight and well-requirements. The large contact area of the slips provides best distribution of the resulting forces which reduces the maximum effective load on the host casing area in contrast to conventional slips. Before use all DEW slips are case hardened to withstand high surface pressure on the areas in contact. To avoid premature setting the DEW standard Liner Hanger has built-in pockets in a special coned sleeve. The sleeve is able to isolate the slips against any outer friction forces. A further safety device for premature setting is a mechanic lock system, which stops the slips of any movement before the hydraulic sleeve of the hydraulic Liner Hanger or the mechanical sleeve of the mechanical Liner Hanger is activated. For increasing the bypass flow area the sleeve and the guide ring are designed with multiple grooves. Depending on the loading case it is possible to choose between single, double or multi cone Liner Hanger systems.
Hydraulic Liner Hanger
The hydraulic Liner Hanger is set by building up differential pressure in the running string. The pressure shears the hydraulic cylinder which pushes the outer slips into engagement with the casing string.
A guide ring at the end of the Liner Hanger ensures centralization of the Liner Hanger in the Casing as well as providing a safety feature against damage affecting the hydraulic cylinder and the slips-sleeve combination during run-in-hole. It provides multiple flow grooves to provide a high bypass flow area. Furthermore the guide ring allows an easy run in hole due to the seamless transition between the guide ring and the Liner Hanger body
The hydraulic rotating Liner Hanger is able to rotate before and after setting (e.g. during run-in-hole, circulation, reaming, cementation).
Mechanic Liner Hanger
The mechanical Liner Hanger is mechanically set by a quarter turn clockwise (if necessary counter clockwise is possible). A centralizer on the bottom end of the body gives the required friction force to set the Liner Hanger. Because there is no hydraulic component the equipment allows a high flow rate and flow pressure while run-in-hole.
The mechanical rotating Liner Hanger is able to rotate before and after setting (e.g. during run-in-hole, circulation, reaming, cementation).