It is a important well completion tool. It’s mainly used in complex oil, gas or water well completion engineering to realize downhole packing or plugging, improve well cementation and well completion.
It is used for staged packing of open holes for further operation. The pressure opens the packer’s rubber for setting. It mainly consists of central pipe, rubber, open/close valve. The open valve is activated by enough pressure to demanding value, and then set the packer. More pressure shall activate the close valve to close the packer.
Structure and work principle
It adopts expanding steel frame rubber as sealing element, it is a permanent external casing packer that setting controlled by Combination valves. It is mainly composed of valve joint, rubber assembly,central tube, pup joint, coupling and so on. During construction, when rubber plug go through valve joint, rod in the sealing inlet hole break off to open the inlet hole. When the rubber plug run to spoiler, start built pressure in casing. Liquid run into open valve from valve joint, when the pressure reached to the design, pin on open valve was cut to realize open the open valve. Liquid go through check valve and pressure limiting valve, run into the cavity between central tube and rubber. Then packer expansion and close to well wall to from seal. When expansion cavity pressure reached to the design of pressure limiting valve pin, pin break off, pressure limiting valve take movement to close the inlet hole in order to realize sealing safety. Wellhead release pressure to 0, open valve self-ocking to realize permanently closed. Downhole pressure operation has no influence of packer. In the special pipe string precess, it can run inner pipe tools to set packer in order to realize special well completion(eg: well completion by packer or packer sieve tube).
Characteristics
- Simple operation, no need to change the original operating craft.
- Better adaptability, being applicable to oil/water well under various different condition.
- Valve system can effectively protect and exactly control the tools to take setting safely.
- Big expansion coefficient, small diameter rubber barrel can seal the big diameter well. WhenФ70mm packer is used in 7“casing, breakdown pressure can reach 28Mpa.
- Small residual deformation.
- It has high temperature resistant level, and can bear big differential pressure, with small residual deformation.
- Long sealing section, reliable setting.
