Bidirectional expansion sealing mechanism and bidirectional expansion sealing packer thereof

Abstract

The invention discloses a bidirectional expansion sealing mechanism, and belongs to the technical field of oil field mechanical equipment. The bidirectional expansion sealing mechanism comprises a plugging mechanism with one end kept still and the other end connected with a central pipe in a sliding mode; a first liquid inlet cavity and a second liquid inlet cavity are arranged between the plugging mechanism and the central pipe; the central pipe is provided with a first liquid inlet and a second liquid inlet which are communicated with the first liquid inlet cavity and the second liquid inlet cavity respectively; and fracturing liquid enters into the first liquid inlet cavity and the second liquid inlet cavity from the central pipe and jointly extrudes the plugging mechanism in the radial direction and the axial direction, so that the expansion plugging effect is improved, and the problem that plugging is not tight is solved. The invention further discloses a bidirectional expansion sealing packer which comprises an upper connector, a lower connector and the central pipe in threaded connection with the upper connector and the lower connector; the immovable end of the plugging mechanism is kept immovable on the upper connector through a fixing mechanism; during fracturing, under the flow limiting effect of a sand blower connected with the lower connector, pressure difference is generated inside and outside the central pipe; and the pressure difference plugging mechanism can be expanded to plug an oil well, so that layered sealing during fracturing is guaranteed.

Description

technical field [0001] The invention relates to the technical field of oilfield mechanical equipment, in particular to a bidirectional expansion sealing mechanism and a bidirectional expansion sealing packer thereof. Background technique [0002] After the production of oil wells reaches a certain stage, the production capacity and permeability gradually decrease. In order to enhance the oil drainage capacity and increase the production of oil wells, fracturing technology is usually used. The pump, using the principle of liquid pressure transmission, injects fracturing fluid into the oil layer at a pressure greater than the absorption capacity of the oil layer, and increases the pressure in the wellbore, forming fractures in the formation near the bottom of the well, and then continues to inject sand-carrying fluid with proppant After the well is closed, the fractures are closed on the proppant, so that sand-filled fractures with a certain geometric size and high conductivit...

AI Technical Summary

Problems solved by technology

When the above-mentioned packer rubber sleeve is set, the rubber sleeve is squeezed from the axial direction of the rubber sleeve, and then the rubber sleeve is radially expanded. However, the above-mentioned expansion sealing method is prone to insufficient pressure and poor sealing. problems, which in turn lead to the failure of seal layer fracturing; at the same time, during the fracturing process, sand deposits will accumulate on the upper part of the packer, forming a "sand bridge". The backlog of sand deposits has a certain strength. It is still easy to get stuck when lifting the fracturing pipe, causing the phenomenon of "well stuck"

Images