A double-acting external casing packer for use in oil well completion

Abstract

The application relates to a double-acting pipe-out packer rubber sleeve suitable for oil well completion, which comprises a left blocking ring, a rubber sleeve and a right blocking ring, wherein the rubber sleeve is a combined rubber sleeve structure of three-layer rubber sleeves in radial superposition, the outer rubber sleeve and the inner rubber sleeve are made of self-expanding materials, the combined rubber sleeve structure is arranged between the left blocking ring and the right blocking ring, a closed liquid storage cavity is arranged in the inner rubber sleeve, and a liquid injection hole and a one-way valve are arranged on one side of the liquid storage cavity. The application has the following advantages: (1) the rubber sleeve can be fully set under the combined action of compression and self-expansion when meeting oil and water; (2) the outer rubber sleeve and the inner rubber sleeve are made of self-expanding rubber, and both have the self-expanding action when meeting oil and water, so that the contact stress between the rubber sleeve and the well wall is increased, and the setting effect is ensured; and (3) the inner surface of the liquid storage cavity of the inner rubber sleeve is coated with a slow-release coating to prevent the rubber sleeve from being set in advance during the downhole process, and the safety of the well completion operation construction is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to a pipe external packer rubber sleeve in the field of well completion tools. BACKGROUND

[0002] Pipe external packer is a commonly used well completion tool in oil well completion operation. Its main function is to realize the isolation between different pressure (or temperature) oil and gas layers or oil and gas layers and non-production layers (such as water layers), so as to prevent different fluids or pressure systems between different layers from interfering with each other, so as to realize the separate production of production layers, increase the oil recovery rate, and maximize the development benefit of oil wells. The rubber sleeve is the core component of the pipe external packer, which realizes the contact with the well wall (or casing) and the function of sealing the annular gap. The conventional packer rubber sleeve realizes setting by hydraulic or mechanical method. The self-expanding rubber automatically expands in volume after contacting with water, hydrocarbons and other substances until it contacts with the well wall, forming a stable annular isolation. Both of the two ways have their own advantages. Therefore, how to combine the two setting methods to realize the continuous and stable pressure bearing of the pipe external packer rubber sleeve is the development direction of well completion technology. SUMMARY

[0003] The purpose of the present application is to combine the advantages of extrusion setting and self-expanding setting, realize the continuous sealing of the pipe external packer rubber sleeve, and provide a double-acting pipe external packer rubber sleeve which is reasonable in structure design, simple and reliable, and suitable for oil well completion.

[0004] A double-acting pipe external packer rubber sleeve suitable for oil well completion, comprising a left retaining ring, a rubber sleeve and a right retaining ring, wherein: the rubber sleeve is a combined rubber sleeve structure composed of three layers of rubber sleeves, i.e. an outer rubber sleeve, a supporting rubber sleeve and an inner rubber sleeve, which are radially superimposed, the outer rubber sleeve and the inner rubber sleeve are made of self-expanding material, the combined rubber sleeve structure is arranged between the left retaining ring and the right retaining ring, a closed liquid storage cavity is arranged in the inner rubber sleeve, and a liquid injection hole and a one-way valve are arranged on one side of the liquid storage cavity.

[0005] The above scheme further comprises:

[0006] The left retaining ring or the right retaining ring is in the form of a circular ring, has a circular hole in the center, and has an inclined surface at an angle of 45° inside. The outer rubber sleeve is in the form of a circular ring, has an outer diameter larger in the middle than on both sides, has a sawtooth-shaped groove on the inner side of the middle, and one end of the sawtooth-shaped groove is in the form of an inclined surface at an angle of 45° and fits with the left retaining ring or the right retaining ring. The supporting rubber sleeve is in the form of a circular ring, has a sawtooth-shaped protrusion on the outer side of the middle, has a sawtooth-shaped groove on the inner side of the middle, and one end of the sawtooth-shaped groove is in the form of an inclined surface at an angle of 45° and fits with the left retaining ring or the right retaining ring. The inner rubber sleeve is in the form of a circular ring and has a sawtooth-shaped protrusion on the outer side of the middle.

[0007] Or the left and right blocking ring are both circular ring structure, the center part has a round hole, the inside has a 45° angle bevel.The outer rubber tube is circular ring structure, the middle part outer diameter is larger than both sides outer diameter, the middle part inside has serrated groove, two end parts are 45° angle bevel respectively and left blocking ring or right blocking ring fit;The support rubber tube is circular ring structure, the middle part outside has serrated protrusion, the middle part inside has serrated groove, two end parts are 45° angle bevel respectively and left blocking ring or right blocking ring fit.

[0008] Further, the left and right blocking ring outside radial extension has centralizing ring.

[0009] Further, the left and right blocking ring outside opposite end extends limited limit convex ring along the axial direction.

[0010] Further, the one-way valve is cylindrical structure, one side has liquid inlet, the other side has liquid outlet, and is connected with the inner rubber tube by bonding mode.

[0011] Further, the inner rubber tube storage cavity inner surface is provided with slow-release coating.

[0012] The pipe outside packer rubber tube of the application can realize double setting under the double action of plunger pushing action or self-expansion after soaking in liquid. The plunger pushing setting can be realized by pushing the left blocking ring or the right blocking ring, and the blocking ring extrudes the middle part of the outer rubber tube, the support rubber tube and the inner rubber tube. The rubber tube is in contact with the well wall after the outer part of the rubber tube is raised, and the setting is completed. The serrated structure on the outer rubber tube, the support rubber tube and the inner rubber tube can prevent the rubber tube from tearing due to stress concentration during deformation, which can cause sealing failure. The self-expansion setting is realized by the self-expansion property of the outer rubber tube and the inner rubber tube. Before entering the well, the liquid (water or diesel oil) is injected into the liquid storage cavity of the inner rubber tube. After entering the well, the outer rubber tube is in full contact with the liquid in the wellbore, and the volume expands. The outer surface of the rubber tube is in contact with the well wall to complete the setting. The inner surface of the inner rubber tube is in full contact with the liquid in the liquid storage cavity, and the volume also expands. The support rubber tube and the outer rubber tube are further extruded, the contact stress between the outer rubber tube and the well wall is increased, and the setting of the rubber tube is ensured. The slow-release coating on the inner surface of the inner rubber tube storage cavity can prevent the internal liquid from acting on the rubber tube to cause premature setting.

[0013] Compared with the prior art, the double-acting pipe outside packer rubber tube of the application has the following advantages: (1) the rubber tube can be fully set under the combined action of compression and self-expansion when encountering oil and water; (2) the outer rubber tube and the inner rubber tube are made of self-expanding rubber that encounters oil and water, and both have self-expansion effect when encountering oil and water, which increases the contact stress between the rubber tube and the well wall and ensures the setting effect; (3) the slow-release coating on the inner surface of the inner rubber tube storage cavity prevents the rubber tube from setting prematurely during the process of going down the well, which ensures the safety of well completion operation. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Figure is a structural diagram of a double-acting pipe external packer rubber sleeve suitable for oil well completion.

[0015] Figure: 1 - left retaining ring, 2 - outer rubber sleeve, 3 - support rubber sleeve, 4 - one-way valve, 5 - inner rubber sleeve, 6 - right retaining ring. DETAILED DESCRIPTION

[0016] In the following, the application will be described from the point of view of examples and with reference to the drawings.

[0017] Example 1

[0018] A double-acting pipe external packer rubber sleeve suitable for oil well completion, comprising a left retaining ring 1, a rubber sleeve and a right retaining ring 6, wherein: the rubber sleeve is a combined rubber sleeve structure of three layers of rubber sleeves stacked radially, the outer rubber sleeve 2 and the inner rubber sleeve 5 are made of self-expanding rubber material, the combined rubber sleeve structure is arranged between the left retaining ring 1 and the right retaining ring 6, a sealed liquid storage cavity is provided inside the inner rubber sleeve 5, and a liquid injection hole and a one-way valve 4 are arranged on the left side of the liquid storage cavity.

[0019] The left retaining ring 1 is a circular ring structure with a circular hole in the center and a 45° inclined surface inside, and the right retaining ring 5 is a common retaining ring. The outer rubber sleeve 2 is a circular ring structure with an outer diameter larger in the middle than on both sides, a sawtooth-shaped groove on the inner side of the middle, a 45° inclined surface on the left end and fitted with the left retaining ring 1, and a right angle on the right end and butted with the right retaining ring 5. The support rubber sleeve 3 is a circular ring structure with a sawtooth-shaped protrusion on the outer side of the middle and a sawtooth-shaped groove on the inner side of the middle, a 45° inclined surface on the left end and fitted with the left retaining ring 1, and a right angle on the right end and butted with the right retaining ring 5. The inner rubber sleeve 5 is a circular ring structure with a sawtooth-shaped protrusion on the outer side of the middle.

[0020] Example 2

[0021] A double-acting pipe external packer rubber sleeve suitable for oil well completion, comprising a left retaining ring 1, a rubber sleeve and a right retaining ring 6, wherein: the rubber sleeve is a combined rubber sleeve structure of three layers of rubber sleeves stacked radially, the outer rubber sleeve 2 and the inner rubber sleeve 5 are made of self-expanding rubber material, the combined rubber sleeve structure is arranged between the left retaining ring 1 and the right retaining ring 6, a sealed liquid storage cavity is provided inside the inner rubber sleeve 5, and a liquid injection hole and a one-way valve 4 are arranged on the left side of the liquid storage cavity.

[0022] The right blocking ring 1 is a circular ring structure, has a circular hole in the center part, and has a 45° angle inclined surface inside; the left blocking ring 5 is a common blocking ring. The outer rubber cylinder 2 is a circular ring structure, has a serrated groove on the inner side of the middle part, and has a 45° angle inclined surface on the right end part and a right angle on the left end part which are matched with the right blocking ring 1 and the left blocking ring 5 respectively; the supporting rubber cylinder 3 is a circular ring structure, has a serrated protrusion on the outer side of the middle part, and has a 45° angle inclined surface on the right end part and a right angle on the left end part which are matched with the right blocking ring 5 and the left blocking ring 1 respectively; the inner rubber cylinder 5 is a circular ring structure, has a serrated protrusion on the outer side of the middle part.

[0023] Example 3

[0024] A double-acting pipe external packer rubber cylinder suitable for oil well completion, comprising a left blocking ring 1, a rubber cylinder and a right blocking ring 6, wherein: the rubber cylinder is a combined rubber cylinder structure of three-layer rubber cylinders of the outer rubber cylinder 2, the supporting rubber cylinder 3 and the inner rubber cylinder 5 stacked radially, the outer rubber cylinder 2 and the inner rubber cylinder 5 are made of self-expanding rubber material, the combined rubber cylinder structure is arranged between the left blocking ring 1 and the right blocking ring 6, a sealed liquid storage cavity is arranged in the inner rubber cylinder 5, and a liquid injection hole and a one-way valve 4 are arranged on the left side of the liquid storage cavity.

[0025] The left blocking ring 1 and the right blocking ring 5 are both circular ring structures, have a circular hole in the center part, and have a 45° angle inclined surface inside. The outer rubber cylinder 2 is a circular ring structure, has a serrated groove on the inner side of the middle part, and has a 45° angle inclined surface on the two end parts which are matched with the left blocking ring 1 and the right blocking ring 5 respectively; the supporting rubber cylinder 3 is a circular ring structure, has a serrated protrusion on the outer side of the middle part, and has a 45° angle inclined surface on the two end parts which are matched with the left blocking ring 1 and the right blocking ring 5 respectively; the inner rubber cylinder 5 is a circular ring structure, has a serrated protrusion on the outer side of the middle part.

[0026] Example 4

[0027] On the basis of the above-mentioned examples 1, 2 or 3, further:

[0028] The left blocking ring and the right blocking ring have a centralizing ring radially extended outside, so as to be easily centered in the well bore or the well wall. The left blocking ring and the right blocking ring have a limiting protruding ring axially extended on the opposite end outside, for clamping the outer rubber cylinder 2. The one-way valve is a cylindrical structure, has a liquid inlet on one side and a liquid outlet on the other side, and is connected with the inner rubber cylinder in a bonding mode. The inner surface of the liquid storage cavity of the inner rubber cylinder is provided with a slow-release coating.

[0029] The double-acting pipe external packer rubber cylinder of the present application is used for oil well completion, and before being put into the well, liquid (water or diesel oil) is injected into the liquid storage cavity of the inner rubber cylinder 5 through the one-way valve 4. Then, it is installed on the pipe external packer and is put into the well with the completion pipe string.

[0030] After the double-acting pipe external packer rubber sleeve is lowered to the predetermined position with the completion tool, the piston on the packer pushes the left and right retaining rings 1 and 6, extruding the outer rubber sleeve 2, the support rubber sleeve 3 and the inner rubber sleeve 5. The outer rubber sleeve 2 expands in diameter until it is in contact with the well wall, completing the compression-based setting.

[0031] After the inner wall of the inner rubber sleeve 5 is in contact with the liquid in the liquid storage cavity, the volume expands and increases, further extruding the support rubber sleeve 3 and the outer rubber sleeve 2, completing the secondary setting under the action of the oil and water self-expansion.

[0032] After the outer rubber sleeve 2 is in full contact with the liquid in the well, it can also expand in volume, ensuring the setting effect of the packer.

[0033] The double-acting pipe external packer rubber sleeve described above can achieve double stable setting in both compression and oil and water self-expansion.

Claims

1. A dual acting external casing packer cup suitable for use in oil well completions comprising a left retainer, a cup and a right retainer, characterised in that: The rubber cylinder is composed of three layers of rubber cylinders, i.e., an outer rubber cylinder, a supporting rubber cylinder and an inner rubber cylinder, the outer rubber cylinder and the inner rubber cylinder are made of self-expanding material, the combined rubber cylinder structure is arranged between the left blocking ring and the right blocking ring, a closed liquid storage cavity is arranged in the inner rubber cylinder, and a liquid injection hole and a one-way valve are arranged on one side of the liquid storage cavity; The left blocking ring or the right blocking ring is a circular ring structure, has a circular hole in the center part, and has an inclined surface with an angle of 45° in the inside; the outer rubber cylinder is a circular ring structure, has an outer diameter larger than that of the two sides in the middle part, has a sawtooth-shaped groove in the inner side of the middle part, and has an inclined surface with an angle of 45° in one end part and matched with the left blocking ring or the right blocking ring; the supporting rubber cylinder is a circular ring structure, has a sawtooth-shaped protrusion on the outer side of the middle part, has a sawtooth-shaped groove in the inner side of the middle part, and has an inclined surface with an angle of 45° in one end part and matched with the left blocking ring or the right blocking ring; the inner rubber cylinder is a circular ring structure, has a sawtooth-shaped protrusion on the outer side of the middle part; the one-way valve is a cylindrical structure, has a liquid inlet on one side and a liquid outlet on the other side, and is connected with the inner rubber cylinder in a bonding manner; the inner surface of the liquid storage cavity of the inner rubber cylinder is provided with a slow-release coating; the outer rubber cylinder is a circular ring structure, has an outer diameter larger than that of the two sides in the middle part, has a sawtooth-shaped groove in the inner side of the middle part, and has an inclined surface with an angle of 45° in the two end parts and matched with the left blocking ring or the right blocking ring; the supporting rubber cylinder is a circular ring structure, has a sawtooth-shaped protrusion on the outer side of the middle part, has a sawtooth-shaped groove in the inner side of the middle part, and has an inclined surface with an angle of 45° in the two end parts and matched with the left blocking ring or the right blocking ring.

2. The dual-acting external casing packer cup suitable for use in oil well completion according to claim 1, characterized in that, The left blocking ring and the right blocking ring are both circular ring structures, have a circular hole in the center part, and have an inclined surface with an angle of 45° in the inside.

3. The dual-acting external casing packer cup suitable for use in oil well completion according to claim 2, characterized in that, The left blocking ring and the right blocking ring have a centralizing ring radially extended on the outside.

4. The dual-acting external casing packer cup suitable for use in oil well completion according to claim 3, characterized in that, The left blocking ring and the right blocking ring have a limiting protruding ring axially extended on the opposite ends of the outside.

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