A double-sealed blowout preventer for pressure-lifting and lowering rod operation and its use method

Abstract

The present invention proposes a double-sealed lubricant pipe for pressure-lifting rod column operation, comprising a lubricant pipe body; blowout preventers arranged at both ends of the lubricant pipe body, the blowout preventers comprising a top blowout preventer arranged at the upper end of the lubricant pipe body, and a bottom blowout preventer arranged at the lower end of the lubricant pipe; wherein the lubricant pipe body connects the top blowout preventer and the bottom blowout preventer, passes through the polished rod and is connected to the wellhead blowout preventer through a lower joint. The double-sealed lubricant pipe for pressure-lifting rod column operation of the present invention is simple to operate, efficient, saves time and achieves the purpose of increasing oil.

Description

Technical Field

[0001] The invention relates to a double-sealed blowout preventer for pressure-lifting rod column operation and a use method thereof, belonging to the field of oilfield mining equipment. Background Art

[0002] When the sucker rod is raised and lowered, the blowout preventer at the wellhead is in a long-open state. At this time, the wellhead is out of control. Therefore, a well-killing operation is required before the operation to prevent formation fluid from rushing into the wellbore to cause a blowout or overflow at the wellhead, causing a blowout accident or large-scale pollution at the wellhead. Each well-killing operation requires at least one pump truck or tank truck, which is equipped with a certain density of well-killing fluid, which is pumped into the wellbore by the pump truck to kill the well. However, this process is time-consuming and labor-intensive, increases cost investment, and pollutes the formation. Summary of the invention

[0003] In view of the above-mentioned technical problems existing in the prior art, the present invention proposes a double-sealed blowout preventer for rod string lifting and lowering operation under pressure and a method of using the same, which can realize the waiting pressure operation for all rod string lifting and lowering operations of the stationary wellhead Christmas tree and the stationary downhole tubing in the machine-pumping well, eliminating the well-killing step.

[0004] In one aspect of the present invention, a double-sealed lubricant preventer for pressure-lifting and lowering rod operation is provided, comprising:

[0005] Blowout preventer body;

[0006] BOPs are arranged at both ends of the lubricant preventer body, the bop preventers comprising a top bop preventer arranged at the upper end of the lubricant preventer body, and a bottom bop preventer arranged at the lower end of the lubricant preventer;

[0007] The blowout preventer body is connected to the top blowout preventer and the bottom blowout preventer, passes through the polished rod and is connected to the wellhead blowout preventer through the lower joint.

[0008] A further improvement of the present invention is that a packing box with double female variable wire connections is arranged above the top lubricant preventer, a sealing member is arranged in the packing box, and the sealing member seals the polished rod.

[0009] A further improvement of the present invention is that a pressure cap is detachably provided at the top of the packing box; a connecting hole connected to the polished rod is provided in the middle of the pressure cap;

[0010] Wherein, the connection holes of different pressing caps have different apertures to adapt to polished rods of different sizes.

[0011] A further improvement of the present invention is that the pressure cap is a split concave-convex plug-in metal gland pressure cap.

[0012] A further improvement of the present invention is that a pressure relief valve is provided on the side wall of the blowout preventer body.

[0013] A further improvement of the present invention is that a spring limit pin is provided on the blowout preventer body.

[0014] A further improvement of the present invention is that the blowout preventer comprises a blowout preventer housing connected to the blowout preventer pipe, a sealing gate is arranged inside the blowout preventer housing, and the sealing gate is sealed and connected to the polished rod through a sealing rubber core;

[0015] The blowout preventer housing is also provided with a blowout preventer switch for pushing the sealing gate to move.

[0016] A further improvement of the present invention is that the sealing rubber core of the blowout preventer and the sealing element in the packing box are both made of HNBR material.

[0017] A further improvement of the present invention is that the lower joint is a special variable thread joint for male and female blowout preventers.

[0018] Another aspect of the present invention further provides a method for using a double-sealed lubricant preventer in a pressure-lifting rod operation, comprising:

[0019] Remove the hanging rope, clamp, bare rod anti-drop cap and wellhead packing box at the wellhead;

[0020] Assemble the lubricant preventer body and two blowout preventers and pass the whole body through the polished rod, and connect them to the wellhead blowout preventer through the lower joint;

[0021] The packing box and the pressure cap are installed above the top blowout preventer.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The double-sealed blowout preventer for rod lifting and lowering operation under pressure of the present invention can realize the waiting operation for rod lifting and lowering operation without the fixed wellhead Christmas tree and the fixed downhole pipe string of the pumping well, and eliminate the well killing step. The double-sealed blowout preventer for rod lifting and lowering operation under pressure of the present invention is simple to operate and efficient, saving time and achieving the purpose of increasing oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0025] Figure 1 It is a schematic structural diagram of a double-sealed blowout preventer for pressure-lifting rod operation according to an embodiment of the present invention.

[0026] In the drawings, the same reference numerals are used for the same components, but the drawings are not drawn to scale.

[0027] The meanings of the reference numerals in the accompanying drawings are as follows: 1, blowout preventer body, 2, top blowout preventer, 3, bottom blowout preventer, 4, packing box, 5, pressure cap, 6, lower joint, 7, double female variable wire, 8, sealing element, 9, pressure relief valve, 10, spring limit pin. DETAILED DESCRIPTION

[0028] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0029] Figure 1 A double-sealed lubricant preventer for pressure-lifting rod operation according to an embodiment of the present invention is schematically shown, which includes a lubricant preventer body 1. The lubricant preventer body is a circular tube structure, and a group of blowout preventers are respectively arranged at the upper end and the lower end. The blowout preventer includes a top blowout preventer 2 arranged at the upper end of the lubricant preventer body 1, and a bottom blowout preventer 3 arranged at the lower end of the lubricant preventer.

[0030] In this embodiment, the lubricant preventer body 1 connects the top blowout preventer 2 and the bottom blowout preventer 3 , passes through the polished rod, and is connected to the wellhead blowout preventer through the lower joint 6 .

[0031] When using the double-sealed lubricant preventer for rod lifting and lowering operation under pressure according to this embodiment, for all unmoving wellhead Christmas trees and unmoving downhole pipe strings in the pumping well, the waiting operation can be realized, eliminating the well killing step. The double-sealed lubricant preventer for rod lifting and lowering operation under pressure in this embodiment is simple and efficient to operate, saving time and achieving the purpose of increasing oil production.

[0032] In one embodiment, a packing box is connected above the top lubricator, and a seal 8 is arranged inside the packing box to seal the annulus between the packing box and the polished rod. The packing box and the top lubricator are connected via a double female variable thread 7.

[0033] In the double-sealed blowout preventer for pressure-lifting rod operation according to this embodiment, a set of blowout preventers are provided at both the upper and lower ends of the blowout preventer, and a packing box with a seal 8 is provided on the upper part. The two sets of blowout preventers and the packing box form a three-line sealing structure, which can achieve a multiple insurance effect.

[0034] In one embodiment, a pressure cap 5 is detachably provided at the top of the packing box 4, and a connecting hole connected to the polished rod is provided in the middle of the pressure cap 5. The diameters of the connecting holes of different pressure caps 5 are different to accommodate polished rods of different sizes.

[0035] Preferably, the pressure cap 5 is a split concave-convex plug-in metal gland pressure cap. In this embodiment, the upper end of the packing box is provided with a mounting groove, and the pressure cap is provided with a protruding structure, which is plugged into the groove and fixedly connected to the packing box.

[0036] In one embodiment, a pressure relief valve 9 is provided on the side wall of the blowout preventer body. When the rod is raised or lowered, the bottom and top blowout preventers 2 of the tool of this embodiment are switched and adjusted, and the rod is raised or lowered after the pressure relief is completed.

[0037] In one embodiment, a spring stop pin 10 is provided on the blowout preventer body. The spring stop pin 10 indicates the position of the light rod and the sucker rod connection coupling in the blowout preventer to protect the top single gate blowout preventer from being damaged by hard pulling. Its working principle and method are as follows: the light rod and the sucker rod will not touch the spring stop pin 10 during the up and down stroke of the blowout preventer body 1. The light rod coupling and the sucker rod coupling are relatively thick. When the coupling hits the limiter during the upward process, the spring stop pin 10 automatically pops out to indicate the position of the coupling in the blowout preventer box; to use it again, you only need to press the spring stop pin 10 in.

[0038] In one embodiment, the blowout preventer comprises a blowout preventer housing connected to the blowout preventer pipe, a sealing gate is arranged inside the blowout preventer housing, and the sealing gate is seal-connected to the polished rod through a sealing rubber core; a blowout preventer switch for pushing the sealing gate to move is also arranged on the blowout preventer housing.

[0039] In one embodiment, the sealant core of the blowout preventer and the seal 8 in the packing box are both made of HNBR material. HNBR material is hydrogenated nitrile rubber, which has good oil resistance; and due to its highly saturated structure, it has good heat resistance, good chemical corrosion resistance to acids and alkalis, and has high resistance to compression permanent deformation. At the same time, hydrogenated nitrile rubber also has the characteristics of high strength, high tearing performance, excellent wear resistance, etc.

[0040] In one embodiment, the lower joint 6 is a male and female variable thread joint dedicated to a blowout preventer.

[0041] According to another aspect of the present invention, a method for using a double-sealed lubricant preventer in a rod lifting operation with pressure is also provided, comprising the following steps:

[0042] Remove the hanging rope, clamp, bare rod anti-drop cap and wellhead packing box at the wellhead;

[0043] Assemble the lubricant pipe body and two blowout preventers and pass the whole body through the polished rod, and connect with the wellhead blowout preventer through the lower joint 6;

[0044] The packing box and the pressure cap are installed above the top blowout preventer.

[0045] The specific method is as follows: Use a crane to lower the bare rod to 1.5m above the wellhead, release the load of the pumping unit, close the wellhead blowout preventer halfway, remove the rope hanger, clamp, bare rod anti-drop cap and wellhead packing box.

[0046] The tool blowout preventer, the top blowout preventer 2, the bottom blowout preventer 3 and the double female variable wire 7 are connected, and the whole after the connection is completed is passed through the polished rod and connected to the wellhead blowout preventer through the lower joint 6.

[0047] Wrap the packing box around the polished rod and put it into the double female variable wire 7, and connect the pressure cap to the double female variable wire 7. When raising and lowering the rod, adjust the switches of the top blowout preventer 2 and the bottom blowout preventer 3, and then release the pressure through the pressure relief valve 9. After the pressure relief is completed, the rod is replaced in series.

[0048] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and / or modifications that fall within the scope of the present invention, and changes and / or modifications made according to the embodiments of the present invention should be included within the scope of protection of the present invention.

Claims

1. A double-sealed blowout preventer for pressure-lifting and lowering rod operation, characterized in that: include: A blowout preventer body (1), wherein a spring stop pin (10) is provided on the blowout preventer body; Blowout preventers are arranged at both ends of the lubricant preventer body (1), the blowout preventer comprising a top blowout preventer (2) arranged at the upper end of the lubricant preventer body (1), and a bottom blowout preventer (3) arranged at the lower end of the lubricant preventer; The blowout preventer body (1) is connected to the top blowout preventer (2) and the bottom blowout preventer (3), passes through the polished rod and is connected to the wellhead blowout preventer through the lower joint (6); A packing box (4) connected with a double female variable thread (7) is arranged above the top anti-blowout pipe, a sealing member (8) is arranged inside the packing box (4), and the sealing member (8) seals the polished rod; The top end of the packing box (4) is detachably provided with a pressure cap (5); the middle portion of the pressure cap (5) is provided with a connection hole connected to the polished rod; Wherein, the connection holes of different pressing caps (5) have different apertures to accommodate polished rods of different sizes; The pressure cap is a split type concave-convex plug-in metal gland pressure cap.

2. The double-sealed lubricant preventer for pressure-lifting operation according to claim 1 is characterized in that: A pressure relief valve (9) is provided on the side wall of the blowout preventer body.

3. The double-sealed lubricant preventer for pressure-lifting and lowering pole operation according to claim 2 is characterized in that: The blowout preventer comprises a blowout preventer housing connected to the blowout preventer pipe, a sealing gate is arranged inside the blowout preventer housing, and the sealing gate is seal-connected to the polished rod through a sealing rubber core; The blowout preventer housing is also provided with a blowout preventer switch for pushing the sealing gate to move.

4. The double-sealed lubricant preventer for pressure-lifting operation according to claim 3 is characterized in that: The sealing rubber core of the blowout preventer and the sealing element (8) in the packing box are both made of HNBR material.

5. The double-sealed lubricant preventer for pressure-lifting operation according to claim 4 is characterized in that: The lower joint (6) is a special variable thread joint for male and female blowout preventers.

6. A method for using a double-sealed lubricant preventer for a pressure-lifting operation according to any one of claims 1 to 5, characterized in that: include: Remove the hanging rope, clamp, bare rod anti-drop cap and wellhead packing box at the wellhead; Assemble the blowout preventer body and two blowout preventers and pass the whole body through the polished rod, and connect them to the wellhead blowout preventer through the lower joint (6); The packing box and the pressure cap are installed above the top blowout preventer.

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