Screw pump wellhead steam injection sealing device and injection-production integrated polished rod sealing device

Abstract

The present invention discloses a screw pump wellhead steam injection sealing device and an injection-production integrated bare rod sealing device, wherein the wellhead steam injection sealing device, the outer wall of the sealer base is sealedly connected to the upper port of the oil pipe four-way of the wellhead, the inner wall of the sealer base is connected to the steam injection sealing cylinder, the lower end of the steam injection sealing core is connected to the sucker rod, the inner wall of the lower port of the steam injection sealing cylinder is provided with a sealing cylinder lower end conical surface sealing structure, the outer wall of the steam injection sealing core is provided with a sealing core outer wall conical surface sealing structure, the sealing cylinder lower end conical surface sealing structure and the sealing core outer wall conical surface sealing structure cooperate to seal, the inner wall of the upper port of the sealer base is provided with a base upper end conical surface sealing structure, the outer wall of the suspension short section is provided with a metal conical surface sealing ring, and the base upper end conical surface sealing structure cooperates to seal with the metal conical surface sealing ring. The present invention optimizes the design of steam injection, pumping, production and other processes of the screw pump injection-production integrated process, improves safety, and improves the screw pump well injection-production integrated process.

Description

Technical Field

[0001] The invention relates to oil production technology, in particular to a screw pump wellhead steam injection sealing device and an injection-production integrated polished rod sealing device. Background Art

[0002] The stator and rotor of the all-metal screw pump are both made of metal, and the integrated injection and production process can be implemented in heavy oil thermal recovery wells. After steam injection, the pipe string can be pumped without moving, simplifying the operation process. According to the survey, the existing all-metal screw pump integrated injection and production technology still uses the screw pump bare rod sealer that only replaces the high-temperature resistant sealing disk as the wellhead sealing device during steam injection. This method is that once the packing seal fails during the steam injection process, the well cannot be sealed in time, and the leakage of high-temperature and high-pressure steam cannot be controlled; second, when this sealer is used to implement the integrated injection and production process, the entire bare rod stands above the wellhead during steam injection, which also poses certain safety risks.

[0003] After searching for keywords such as wellhead seal and cone surface, the following public documents were found. After careful comparison with the present application, the relevant components applied to the cone surface are completely different from those of the present application, that is, the overall technical scheme, technical effects, etc. are all different. Except for the well-known technical principles of cone surface sealing, there are no other technical inspirations.

[0004] Application No.: 201410828506.1, Publication Date: 2015-04-29, discloses a leak-proof wellhead sealing device, including a box body, a polished rod, a spring and inner and outer sleeves are arranged in a hole in the middle of the box body, the lower part of the outer peripheral surface of the inner sleeve is a conical surface with a large diameter at the upper end and a small diameter at the lower end, the upper part is a stepped cylindrical surface, and an annular groove surface is between the conical surface and the stepped cylindrical surface, the upper end surface of the stepped cylindrical surface of the upper part contacts the lower end surface of the cover, the cone at the lower part of the inner sleeve is composed of blocks uniformly distributed along the circumference, each block is a block oblique to the axial direction, and the upper end of each block is connected to the annular groove body, the inner hole of the outer sleeve is a conical hole matching the outer conical surface of the inner sleeve, the outer cylindrical surface of the outer sleeve matches the sleeve tube hole outside it, and the polished rod is slidably fitted in the sealing ring hole, the inner sleeve hole and the cover hole in the box body. The invention has the significant advantages of good sealing effect and long service life. Summary of the invention

[0005] The purpose of the present invention is to provide a screw pump wellhead steam injection sealing device and an injection-production integrated bare rod sealing device, to optimize the design of the steam injection, pumping, production and other processes of the screw pump injection-production integrated process, to improve safety, and to improve the screw pump well injection-production integrated process.

[0006] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a screw pump wellhead steam injection sealing device, including a sealer base, a steam injection sealing cylinder, a steam injection sealing core, and a suspension short section. The outer wall of the sealer base is sealedly connected to the upper port of the oil pipe four-way at the wellhead, and the inner wall of the sealer base is connected to the steam injection sealing cylinder. The steam injection sealing core penetrates from the lower port of the steam injection sealing cylinder and extends into the interior of the sealer base. A connecting column is provided at the center of the lower end face of the suspension short section. The connecting column is threadedly connected to the connecting groove on the upper end face of the steam injection sealing core. The lower end of the steam injection sealing core is connected to the sucker rod. A sealing cylinder is provided on the inner wall of the lower port of the steam injection sealing cylinder. A conical sealing structure at the lower end, a conical sealing structure at the outer wall of the steam injection sealing core is provided, the conical sealing structure at the lower end of the sealing tube cooperates with the conical sealing structure at the outer wall of the sealing core for sealing, the inner wall of the upper port of the sealer base opens a conical sealing structure at the upper end of the base, a metal conical sealing ring with a hardness smaller than that of the sealer base is provided on the outer wall of the suspension short section, the conical sealing structure at the upper end of the base cooperates with the metal conical sealing ring for sealing, the upper end of the sealer base is connected to a sealing cover, the suspension short section is completely located in the sealing cover, the upper end of the oil pipe cross is connected to a protective cover, and the sealer base and the sealing cover are completely located in the protective cover.

[0007] The sealing cover is provided with a sealing cover pressure relief hole, and the hole is installed with a wire plug; the protective cover is provided with a protective cover pressure relief hole, and the hole is installed with a wire plug.

[0008] The outer wall of the steam injection sealing core is provided with an elevator table; the outer wall of the suspension short section is also provided with an elevator table.

[0009] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a screw pump wellhead injection and production integrated polished rod sealing device, including a polished rod sealer, the polished rod sealer is sealed on the outer wall of the polished rod, and also includes a sealer base, a steam injection sealing cylinder, and a steam injection sealing core. The outer wall of the sealer base is sealedly connected to the upper port of the oil pipe four-way at the wellhead, the inner wall of the sealer base is connected to the steam injection sealing cylinder, the upper end of the sealer base is connected to the polished rod, the upper end of the steam injection sealing core is connected to the polished rod, and the lower end of the steam injection sealing core is connected to the sucker rod. The inner wall of the lower port of the steam injection sealing cylinder is provided with a sealing cylinder lower end conical surface sealing structure, the outer wall of the steam injection sealing core is provided with a sealing core outer wall conical surface sealing structure, and the sealing cylinder lower end conical surface sealing structure cooperates with the sealing core outer wall conical surface sealing structure for sealing.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] The smooth rod seal device for the integrated injection and production of the screw pump wellhead adopts a structure similar to that of the existing smooth rod seal of the screw pump, and adopts a high-temperature resistant sealing filler inside, which is mainly used to seal the rod pipe annulus during normal production. The seal base is connected to the lower part of the smooth rod seal and installed on the top of the existing screw pump thermal production wellhead. Its lower part is connected to the steam injection seal cylinder, and a sealing structure is arranged on the inner side of the top. The inner surface of the steam injection seal cylinder is a high-precision smooth surface, which cooperates with the high-precision smooth outer surface of the steam injection seal core to block the passage of steam and liquid. The bottom of the steam injection seal cylinder and the bottom of the steam injection seal core are respectively provided with sealing structures that can cooperate with each other, so as to prevent the seal core from rising when the pressure in the well is too high and the seal core rises, and at the same time, the upward force of the seal core is used to make the sealing surface contact and isolate the pressure. The lower part of the gas injection seal core is connected to the sucker rod, and the upper part can be connected to the smooth rod. A hanging card table is arranged on the outer side of its upper part for use when installing the hanging card during construction.

[0012] The screw pump wellhead steam injection sealing device has a suspension nipple connected to the top of the steam injection sealing core. The bottom outer side is provided with a soft metal sealing structure with a hardness lower than the inner sealing structure of the top of the sealer base. It can cooperate with the sealing structure on the inner side of the top of the sealer base during the steam injection process, bear the weight of the rod column in the well and rely on the deadweight of the rod column to seal the rod pipe annulus; the main body is provided with an elevator table for use when installing the elevator during the construction process. The sealing cover is installed on the outer side of the upper part of the sealing base, and the upper opening of the sealer base is wrapped and sealed as a whole to prevent the high-temperature and high-pressure fluid from leaking from the gap between the gas injection sealing cylinder and the steam injection sealing core. The protective cover is installed on the top flange surface of the thermal recovery wellhead in a flange connection type, and the exposed sealer base and sealing cover are wrapped inside to prevent pressure leakage at the connection between the sealer base and the wellhead or the connection between the sealing cover and the sealer base. Pressure relief holes are provided on the sealing cover and the protective cover to observe the internal pressure and perform pressure relief operations when necessary. The safety and reliability of the steam injection sealing device are greatly improved due to the use of multiple sealing means such as gap sealing between the steam injection sealing tube and the steam injection sealing core, soft metal sealing between the suspension short section and the sealer base, threaded sealing between the sealing cover and the sealer base, and flange sealing between the protective cover and the thermal wellhead. In particular, the flange connection between the protective cover and the thermal wellhead makes the sealing performance of the device reach the same level as that of the thermal wellhead, eliminating the problem of reduced wellhead pressure resistance level caused by the prior art using a bare rod sealing device as a steam injection seal.

[0013] During the steam injection construction, the device lifts the polished rod to make the steam injection sealing cylinder and the steam injection sealing core cooperate with each other, then removes the polished rod and installs the suspension short section to suspend the sucker rod column, so that the screw pump rotor is out of the stator to make way for the steam injection channel, and then installs the sealing cover and protective cover to seal the wellhead in sequence, and finally starts steam injection from the tubing spool. After steam injection, wait for the well to be vented and sprayed until the wellhead pressure and temperature drop to a certain level, connect the production process and open the tubing gate, then remove the wellhead steam injection sealing device, connect the polished rod to the steam injection sealing core and lower it, install the polished rod sealer, the screw pump rotor enters the stator, and finally install the drive device to start pumping.

[0014] During steam injection, multiple steam injection sealing technologies with the same safety level as thermal production wellheads are used. Compared with the existing technical solutions that only use bare rod seals for steam injection sealing, this technology has a higher safety level and avoids the defects of a single sealing form that reduces the wellhead pressure resistance level and makes it impossible to control pressure after failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic structural diagram of a screw pump wellhead steam injection sealing device of the present invention;

[0016] Figure 2 It is a schematic structural diagram of the integrated polished rod sealing device for the wellhead injection and production of a screw pump according to the present invention.

[0017] In the figure: protective cover 1, protective cover pressure relief hole 1-1, sealing cover 2, sealing cover pressure relief hole 2-1, sealer base 3, cone sealing structure 3-1 at the upper end of the base, steam injection sealing cylinder 4, cone sealing structure 4-1 at the lower end of the sealing cylinder, steam injection sealing core 5, cone sealing structure 5-1 on the outer wall of the sealing core, hanging card table 5-2, hanging short section 6, metal cone sealing ring 6-1, hanging card table 6-2. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] See also Figure 1The present invention provides a technical solution: a screw pump wellhead steam injection sealing device, comprising a sealer base 3, a steam injection sealing cylinder 4, a steam injection sealing core 5, and a suspension short section 6. The outer wall of the sealer base 3 is sealedly connected to the upper port of the oil pipe cross of the wellhead, the inner wall of the sealer base is connected to the steam injection sealing cylinder 4, the steam injection sealing core 5 penetrates from the lower port of the steam injection sealing cylinder and extends into the inside of the sealer base. The center of the lower end face of the suspension short section 6 has a connecting column, the connecting column and the connecting groove of the upper end face of the steam injection sealing core are threadedly connected, the lower end of the steam injection sealing core is connected to the sucker rod 105, and the inner wall of the lower port of the steam injection sealing cylinder is provided with a sealing cylinder lower end conical surface sealing Structure 4-1, the outer wall of the steam injection seal core is provided with a seal core outer wall conical surface sealing structure 5-1, the lower end conical surface sealing structure of the seal tube cooperates with the seal core outer wall conical surface sealing structure for sealing, the upper end conical surface sealing structure 3-1 of the base is provided on the inner wall of the upper port of the sealer base, the outer wall of the suspension short section is provided with a metal conical surface sealing ring 6-1 with a hardness smaller than that of the sealer base, the upper end conical surface sealing structure of the base cooperates with the metal conical surface sealing ring for sealing, the upper end of the sealer base is connected to the sealing cover 2, the suspension short section is completely located in the sealing cover, the upper end of the oil pipe cross is connected to the protective cover 1, the sealer base and the sealing cover are completely located in the protective cover. The sealing cover is provided with a sealing cover pressure relief hole 2-1, which is installed with a screw plug; the protective cover is provided with a protective cover pressure relief hole 1-1, which is installed with a screw plug. The outer wall of the steam injection seal core is provided with an elevator table; the outer wall of the suspension short section is also provided with an elevator table.

[0020] As attached Figure 2 As shown, the screw pump wellhead injection and production integrated bare rod sealing device includes a bare rod sealer 109, which is sealed on the outer wall of the bare rod 108, and also includes a sealer base 3, a steam injection sealing cylinder 4, and a steam injection sealing core 5. The outer wall of the sealer base is sealedly connected to the upper port of the oil pipe cross at the wellhead, the inner wall of the sealer base is connected to the steam injection sealing cylinder, the upper end of the sealer base is connected to the bare rod, the upper end of the steam injection sealing core is connected to the bare rod, and the lower end of the steam injection sealing core is connected to the sucker rod. The inner wall of the lower port of the steam injection sealing cylinder is provided with a sealing cylinder lower end conical surface sealing structure, the outer wall of the steam injection sealing core is provided with a sealing core outer wall conical surface sealing structure, and the sealing cylinder lower end conical surface sealing structure cooperates with the sealing core outer wall conical surface sealing structure for sealing.

[0021] As attached Figure 2As shown, the tubing spool 101 is connected to the casing spool 102, the lower end of the tubing spool 101 is connected to the tubing 104, and the lower end of the casing spool 102 is connected to the casing 103. During normal production, the sealer base 3 of the wellhead sealing device is installed in the center hole of the top flange surface of the tubing spool 101 of the thermal recovery wellhead, and a polished rod sealer 109 is installed on the upper part thereof, and a steam injection seal cylinder 4 is installed on the lower part thereof. The polished rod 108 of the oil well is installed inside the polished rod sealer, and extends into the central channel of the wellhead through the sealer base 3 and the steam injection seal cylinder 4. The steam injection seal core 5 is connected to the lower end of the polished rod 108, and its lower part is connected to the pumping rod 105 in the well. At this time, the steam injection seal core 5 is separated from the steam injection seal cylinder 4 and is located below it. A sealing packing can also be installed in the annulus between the sealer base 3 and the polished rod to enhance the sealing effect of the polished rod sealer during production.

[0022] As attached Figure 1 As shown, when steam injection is needed, the driving motor 106 and the motor bracket 107 are removed, and the polished rod 108 is lifted up. The polished rod drives the steam injection sealing core 5 and the sucker rod in the well upward. After the steam injection sealing core 5 enters the steam injection sealing tube 4, the two cooperate to form a seal and cut off the pressure in the well. Thereafter, the connection between the polished rod sealer and the sealer base 3 is loosened, and the polished rod is continuously lifted up so that the steam injection sealing core 5 pushes out the sealing packing in the sealer base 3. After the hanging card table 5-2 on the upper part of the steam injection sealing core 5 exposes the upper end surface of the sealer base 3, the hanging card is installed at the hanging card table 5-2 to hang the steam injection sealing core 5 and the downhole sucker rod on the upper end surface of the sealer base 3. After that, the connection between the polished rod and the steam injection sealing core 5 is disconnected, and the polished rod and the polished rod sealer are removed. Then, the suspension nipple 6 is installed to the steam injection seal core 5, and the hanging card is installed at the hanging card table 6-2. The suspension nipple 6, the steam injection seal core 5 and the sucker rod in the well are slightly lifted, and the hanging card installed at the hanging card table 5-2 is removed. Then, the suspension nipple 6 is lowered, so that the metal cone sealing ring 6-1 at the bottom is sealed at the cone sealing structure 3-1 at the upper end of the sealer base 3, which plays the role of hanging the sucker rod and sealing the rod tube annulus. At this time, the outer wall cone sealing structure 5-1 of the sealing core at the bottom of the steam injection seal core 5 and the lower end cone sealing structure 4-1 of the sealing tube at the bottom of the steam injection seal tube 4 are in a separated state. When the pressure in the well is too high or rises suddenly, causing the sucker rod to push up, the outer wall cone sealing structure 5-1 of the sealing core and the lower end cone sealing structure 4-1 of the sealing tube fit each other, which prevents the rod column from continuing to rise on the one hand, and forms a self-sealing sealing effect on the other hand, cuts off the pressure in the well, and can play a role of safety protection during the construction operation. Next, remove the elevator at 6-2 on the elevator table, install the sealing cover 2 to the sealer base 3, tighten the bolts at the pressure relief hole 2-1, and finally install the protective cover 1 to the top flange surface of the oil pipe spool at the thermal wellhead, tighten the bolts at the pressure relief hole 1-1, or install a pressure gauge. Figure 1At this time, the thermal recovery wellhead is in a high temperature and high pressure sealing state, and after the sucker rod in the well is lifted up, the screw pump rotor is separated from the stator, the steam injection channel is opened, and the steam injection operation can be carried out.

[0023] After the steam injection is completed and the well is soaked and released, when it is necessary to switch to pumping, install a pressure gauge at the pressure relief hole 1-1 of the protective cover 1 to detect the internal pressure value of the protective cover 1. When it is ensured to be within the safe range, remove the protective cover 1, otherwise open the pressure relief hole to release the pressure. After removing the protective cover 1, test the internal pressure value of the sealing cover 2 from the pressure relief hole 2-1 of the sealing cover 2. When it is ensured to be within the safe range, remove the sealing cover 2, otherwise open the pressure relief hole to release the pressure. After removing the sealing cover 2, install the elevator at the elevator table 6-2 to slightly lift the suspension short section 6. After the elevator table 5-2 is exposed to the upper end surface of the sealer base 3, install the elevator at the elevator table 5-2 to hang the sucker rod in the well, and remove the suspension short section 6. Then, pass the light rod through the light rod sealer and connect it to the top of the steam injection seal core 5. After removing the elevator at the elevator table 5-2, lower the light rod. After the steam injection seal core 5 is completely inserted into the steam injection seal tube 4, the sealing packing can be installed in the annulus between the sealer base 3 and the polished rod to enhance the sealing effect of the polished rod sealer during production, and then the polished rod sealer is connected to the sealer base 3. Continue to lower the polished rod until the light margin is appropriate, install the polished rod clamp to hang the polished rod, and then continue to install the motor bracket, drive motor, torque clamp and other accessories. After completion, as shown in the attached Figure 2 Finally, after connecting the motor control cabinet and turning on the power, you can enter the production mode.

[0024] In the description of the present invention, it is necessary to understand that the orientation indications or positional relationships are based on the orientations or positional relationships shown in the drawings and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A screw pump wellhead steam injection sealing device, characterized in that: It includes a sealer base, a steam injection sealing cylinder, a steam injection sealing core, and a suspension short section. The outer wall of the sealer base is sealedly connected to the upper port of the oil pipe cross at the wellhead, and the inner wall of the sealer base is connected to the steam injection sealing cylinder. The steam injection sealing core penetrates from the lower port of the steam injection sealing cylinder and extends into the interior of the sealer base. A connecting column is provided at the center of the lower end surface of the suspension short section. The connecting column is threadedly connected to the connecting groove on the upper end surface of the steam injection sealing core. The lower end of the steam injection sealing core is connected to the sucker rod. The inner wall of the lower port of the steam injection sealing cylinder is provided with a sealing cylinder lower end conical surface sealing structure, and the outer wall of the steam injection sealing core is provided with a sealing core outer wall conical surface sealing structure. The sealing cylinder lower end conical surface sealing structure is sealed with the sealing core outer wall conical surface The structures cooperate to seal, the inner wall of the upper port of the sealer base is provided with a base upper conical sealing structure, the outer wall of the suspension short section is provided with a metal conical sealing ring with a hardness smaller than that of the sealer base, the base upper conical sealing structure cooperates with the metal conical sealing ring to seal, the upper end of the sealer base is connected to a sealing cover, the suspension short section is completely located in the sealing cover, the upper end of the oil pipe cross is connected to a protective cover, the sealer base and the sealing cover are completely located in the protective cover, the sealing cover is provided with a sealing cover pressure relief hole, and the hole is installed with a thread plug; the protective cover is provided with a protective cover pressure relief hole, and the hole is installed with a thread plug; the outer wall of the steam injection sealing core is provided with a hanging card table; the outer wall of the suspension short section is also provided with a hanging card table.

2. A method for using the screw pump wellhead steam injection sealing device according to claim 1, characterized in that: include: Remove the drive motor and motor bracket, lift the polished rod, and the polished rod drives the steam injection seal core and the well pump rod upward. After the steam injection seal core enters the steam injection seal tube, the two cooperate to form a seal and cut off the pressure in the well. Thereafter, loosen the connection between the polished rod seal and the seal base, continue to lift the polished rod to make the steam injection seal core push out the sealing packing in the seal base. After the hanging card table on the upper part of the steam injection seal core is exposed to the upper end surface of the seal base, install the hanging card on the hanging card table to lift the steam injection seal The core and the downhole sucker rod are suspended at the upper end surface of the sealer base; then the connection between the polished rod and the steam injection seal core is disconnected, and the polished rod and the polished rod sealer are removed; then the suspension nipple is installed to the steam injection seal core, and the elevator is installed on the elevator table on the suspension nipple, and the suspension nipple, the steam injection seal core and the downhole sucker rod are slightly lifted, and the elevator installed on the elevator table of the steam injection seal core is removed, and then the suspension nipple is lowered so that the metal cone sealing ring seat at the bottom is sealed on the upper end cone of the base at the upper end of the sealer base. The face sealing structure plays the role of hanging the sucker rod and sealing the rod pipe annulus; at this time, the conical sealing structure of the outer wall of the sealing core at the lower part of the steam injection sealing core and the conical sealing structure of the lower end of the sealing tube at the lower part of the steam injection sealing tube are in a separated state. When the pressure in the well is too high or rises suddenly, causing the sucker rod to be pushed up, the conical sealing structure of the outer wall of the sealing core and the conical sealing structure of the lower end of the sealing tube fit each other, on the one hand, preventing the rod column from continuing to rise, and on the other hand, forming a self-sealing sealing effect, isolating the pressure in the well, and playing a safety protection role during the construction operation; next, remove the hanging card at the hanging card table on the hanging short section, install the sealing cover to the sealer base, tighten the bolts at the pressure relief hole, and finally install the protective cover to the top flange surface of the oil pipe four-way of the thermal production wellhead, tighten the bolts at the pressure relief hole, or install a pressure gauge; all installations are completed; the thermal production wellhead is in a high temperature and high pressure resistant sealing state. At this time, due to the upward lifting of the light rod, the sucker rod in the well drives the screw pump rotor upward and out of the stator, and the steam injection channel is opened for steam injection operation.

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