A new type of continuous conversion device for rod pump and coiled tubing

Abstract

A novel device for continuous conversion between a rod pump and a continuous pipe comprises a continuous oil pipe and a pump, and a casing outside the continuous oil pipe. The continuous oil pipe is connected to the pump in the gas well through an oil pipe coupling. A floating valve cover is installed inside the oil pipe coupling. The floating valve cover is divided into a wide-mouth pipe part and a narrow-mouth pipe part. A drainage port is opened circumferentially at the top of the wide-mouth pipe part. The through hole on the pipe wall at the bottom of the wide-mouth pipe part is blocked by a floating ball valve. A continuous pipe joint that is threadedly matched with the inner wall of the narrow-mouth pipe part is arranged in the narrow-mouth pipe part. The continuous pipe joint is connected to the continuous pipe through a continuous pipe coupling. A side opening is opened on the side wall at the bottom of the continuous pipe joint. The continuous pipe coupling and the floating valve cover are sealed by a sealing ring. The present invention aims to provide a continuous conversion device for drainage operations between rod pumps and continuous pipes, so as to avoid damage to the formation caused by well shutdown, increase the time of stable production, and improve the drainage efficiency of coalbed methane wells.

Description

Technical Field

[0001] The invention relates to the technical field of gas production equipment, and in particular to a novel continuous conversion operation device for a rod pump and a continuous pipe. Background Art

[0002] At present, the production of coalbed methane wells in my country has a high water production in the early stage, and it takes a period of drainage before gas production. This process generally requires the use of a rod pump to drain and reduce pressure. After entering the stable production stage, the bottom hole pressure of coalbed methane generally cannot meet the requirements of using the oil pipe or casing annulus to carry water by jetting, so the production mode of rod pump drainage and casing annulus gas production is generally adopted. However, for high-yield gas wells, due to their high gas production and low water production, the water entering the wellbore can be carried to the wellhead by increasing the gas flow velocity, and gas-carrying water production can be carried out. In this way, the production cost of drainage and gas production can be significantly reduced. This requires the use of continuous tubing as a velocity column for operation. Due to the complex downhole environment of coalbed methane wells and the desorption of gas, if the operation is replaced, the gas well production will drop significantly after the liquid level rises, making it unsuitable for gas-carrying water drainage. In addition, the water production cannot be accurately predicted, so it is necessary to continuously switch between the two operation modes according to the actual situation. However, when switching between the two operations, it is necessary to stop production and replace the pipe string, which will cause damage to the formation and reduce production, seriously affecting the continuous production of the coalbed methane well. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a continuous conversion device for rod pump drainage and coiled pipe drainage operations, so as to avoid damage to the formation due to well shutdown, increase the time of stable production, and improve the drainage efficiency of coalbed methane wells.

[0004] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0005] A novel continuous conversion operation device for a rod pump and a coiled tubing comprises a coiled tubing and a pump, and a casing outside the coiled tubing. The coiled tubing is connected to the pump in a gas well through a tubing coupling. A floating valve cover is installed in the tubing coupling. The floating valve cover is divided into a wide-mouthed tubing portion and a narrow-mouthed tubing portion. A drainage port is provided in the circumferential direction of the top end of the wide-mouthed tubing portion. A through hole on the tubing wall at the bottom of the wide-mouthed tubing portion is blocked by a floating ball valve. A continuous tubing joint matching with the inner wall of the narrow-mouthed tubing portion is provided in the narrow-mouthed tubing portion. The continuous tubing joint is connected to the continuous tubing through a continuous tubing coupling. The pipes are connected, and a side opening is provided on the side wall at the bottom of the continuous pipe joint; the continuous pipe coupling and the floating valve cover are sealed and connected by a sealing ring; the inner wall of the oil pipe coupling has a symmetrical inner protrusion, and the outer wall of the wide-mouthed pipe portion of the floating valve cover has a groove that slides with the inner protrusion; when performing drainage operations with a rod pump, the outer thread on the continuous pipe coupling cooperates with the inner thread of the floating valve cover, and the bottom end of the continuous pipe coupling is rotated into the floating valve cover, so that the side opening at the bottom of the continuous pipe coupling is blocked by the inner wall of the floating valve cover, and the tube cavity of the continuous pipe is closed. After the continuous pipe is closed, the water in the gas well is lifted up by the oil pump into the floating valve cover, and flows out from the drainage port at the top of the wide-mouthed pipe portion of the floating valve cover. The continuous pipe is used as an oil push rod, and drainage operations are performed from the channel between the continuous pipe and the continuous oil pipe, and the oil casing annulus between the continuous oil pipe and the casing is vented.

[0006] Compared with the prior art, the present invention has the following beneficial effects:

[0007] The present invention transmits torque through the threaded cooperation between the floating valve cover and the continuous pipe joint, and further transmits torque to the continuous pipe through the continuous pipe coupling, and then realizes the screwing out and screwing in of the continuous pipe by twisting the internal continuous pipe and the continuous oil pipe, so as to control the opening and closing of the side opening of the continuous pipe joint, thereby blocking or connecting the inner cavity of the continuous pipe, and realizing the continuous conversion between the exhaust of the rod pump and the drainage of the continuous pipe gas. The continuous conversion between the rod pump operation and the continuous pipe operation is realized, the drainage process is optimized, the damage to the formation caused by the well stop is avoided, the stable production time is increased, and the efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a structural schematic diagram of the present invention;

[0009] Figure 2 It is a structural schematic diagram of the continuous pipe coupling in the present invention;

[0010] Figure 3 It is a schematic diagram of the structure of the continuous pipe joint in the present invention;

[0011] Figure 4 It is a structural schematic diagram of the floating valve cover in the present invention;

[0012] Figure 5 for Figure 4A side view schematic diagram of the structure;

[0013] Figure 6 It is a structural schematic diagram of the oil pipe coupling in the present invention;

[0014] Figure 7 for Figure 6 Schematic diagram of the side structure.

[0015] Description of reference numerals:

[0016] 1-continuous pipe coupling, 2-continuous pipe joint, 3-floating valve cover, 4-oil pipe coupling, 5-continuous pipe, 6-continuous oil pipe, 7-sealing ring, 8-casing, 9-oil pump, 21-side opening, 31-groove, 32-floating ball valve, 33-drain port, 41-inner protrusion. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0018] like Figures 1 to 7 As shown, a novel rod pump and coiled tubing continuous conversion operation device comprises a coiled tubing 6 and a pump 9, and a casing 8 outside the coiled tubing 6, wherein the coiled tubing 6 is connected to the pump 9 in the gas well through a tubing coupling 4, and a floating valve cover 3 is sleeved inside the tubing coupling 4; the floating valve cover 3 is divided into a wide-mouthed tube portion and a narrow-mouthed tube portion, a drainage port 33 is circumferentially provided at the top of the wide-mouthed tube portion, a through hole on the tube wall at the bottom of the wide-mouthed tube portion is blocked by a floating ball valve 32, and a continuous pipe joint 2 threadedly matched with the inner wall of the narrow-mouthed tube portion is provided in the narrow-mouthed tube portion; the continuous pipe joint 2 is connected to the coiled tubing 5 through a coiled tubing coupling 1, and a side opening 21 is provided on the side wall at the bottom of the coiled tubing coupling 2; the continuous pipe coupling 1 and the floating valve cover 3 are sealed and connected by a sealing ring 7; the inner wall of the tubing coupling 4 has symmetrical inner protrusions, and the outer wall of the wide-mouthed tube portion of the floating valve cover 3 has a groove 31 slidably matched with the inner protrusion.

[0019] The present invention uses a coiled pipe 5 with a smaller diameter to replace a velocity column for operation, and connects the coiled pipe 5 through a coiled pipe coupling 1 to perform exhaust and drainage operations. When performing drainage operations with a rod pump, the outer thread on the coiled pipe joint 2 is matched with the inner thread of the traveling valve cover 3, and the bottom end of the coiled pipe joint 2 is rotated into the traveling valve cover 3, so that the side opening 21 at the bottom of the coiled pipe joint 2 is blocked by the inner wall of the traveling valve cover 3, so that the tube cavity of the coiled pipe 5 is closed. After the coiled pipe 5 is closed, the water in the gas well is lifted up by the oil pump 9 and enters the traveling valve cover 3, and flows out from the drainage port 33 at the top of the wide-mouth pipe part of the traveling valve cover 3, and the coiled pipe 5 is used as an oil push rod, and drainage operations are performed from the channel between the coiled pipe 5 and the coiled tubing 6, and the oil casing annulus between the coiled tubing 6 and the casing 8 is exhausted.

[0020] When the water production of the gas well is small and the gas production is high, the rod pump can be replaced with a coiled tubing for operation. By changing the small-diameter pipeline to increase the air flow velocity, the water in the gas well can be carried to the wellhead for gas-carrying water production. Keep the coiled tubing 6 stationary, rotate the coiled tubing 5, transfer the torque to the coiled tubing joint 2 through the coiled tubing coupling 1, screw the side opening 21 at the bottom of the coiled tubing joint 2 into the wide-mouthed pipe part of the floating valve cover 3, so that the coiled tubing joint 2 is connected to the floating valve cover 3. Let the water-gas mixture in the gas well be lifted up by the oil pump 9 and enter the coiled tubing joint 2, and then discharge the water-gas mixture from the coiled tubing 5.

[0021] When the water production of the gas well increases and the gas production decreases, and the conditions for the coiled tubing to be used as a velocity tube for production are no longer met, the coiled tubing 6 can be rotated, and the inner protrusion 41 of the tubing coupling 4 and the groove 31 of the traveling valve cover 3 transmit the torque to the traveling valve cover 3, so that the traveling valve cover 3 rotates downward, and the bottom of the coiled tubing joint 2 is screwed into the traveling valve cover 3, thereby closing the coiled tubing 5, and converting the coiled tubing operation into a rod pump drainage operation to produce gas from the oil casing annulus.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A novel device for continuous conversion of a rod pump and a coiled tubing, comprising a coiled tubing, a pump, and a casing outside the coiled tubing, characterized in that: The continuous oil pipe is connected with the oil pump in the gas well through the oil pipe coupling, and a floating valve cover is installed in the oil pipe coupling; the floating valve cover is divided into a wide-mouth pipe part and a narrow-mouth pipe part, and a drainage port is opened in the circumferential direction at the top of the wide-mouth pipe part, and the through hole on the pipe wall at the bottom of the wide-mouth pipe part is blocked by a floating ball valve, and a continuous pipe joint that is threadedly matched with the inner wall of the narrow-mouth pipe part is arranged in the narrow-mouth pipe part; the continuous pipe joint is connected with the continuous pipe through the continuous pipe coupling, and a side opening is opened on the side wall at the bottom of the continuous pipe joint; the continuous pipe coupling and the floating valve cover are sealed by a sealing ring; the inner wall of the oil pipe coupling has symmetrical inner protrusions, and the floating valve cover has a symmetrical inner protrusion. The outer wall of the wide-mouth pipe part is provided with a groove which is slidably matched with the inner protrusion; when the rod pump is used for drainage operation, the outer thread on the continuous pipe joint is matched with the inner thread of the traveling valve cover, and the bottom end of the continuous pipe joint is rotated into the traveling valve cover, so that the side opening at the bottom of the continuous pipe joint is blocked by the inner wall of the traveling valve cover, so that the tube cavity of the continuous pipe is closed. After the continuous pipe is closed, the water in the gas well is lifted up by the oil pump into the traveling valve cover, and flows out from the drainage port at the top of the wide-mouth pipe part of the traveling valve cover. The continuous pipe is used as an oil pusher, and drainage operation is carried out from the channel between the continuous pipe and the continuous oil pipe, and the oil casing annulus between the continuous oil pipe and the casing is vented.

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