Balance weight device and method for oil removal card

Abstract

The invention belongs to the field of oil-water well pressure testing, and discloses an oil removal card counterweight device and method, a guide cone is in threaded connection with a counterweight main body, a lower cavity is located at the middle-upper part of the counterweight main body, a cavity sealing nut is in threaded connection with the lower cavity, a hole is formed in the middle and serves as a channel of the upper and lower cavities, and a through hole rubber plug is arranged in the sealing nut, is hollow and assists in sealing. The lower end of the connecting rod is conical, is inserted into the through hole rubber plug and temporarily seals the through hole together with the rubber plug, and the upper end of the connecting rod is in threaded connection with the external connecting piece; the temporary limiting piece is in threaded connection with the screw rod; the fixed limiting piece is in threaded connection with the screw rod; the lower portion of the external connecting piece is in threaded connection with the connecting rod, the upper portion of the external connecting piece is provided with internal threads, and the external connecting piece is connected with a pressure meter. By heating the counter weight, crude oil near the counter weight is further heated, viscous resistance is reduced, jam releasing is achieved, and steel wire breakage accidents are avoided.

Description

Technical Field

[0001] The invention belongs to the field of oil and water well pressure testing, and relates to a counterweight device and method for releasing an oil jam, and in particular to a counterweight device and method for releasing an oil jam in a self-heating manner for pressure testing an oil and water well. Background Art

[0002] Oil and water well pressure testing is an important means to understand the injection and production balance of the reservoir and evaluate the reservoir pressure maintenance. The data obtained is an important basis for development adjustment and potential tapping. The most common method for oil and water well pressure testing is the steel wire test. The instrument (because the pressure gauge body is light, the instrument is composed of a pressure gauge and a counterweight, the two are connected by threads, and the counterweight is a solid steel structure) is hung on the steel wire using ground testing equipment. After the test is completed, the downhole instrument is brought up to play back the recorded data.

[0003] Due to the gravity differentiation of oil and water, the liquid column in some pressure test wells has oil and water in the wellbore. Affected by the properties of the oil itself and the degassing of crude oil, the oil column in some wells has high viscosity and large viscous resistance. During the test construction, after the test instrument enters the oil column, heavy oil will adhere to the surface of the instrument, and even stick to the surrounding heavy oil. Due to the viscous resistance of the heavy oil in the well, it is difficult to lift it up at the end of the construction. The longer the instrument stays in the well, the more difficult it is. Since the pressure gauge is usually about 30cm long and the counterweight part is about 100cm long, the viscous resistance mainly comes from the counterweight part. The oil card cannot be lifted up, and the steel wire breaks due to the effort, resulting in the accident of the instrument falling into the well from time to time, and salvage operations are forced to be carried out, consuming a lot of manpower and material resources. Summary of the invention

[0004] Under normal circumstances, the test instrument can be smoothly lifted out of the oil column. Considering that the main reason for oil sticking is that the instrument stays relatively still in the oil column for too long, the outer surface is attached with heavy oil, and even sticks to the surrounding heavy oil, resulting in excessive viscous resistance. If the heavy oil adhesion on the surface of the instrument can be removed and the viscous resistance can be reduced, the instrument can be smoothly lifted out by the steel wire.

[0005] In order to solve the problem that the test instrument cannot be lifted up due to the viscous resistance of crude oil in the wellbore, the present invention starts from removing the adhesion of heavy oil and reducing the viscous resistance, and proposes a counterweight device with an upper and lower double-cavity structure, a connecting rod with a double limit connection is provided in the upper cavity, and the connecting rod is connected to the pressure gauge body through a thread. When the device encounters resistance when lifting the test equipment, the water pre-added in the upper cavity enters the lower cavity through a specific through hole, and reacts with the chemical agent (such as quicklime) in the lower cavity to heat the instrument body, and then heat the crude oil around the instrument, so as to achieve the purpose of reducing the viscous resistance, ensure that the test equipment passes through the wellbore oil column smoothly, and avoid the occurrence of oil jams and steel wire tensile fracture accidents.

[0006] The above object of the present invention is achieved through the following technical solutions:

[0007] An oil release card counterweight device, composed of a guide cone, a counterweight body, a lower cavity, a lower cavity sealing nut, a through-hole rubber plug, an upper cavity, a connecting rod, a temporary limiter, a fixed limiter, an upper seal, and an external part. The temporary limiter is made of hard plastic, and the other parts except the through-hole rubber plug are made of manganese steel with a high density. The connection methods and functions of each part are as follows:

[0008] The guide cone is threadedly connected to the counterweight body, and is used to guide the instrument down the wellbore.

[0009] The lower cavity is located in the upper middle part of the counterweight body and is a part of the body.

[0010] The lower cavity sealing nut is threadedly connected to the lower cavity, and has a hole in the middle, which serves as a passage for the upper and lower cavities.

[0011] The through-hole rubber plug is placed in the sealing nut and is hollow to assist in sealing.

[0012] The upper cavity is the space where the main body of the counterweight is located on the upper part of the lower cavity, and the lower cavity sealing nut is located in the middle of the upper and lower cavities.

[0013] The lower end of the connecting rod is conical and inserted into the through-hole rubber plug to temporarily seal the through-hole together with the rubber plug, and the upper end is threadedly connected with the external connecting part.

[0014] The temporary limiter is a hard plastic part, which is connected to the screw thread. When the instrument is lowered or lifted without resistance, it works together with the connecting rod to bear the weight of the counterweight. When the instrument encounters resistance when moving upward and the pulling force exceeds 500N, it fails.

[0015] The fixed limiter is a steel part, which is threadedly connected to the screw rod. When the temporary limiter fails, it limits the connecting rod from continuing to move upward, and at the same time, it plays a role in bearing the gravity of the counterweight together with the connecting rod.

[0016] The upper sealing member is provided with a middle hole which is a connecting rod passage, and the sealing member is threadedly connected with the upper cavity.

[0017] The lower part of the external connection part is threadedly connected to the connecting rod, and the upper part is provided with an internal thread, which is connected to a pressure gauge.

[0018] A method for unblocking oil jams: using water pre-injected into the upper cavity to react with chemicals (such as quicklime) in the lower cavity to generate an exothermic chemical reaction, heating the instrument body and surrounding crude oil, reducing viscous resistance, and achieving unblocking.

[0019] Before the test, water is placed in the upper cavity, quicklime is placed in the lower cavity, and the middle is sealed and isolated by the lower end of the connecting rod and the through-hole rubber plug. When the oil card cannot be lifted due to the viscous resistance of the crude oil, the connecting rod overcomes the resistance of the temporary limiter and moves upward relative to the counterweight body. The conical part of the bottom of the connecting rod is pulled out of the nut, and the water in the upper cavity flows into the lower cavity and reacts with the quicklime in the lower cavity. The reaction equation is as follows:

[0020] CaO+H2O=Ca(OH)2+heat

[0021] At the same time, a large amount of heat is released, generating a high temperature of up to 300°C. The heat heats the counterweight through heat conduction. According to calculations, every 100 grams of quicklime can generate 116 kilojoules of heat, which can heat 10 kg of steel by 25°C. The crude oil in contact with the steel surface is melted by the heat, the viscous resistance is removed, and the instrument is lifted up and out by the pull of the steel wire.

[0022] The beneficial effects of the present invention compared with the prior art are:

[0023] The existing oil and water well pressure test counterweight is a solid steel structure. When oil is stuck, the instrument cannot be lifted up and even the steel wire breaks. When the test instrument is stuck, the device of the present invention can heat the counterweight and then heat the crude oil near the counterweight to reduce the viscosity resistance to achieve unblocking and avoid the steel wire breakage accident. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0025] Figure 1 It is a schematic diagram of the structure of the present invention.

[0026] Among them: 1 guide cone, 2 counterweight body, 3 lower cavity, 4 lower cavity sealing nut, 5 through-hole rubber plug, 6 upper cavity, 7 connecting rod, 8 temporary limiter, 9 fixed limiter, 10 upper sealing part, 11 external part. DETAILED DESCRIPTION

[0027] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical scheme of the present invention is now described in detail in conjunction with the following specific embodiments, but it should not be understood as limiting the scope of the present invention. Unless otherwise specified, the experimental methods used in the present invention are all conventional methods, and the equipment used can be obtained from commercial channels.

[0028] Example 1

[0029] The structure of the device of the present invention is as follows:

[0030] The guide cone 1 is threadedly connected to the counterweight body 2. The lower cavity 3 is located in the upper and middle part of the counterweight body 2 and is a part of the body. The lower cavity sealing nut 4 is threadedly connected to the lower cavity 3 and has a hole in the middle, which serves as a passage for the upper and lower cavities. The through-hole rubber plug 5 is placed in the sealing nut 4, which is hollow and provides auxiliary sealing. The upper cavity 6 is the space where the counterweight body 2 is located in the upper part of the lower cavity 3. The middle of the upper and lower cavities is the lower cavity sealing nut. The lower end of the connecting rod 7 is conical and is inserted into the through-hole rubber plug 5 to temporarily seal the through hole together with the rubber plug. The upper end is threadedly connected to the external connecting part 11, the temporary limiter 8 is threadedly connected to the screw, the fixed limiter 9 is threadedly connected to the screw, the upper sealing part 10 is provided with a middle hole, which is a connecting rod passage. The sealing part is threadedly connected to the upper cavity, the lower part of the external connecting part 11 is threadedly connected to the connecting rod, the upper part is provided with an internal thread, and a pressure gauge is connected to it.

[0031] 1. Preparation before the test:

[0032] The device of the present invention consists of 1, a guide cone, 2, a counterweight body, 3, a lower cavity, 4, a lower cavity sealing nut, 5, a through-hole rubber plug, 6, an upper cavity, 7, a connecting rod, 8, a temporary limiter, 9, a fixed limiter, 10, an upper sealing part, and 11, an external part 11.

[0033] (1) threaded connection between the guide cone 1 and the counterweight body 2;

[0034] (2) Place quicklime in the lower cavity 3; Connect the plunger and connecting rod: Lower the plunger 4 to the bottom of the inner cavity, insert the connecting rod 5 into the inner cavity, and connect the plunger with the plunger thread by friction with the bottom of the inner cavity 3;

[0035] (3) The lower cavity sealing nut 4 is threadedly connected to the lower cavity; and the through-hole rubber plug 5 is inserted into the hole of the sealing nut 4;

[0036] (4) The temporary limiting member 8 and the fixed limiting member 9 are respectively threadedly connected to the connecting rod, with the temporary limiting member 8 being on the top and the fixed limiting member 9 being on the bottom.

[0037] (5) Insert the conical lower end of the connecting rod 7 into the through-hole rubber plug 5 to seal the through-hole.

[0038] (6) Water is injected into the upper cavity 6, and the water level should leave space for the threads of the upper sealing member 10.

[0039] (7) The upper seal 10 is inserted through the top end of the connecting rod and threadedly connected to the counterweight body.

[0040] (8) The top end of the connecting rod 7 is threadedly connected to the external connection part 11. The connecting rod 7 is threadedly connected to the pressure gauge through the thread on the external connection part to form a test instrument.

[0041] 2 Lowering test: The above test instrument is hung on the steel wire and lowered into the well for testing through the ground test equipment. During the lowering process, the counterweight is actually hung on the temporary limiter 8 through the connecting rod, and the weight of the counterweight device is borne by the temporary limiter 8 and the connecting rod.

[0042] 3. After the test, the card will be automatically decomposed by heating when the upward pull encounters resistance.

[0043] (1) The test instrument cannot be lifted due to the viscous resistance of the oil column in the wellbore.

[0044] (2) As the lifting force increases, when the force exceeds 500N, the connecting rod 7 overcomes the resistance of the temporary limiter 8, moves relative to the counterweight body, and moves upward. The fixed limiter 9 moves upward, preventing the connecting rod 7 from moving further upward, and takes over the weight of the counterweight.

[0045] (3) The conical part at the bottom of the connecting rod is pulled out from the nut, and the water in the upper cavity flows into the lower cavity and reacts with the quicklime in the lower cavity to release heat.

[0046] (4) The heat is heated by heat conduction, thereby heating the crude oil in contact with the surface of the counterweight, reducing the viscous resistance, and the instrument is lifted up and out by the pull of the steel wire.

[0047] The test wire specification has a diameter of 2.083mm~3.810mm, a minimum breaking force of 5380N, and a designed limit connection resistance limit of 500N. That is, when subjected to a tensile force of 50kg, the temporary limit component 9 wears out and fails, and the limit tension is adjusted by fixing the sealing limit component 10 thread.

[0048] The above-described embodiments are only preferred embodiments of the present invention, but not all feasible embodiments of the present invention. For those skilled in the art, any obvious changes made thereto without departing from the principles and spirit of the present invention should be considered to be included in the scope of protection of the claims of the present invention.

Claims

1. A counterweight device for an oil release card, characterized in that: The guide cone (1) is threadedly connected to the counterweight body (2); the lower cavity (3) is located in the middle and upper part of the counterweight body (2) and is a part of the body; the lower cavity sealing nut (4) is threadedly connected to the lower cavity (3) and has a hole in the middle, which serves as a passage for the upper and lower cavities; the through-hole rubber plug (5) is placed in the sealing nut (4) and is hollow and assists in sealing; the upper cavity (6) is the space where the counterweight body (2) is located above the lower cavity (3); the space between the upper and lower cavities is the lower cavity sealing nut. The cap, the lower end of the connecting rod (7) is conical and inserted into the through-hole rubber plug (5), and together with the rubber plug, temporarily seals the through-hole, the upper end is threadedly connected to the external connecting member (11), the temporary limiter (8) is threadedly connected to the screw, the fixed limiter (9) is threadedly connected to the screw, the upper sealing member (10) is provided with a middle hole for the connecting rod passage, the sealing member is threadedly connected to the upper cavity, the lower part of the external connecting member (11) is threadedly connected to the connecting rod, the upper part is provided with an internal thread, and the upper part is connected to a pressure gauge.

2. The oil release card counterweight device according to claim 1, characterized in that: The temporary limiting member (8) is made of hard plastic.

3. The oil release card counterweight device according to claim 1, characterized in that: The maximum pulling force that the temporary limiting member (8) can bear is 500N. When the pulling force exceeds 500N, the temporary limiting member (8) fails.

4. The oil release card counterweight device according to claim 1, characterized in that: The guide cone (1), the counterweight body (2), the lower cavity (3), the lower cavity sealing nut (4), the upper cavity (6), the connecting rod (7), the fixed limiter (9), the upper sealing member (10), and the external connecting member (11) are made of manganese steel with a relatively high density.

5. The oil release card counterweight device according to claim 1, characterized in that: Before the test, water is placed in the upper cavity (6) and quicklime is placed in the lower cavity (3), and the middle is sealed and isolated by the lower end of the connecting rod (7) and the through-hole rubber plug (5).

6. A method for removing oil jams, characterized in that: The steps include: (1) Preparation before testing: assemble the oil release card counterweight device described in claim 1; (2) Lowering test: hang the above-mentioned test instrument on the steel wire and lower it into the well for testing through the ground test equipment; (3) After the test, the card is automatically released by heating when the upward movement encounters resistance: ①The test instrument cannot be lifted due to the viscous resistance of the oil column in the wellbore; ② As the lifting force increases, when the force exceeds 500N, the connecting rod (7) overcomes the resistance of the temporary limiter (8), moves relative to the counterweight body, and moves upward. The fixed limiter (9) moves upward, preventing the connecting rod (7) from moving further upward, and takes over the weight of the counterweight; ③ The conical part of the connecting rod bottom is pulled out from the nut, and the water in the upper cavity flows into the lower cavity and reacts with the quicklime in the lower cavity to release heat; ④The heat is heated by heat conduction, and then the crude oil in contact with the surface of the counterweight is heated, reducing the viscosity resistance, and the instrument is lifted up and out by the pull of the steel wire.

7. The method for removing an oil jam according to claim 6, characterized in that: Assembling the oil release card counterweight device includes the following steps: ① Threading the guide cone (1) and the counterweight body (2); ② Place quicklime in the lower cavity 3; connect the plunger and connecting rod: lower the plunger (4) to the bottom of the inner cavity, insert the connecting rod 5 into the inner cavity, and connect the plunger with the plunger thread by friction with the bottom of the inner cavity (3); ③ The lower cavity sealing nut (4) is threadedly connected to the lower cavity; and the through-hole rubber plug 5 is inserted into the middle hole of the sealing nut (4); ④ Connect the temporary limiting member (8) and the fixed limiting member (9) to the connecting rod through threads, respectively, with the temporary limiting member (8) being on the top and the fixed limiting member (9) being on the bottom; ⑤ Insert the conical lower end of the connecting rod (7) into the through-hole rubber plug (5) to seal the through-hole; ⑥ Inject water into the upper cavity (6) to a water level high enough to leave space for the threads of the upper sealing member (10); ⑦ Insert the upper seal (10) through the top end of the connecting rod and connect it with the counterweight body through threads; ⑧ The top end of the connecting rod (7) is threadedly connected to the external connection member (11), and is connected to the pressure gauge through the thread on the external connection member to form a testing instrument.

8. The method for removing an oil jam according to claim 6, characterized in that: During the lowering process of step (2), the counterweight is actually hung on the temporary limiter (8) through the connecting rod, and the weight of the counterweight device is borne by the temporary limiter (8) and the connecting rod.

Images