CN112746827B - Packer, pipe column and method for quickly finding leakage of whole shaft - Google Patents

Abstract

The invention provides a packer, a tubular column and a method thereof for quickly finding leakage of a whole shaft in the technical field of petroleum drilling, wherein the packer comprises a first central tube, the upper end and the lower end of the first central tube are respectively connected with a first upper connector and a first lower connector, a first rubber sleeve and a lower rubber sleeve seat are sleeved on the first central tube, the lower rubber sleeve seat can slide up and down along the outer wall of the first lower connector, a first sliding sleeve is connected in the first central tube, a first shearing pin is arranged between the first sliding sleeve and the first central tube, and the lower rubber sleeve seat abuts against the downward end of the lower rubber sleeve seat; the invention realizes quick leakage finding of the pipe column once.

Description

Packer, pipe column and method for quickly finding leakage of whole shaft

Technical Field

The invention relates to the technical field of petroleum drilling, in particular to a full-wellbore quick leakage finding tubular column and a method.

Background

In the long-term development process of the oil field, due to factors such as frequent operation, casing corrosion and the like, the casing of the oil-water well is leaked, the water content of the oil well rises, the water well can not be injected with water normally, and the normal development of the oil field is influenced. Usually, a mechanical leakage finding pipe column is adopted to verify the leakage condition of the casing pipe, so that a leakage point is accurately found, and a reliable basis is provided for formulating a reasonable construction scheme in the next step.

In the prior art, the leakage finding process pipe column using the packer can accurately judge the leakage position, is simple in construction and reliable in structure, is an effective leakage finding method, but has low success rate, is unreasonable in pipe column configuration for finding leakage, can find leakage only by several times of pipe columns, and cannot find leakage quickly in the whole well barrel of the pipe column once.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to solve the technical problems that the structure of a tubular column is unreasonable and leakage can be found only by a plurality of times of tubular columns in the prior art, and provides a packer, a tubular column and a method for quickly finding leakage of a whole shaft.

The purpose of the invention is realized as follows: a packer that is used for whole pit shaft to look for hourglass fast, the packer includes center tube one, the upper end and the lower extreme of center tube one are connected with joint one and lower clutch one respectively, the cover is equipped with packing element and packing element seat down on the center tube one, and the packing element seat down can slide from top to bottom along the lower clutch outer wall, and center tube in-connection has sliding sleeve one, set up shearing pin one between sliding sleeve one and the center tube one, the packing element seat is contradicted in the packing element seat one end down under.

In order to further realize fine leakage finding during upper bound leakage finding, a limiting ring is in threaded connection with the inner wall of the lower part of the lower rubber cylinder seat, the limiting ring can slide up and down along a first lower joint, a limiting step is arranged at one end, facing the limiting ring, of the first lower joint, a return spring is sleeved on the lower joint in the lower rubber cylinder seat, the return spring is arranged between the limiting step and the limiting ring, and the limiting ring can abut against the limiting step; in the design, in an initial state, the return spring is in a natural state, when the lower rubber cylinder seat moves upwards, the maximum stroke touches the limiting step, meanwhile, the effective stroke of the return spring is ensured, and when pressure is relieved, the return spring pushes the limiting ring to move downwards quickly; the length of the spring in a natural state is based, the starting pressure of the restrictor is greater than the seat sealing pressure of the packer, and when the restrictor is opened, the limiting ring is not yet in contact with the return spring, so that the influence on the sealing reliability of the packer is reduced.

As a further improvement of the invention, the first lower joint is connected with a protection ring, and in an initial state, the downward end of the limiting ring is contacted with the upward end of the protection ring; in the design, when the protection ring protects the upper bound leakage finding pipe column to move downwards, the rubber sleeve is sealed in advance when the pipe column is not centered.

As a further improvement of the invention, the rubber cylinder is provided with a compression end face, and the upper end of the lower seat of the rubber cylinder can extrude the compression end face; in this design, inside feed liquor arouses the packing element expansion, and the packing element is lower to be located through compression end face compression packing element simultaneously, and the packing element can be sealed fast like this, and is sealed more reliable.

The upper bound leakage finding tubular column for finding leakage by using the packer comprises an upper bound tubular column body, wherein the upper bound tubular column body is sequentially connected with an upper bound packer II, a pressure release valve I, a packer, a pressure test valve I, an upper bound flow controller, an upper bound packer I and a ball seat I from top to bottom.

The method for upper bound leakage finding by using the upper bound leakage finding pipe column comprises the following steps that the upper end of an upper bound pipe column body is connected with a leakage finding pipe string, the leakage finding pipe string comprises a first hose and a second hose which are connected with the pipe column body, the first hose is communicated with an oil pipe, the second hose is communicated with the oil sleeve annulus outside the oil pipe, a first valve and a second valve are respectively connected with the first hose and the second hose outside a well head, the first valve is connected with a liquid inlet of the valve through a liquid inlet pipe, and a pump truck is connected with the liquid inlet of the liquid inlet pipe,

(101) lowering the upper bound leakage finding pipe column to 20 meters above the initial judgment position of the leakage point;

(102) the ball throwing pressure testing valve I is opened, the valve II is opened, the valve I is opened, the pump truck is used for pressurizing to 12MPa, the pressure is stabilized for 10min, if no pressure reduction occurs, more than one pipe column of the pressure testing valve is intact, and at the moment, the upper packer II is set;

(103) closing the first valve, performing annular pressure test without pressure reduction, and turning to the step (104); if the pressure is reduced, lifting the leakage finding pipe column, and turning to (102);

(104) opening the second valve and the first valve to release pressure, continuing to lower the upper bound leakage finding pipe column, if the internal pressure and the external pressure are not reduced, continuing to lower the upper bound leakage finding pipe column until the pressure is reduced, finding the upper bound position, and turning to the step (105);

(105) opening a second valve and a first valve, continuously pressurizing, shearing a pressure test shearing pin on the first pressure test valve, and moving a pressure test sliding sleeve on the first pressure test valve downwards to the first ball seat;

(106) continuing to lower the upper bound leakage finding pipe column until the bottom of the well, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (107);

(107) opening a second valve and a first valve, throwing the ball packer, continuously pressurizing, cutting off a first shearing pin on the packer, moving a sliding sleeve on the packer downwards to a first ball seat, lifting an upper bound leakage finding pipe column from the bottom of the well at the moment, and carrying out fine leakage finding on all recorded leakage positions by adopting the packer and the first upper bound packer until the leakage finding is finished;

(108) and (3) throwing the oil pipe, continuously pressurizing, cutting off a pressure relief shearing pin of the first pressure relief valve, moving a pressure relief sliding sleeve of the first pressure relief valve downwards to the first ball seat, realizing pressure relief of the upper bound leakage finding pipe column, quickly recovering the upper bound packer I, the upper bound packer II and the packer, starting the upper bound leakage finding pipe column, and completing quick leakage finding of the whole shaft of the pipe column once.

The lower bound leakage finding pipe column for finding leakage by using the packer is sequentially connected with a second lower bound packer, a second pressure release valve, the packer, a first lower bound flow controller, a second pressure test valve, a first lower bound packer, a sliding sleeve seat, a second lower bound flow controller and a second ball seat from top to bottom, and the first sliding sleeve on the packer can fall down to the sliding sleeve seat for seat sealing.

In order to further realize the fine leakage finding of the lower bound leakage finding pipe column, the first lower bound choke comprises a second central pipe, the upper end and the lower end of the second central tube are respectively connected with a second upper joint and a second lower joint, the second upper joint is in threaded connection with a fixed ring, the outer wall of the second central tube close to one side of the fixed ring is connected with a backing ring, the second central tube is sleeved with a return spring, the second central tube close to one end of the second lower joint is internally connected with a second sliding sleeve, a second shearing pin is arranged between the second sliding sleeve and the second central tube, a piston is sleeved on the second central tube, the upper end of a return spring is abutted against the backing ring, the lower end of the return spring is abutted against the piston, and the outer wall of the piston is in threaded connection with a sealing sleeve, the lower end of the piston is abutted against the second lower joint, a T-shaped sealing ring is connected between the piston and the sealing sleeve, a throttling hole leading to the piston is formed in the second central pipe, and the throttling hole is formed in the position where the second sliding sleeve is connected with the second central pipe.

As a further improvement of the invention, a rigid framework is arranged in the T-shaped sealing ring; in the design, a rigid framework is added in the T-shaped sealing ring for supporting and positioning, so that the accumulation of rubber under pressure is avoided, and the repeated setting capability is improved.

The method for detecting the leakage of the lower bound by using the lower bound leakage detecting pipe column, wherein the upper end of the lower bound leakage detecting pipe column is connected with a leakage detecting pipe string, comprises the following steps,

(201) the lower boundary leakage finding pipe column is lowered to 20 meters below the initial judgment position of the leakage point;

(202) opening a second valve and a first valve, throwing a ball to test a second valve, pumping the pump truck to 12MPa, stabilizing the pressure for 10min, avoiding pressure reduction, and enabling more than two pressure testing valves to be intact;

(203) continuously pressurizing, shearing a pressure test shearing pin of the pressure test valve II, moving a pressure test sliding sleeve of the pressure test valve II downwards to the ball seat II, and sealing the lower boundary packer II;

(204) continuously pressurizing, wherein the pressure of the oil pipe is stable, and the lower pipe column is proved to be intact;

(205) lifting the lower bound leakage finding pipe column, stabilizing the pressure, returning to the step (204), preliminarily finding a lower bound position when the pressure is reduced, and turning to the step (206);

(206) opening a first valve and a second valve, throwing a ball to a second lower-bound restrictor, continuously pressurizing, shearing a second shearing pin, moving a second sliding sleeve downwards to a sliding sleeve seat, and sealing;

(207) continuing to lift the lower boundary leakage finding pipe column, realizing leakage finding at a large distance to the uppermost part of the shaft needing leakage finding, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (208);

(208) opening a second valve and a first valve, throwing a ball through an oil pipe, continuously pressurizing the oil pipe, cutting off a first shearing pin on the packer, moving a sliding sleeve on the packer downwards to a sliding sleeve seat, finding the leakage pipe column from the lower bound, performing fine leakage finding on all recorded leakage positions by adopting the packer and the first lower bound packer until the leakage finding is finished, and turning to the step (209);

(209) opening the first valve and the second valve, throwing the ball into the oil pipe to release the second pressure release valve, continuously pressurizing the oil pipe, cutting off the pressure release shear pin on the second pressure release valve, moving the pressure release sliding sleeve on the second pressure release valve down to the sliding sleeve seat, realizing the pressure release of the lower bound leakage finding pipe column, quickly recovering the first lower bound packer, the second lower bound packer and the packer, starting the lower bound leakage finding pipe column, and completing the quick leakage finding of the whole shaft of the lower bound leakage finding pipe column.

In the invention, the structures of an upper boundary packer I, an upper boundary packer II, a lower boundary packer I and a lower boundary packer II are the same, the difference between the upper boundary packer I and the packer is only that a sliding sleeve I and a shearing pin I do not exist, and other structures are the same as the structures of the packers; compared with the prior art, the upward moving stroke of the lower rubber sleeve seat is limited, the maximum stroke of the lower rubber sleeve seat is in contact with a limit step when the lower rubber sleeve seat moves upward, the problem of trousers removal is solved, the lower rubber sleeve seat cannot be separated from a sealing ring, the effective stroke of a return spring is ensured, the return spring pushes a limit ring to rapidly move downward during pressure relief, and the rubber sleeve is sealed in advance when the upper limit leakage finding pipe column moves downward and the pipe column is not centered when the protection ring protects the upper limit leakage finding pipe column; when the oil pipe is not pressurized and is in an initial state, the return spring is in a natural state, the starting pressure of the restrictor is greater than the setting pressure of the packer, and when the upper-bound restrictor or the lower-bound restrictor is opened, the limiting ring just contacts the return spring, so that the influence on the sealing reliability of the packer is reduced; meanwhile, when the rubber cylinder is sealed, the rubber cylinder is expanded due to the internal liquid inlet, and meanwhile, the lower seat of the rubber cylinder compresses the end face to compress the rubber cylinder, so that the rubber cylinder is quickly sealed, and the sealing is more reliable; when finding the leakage, the method is divided into upper bound leakage finding and lower bound leakage finding, the leakage finding distance is shortened, the leakage finding times are reduced, long distance finding is carried out first, then short distance finding is carried out, the leakage finding times are further reduced, accurate leakage finding is realized, and the leakage finding of the whole well casing of the tubular column is realized by the method; the method can be applied to the leakage finding work of the shaft.

Drawings

FIG. 1 is a diagram of the upper bound leak-finding column according to the present invention.

FIG. 2 is a block diagram of the lower boundary leak-finding column of the present invention.

Fig. 3 is a structural diagram of the second lower bound choke of the present invention.

Fig. 4 is a partially enlarged view of a portion a in fig. 3.

FIG. 5 is a block diagram of the packer of the present invention.

Fig. 6 is a partially enlarged view of fig. 5 at B.

Wherein, 1 is used for finding a leakage pipe string, 101 is a first hose, 102 is a first valve, 103 is a pump truck, 104 is a second valve, 105 is a second hose, 2 is a second upper limit packer, 3 is a first pressure relief valve, 4 is a first pressure testing valve, 5 is an upper limit restrictor, 6 is a first upper limit packer, 7 is a first ball seat, 8 is an upper limit pipe column body, 9 is a packer, 901 is a first lower connector, 902 is a protection ring, 903 is a first upper connector, 904 is a first central pipe, 905 is a rubber cylinder, 906 compression end face, 907 is a lower rubber cylinder base, 908 is a first sliding sleeve, 909 is a first shearing pin, 910 return spring, 911 is a limiting ring, 912 is a first cutting gap, 913 is a limiting step, 10 is a second pressure relief valve, 12 is a first lower limit restrictor, 1201 is a second sliding sleeve, 1202 is a second upper connector, 1203 is a fixing ring, 1204 is a cushion ring, 1205 return spring, 1206, 1207T-shaped sealing ring, 1208 is a shearing pin, 1209 is a second lower connector, 1210 is a second cutting gap, a rigid framework, 1212 is a second central pipe, 1213 is a piston, 13 is a second pressure testing valve, 14 first lower boundary packer, 15 second lower boundary choke device, 16 second ball seat, 17 sliding sleeve seat, 18 second lower boundary leak-detecting pipe column and 19 second lower boundary packer.

Detailed Description

The invention will be further described with reference to the accompanying drawings.

Example 1

As shown in fig. 5 and 6, the packer 11 for quickly finding leakage of a whole wellbore, the packer 9 includes a first central tube 904, the upper end and the lower end of the first central tube 904 are respectively connected with a first upper joint 903 and a first lower joint 901, a rubber sleeve 905 and a lower rubber sleeve seat 907 are sleeved on the first central tube 904, the lower rubber sleeve seat 907 can slide up and down along the outer wall of the lower joint, a first sliding sleeve 908 is connected in the first central tube 904, a first shear pin 909 is arranged between the first sliding sleeve 908 and the first central tube 904, and the lower rubber sleeve seat 907 butts against the downward end of the lower rubber sleeve seat 907; the inner wall of the lower portion of the rubber cylinder lower seat 907 is in threaded connection with a limiting ring 911, the limiting ring 911 can slide up and down along a first lower joint 901, one end, facing the limiting ring 911, of the first lower joint 901 is provided with a limiting step 913, a return spring 910 is sleeved on the lower joint in the rubber cylinder lower seat 907, the return spring 910 is arranged between the limiting step 913 and the limiting ring 911, and the limiting ring 911 can abut against the limiting step 913; the first lower joint 901 is connected with a protection ring 902, and in an initial state, the downward end of the limiting ring 911 is contacted with the upward end of the protection ring 902; a compression end face 906 is arranged on the outer wall of the rubber cylinder 905, and the upper end of the lower seat 907 of the rubber cylinder can extrude the compression end face 906; the first central pipe 904 is provided with a first slotting gap 912, the first slotting gap 912 is positioned close to the upper part of the first lower connector 901, the first slotting gap 912 is cut by a wire, the width of the slot is 0.1-0.2mm, and sand is prevented from entering the rubber barrel 905.

Example 2

The upper bound leakage finding pipe column for performing upper bound leakage finding by using the packer 9 as shown in fig. 1 comprises an upper bound pipe column body 8, wherein the upper bound pipe column body 8 is sequentially connected with an upper bound packer II 2, a pressure release valve I3, the packer 9, a pressure testing valve I4, an upper bound choke 5, an upper bound packer I6 and a ball seat I7 from top to bottom, and the outer diameter of the ball seat I7 is less than or equal to the diameter of a drift size gauge, so that the functions of drifting, protecting and centering a packer rubber sleeve 905 are achieved; the upper bound packer 6, the upper bound packer 2, the packer 9, the upper bound choke 5, the pressure test valve 4, the ball seat 7 and the pressure release valve 3 are all coaxially arranged.

Example 3

The method for detecting the upper bound leakage by using the upper bound leakage detecting pipe column comprises the following steps that the upper end of an upper bound pipe column body 8 is connected with a leakage detecting pipe string 1, the leakage detecting pipe string 1 comprises a first hose 101 and a second hose 105 which are connected with the pipe column body, the first hose 101 is communicated with an oil pipe, the second hose 105 is communicated with an oil sleeve annulus outside the oil pipe, the first hose 101 and the second hose 105 outside a wellhead are respectively connected with a first valve 102 and a second valve 104, the first valve 102 is connected with a liquid inlet of the valve through a liquid inlet pipe, and a pump truck 103 is connected at a liquid inlet of the liquid inlet pipe,

(101) lowering the upper bound leakage finding pipe column to the initial leakage point judgment position by 20 meters;

(102) the ball throwing pressure testing valve I4 is opened, the valve II 104 is opened, the valve I102 is opened, the pump truck 103 is used for pressurizing to 12MPa, the pressure is stabilized for 10min, if no pressure reduction occurs, the pipe column of more than 4 of the pressure testing valve I is intact, and at the moment, the upper packer II 2 is set;

(103) closing the first valve 102, carrying out annular pressure test without pressure reduction, and turning to the step (104); if the pressure is reduced and the initial judgment position of the leakage point is wrong, lifting the leakage finding pipe column and turning to (102);

(104) opening a second valve 104 and a first valve 102 to release pressure, continuing to lower the upper bound leakage finding pipe column, if the internal pressure and the external pressure are not reduced, continuing to lower the upper bound leakage finding pipe column until the pressure is reduced, finding an upper bound position, and turning to the step (105);

(105) opening a second valve 104 and a first valve 102, continuing pressurization, shearing a pressure test shearing pin on the first pressure test valve 4, and moving a pressure test sliding sleeve on the first pressure test valve 4 downwards to a first ball seat 7;

(106) continuing to lower the upper bound leakage finding pipe column until the bottom of the well, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (107);

(107) opening a second valve 104 and a first valve 102, throwing the ball packer 9, continuing pressurizing, cutting off a first shearing pin 909 on the packer 9, moving a first sliding sleeve 908 on the packer 9 downwards to a first ball seat 7, lifting an upper bound leakage finding pipe column from the bottom of the well, and performing fine leakage finding at all recorded leakage positions by adopting the packer 9 and the upper bound packer 6 until leakage finding is completed;

(108) and (3) throwing the oil pipe, continuously pressurizing, cutting off a pressure relief shearing pin of the first pressure relief valve 3, moving a pressure relief sliding sleeve of the first pressure relief valve 3 down to the first ball seat 7, realizing pressure relief of the upper bound leakage finding pipe column, quickly recovering the first upper bound packer 6, the second upper bound packer 2 and the packer 9, starting the upper bound leakage finding pipe column, and completing quick leakage finding of the whole shaft of the pipe column once.

Example 4

As shown in fig. 2, a lower bound leakage finding pipe column 18 for finding leakage by using a packer 9 is characterized in that the lower bound leakage finding pipe column 18 is sequentially connected with a second lower bound packer 19, a second pressure release valve 10, the packer 9, a first lower bound choke 12, a second pressure test valve 13, a first lower bound packer 14, a sliding sleeve seat 17, a second lower bound choke 15 and a second ball seat 16 from top to bottom, the outer diameter of the second ball seat 16 is smaller than or equal to the diameter of a drift gauge, and a first sliding sleeve 908 on the packer 9 can fall to the sliding sleeve seat 17 for seating; as shown in fig. 3 and 4, the lower bound choke 12 includes a second center tube 1212, the upper end and the lower end of the second center tube 1212 are respectively connected with a second upper joint 1202 and a second lower joint 1209, a fixing ring 1203 is threadedly connected to the second upper joint 1202, a grommet 1204 is connected to the outer wall of the second center tube 1212 close to one side of the fixing ring 1203, a return spring 1205 is sleeved on the second center tube 1212, a second sliding sleeve 1201 is connected to the second center tube 1212 near one end of the second lower joint 1209, a second shear pin 1208 is disposed between the second sliding sleeve 1201 and the second center tube 1212, a piston 1213 is sleeved on the second center tube 1212, the upper end of the return spring 1205 abuts against the grommet 1204, the lower end of the return spring 1205 abuts against the piston 1213, a sealing sleeve 1206 is threadedly connected to the outer wall of the piston 1213, the lower end of the piston 1213 abuts against the second lower joint 1207 is connected between the piston 1213 and 1206, a rigid framework 1211 is disposed in the T-shaped sealing ring 1207, an orifice leading to the piston 1213 is formed in the second central tube 1212, and the orifice is at the position where the second sliding sleeve 1201 is connected with the second central tube 1212; a second slotting slit 1210 is formed in the second central tube 1212, the second slotting slit 1210 is located at the lower portion of the piston 1213, the second slotting slit 1210 is cut by a wire, the width of the slot is 0.1-0.2mm, and sand is prevented from entering the piston 1213; and the first lower-bound packer 14, the second lower-bound packer 19, the packer 9, the first lower-bound choke holder 12, the second lower-bound choke holder 15, the second pressure test valve 13, the second ball seat 16, the second pressure release valve 10 and the sliding sleeve seat 17 are coaxially arranged.

Example 5

The method for detecting the leakage of the lower bound by using the lower bound leakage detecting pipe column 18 is characterized in that the upper end of the lower bound pipe column body 18 is connected with the leakage detecting pipe string 1, and comprises the following steps,

(201) the lower boundary leakage finding pipe column 18 is lowered to 20 meters below the initial judgment position of the leakage point;

(202) opening a second valve 104 and a first valve 102, throwing a ball to test a second valve 13, pumping by a pump truck 103 to 12MPa, stabilizing the pressure for 10min, avoiding pressure reduction, and enabling the pipe column above the second valve 13 to be intact;

(203) continuously pressurizing, shearing a pressure test shearing pin of the second pressure test valve 13, moving a pressure test sliding sleeve of the second pressure test valve 13 downwards to the second ball seat 16, and sealing a second lower boundary packer 19;

(204) continuously pressurizing, wherein the pressure of the oil pipe is stable, and the lower pipe column is proved to be intact;

(205) lifting the lower bound leakage finding pipe column 18, stabilizing the pressure, returning to the step (204), initially finding a lower bound position when the pressure is reduced, and turning to the step (206);

(206) the second pitching lower bound choke 15 is continuously pressurized, the second shearing pin 1208 is sheared, and the second sliding sleeve 1201 moves downwards to the sliding sleeve seat 17 and is sealed;

(207) continuing to lift the lower boundary leakage finding pipe column 18, realizing the leakage finding at the uppermost part of the shaft needing leakage finding at a large distance, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (208);

(208) throwing a ball into the oil pipe, continuously pressurizing the oil pipe, shearing a shearing pin I909 on the packer 9, moving a sliding sleeve I908 on the packer 9 downwards to a sliding sleeve seat 17, lowering the lower bound leakage finding pipe column 18, finely finding leakage at all the recorded leakage positions by adopting the packer 9 and the lower bound packer I14 until the leakage finding is finished, and turning to the step (209);

(209) and (3) the oil pipe is used for throwing the ball to release the second pressure release valve 10, the oil pipe is continuously pressurized, the pressure release shear pin on the second pressure release valve 10 is sheared, the pressure release sliding sleeve on the second pressure release valve 10 moves downwards to the sliding sleeve seat 17, the pressure release of the lower bound leakage finding pipe column 18 is realized, the first lower bound packer 14, the second lower bound packer 19 and the packer 9 are quickly recovered, the lower bound leakage finding pipe column 18 is lifted, and the quick leakage finding of the whole well bore of the lower bound leakage finding pipe column 18 is completed.

Wherein, the initial judgment of the leakage point comprises the following steps,

(1) determining a leakage finding starting point: the cement height return is used as a leakage finding starting point, and the sealing well sections are provided with broken leakage, deformation and error sections, but the broken leakage is more in the free well section because the leakage is easy to occur under the long-term corrosion of an acid medium in oil and water;

the working fluid level is used as a leakage finding starting point, and in some oil wells, because the productivity is low and the working fluid level is often below the cement return height in the production process, if the cement return height is used as the starting point, certain deviation can be caused;

(2) finding leakage by adopting a one-half method: verifying the leakage condition of the upper casing by taking the cement return height or the working fluid level as a base point, enabling the upper seal to be positioned in the middle between the cement return height and the upper boundary of an oil layer by the lower pipe column to carry out positive and negative pressing leakage finding, and after the leakage finding is finished, lifting the packer to the well section with the intact casing to verify the sealing property of the packer;

(3) counting the leakage breaking rule by taking the block as a unit according to the casing damage reason; and (4) determining the initial judgment position of the leakage point through the steps (1) to (3), and determining whether to find the upper boundary or the lower boundary first, so that the leakage finding distance is shortened, and the leakage finding times are greatly reduced.

In the invention, the structures of an upper boundary packer I6, an upper boundary packer II 2, a lower boundary packer I14 and a lower boundary packer II 19 are the same, the difference between the upper boundary packer I6 and the packer 9 is only that a sliding sleeve I908 and a shearing pin I909 do not exist, and the other structures are the same as the structure of the packer 9; compared with the prior art, the upward moving stroke of the rubber cylinder lower seat 907 is limited, the maximum stroke of the rubber cylinder lower seat 907 contacts with the limiting step 913 when the rubber cylinder lower seat 907 moves upward, the problem of trousers falling is solved, the rubber cylinder lower seat 907 cannot be separated from a sealing ring, the effective stroke of the return spring 910 is guaranteed, the return spring 910 pushes the limiting ring 911 to rapidly descend during pressure relief, and the rubber cylinder 905 performs seat sealing in advance when the upper boundary leakage detection pipe column descends and the pipe column is not centered under the protection of the protection ring 902; when the oil pipe is not pressurized and is in an initial state, the return spring 910 is in a natural state, the starting pressure of the restrictor is greater than the setting pressure of the packer, and when the upper-bound restrictor 5I or the lower-bound restrictor 12I is opened, the limit ring 911 just contacts the return spring 910, so that the influence on the sealing reliability of the packer is reduced; meanwhile, when the rubber sleeve 905 is sealed, the rubber sleeve 905 is expanded due to internal liquid feeding, and meanwhile, the compression end face 906 pushes the rubber sleeve lower seat 907 to compress the rubber sleeve 905, so that the rubber sleeve 905 is sealed quickly and more reliably; when finding the leakage, the method is divided into upper bound leakage finding and lower bound leakage finding, the leakage finding distance is shortened, the leakage finding times are reduced, long distance finding is carried out first, then short distance finding is carried out, the leakage finding times are further reduced, accurate leakage finding is realized, and the leakage finding of the whole well casing of the tubular column is realized by the method; the method can be applied to the leakage finding work of the shaft.

The present invention is not limited to the above embodiments, and based on the technical solutions disclosed in the present invention, those skilled in the art can make some substitutions and modifications to some technical features without creative efforts based on the disclosed technical solutions, and these substitutions and modifications are all within the protection scope of the present invention.

Claims (7)

1. The method for detecting the upper bound leakage by using the upper bound leakage detecting pipe column is characterized in that the upper bound leakage detecting pipe column comprises an upper bound pipe column body, wherein an upper bound packer II, a pressure relief valve I, a packer, a pressure test valve I, an upper bound flow controller, an upper bound packer I and a ball seat I are sequentially connected to the upper bound pipe column body from top to bottom, the upper bound pipe column body is connected with a leakage detecting pipe string at the upper end, the leakage detecting pipe string comprises a hose I and a hose II which are connected with the pipe column body, the hose I is communicated with an oil pipe, the hose II is communicated with an oil sleeve annulus outside the oil pipe, the hose I and the hose II outside a well head are respectively connected with a valve I and a valve II, liquid inlets of the valve I and the valve II are connected together through a liquid inlet pipe, and a pump truck is connected to a liquid inlet of the liquid inlet pipe; the packer comprises a first central tube, the upper end and the lower end of the first central tube are respectively connected with a first upper connector and a first lower connector, a rubber cylinder and a lower rubber cylinder seat are sleeved on the first central tube, the lower rubber cylinder seat can slide up and down along the outer wall of the lower connector, a first sliding sleeve is connected in the first central tube, a first shearing pin is arranged between the first sliding sleeve and the first central tube, the lower rubber cylinder seat is abutted against the downward end of the lower rubber cylinder seat, and the packer comprises the following steps,

(101) lowering the upper bound leakage finding pipe column to the initial leakage point judgment position by 20 meters;

(102) the ball throwing pressure testing valve I is opened, the valve II is opened, the valve I is opened, the pump truck is used for pressurizing to 12MPa, the pressure is stabilized for 10min, if no pressure reduction occurs, more than one pipe column of the pressure testing valve is intact, and at the moment, the upper packer II is set;

(103) closing the first valve, performing annular pressure test without pressure reduction, and turning to the step (104); if the pressure is reduced, lifting the leakage finding pipe column, and turning to (102);

(104) opening the second valve and the first valve to release pressure, continuing to lower the upper bound leakage finding pipe column, if the internal pressure and the external pressure are not reduced, continuing to lower the upper bound leakage finding pipe column until the pressure is reduced, finding the upper bound position, and turning to the step (105);

(105) opening a second valve and a first valve, continuously pressurizing, shearing a pressure test shearing pin on the first pressure test valve, and moving a pressure test sliding sleeve on the first pressure test valve downwards to the first ball seat;

(106) continuing to lower the upper bound leakage finding pipe column until the bottom of the well, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (107);

(107) opening a second valve and a first valve, throwing the ball packer, continuously pressurizing, cutting off a first shearing pin on the packer, moving a sliding sleeve on the packer downwards to a first ball seat, lifting an upper bound leakage finding pipe column from the bottom of the well, and performing fine leakage finding at all recorded leakage positions by adopting the packer and the first bound packer until the leakage finding is finished;

(108) and (3) throwing the oil pipe, continuously pressurizing, cutting off a pressure relief shearing pin of the first pressure relief valve, moving a pressure relief sliding sleeve of the first pressure relief valve downwards to the first ball seat, realizing pressure relief of the upper bound leakage finding pipe column, quickly recovering the upper bound packer I, the upper bound packer II and the packer, starting the upper bound leakage finding pipe column, and completing quick leakage finding of the whole shaft of the pipe column once.

2. The method for upper bound leakage finding by using the upper bound leakage finding pipe column as claimed in claim 1, wherein a limiting ring is in threaded connection with the inner wall of the lower part of the lower rubber cylinder seat, the limiting ring can slide up and down along a first lower joint, a limiting step is arranged at one end of the first lower joint facing the limiting ring, a return spring is sleeved on the lower joint in the lower rubber cylinder seat, the return spring is arranged between the limiting step and the limiting ring, and the limiting ring can abut against the limiting step.

3. The method of upper bound leak hunting using an upper bound leak hunting string according to claim 2 wherein the lower coupling has a protective ring attached thereto and wherein initially the downwardly facing end of the stop collar contacts the upwardly facing end of the protective ring.

4. The method for upper bound leakage detection by using the upper bound leakage detection tubular column as claimed in any one of claims 1 to 3, wherein a compression end face is arranged on the outer wall of the rubber cylinder, and the upper end of the lower seat of the rubber cylinder can press the compression end face.

5. The lower boundary leakage finding pipe column for finding leakage of the lower boundary is characterized in that a second lower boundary packer, a second pressure release valve, a packer, a first lower boundary restrictor, a second pressure test valve, a first lower boundary packer, a sliding sleeve seat, a second lower boundary restrictor and a second ball seat are sequentially connected with the lower boundary leakage finding pipe column from top to bottom, the first sliding sleeve on the packer can downwards fall on the sliding sleeve seat for sealing, the first lower boundary restrictor comprises a second central pipe, the upper end and the lower end of the second central pipe are respectively connected with a second upper connector and a second lower connector, a fixing ring is in threaded connection with the second upper connector, a backing ring is connected to the outer wall of the second central pipe on one side of the fixing ring, a reset spring is sleeved on the second central pipe, the second central pipe which is close to one end of the second lower connector is connected with the second sliding sleeve, a second shear pin is arranged between the second sliding sleeve and the second central pipe, a piston is sleeved on the second central pipe, and the upper end of the reset spring is abutted against the backing ring, the lower end of the return spring abuts against the piston, the outer wall of the piston is in threaded connection with a sealing sleeve, the lower end of the piston abuts against the second lower connector, a T-shaped sealing ring is connected between the piston and the sealing sleeve, a throttling hole leading to the piston is formed in the second central pipe, and the throttling hole is formed in the position where the second sliding sleeve is connected with the second central pipe; the packer comprises a first central tube, the upper end and the lower end of the first central tube are respectively connected with a first upper connector and a first lower connector, the first central tube is sleeved with a first rubber sleeve and a first lower rubber sleeve, the first lower rubber sleeve can slide up and down along the outer wall of the lower connector, a first sliding sleeve is connected in the first central tube, a first shearing pin is arranged between the first sliding sleeve and the first central tube, and the first lower rubber sleeve is abutted against one end of the first lower rubber sleeve, which is positioned downwards.

6. The lower bound leak finding string as claimed in claim 5, wherein a rigid skeleton is provided inside the T-shaped seal ring.

7. The method for lower boundary leak hunting using the lower boundary leak hunting string according to claim 5 or 6, wherein the upper end of the lower boundary leak hunting string is connected with a leak hunting string, comprising the steps of,

(201) the lower boundary leakage finding pipe column is lowered to 20 meters below the initial judgment position of the leakage point;

(202) opening a second valve and a first valve, throwing a ball to test a second valve, pumping the pump truck to 12MPa, stabilizing the pressure for 10min, avoiding pressure reduction, and enabling more than two pressure testing valves to be intact;

(203) continuously pressurizing, shearing a pressure test shearing pin of the pressure test valve II, moving a pressure test sliding sleeve of the pressure test valve II downwards to the ball seat II, and sealing the lower boundary packer II;

(204) continuously pressurizing, wherein the pressure of the oil pipe is stable, and the lower pipe column is proved to be intact;

(205) lifting the lower bound leakage finding pipe column, stabilizing the pressure, returning to the step (204), preliminarily finding a lower bound position when the pressure is reduced, and turning to the step (206);

(206) opening a first valve and a second valve, throwing a ball to a second lower-bound restrictor, continuously pressurizing, shearing a second shearing pin, moving a second sliding sleeve downwards to a sliding sleeve seat, and sealing;

(207) continuing to lift the lower boundary leakage finding pipe column, realizing leakage finding at a large distance to the uppermost part of the shaft needing leakage finding, recording all leakage positions, carrying out more precise leakage finding, and turning to the step (208);

(208) opening a second valve and a first valve, throwing a ball through an oil pipe, continuously pressurizing the oil pipe, cutting off a first shearing pin on the packer, moving a sliding sleeve on the packer downwards to a sliding sleeve seat, finding the leakage pipe column from the lower bound, performing fine leakage finding on all recorded leakage positions by adopting the packer and the first lower bound packer until the leakage finding is finished, and turning to the step (209);

(209) opening the first valve and the second valve, throwing the ball into the oil pipe to release the second pressure release valve, continuously pressurizing the oil pipe, cutting off the pressure release shear pin on the second pressure release valve, moving the pressure release sliding sleeve on the second pressure release valve down to the sliding sleeve seat, realizing the pressure release of the lower bound leakage finding pipe column, quickly recovering the first lower bound packer, the second lower bound packer and the packer, starting the lower bound leakage finding pipe column, and completing the quick leakage finding of the whole shaft of the lower bound leakage finding pipe column.

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