Method and tool for rapid breaking of cement in the annulus of an oil gage collar

Abstract

The tool for quickly breaking oil surface sleeve annular cement is composed of a composite breaking tool and a screw-in nozzle bin, the body of the composite breaking tool is provided with an upper joint, an upper mounting hole, a lower mounting hole, a water eye and a drill bit; a high-frequency sound wave generating bin is arranged in the central hole in the center of the body, and the upper and lower mounting holes can be mounted with the screw-in nozzle bin. The application also provides a method for breaking oil surface sleeve annular cement by using the tool, which comprises the following steps: engineering logging, temporarily sealing the wellbore by a barrier, lowering a guide tracer pipe, lowering a process pipe column, breaking cement, raising the process pipe column and taking out the oil layer sleeve and the like. The application can solve the problems of eccentric cutting, slow footage and long construction period when milling the oil layer sleeve in the oil surface sleeve annular cement sealing well replacement sleeve construction, and can quickly clean the consolidated cement in the oil surface sleeve annular, so that the eccentric oil layer sleeve is centered, the sleeve milling efficiency is greatly improved, and technical support is provided for efficient treatment of oil field shallow layer sleeve damage wells.

Description

Technical fields:

[0001] This invention relates to the field of oilfield downhole operation technology, and in particular to a method and tool for rapidly breaking up cement in the annulus of an oil well casing. Background technology:

[0002] During the production of oil and water wells, shallow oil layer casing often deforms or leaks due to formation compression, fluid corrosion, and other reasons. The most thorough repair method is to replace the casing, remove the damaged part and the upper oil layer casing, and replace it with a new casing.

[0003] In the early stages of well completion in oilfields, cement was injected into the annulus between the oil layer casing and the surface casing (referred to as the "oil-surface-casing annulus"). This caused the annulus to solidify, and the oil layer casing to shift to one side. Figure 1 (As shown). During the casing replacement process, the damaged oil layer casing cannot be removed by lifting or backing; milling and removal of the cement sheath are required. However, under these conditions, the milling tool is prone to causing deflection of the eccentrically fixed oil layer casing during milling. Figure 2 As shown in the figure, the well repair cycle has become significantly longer.

[0004] Utility model CN205558850U discloses a casing guide structure for re-entry of a casing milling cylinder, including a casing guide head and a tracer string. The casing guide head includes an upper guide head, an annular platform, and a lower guide head welded together from top to bottom. The annular platform is designed so that an annular boss is formed on both the outer and inner walls of the casing guide head. The tracer string includes a first string body and a tracer tube upper connector fixed to the upper side of the string body. The outer diameter of the tracer tube upper connector is larger than the inner diameter of the annular platform, so that the tracer string is fitted inside the casing guide head and the lower end face of the tracer tube upper connector is pressed against the upper end face of the annular boss on the inner wall of the casing guide head. In addition, multiple second string bodies are connected sequentially at the bottom end of the tracer string to form a long string that extends all the way to the bottom of the well. This casing guide structure for re-entry of a casing milling cylinder is low in cost, solves the problem of difficulty in re-entering the casing milling cylinder after it has been pulled out, and prevents the loss or damage of the casing head to be retrieved downhole.

[0005] Utility model CN210918952U discloses a tool for cleaning and drilling cement rings in an oil jacket annulus. It includes an upper connector, a connecting cap, and a rotary injector. The upper connector and the rotary injector are rotatably connected by a bearing. The connecting cap is used to fix the upper connector and the rotary injector axially. One end of the inner cavity of the rotary injector is open and communicates with the inner cavity of the upper connector, and the other end is provided with a lower nozzle. The outer wall of the rotary injector is provided with a side nozzle and a side scraper. The side scraper is located between the side nozzle and the lower nozzle. The end of the rotary injector near the lower nozzle is provided with milling teeth.

[0006] Utility model CN202300267U discloses a ball bearing anti-cutting milling head for directional well casing retrieval. The front end of the head is equipped with a cutter body and cutting teeth. The inner cutting edge of the cutter body has a chamfer, and the cutting teeth are equipped with steel balls and plugs. This tool has the functions of straightening and anti-cutting, and can meet the requirements of directional well casing milling operations.

[0007] In the aforementioned related patents, due to the oil layer casing being fixed to the inner wall of the surface casing, mechanical cutting cannot avoid cutting the oil layer casing off-center; the jet-type cement cleaning tool cannot achieve pressurization, and the rotation of the drill bit is only affected by the reaction force of the jet, which cannot meet the torque requirements for breaking cement. Summary of the Invention:

[0008] The purpose of this invention is to provide a method and tool for rapidly breaking up cement in the annulus of the oil well casing. By cleaning the solidified cement in the annulus between the oil layer casing and the surface casing, this invention solves the problems of deflection, slow advance, and long construction period that occur when milling the oil layer casing during the casing replacement operation in the case of cement-sealed wells with annulus of the oil well casing, thus ensuring that the casing replacement operation is carried out efficiently.

[0009] The technical solution of this invention is as follows:

[0010] A rapid crushing tool for cement in the annulus of an oil gauge sleeve, characterized in that it consists of a composite crushing tool and a spiral nozzle chamber; the composite crushing tool includes a body, an upper connector on the upper part of the body, an upper mounting hole and a lower mounting hole in the middle part, a water eye at the bottom, and a drill bit at the bottom;

[0011] The main body has a central hole extending from the top to the bottom water eye. The central hole at the top of the main body is equipped with a high-frequency acoustic wave generating chamber for forming an ultra-high frequency acoustic wave vibration sand-carrying jet.

[0012] The upper and lower mounting holes are through holes with internal threads, with a phase of 180° between them, and the radial distance along the center line of the body 11 is 1 to 2 times the diameter of the holes; the surface of the screw-in nozzle chamber is provided with external threads, and the screw-in nozzle chamber can be fixed in the upper and lower mounting holes by threaded connection.

[0013] Furthermore, the high-frequency acoustic wave generating chamber is composed of an upper sheath, a diverting flow connector, a jet nozzle, a vibration chamber, a vibration spring, and a lower sheath from top to bottom. The upper sheath has a connecting ring at its upper part, which is threadedly connected to the inner wall of the central hole of the main body. The upper sheath contains an inner cylinder with multiple slotted sand-filtering channels. The top of the annular space between the upper sheath and the inner cylinder is sealed by a sealing ring. The bottom of the upper sheath and the inner cylinder are simultaneously threadedly connected to the upper part of the diverting flow connector. The lower part of the diverting flow connector is threadedly connected to the upper part of the vibration chamber. The jet nozzle is threadedly connected to a step in the middle of the vibration chamber. The lower sheath is threadedly connected to the lower end of the vibration chamber, and the vibration spring is fixed between the vibration chamber and the lower sheath.

[0014] Furthermore, the screw-in nozzle chamber consists of a central nozzle mounting hole, a sealing groove, a pressure cap mounting groove, and a pressure cap. The pressure cap can be fixed in the pressure cap mounting groove by means of a threaded connection.

[0015] Furthermore, the nozzle mounting hole of the screw-in nozzle chamber is equipped with a cylindrical, wear-resistant jet nozzle with a through hole, and the diameter of the inner hole of the pressure cap is between the nozzle orifice diameter and the nozzle outer diameter.

[0016] Furthermore, the outer edge of the drill bit is covered with an alloy.

[0017] On the other hand, the present invention provides a method for rapidly breaking cement in the annulus of an oil gauge using the aforementioned tools, specifically including the following steps:

[0018] 1) Conduct engineering logging to determine the cement consolidation range of the oil gauge annulus;

[0019] 2) Construct a temporary barrier to seal the wellbore below the designed replacement depth;

[0020] 3) Remove the wellhead equipment and lower the guide tracer tube to the top of the temporary barrier. The upper end of the guide tracer tube should be higher than the top surface of the oil layer casing.

[0021] 4) Connect the tubing (drill rod) and the oil gauge sleeve annular cement rapid crushing tool sequentially from top to bottom to assemble the process tubing;

[0022] 5) Insert the process tubing into the annulus of the oil gauge sleeve, drill holes on the surface of the annulus cement by rotating it, and inject sand-carrying fluid through the tubing. The annulus cement is then broken by a high-frequency vibrating sand-carrying jet formed by the oil gauge sleeve annulus cement rapid crushing tool.

[0023] 6) When the treatment depth reaches below the coupling of each oil layer casing, remove the process tubing and take out the oil layer casing above the cement-consolidated section.

[0024] 7) Lower the process tubing again and repeat steps 5 and 6 until the remaining cementing cement in the annulus of the oil gauge is completely broken up and removed.

[0025] Optionally, step 4, before assembling the process tubing, further includes the following drilling and milling process: connecting the tubing (oil tubing or drill pipe), hydraulic drilling tool, and the oil gauge sleeve annulus cement rapid breaking tool sequentially from top to bottom; lowering the oil gauge sleeve annulus; pumping unmixed workover fluid into the hydraulic drilling tool; and rotating the drill bit at the front end through the hydraulic drilling tool to drill and mill holes on the annulus cement surface.

[0026] Optionally, in the sand-carrying fluid used in step 5, the abrasive is quartz sand with a sand ratio of 5%, and the liquid is guar gum; in step 5, when the annular cement is being crushed, the jet velocity of the high-speed sand-carrying jet formed by the oil gauge sleeve annular cement rapid crushing tool is 115-200 m / s.

[0027] Furthermore, the maximum outer diameter of the process tubing satisfies the following inequality:

[0028] W < (dsc - Dbc) - 6mm

[0029] W<(dsc-Dde)-6mm(when Dbc<Dde)

[0030] In the formula, W is the maximum outer diameter of the process tubing, dsc is the inner diameter of the surface casing, Dbc is the outer diameter of the oil layer casing coupling, and Dde is the maximum outer diameter of the deformed section of the oil layer casing.

[0031] The method and tools for rapidly breaking up cement in the annulus of the oil well casing can solve the problems of deflection, slow advance, and long construction period during casing replacement construction in wells with cemented annulus of the oil well casing. By cleaning the solidified cement in the annulus between the oil well casing and the surface casing, the solidified oil well casing is more easily centered during the milling process, which greatly improves the milling efficiency and provides technical support for the efficient treatment of shallow casing-damaged wells in oil fields. Attached image description:

[0032] Figure 1 This is a schematic diagram of a well with cement-sealed annulus around the oil level (the oil layer casing is biased to one side).

[0033] Figure 2 This is a photograph of the removed, offset oil layer casing.

[0034] Figure 3 This is a schematic diagram of the basic structure of the composite crushing tool of the present invention.

[0035] Figure 4 This is a schematic diagram of the basic structure of the high-frequency sound wave generating chamber of the present invention.

[0036] Figure 5 This is a schematic diagram of the basic structure of the screw-in nozzle chamber of the present invention.

[0037] Figure 6 yes Figure 5 A-direction view.

[0038] Figure 7 This is a schematic diagram of the cement crushing and removal process for the oil gauge annulus. Detailed implementation method:

[0039] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Example 1

[0041] like Figure 3 , 5 As shown, the present invention provides a rapid cement crushing tool for annular oil gauge sleeves, which consists of a composite crushing tool 1 and a spiral nozzle chamber 2; wherein, the composite crushing tool 1 includes a body 11, an upper connector 12 is provided on the upper part of the body 11, an upper mounting hole 13 and a lower mounting hole 14 are provided in the middle part, a water eye 15 is provided at the lower part, and a drill bit 16 is provided at the bottom.

[0042] The main body 11 has a central hole extending from the top to the bottom of the water eye 15. The central hole at the top of the main body 11 is equipped with a high-frequency acoustic wave generating chamber 17 for forming an ultra-high frequency acoustic wave vibration sand-carrying jet.

[0043] The upper mounting hole 13 and the lower mounting hole 14 are through holes with internal threads, and the phase between them is 180°. The radial distance along the center line of the body 11 is 1 to 2 times the diameter of the holes. The surface of the screw-in nozzle chamber 2 is provided with external threads. The screw-in nozzle chamber 2 can be fixed in the upper mounting hole 13 and the lower mounting hole 14 by threaded connection.

[0044] like Figure 4 As shown, the high-frequency sound wave generating chamber 17 is composed of an upper sheath 171, a diverting flow guide connector 175, a jet nozzle 176, a vibration chamber 177, a vibration spring 178, and a lower sheath 179 from top to bottom. The upper sheath 171 is provided with a connecting ring 172 at its upper part, and is threadedly connected to the inner wall of the central hole of the body 11 through the connecting ring 172. The upper sheath 171 is provided with an inner cylinder 174 inside, and the inner cylinder 174 is provided with a plurality of slit sand filtering channels. The top of the annular space between the upper sheath 171 and the inner cylinder 174 is sealed by a sealing ring 173. Specifically, the sealing ring 173 is threadedly connected to the inner cylinder 174, and a sealing element is provided between the contact surface of the sealing ring 173 and the upper sheath 171.

[0045] The upper sheath 171 and the bottom of the inner cylinder 174 are simultaneously threaded to the upper part of the diversion flow guide 175; the lower part of the diversion flow guide 175 is threaded to the upper part of the vibration chamber 177; the jet nozzle 176 is threaded to the step in the middle of the vibration chamber 177; the lower sheath 179 is threaded to the lower end of the vibration chamber 177; and the vibration spring 178 is fixed between the vibration chamber 177 and the lower sheath 179.

[0046] The high-frequency acoustic wave generating chamber 17 is used to generate an ultra-high frequency acoustic wave vibration jet. In use, when the sand-mixing liquid enters the body 11 and passes through the high-frequency acoustic wave generating chamber 17, sand and liquid can be separated through the inner cylinder 174. The liquid then passes through the diverting guide joint 175 and the jet nozzle 176 in sequence to cause fluid reversal and liquid phase pressurization injection. This drives the vibration chamber 177 and the vibration spring 178 to generate hydraulic vibration, cavitation, jetting and remixing sand conversion processes. The resulting ultra-high frequency acoustic wave vibration sand-carrying jet is sprayed radially from the nozzles in the spiral nozzle chamber 2 in the upper mounting hole 13 and the lower mounting hole 14.

[0047] like Figure 5 , 6 As shown, the screw-in nozzle chamber 2 consists of a nozzle mounting hole 21 (in this embodiment, an internal hexagonal hole), a sealing groove 22, a pressure cap mounting groove 23, and a pressure cap 24. The pressure cap 24 can be fixed in the pressure cap mounting groove 23 by means of a threaded connection.

[0048] The nozzle mounting hole 21 of the screw-in nozzle chamber 2 is equipped with a cylindrical, wear-resistant jet nozzle with a through hole, and the diameter of the inner hole of the pressure cap 24 is between the nozzle orifice diameter and the nozzle outer diameter.

[0049] The outer edge of the drill bit 16 is covered with an alloy.

[0050] Example 2

[0051] This embodiment is a construction operation example using the rapid cement breaking tool for the annulus of the oil layer casing of the present invention. The well conditions for the construction operation are as follows: the inner diameter of the surface casing is 320 mm, the outer diameter of the oil layer casing is 177.8 mm, the outer diameter of the oil layer casing coupling is 194.5 mm, and the depth of the oil layer casing failure point is 60 m. In this well, the oil layer casing is biased to one side, and the oil layer casing 4 and the surface casing 3 are in close contact on one side with a distance dmin = 0, while the maximum distance on the other side is dmax = 125.9 mm.

[0052] The following combination Figure 7 The details of each step of the construction operation are as follows:

[0053] 1) Conduct engineering logging to determine the cement consolidation range of the annulus of the oil layer casing; the specific operation is as follows: conduct engineering logging on the cementing quality of the oil layer casing 4, with the range from the wellhead to 200m, and determine that the cement consolidation range of the annulus between the oil layer casing 4 and the surface casing 3 is 20m to 55m.

[0054] 2) Establish a temporary barrier to seal the wellbore below the designed replacement casing depth; the specific operation is as follows: inject cement plugs into the inside of the oil layer casing 4 to temporarily seal the wellbore, with a cement plug thickness of 30m and a cement surface depth of 200m.

[0055] 3) Remove the wellhead device and lower the guide tracer tube 6 to the top surface of the temporary barrier (let it fall onto the cement plug surface). The upper end of the guide tracer tube 6 is higher than the top surface of the oil layer casing. The guide tracer tube 6 is a D73.02mm thickened tubing.

[0056] 4) Connect the tubing string 7, hydraulic drill string 8, and the oil level casing annulus cement rapid breaking tool (the tubing string 7 is a D50.4mm geological drill pipe, and the hydraulic drill string 8 is a D54mm screw drill) sequentially from top to bottom and lower them into the oil level casing annulus. The actual depth of the cement surface 5 is 21m. Start the pump to circulate and pump the unmixed workover fluid from the tubing 7 into the hydraulic drill string 8. The rotation of the hydraulic drill string 8 drives the drill bit at the end to drill holes in the annulus cement surface. The process is continued until the bottom coupling depth of the oil layer casing 4 is reached, and the process tubing string is pulled out.

[0057] The tubing string 7 and the oil gauge sleeve annular cement rapid crushing tool are connected sequentially from top to bottom to form a process tubing string; the tubing string 7 is a D50.4mm geological drill pipe, and the maximum outer diameter of the process tubing string is the part of the alloy drill bit 16 laid on the outside of the composite crushing tool 1, with an outer diameter W of 80mm.

[0058] 5) Lower the process tubing into the annulus of the oil gauge sleeve, start the pump, rotate and lower it, drill to the previous drilling depth, reduce the lifting force on the tubing 7 by about 0.5t, pump the sand-carrying fluid into the tubing 7, and form a high-speed sand-carrying jet to break the annulus cement 5 through the cement rapid crushing tool of the oil gauge sleeve; the cement 5 debris returns to the ground through the annulus, and continues to be lowered when the suspended weight increases; the abrasive used in the sand-carrying fluid is quartz sand with a sand ratio of 5%, and the liquid is guar gum;

[0059] During the rapid crushing process of annular cement, the sand-carrying liquid injected through the tubing 7 undergoes a series of transformations as it passes through the high-frequency acoustic wave generator chamber 17 of the composite crushing tool 1. These transformations include sand and liquid separation, fluid reversal, liquid-phase pressurization injection, hydraulic vibration, cavitation, injection, and remixing of sand. This causes the nozzles of the two spiral nozzle chambers 2 to generate radial high-speed, ultra-high-frequency acoustic wave vibration sand-carrying jets (jet velocity of 120 m / s). This causes the cement around the orifice to vibrate and stimulates crack propagation, thereby expanding the crushing range of the abrasive jet on the annular cement in a short time and achieving the effect of rapid and large-scale crushing of the cement around the orifice.

[0060] 6) When the treatment depth reaches below the coupling of each oil layer casing 4, remove the process tubing and take out the oil layer casing 4 above the cement 5 consolidation section.

[0061] 7) Lower the process tubing again and repeat steps 5 and 6 until the remaining cement 5 in the annulus of the oil gauge is completely broken up and removed.

[0062] The above-described specific embodiments are only used to illustrate the present invention. Any equivalent modifications made based on the technical solutions of the present invention should not be excluded from the protection scope of the present invention.

Claims

1. A method for rapidly breaking up cement in the annulus of an oil gauge, characterized in that... Includes the following steps: 1) Conduct engineering logging to determine the cement consolidation range of the oil gauge annulus; 2) Construct a temporary barrier to seal the wellbore below the designed replacement depth; 3) Remove the wellhead equipment and lower the guide tracer tube to the top of the temporary barrier. The upper end of the guide tracer tube should be higher than the top surface of the oil layer casing. 4) Connect the drill pipe and the oil gauge sleeve annular cement rapid crushing tool from top to bottom and assemble them into a process tubing; 5) Insert the process tubing into the annulus of the oil gauge sleeve, drill holes on the surface of the annulus cement by rotating it, and inject sand-carrying fluid through the tubing. The annulus cement is then broken by a high-frequency vibrating sand-carrying jet formed by the oil gauge sleeve annulus cement rapid crushing tool. 6) When the treatment depth reaches below the coupling of each oil layer casing, remove the process tubing and take out the oil layer casing above the cement-consolidated section. 7) Lower the process tubing again and repeat steps 5 and 6 until the remaining cementing cement in the annulus of the oil gauge is completely broken up and removed. The oil gauge sleeve annular cement rapid crushing tool consists of a composite crushing tool and a spiral nozzle chamber; the central hole at the top of the composite crushing tool body is equipped with a high-frequency acoustic wave generating chamber for forming an ultra-high frequency acoustic wave vibration sand-carrying jet; the spiral nozzle chamber is equipped with a nozzle. The high-frequency acoustic wave generating chamber is composed of an upper sheath, a diverting flow connector, a jet nozzle, a vibrating chamber, a vibrating spring, and a lower sheath, from top to bottom. The upper sheath has a connecting ring at its upper part, which is threaded to the inner wall of the central hole of the main body. The upper sheath contains an inner cylinder with multiple slotted sand-filtering channels. The top of the annular space between the upper sheath and the inner cylinder is sealed by a sealing ring. The bottom of both the upper sheath and the inner cylinder are threaded to the upper part of the diverting flow connector. The lower part of the diverting flow connector is threaded to the upper part of the vibrating chamber. The jet nozzle is threaded to a step in the middle of the vibrating chamber. The lower sheath is threaded to the lower end of the vibrating chamber, and the vibrating spring is fixed between the vibrating chamber and the lower sheath. When the sand-mixing liquid enters the main body and passes through the high-frequency acoustic wave generating chamber, it can cause sand and liquid to separate through the inner cylinder. Then, it can cause fluid reversal and liquid phase pressurization injection through the diverting guide joint and the jet nozzle in sequence. This drives the vibration chamber and the vibrating spring to generate hydraulic vibration, cavitation, jetting and remixing sand conversion process. The resulting ultra-high frequency acoustic wave vibration carrying sand jet is sprayed radially from the nozzle in the spiral nozzle chamber in the upper and lower mounting holes.

2. The method for rapidly crushing cement in the annulus of an oil gauge according to claim 1, characterized in that: Step 4, before assembling the process tubing, also includes the following drilling and grinding process: connecting the tubing, hydraulic drill bit, and the oil gauge annulus cement rapid breaking tool from top to bottom, lowering the oil gauge annulus, pumping unmixed workover fluid into the hydraulic drill bit, and rotating the drill bit at the front end through the hydraulic drill bit to drill and grind holes on the annulus cement surface.

3. The method for rapidly crushing cement in the annulus of an oil gauge according to claim 1 or 2, characterized in that: In step 5, the abrasive used in the sand-carrying fluid is quartz sand with a sand ratio of 5%, and the liquid is guar gum. In step 5, when the annular cement is being crushed, the jet velocity of the high-speed sand-carrying jet formed by the oil gauge sleeve annular cement rapid crushing tool is 115-200 m / s.

4. The method for rapidly crushing cement in the annulus of an oil gauge according to claim 3, characterized in that: The maximum outer diameter of the process tubing satisfies the following inequality: W < (Dsc - Dbc) - 6mm W<(Dsc-Dde)-6mm (when Dbc<Dde) In the formula, W is the maximum outer diameter of the process tubing, dsc is the inner diameter of the surface casing, Dbc is the outer diameter of the oil layer casing coupling, and Dde is the maximum outer diameter of the deformed section of the oil layer casing.

5. The method for rapidly crushing cement in the annulus of an oil gauge according to claim 1, characterized in that: The composite crushing tool has an upper connector on its upper part, an upper mounting hole and a lower mounting hole in the middle, a water eye at the bottom, and a drill bit at the bottom. The central hole inside the body extends from the top to the lower water eye. The upper and lower mounting holes are through holes with internal threads, with a phase of 180° between them, and the radial distance along the center line of the body is 1 to 2 times the diameter of the holes. The surface of the screw-in nozzle chamber has external threads, and the screw-in nozzle chamber is fixed in the upper and lower mounting holes by threaded connection.

6. The method for rapidly crushing cement in the annulus of an oil gauge according to claim 5, characterized in that: The screw-in nozzle chamber consists of a central nozzle mounting hole, a sealing groove, a pressure cap mounting groove, and a pressure cap. The pressure cap is fixed in the pressure cap mounting groove by a threaded connection. A cylindrical, wear-resistant jet nozzle with a through hole is installed in the nozzle mounting hole. The diameter of the inner hole of the pressure cap is between the nozzle orifice diameter and the nozzle outer diameter.

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