Reverse circulation well washing device and well washing method thereof

Abstract

The invention discloses a reverse circulation well washing device and a well washing method thereof. The reverse circulation well washing device comprises a hollow columnar outer cylinder, one end of the outer cylinder is in threaded connection with an upper connector, one end, close to the upper connector, in the outer cylinder is sleeved with an inner cylinder, a reverse circulation cavity is formed in the inner cylinder, and one end, away from the upper connector, of the inner cylinder is connected with a plug; and a pin is arranged on one side, close to the upper joint, of the outer wall of the inner barrel. The problems that in the prior art, after drifting, a well washing pipe column needs to be lowered to wash a well, and reverse circulation well washing cannot be achieved are solved.

Description

Technical Field

[0001] The invention belongs to the field of oilfield well repair, and in particular relates to a reverse circulation well flushing device and a well flushing method of the reverse circulation well flushing device. Background Art

[0002] Well repair technology under pressure is an underground well repair operation without well pressure or pressure relief. This technology reduces reservoir pollution and damage caused by underground operations, has obvious application advantages, and is an important well repair technology in the development of oil and gas fields. At present, the wellbore treatment process of well repair under pressure mainly adopts the pipe string structure of treatment tools (well clearing gauge, inclined tip, fishing tools, etc.) + check valve, which meets the requirements of blowout prevention and positive circulation of the pipe string. However, due to the large-diameter tools such as the well clearing gauge, reverse circulation is not possible to wash the well. After clearing the well, it is necessary to lower the well washing pipe string to wash the well, and the operation efficiency is not high. Summary of the invention

[0003] The purpose of the present invention is to provide a reverse circulation well washing device, which solves the problem in the prior art that after the well is dredged, a well washing pipe string needs to be lowered to wash the well, and reverse circulation well washing is not possible.

[0004] Another object of the present invention is to provide a well flushing method for a reverse circulation well flushing device.

[0005] The technical solution adopted by the present invention is that it includes an outer tube in the shape of a hollow column, one end of the outer tube is threadedly connected to an upper joint, an inner tube is sleeved on the end of the outer tube close to the upper joint, a reverse circulation chamber is opened in the inner tube, the end of the inner tube away from the upper joint is connected to a plug, an anti-blowout plugger is installed on the end of the outer wall of the inner tube close to the upper joint, and a pin is installed on the side of the outer wall of the inner tube close to the upper joint.

[0006] The present invention is also characterized in that:

[0007] A plurality of through holes are radially opened on the outer wall of the inner cylinder, and the pins pass through the through holes of the inner cylinder and are clamped with the anti-blowout plugger.

[0008] The other end of the outer tube is connected with a lower joint, and the other end of the lower joint is connected with an oil pipe.

[0009] A sealing ring is installed between the inner tube and the blowout preventer.

[0010] Another technical solution adopted by the present invention is a well washing method of a reverse circulation well washing tool, the steps are as follows:

[0011] Step 1: Match the reverse circulation well-washing device with the well-draining gauge to clear the well;

[0012] Step 2: After the well is cleared, pressurize to remove the blowout preventer and open the well washing channel;

[0013] Step 3: After opening the well-washing channel, pressurize the reverse circulation well-washing device;

[0014] Step 4: After the well is cleaned, plug the oil pipe and remove the well gauge.

[0015] Another technical solution of the present invention is also characterized in that:

[0016] Step 1 specifically includes: installing the reverse circulation well-washing device on the upper end of the well-draining gauge, inserting the well-draining gauge and the circulating well-washing device into the casing, and conducting well-draining.

[0017] Step 2 is specifically as follows: after the well is dredged, the oil pipe is pressurized from the wellhead to knock out the blowout preventer plug of the reverse circulation well washing device, and the blowout preventer plug falls into the plug of the device.

[0018] Step 3 is specifically as follows: after the well-washing channel is opened, the reverse circulation well-washing device is pressurized from the casing annulus.

[0019] The beneficial effects of the present invention are:

[0020] The present invention provides a reverse circulation well washing device and a use method thereof. After the device is equipped, the drilling can be washed in one trip. Compared with the current processing flow, one down-slant well washing process is reduced, and the effect of reducing costs and increasing efficiency is remarkable. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the reverse circulation well-washing device of the present invention;

[0022] Figure 2 The present invention is a reverse circulation well-washing device application flow chart.

[0023] In the figure, 1. lower joint, 2. outer tube, 3. plug, 4. inner tube, 5. reverse circulation chamber, 6. blowout preventer, 7. pin, 8. sealing ring, 9. upper joint. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] like Figure 1 As shown, the reverse circulation well washing device includes an outer tube 2 in the shape of a hollow column, the outer tube 2 is respectively connected with an upper joint 9 and a lower joint 1, the lower joint 1 is connected with the oil pipe, the outer tube 2 is sleeved with an inner tube 4, both ends of the inner tube 4 are external threads, one end of the inner tube 4 is connected with the upper joint 9, and the other end is connected with the plug 3, a blowout preventer 6 is also installed in the inner tube 4, after the blowout preventer 6 is knocked out by pressure, it can directly fall into the plug, a sealing ring 8 is provided between the inner tube 4 and the blowout preventer 6, a plurality of grooves are opened in the inner tube 4 to form a reverse circulation chamber 5, a pin 7 hole is penetrated to form a card edge, and the outer side is opened with an internal thread, a sliding sleeve is placed on the inner side of the card edge of the upper joint of the inner tube 4, and the blowout preventer 6 is fixed by shear nails.

[0026] The well washing method of the reverse circulation well washing device comprises the following steps:

[0027] 1. The reverse circulation well washing device is equipped with the upper part of the well cleaning gauge and goes down into the well. During the well cleaning process, the reverse circulation well washing device plays a role in preventing blowout;

[0028] 2. After it is in place, pressurize the oil pipe from the wellhead to knock out the blowout preventer of the reverse circulation well washing device. The blowout preventer falls into the plug of the device, which not only prevents the well washing channel from being blocked again by the blowout preventer, but also allows the blowout preventer to be recovered to prevent it from falling into the well;

[0029] 3. After the channel is opened, backwash the well by pressurizing the annulus of the casing;

[0030] 4. After completion, plug the oil pipe and remove the well cleaning pipe string.

[0031] Example 1

[0032] This embodiment provides a method for using a reverse circulation well flushing tool, and the specific steps are as follows:

[0033] Operation purpose: To carry out pressure inspection on high-pressure water injection wells, and use reverse circulation well washing equipment to achieve a combination of well cleaning and flushing to improve operation efficiency.

[0034] Basic situation: The bottom of the artificial well is 2129m, the injection process is two seals and two distributions, daily distribution injection is 10m3, daily actual injection is 10m3, the wellhead oil pressure is 14.2MPa, and the cumulative water injection volume is 19803m3.

[0035] String inspection process:

[0036] The pipe string of the original well. The combination of the pulling out pipe string is: 250 type wellhead + hanger + 213 pieces of Ф73mm oil pipes + 1 piece of Ф73mm oil pipe short joint + hydraulic anchor + 1 piece of Ф73mm oil pipe + Y341-114 washable well packer + 1 piece of Ф73mm oil pipe + 1 piece of Ф73mm oil pipe short joint + bridge-type eccentric water distributor + 1 piece of Ф73mm oil pipe + 1 piece of Ф73mm oil pipe short joint + Y341-114 washable well packer + 2 pieces of Ф73mm oil pipes + bridge-type eccentric water distributor + 1 piece of Ф73mm oil pipe + prefabricated working cylinder + double-acting valve + 1 piece of Ф73mm oil pipe short joint + plug screen pipe (2100.5m).

[0037] Run the wellbore cleaning string down. Figure 2 As shown in step ①, the reverse circulation well washing device is matched to the upper part of the well clearing gauge, and the downhole drilling tool assembly is: Φ118 well clearing gauge + φ114mm reverse circulation well washing device with pressure operation × 1.12m + 224 tool oil pipes (2125.69m) + last pipe entering the well 2.0m + oil replenishment distance × 3.9m-platform height × 5.69m, the well clearing position is 2128.61m, and the artificial well bottom is 2129m (0.39m from the artificial well bottom).

[0038] Reverse circulation well washing. Lead the chemical materials for well washing, connect to the 700 type cement truck, such as Figure 2 As shown in step ②, firstly pressurize the blockage by positive circulation. After the well washing channel is opened, proceed to step ③, reverse the process, pressurize the well from the casing annulus, wash the well by reverse circulation until the water quality of the inlet and outlet is consistent, then stop the pump (the displacement during the well washing process is 500L / min, the displacement increases from small to large, the water consumption is 75m3, and the well washing is maintained steadily), re-explore the sand surface for the second time, and the position remains unchanged (2128.61m).

[0039] Start to clear the wellbore string. Figure 2 Step ④, after plugging, pull out the well cleaning pipe string, and the well cleaning gauge will not be deformed or scratched after being pulled out.

[0040] The completion string is lowered. The drilling tool structure (from bottom to top): plugging screen tube × 1.1m (2099.08m) + double-acting valve + 1 Φ73mm oil pipe + bridge-type concentric water distributor + 2 Φ73mm oil pipes + Y341-114 washable well spacer + 1 Φ73mm oil pipe + bridge-type concentric water distributor + 1 Φ73mm oil pipe + Φ73mm oil pipe short joint + Y341-114 washable well spacer + 214 Φ73mm oil pipes + Φ73mm oil pipe short joint + hanger + oil compensation distance × 3.9m + 250 type wellhead. Cooperate with magnetic positioning depth calibration, adjust the tool position according to the magnetic positioning depth calibration data. Replace the water injection wellhead under pressure, pressurize the seat seal, complete the well, and hand over the well.

[0041] Example 2

[0042] Operation purpose: To carry out pressure inspection on high-pressure water injection wells, and use reverse circulation well washing equipment to achieve a combination of well cleaning and flushing to improve operation efficiency.

[0043] Basic situation: The bottom of the artificial well is 2238.5m, the injection process is two seals and two distributions, daily distribution injection is 30m3, daily actual injection is 30m3, the wellhead oil pressure is 10.6MPa, and the cumulative water injection volume is 133072m3.

[0044] String inspection process:

[0045] The original well pipe string was retrieved. 157 original well pipes were retrieved with the couplings, and the remaining pipes fell off. The salvage drill retrieved 74 original well pipes and two seals and two accessories, a double-acting valve, and a screen pipe, totaling 231 pipes in the whole well.

[0046] Run the wellbore cleaning string down. Figure 2As shown in step ①, the reverse circulation well washing device is matched to the upper part of the well clearing gauge. The drilling tool assembly is: Φ118 well clearing gauge × 1.80m + Ф73mm short circuit × 1.00m + φ114mm pressure operation reverse circulation well washing device × 1.12m + Ф73mm tool oil pipes 234 × 2191.34m + end root square entry × 8.22m + oil supplement distance × 2.80m - pressure equipment height × 5.80m, the well clearing position is 2200.48m, repeated three times, the well clearing position remains unchanged, (38.02m from the bottom of the artificial well)

[0047] Reverse circulation well washing. Take the chemical materials for well washing, connect to the 700-type cement truck, and lift the well washing pipe column up 2.0m. Figure 2 As shown in step ②, first use positive circulation pressure to open the blockage, and then proceed to step ③, connect the pipeline to backwash the well, pump pressure 8-9MPa, lasting 150min, displacement 550L / min, use 75 cubic meters of water, a small amount of scale particles are reversed out of the casing, reverse circulation well washing until the inlet and outlet water quality is consistent, stop the pump, and lower the well washing pipe string to 2200.48m, re-explore the sand surface for the second time, and the position remains unchanged.

[0048] Start to clear the wellbore string. Figure 2 Step ④, after plugging, the well cleaning and washing pipe string was pulled out, and the well cleaning pipe string was pulled out. A total of 234 well cleaning pipe strings were pulled out, and the well cleaning gauge had obvious scratches.

[0049] The drilling tool assembly is: Φ118 milling cone × 0.53m + screw drill × 3.00m + Ф73mm short section × 0.50m + check valve × 0.25m + Ф73mm tool oil pipe 234 × 2190.13m + last root square entry × 8.50m + oil compensation distance × 2.80m - equipment height × 5.80m, drilling position 2199.91m, connected to 700 cement truck, displacement 550l / min, pump pressure 8-9MPa, water 75 square circulation drilling, drilling footage 37.80m lasted 150min, final exploration position: 2237.71m (0.79m from the bottom of the artificial well). Drilling is completed and the milling pipe string is lifted.

[0050] Lower the completion string. Drilling tool structure (from bottom to top): plug screen + double-acting valve + 1 Ф73mm oil pipe + digital water distributor + 1 Ф73mm oil pipe + Y341-114 packer + 3 Ф73mm oil pipes + digital water distributor + 1 Ф73mm oil pipe + Y341-114 packer + 1 Ф73mm oil pipe + digital water distributor + 2 Ф73mm oil pipes + short-circuit + Y341-114 packer + 230 Ф73mm oil pipes + oil pipes hung to the wellhead. Cooperate with magnetic positioning depth calibration, adjust the tool position according to the magnetic positioning depth calibration data. Replace the water injection wellhead under pressure, pressurize the seat seal, complete the well, and hand over the well.

[0051] Example 3

[0052] The present embodiment provides a reverse circulation well washing device, comprising an outer cylinder 2 in the shape of a hollow column, one end of the outer cylinder 2 being threadedly connected to an upper joint 9, an inner cylinder 4 being sleeved on one end of the outer cylinder 2 close to the upper joint 9, a reverse circulation chamber 5 being opened in the inner cylinder 4, an end of the inner cylinder 4 away from the upper joint 9 being connected to a plug 3, an end of the outer wall of the inner cylinder 4 close to the upper joint 9 being installed with a blowout preventer 6, and a pin 7 being installed on one side of the outer wall of the inner cylinder 4 close to the upper joint 9.

[0053] A plurality of through holes are radially formed on the outer wall of the inner cylinder 4 , and the pins 7 pass through the through holes of the inner cylinder 4 and are engaged with the blowout preventer 6 .

[0054] The other end of the outer tube 2 is connected to the lower joint 1, and the other end of the lower joint 1 is connected to the oil pipe.

[0055] A sealing ring 8 is installed between the inner tube 4 and the blowout preventer 6.

[0056] Example 4

[0057] The present embodiment provides a reverse circulation well washing device and a well washing method thereof, comprising an outer cylinder 2 in a hollow cylindrical shape, one end of the outer cylinder 2 being threadedly connected to an upper joint 9, an inner cylinder 4 being sleeved on one end of the outer cylinder 2 close to the upper joint 9, a reverse circulation chamber 5 being opened in the inner cylinder 4, an end of the inner cylinder 4 away from the upper joint 9 being connected to a plug 3, an end of the outer wall of the inner cylinder 4 close to the upper joint 9 being installed with a blowout preventer 6, and a pin 7 being installed on the side of the outer wall of the inner cylinder 4 close to the upper joint 9.

[0058] A plurality of through holes are radially formed on the outer wall of the inner cylinder 4 , and the pins 7 pass through the through holes of the inner cylinder 4 and are engaged with the blowout preventer 6 .

[0059] The other end of the outer tube 2 is connected to the lower joint 1, and the other end of the lower joint 1 is connected to the oil pipe.

[0060] A sealing ring 8 is installed between the inner tube 4 and the blowout preventer 6.

[0061] 5. How to use the reverse circulation well washing tool. The specific steps are as follows:

[0062] Step 1: Match the reverse circulation well-washing device with the well-draining gauge to clear the well;

[0063] Step 2: After the well is cleared, pressurize to remove the blowout preventer and open the well washing channel;

[0064] Step 3: After opening the well-washing channel, pressurize the reverse circulation well-washing device;

[0065] Step 4: After the well is cleaned, plug the oil pipe and remove the well gauge.

[0066] Step 1 specifically includes: installing the reverse circulation well-washing device on the upper end of the well-draining gauge, inserting the well-draining gauge and the circulating well-washing device into the casing, and conducting well-draining.

[0067] Step 2 is specifically as follows: after the well is dredged, the oil pipe is pressurized from the wellhead to knock out the blowout preventer plug of the reverse circulation well washing device, and the blowout preventer plug falls into the plug of the device.

[0068] Step 3 is specifically as follows: after the well-washing channel is opened, the reverse circulation well-washing device is pressurized from the casing annulus.

Claims

1. Reverse circulation well washing device, characterized in that: The invention comprises an outer cylinder (2) in the shape of a hollow column, one end of the outer cylinder (2) is threadedly connected to an upper joint (9), an inner cylinder (4) is sleeved on one end of the outer cylinder (2) close to the upper joint (9), a reverse circulation chamber (5) is opened in the inner cylinder (4), one end of the inner cylinder (4) away from the upper joint (9) is connected to a plug (3), an anti-blowout plug (6) is installed on one end of the outer wall of the inner cylinder (4) close to the upper joint (9), and a pin (7) is installed on one side of the outer wall of the inner cylinder (4) close to the upper joint (9).

2. The reverse circulation well flushing device according to claim 1, characterized in that: The outer wall of the inner cylinder (4) is provided with a plurality of through holes in the radial direction, and the pin (7) passes through the through holes of the inner cylinder (4) and is engaged with the blowout preventer (6).

3. The reverse circulation well flushing device according to claim 1, characterized in that: The other end of the outer cylinder (2) is connected to a lower joint (1), and the other end of the lower joint (1) is connected to an oil pipe.

4. The reverse circulation well flushing device according to claim 1, characterized in that: A sealing ring (8) is installed between the inner cylinder (4) and the blowout preventer (6).

5. A well washing method using a reverse circulation well washing tool, characterized in that: Using the reverse circulation well washing tool as described in claims 1-4, the steps are as follows: Step 1: Match the reverse circulation well-washing device with the well-draining gauge to clear the well; Step 2: After the well is cleared, pressurize to remove the blowout preventer and open the well washing channel; Step 3: After opening the well-washing channel, pressurize the reverse circulation well-washing device; Step 4: After the well is washed, plug the oil pipe and remove the well gauge.

6. The well washing method of the reverse circulation well washing device according to claim 5, characterized in that: The step 1 specifically comprises: installing the reverse circulation well-washing device on the upper end of the well-draining gauge, inserting the well-draining gauge and the circulating well-washing device into the casing, and conducting well-draining.

7. The well washing method of the reverse circulation well washing device according to claim 6, characterized in that: The step 2 specifically includes: after the well is dredged, the oil pipe is pressurized from the wellhead to knock out the blowout preventer plug of the reverse circulation well washing device, and the blowout preventer plug falls into the plug of the device.

8. The well washing method of the reverse circulation well washing device according to claim 7, characterized in that: The step 3 specifically includes: after the well-washing channel is opened, pressurizing the reverse circulation well-washing device from the casing annulus.

Images