Uranium mining well gravel packing completion process and gravel packing free hanging suspension pipe column

Abstract

The application discloses a uranium mining well gravel filling completion well technology and a gravel filling releasing and suspending process pipe column, relates to the technical field of in-situ leaching uranium mining completion well, and comprises the following steps: step one, lowering the pipe column into a predetermined depth of a well; step two, pressing the inside of a releasing and suspending setting pipe, so that a releasing and suspending packer is set, and the releasing and suspending tool is separated from the packer; after releasing and suspending, the releasing and suspending setting pipe is lifted out of the well, and a gravel filling pipe column is formed and suspended at the predetermined depth of the well; step three, lowering a filling pipe with a valve opener at the front end to the position of a filling device, opening a normally closed valve of the filling device, and starting filling; and step four, after filling is completed, lifting out the filling pipe with the valve opener, closing the normally closed valve of the filling device, and forming a sand filter pipe column suspended at the predetermined depth of the well. The uranium mining well gravel filling completion well technology and the gravel filling releasing and suspending process pipe column are adopted, two functions of gravel filling and releasing and suspending are realized through one pipe column, construction time is shortened, and construction difficulty and construction cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of uranium leaching well completion technology, and in particular to gravel packing well completion technology and gravel packing drop-off suspension process tubing. Background Technology

[0002] In the field of uranium leaching well completion technology, the open-hole gravel-packing completion process has been researched and applied. This process involves drilling, installing casing, cementing, and then cutting the casing and cement annulus at the target ore formation to create a hydraulic connection between the casing and the reservoir. Next, a drop string including a drop packer, packer, and filter is run into the cut ore formation. Finally, a packer string is run to fill the gravel. Currently, PE material is used as the gravel. Because its density is less than water, a packer fluid (water) is introduced downhole and fills the annulus after passing through the gravel packer. The packer fluid (water) then enters the casing annulus through the auxiliary filter and the packer string, returning to the surface.

[0003] The process string used in this process consists of a Y445 drop-out packer, a secondary filter, a gravel packer, and a main filter, from top to bottom. During field construction, the string is first lowered to the predetermined depth in the well. The packer is then set using hydraulic pressure, and the string is suspended. Pressure is continued to release the drop-out packer, which is then retrieved. Next, a gravel packer string with a filler connector is lowered in. The normally closed valve of the filler is opened, and gravel filling is performed. After filling is complete, the gravel packer string is retrieved (while the normally closed valve of the filler is closed), and gravel filling is finished.

[0004] The process tubing and construction technology have the following problems: during construction, two runs of tubing are required for filling and releasing the packer, which takes a long time, is troublesome, and has high construction costs; the packer and filling device used have relatively complex structures, with many structural parts, resulting in high processing and manufacturing costs. Summary of the Invention

[0005] The purpose of this invention is to provide a gravel-filled well completion process for uranium mining wells and a gravel-filled drop-off suspension process tubing, which reduces construction difficulty, shortens construction time, and reduces manufacturing costs.

[0006] To achieve the above objectives, this invention provides a gravel-packing completion process for uranium wells, comprising the following steps: Step 1: Connect the tubing string in the order of the required depth of each tool and lower it to the predetermined depth in the well. Step 2: Pressurize the release packer into the release setter pipe to set the release packer. Continue pressurizing to disengage the release tool from the packer. After release, pull out the release setter pipe downhole to form a gravel-filled tubing string suspended at a predetermined depth downhole. Step 3: Lower the filling tube with the valve at the front end to the filling device position, open the normally closed valve of the filling device, and start filling. Step 4: After the packing is completed, the packing tube with the valve is pulled out, and the normally closed valve of the packer is closed, forming a filter sand string suspended at the predetermined depth downhole. Preferably, in step three, a ground-based liquid pump is used to pump granulating liquid and gravel into the granulating pipe. The gravel enters the annulus between the granulating pipe column and the casing. The granulating liquid passes through the annulus above the granulator and sequentially enters the annulus of the auxiliary filter and the valve opening pipe of the granulator, the cup-shaped granulating baffle assembly, the filter, the annulus outside the hanger, the annulus between the granulating pipe and the casing, and the ground.

[0007] Preferably, after the filling is completed in step four, a setter / discard ball is inserted into the filling pipe through the wellhead test valve to perform the setter / discard operation. The setter / discard operation includes the following steps: after the setter / discard ball is seated in the hanger ball seat, the ground pressure pushes the discard piston to set the hanger; after the hanger is set, pumping continues to cut the discard pin, and the discard tool is disengaged from the tubing below the hanger; the filling pipe is lifted to remove the discard tool and connecting pipe together, and the normally closed valve of the filling device is closed.

[0008] Preferably, when the process tubing needs to be retrieved after a certain period of service, the retrieval tubing is lowered and connected to the upper connector of the hanger. The hanger is then unsealed by lifting the tubing, and the entire tubing is retrieved from the well by continuing to lift it.

[0009] The gravel filling drop-off suspension process tubing consists of, from top to bottom, a drop-off setter, a drop-off packer, a secondary filter sand tube, a packer, a main filter sand tube, and a guide cone.

[0010] Preferably, an annular space is provided between the filling pipe and the sleeve, and between the secondary filter and the filling device valve opening pipe. The filling device valve opening pipe consists of a pipe and a filling device valve opener. The filling device valve opening pipe, the secondary filter sand pipe, and the cup-shaped particle deflector form a circulation channel for the filling liquid to return upward.

[0011] Preferably, the cup of the ball stopper is made of rubber.

[0012] Preferably, the drop hanger and all metal parts are made of No. 45 steel, and the surface is coated with anti-corrosion coating.

[0013] Therefore, this invention employs the aforementioned gravel-filling completion process and gravel-filling drop-and-suspend process tubing, achieving both gravel filling and drop-and-suspend functions in a single tubing run. This significantly shortens construction time and reduces construction difficulty and costs. Most metal parts are made of 45# steel and feature surface coating for corrosion protection, meeting the operational requirements of in-situ leaching uranium production while also reducing manufacturing costs.

[0014] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0015] Figure 1This is a schematic diagram of the tubing string structure in the downhole state of the present invention; Figure 2 This is a schematic diagram of the tubular column structure in the disengaged setting state of the present invention; Figure 3 This is a schematic diagram of the granulated tubular column structure of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the granulated tubular column structure of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the column structure in the throwing state of the present invention; Figure 6 This is a schematic diagram of the suspended column structure of the present invention in the state of being released from its grip. Figure Labels 1. Sleeve; 2. Particle filling pipe; 3. Drop hanger; 4. Particle filling valve opening pipe; 5. Secondary filter sand pipe one; 6. Particle blocking cup assembly; 7. Secondary filter sand pipe two; 8. Particle filling device; 9. Main filter sand pipe; 10. Guide cone; 11. Drop seat seal pipe; 12. Drop packer; 13. Drop hanging ball. Detailed Implementation

[0016] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] Example Please see Figures 1-6 The present invention provides a gravel filling drop-off suspension process tubing, which consists of a drop-off setter 11, a drop-off packer 12, a secondary filter sand tube, a filler 2, a main filter sand tube 9, and a guide cone 10 from top to bottom.

[0019] An annular space is provided between the filling pipe 2 and the sleeve 1, and between the auxiliary filter and the filling valve opening pipe 4. The filling valve opening pipe 4 consists of a pipe and a filling valve opener. The filling valve opening pipe 4, the auxiliary filter sand pipe, and the cup-shaped particle deflector form a circulation channel for the filling liquid to return upward.

[0020] The rubber cup of the pellet stopper is made of rubber.

[0021] The drop hanger 3 and all metal parts are made of No. 45 steel, and the surface is coated with anti-corrosion coating.

[0022] As attached Figure 1 As shown, the gravel packing process string currently used on site consists of, from top to bottom, a drop-out packer 11, a drop-out packer 12, a secondary filter pipe, a packer 8, a main filter pipe, and a guide cone 10. The secondary filter pipe includes secondary filter pipe one 5 and secondary filter pipe two 7. During downhole installation, the various tools are connected sequentially according to the required downhole depth in the construction plan, and then lowered to the predetermined depth.

[0023] Pressurize the release packer 12 into the packer 11 to first set it. Continue pressurizing to disengage the release tool from the packer, thus releasing it. After release, retrieve the release packer 11 from the well. This forms a gravel-packed string suspended at a predetermined depth downhole, consisting of the release packer 12, auxiliary filter pipe, packer 8, main filter pipe 9, and guide cone 10. Figure 2 As shown.

[0024] Next, lower the filling tube 2 (column) with the valve at the front end to the filling device 8 position, open the normally closed valve of the filling device, and start filling. The filling status is shown in the attached figure. Figure 3 As shown.

[0025] After granulation is complete, the granulation tube 2 (column) with the valve is removed, and the normally closed valve of the granulator is closed. This forms a structure similar to the attached... Figure 2 A filter string is suspended at a predetermined depth in the well. This allows for subsequent uranium production.

[0026] During construction, this invention shall be applied according to the construction plan requirements and as per the appendix. Figure 4 The sequence shown is connected end-to-end. The gravel is lowered into the predetermined section of the uranium well. Then, a surface pump is used to pump filling fluid and gravel into the filling pipe 2 for filling. Carried by the filling fluid, the gravel passes through the filling pipe 2, the central pipe of the release hanger 3, the filling device opening valve connector 4, the secondary filter pipe, the cup-shaped particle blocking assembly 6, the secondary filter pipe, and the filling device 8, entering the annulus between the filling string and the casing 1 (or open hole), and gradually filling the annulus. The filling fluid, however, passes through the annulus above the filling device 8 into the annulus between the secondary filter and the filling device opening valve connector 4, bypasses the cup-shaped particle blocking assembly 6, then passes through the filter and the annulus outside the hanger, entering the annulus between the filling pipe 2 and the casing 1, and returning to the surface.

[0027] After gravel packing is completed, a ball is dropped into the packing pipe 2 through the wellhead test valve. The ball is then released and suspended by the release device 3, allowing it to sit in its seat. The process tubing is positioned as shown in the attached diagram. Figure 5 As shown. After the ball is seated in the suspension unit's ball seat, ground pressure is applied, pushing the release piston and locking the release suspension unit 3. After the suspension unit is locked, pumping continues, shearing the release pin, disengaging the release tool from the tubing below the suspension unit. Lifting the packing pipe 2 allows the release tool and connecting pipe to be removed together. Simultaneously, the normally closed valve of the packing device 8 closes. The gravel packing and locking release operation are complete. The process tubing in the locked release state is shown in the attached figure. Figure 6 As shown.

[0028] Then, subsequent in-situ leaching uranium injection and extraction work can be carried out.

[0029] When the process string needs to be retrieved after a certain period of service, the retrieval string is lowered and connected to the upper connector of the hanger. Then the string is lifted up, the hanger is released, and the entire string can be retrieved from the well.

[0030] Therefore, this invention employs the aforementioned gravel-filling completion process and gravel-filling drop-and-suspend process tubing, achieving both gravel filling and drop-and-suspend functions in a single tubing run. This significantly shortens construction time and reduces construction difficulty and costs. Most metal parts are made of 45# steel and feature surface coating for corrosion protection, meeting the operational requirements of in-situ leaching uranium production while also reducing manufacturing costs.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A gravel-filled well completion process for uranium mining wells, characterized in that, Includes the following steps: Step 1: Connect the tubing string in the order of the required depth of each tool and lower it to the predetermined depth in the well. Step 2: Pressurize the release packer into the release setter pipe to set the release packer. Continue pressurizing to disengage the release tool from the packer. After release, pull out the release setter pipe downhole to form a gravel-filled tubing string suspended at a predetermined depth downhole. Step 3: Lower the filling tube with the valve at the front end to the filling device position, open the normally closed valve of the filling device, and start filling. Step 4: After the filling is completed, the filling tube with the valve is pulled out, and the normally closed valve of the filling tube is closed, forming a filter sand string suspended at a predetermined depth downhole.

2. The gravel-packing completion process for uranium wells according to claim 1, characterized in that: In step three, a ground-based liquid pump is used to pump granulating liquid and gravel into the granulating pipe. The gravel enters the annulus between the granulating pipe column and the casing. The granulating liquid passes through the annulus above the granulator and sequentially enters the annulus of the auxiliary filter and the valve opening pipe of the granulator, the cup-shaped granulating block assembly, the filter, the annulus outside the hanger, the annulus between the granulating pipe and the casing, and the ground.

3. The gravel-packing completion process for uranium wells according to claim 2, characterized in that: After the filling is completed in step four, the setter and release ball is inserted into the filling pipe through the wellhead test valve to perform the setter and release operation. The setter and release operation includes the following steps: after the setter and release ball is seated into the hanger ball seat, the ground pressure is applied to push the release piston, and the release hanger is set; after the hanger is set, pumping continues, the release pin is cut off, and the release tool is disengaged from the tubing below the hanger; the filling pipe is lifted up to remove the release tool and connecting pipe together, and the normally closed valve of the filling device is closed.

4. The gravel-packing completion process for uranium wells according to claim 3, characterized in that: When the process tubing needs to be retrieved after a certain period of service, the retrieval tubing is lowered and connected to the upper connector of the hanger. The hanger is then unsealed by lifting the tubing, and the entire tubing is retrieved from the well by continuing to lift it.

5. A gravel-packing drop-and-suspend process tubing string, employing the gravel-packing completion process for uranium wells as described in any one of claims 1-8, characterized in that: The tubular column consists of, from top to bottom, a drop-off sealing tube, a drop-off packer, a secondary filter sand tube, a granulator, a main filter sand tube, and a guide cone.

6. The gravel-filling drop-off suspension process tubing according to claim 5, characterized in that: An annular space is provided between the filling pipe and the casing, and between the auxiliary filter and the filling valve opening pipe. The filling valve opening pipe consists of a pipe and a filling valve opener. The filling valve opening pipe, the auxiliary filter sand pipe, and the cup-shaped particle deflector form a circulation channel for the filling liquid to return upward.

7. The gravel-filling drop-off suspension process tubing according to claim 6, characterized in that: The rubber cup of the pellet stopper is made of rubber.

8. The gravel-filling drop-off suspension process tubing according to claim 7, characterized in that: The drop hanger and all metal parts are made of No. 45 steel, and the surface is coated with anti-corrosion coating.

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