Well cementation and sand prevention integrated well completion method
The integrated cementing and sand control completion method uses a single tubing string to complete both cementing and sand control operations, solving the problems of complex procedures and high costs in the later stages of offshore oilfield development, and achieving the effects of short operation cycle and low cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-09
- Publication Date
- 2026-03-10
AI Technical Summary
In the current technology, cementing and completion operations are carried out separately during the later stages of offshore oilfield development, resulting in complicated procedures, long operation cycles, high costs, and economic risks, making it difficult to meet the needs of limited wellhead slot resources.
The integrated cementing and sand control completion method is adopted, which completes cementing and sand control operations in one trip of tubing string. This includes steps such as opening the directional drilling window, drilling and well cleaning, running the integrated cementing and sand control tubing string, setting and releasing the packer, and expanding and sealing the packer, which simplifies the process and shortens the operation cycle.
It simplifies procedures, shortens operation cycles, reduces costs, prevents wellbore collapse and formation sand from entering the pump body, and improves operational efficiency and economic benefits in offshore oil fields.
Smart Images
Figure CN121630282A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of offshore oil and gas development technology, and in particular to an integrated cementing and sand control well completion method. Background Technology
[0002] In existing offshore oilfield development technologies, especially in the later stages of development, the difficulty of development increases significantly due to the gradual decrease in high-quality geological targets and the decline in reservoir potential. Simultaneously, with the continuous increase in the number of wells drilled, wellhead slot resources are becoming increasingly scarce, leading to greater difficulty in matching targets with wellhead slots, thus significantly increasing the complexity and cost of drilling and completion operations. Due to the limited resources of wellhead slots, improper matching of targets and wellhead slots can easily lead to high investment and high difficulty problems in drilling and completion operations. Furthermore, due to complex downhole conditions, wellhead slots may become unusable, resulting in drilling operations not only failing to recover costs but also potentially facing even more severe economic losses. To address this dilemma, using existing wellbore for sidetracking development has become an effective solution. However, current sidetracking horizontal well cementing and completion operations still face significant challenges. Current technical processes typically separate cementing and completion operations, requiring multiple operations after cementing, including drilling cement plugs, horizontal section drilling, screen installation, and gravel packing for sand control. These operations are not only complex and time-consuming, resulting in long operation cycles and high costs. Furthermore, this step-by-step approach increases the complexity and uncertainty of the operations, potentially leading to more technical problems and economic risks, thereby further reducing the economic benefits of later-stage offshore oilfield development. Therefore, simplifying procedures, shortening operation cycles, and reducing operating costs have become core issues that urgently need to be addressed by existing technologies. Summary of the Invention
[0003] This invention provides an integrated cementing and sand control completion method to alleviate the problems of complex procedures, long operation cycles, and high costs associated with existing methods.
[0004] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:
[0005] This invention provides an integrated cementing and sand control well completion method, including step S1, cementing operation;
[0006] The tubing string is pulled up to open the cementing sleeve and then pulled up further. The pump is started to establish circulation to confirm that the cementing sleeve is open. Then, the slurry mixing process, the ash injection process, and the displacement process are carried out in sequence. After the displacement process is completed, the tubing string is lowered down to permanently close the cementing sleeve, and a pressure test is performed to confirm.
[0007] Furthermore,
[0008] The following steps are also included before cementing operations:
[0009] S01, Opening window operation for the diagonal device;
[0010] S02. Drilling and well cleaning operations: After drilling to the predetermined depth, the drill string with a strong magnet is pulled out and a well cleaning string is run in. Then, new solids-free mud is introduced into the open hole section, and the well cleaning string is used to absorb and remove iron filings from the mud.
[0011] S03. Run the integrated solids and waterproofing tubing string; the integrated solids and waterproofing tubing string includes an inner tubing string and an outer tubing string; the inner tubing string includes a bottom sealing strip guide shoe, a first tubing and a first short section, a load indicator, an upper seal, safety slips, and a screen pipe hanger; the outer tubing string includes a float shoe, a second short section, a liquid-lock sealing cylinder, a liquid-lock short screen pipe, a filling sleeve, a blind pipe short section, a variable thread, a sand-proof screen pipe, a choke sealing cylinder, a positioning indicator short section, an open hole packer, a top packer, a cementing sleeve, a tailpipe, and a tailpipe hanger;
[0012] S04. Perform hanging and release operations on the external tubing column;
[0013] S05, Expansion seal naked eye packer.
[0014] Furthermore,
[0015] The following steps are also included after cementing operations:
[0016] S2, Top packer;
[0017] S3. Verify the integrity of the integrated solid-state pipeline; lift the inner pipeline so that the load indicator is located at the lower end of the throttling sealing cylinder, and perform annular pressure testing.
[0018] S4. Lower the filling string. The filling string, from top to bottom, includes the bottom guide shoe, two-way switch tool, second tubing, single-closing tool, upper sealing rod, lower sealing rod, flushing string and tubing string.
[0019] S5. Displace the mud in the open hole section, open the blowout preventer, replace the mud with filtered brine, and record the displacement and pressure.
[0020] S6. Filling preparation: inject filling fluid with large-volume positive circulation to displace the annular mud, and lower the filling pipe string to the filling position, connecting the jack, sand control circulation elbow and sandblasting main line;
[0021] S7. Pipeline pressure test, start pump circulation, shut down the pressure tester, and test pressure again;
[0022] S8, positive loop test and negative loop exercise;
[0023] S9. Sand control construction: Connect the construction pipeline and test the pressure. After the pressure test is completed, perform forward circulation filling. When the designed sand filling volume or sand removal pressure is reached, turn on the mud pump and quickly lift the tubing to the reverse circulation position. Use well fluid to reverse circulate and wash the well for more than one week until the outlet is clean and free of sand.
[0024] S10. Pressurize to confirm the condition of the sliding sleeve;
[0025] S11, high-displacement reverse circulation well washing.
[0026] Furthermore,
[0027] In step S04, during the mounting and release operation of the outer tube column, the top drive stop torque is set, and multiple rotations and reversals are performed to ensure the normal release of the tailpipe suspension. The number of rotations and torque during release are closely monitored and recorded.
[0028] Furthermore,
[0029] In step S05, expanding and sealing the open hole packer, the pressure is gradually increased and kept within the set value to ensure that the open hole packer is fully expanded and sealed, preventing wellhead pressure drop.
[0030] Furthermore,
[0031] In step S6, filling preparation, the mud engineer is responsible for monitoring the cleanliness of the returned mud and ensuring that the inlet and outlet specific gravities are consistent to confirm that the mud has been completely replaced.
[0032] Furthermore,
[0033] In step S11, during the high-volume reverse circulation well washing, check the condition of the filling tubing to ensure it is intact and free of any residual sand.
[0034] The beneficial effects of this invention are analyzed as follows:
[0035] After drilling to the landing point on the tailpipe side, the horizontal section is continued until completion. Cementing is carried out on the upper part to seal the unstable upper formation, while the lower part is filled with sand control screens and gravel for sand control. This can prevent wellbore collapse and reduced fluid volume caused by continuous development, and also prevent formation sand from entering the electric pump and causing pump jamming. Cementing and sand control operations can be completed in one trip of tubing string, realizing continuous densification drilling under dense well network conditions, sealing weak formations and preventing sand production during the open period from affecting the operation progress. The process is simple, the operation cycle is short, and the cost is low. Attached Figure Description
[0036] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0037] Figure 1 This is a flowchart illustrating the sequence of operations for this invention.
[0038] Figure 2 A schematic diagram of the integrated cementing and sand control completion method provided in this embodiment of the invention;
[0039] icon:
[0040] 1-Tailpipe hanger; 2-Tailpipe; 3-Cementing sleeve; 4-Open hole packer; 5-Throttle seal; 6-Sand screen; 7-Filling sleeve; 8-Liquid lock seal; 9-Float shoe; 10-Tubing string; 11-Upper sealing rod; 12-Lower sealing rod; 13-Bottom sealing band guide shoe. Detailed Implementation
[0041] In the later stages of offshore oilfield development, the decreasing availability of high-quality geological targets and declining reservoir potential, coupled with a continuous increase in the number of wells drilled, makes matching targets with wellhead slots more difficult, significantly increasing the complexity and cost of drilling and completion operations. To address this issue, utilizing existing wellbore for sidetracking development has become an effective solution. However, current sidetracking horizontal well cementing and completion operations still face significant challenges. Current techniques typically separate cementing and completion operations, requiring multiple steps after cementing, including drilling cement plugs, horizontal section drilling, screen installation, and gravel packing for sand control. These operations are not only complex but also time-consuming, resulting in long operation cycles and high costs. Furthermore, this step-by-step approach increases operational complexity and uncertainty, potentially leading to more technical problems and economic risks, further reducing the economic benefits of later-stage offshore oilfield development. Therefore, simplifying procedures, shortening operation cycles, and reducing operating costs have become core issues that current technologies urgently need to address.
[0042] In view of this Figure 1 and Figure 2 As shown, this solution provides an integrated cementing and sand control well completion method, which includes step S1: cementing operation;
[0043] The tubing string is pulled up to open the cementing sleeve 3 and then pulled up further. The pump is started to establish circulation to confirm that the cementing sleeve 3 is open. Then, the mixing process, the ash injection process, and the displacement process are carried out in sequence. After the displacement process is completed, the tubing string is lowered down to permanently close the cementing sleeve 3 and pressure is tested to confirm.
[0044] After drilling to the landing point at tailpipe 2, this plan continues drilling the horizontal section until completion. Cementing is carried out in the upper part to seal the unstable upper formation. Sand control is carried out in the lower part through sand control screen 6 and filled gravel. This can prevent the problem of reduced fluid volume caused by well wall collapse due to continuous development, and also prevent formation sand from entering the pump body and causing pump jamming.
[0045] The forward sequence of steps in this solution is as follows:
[0046] S01. When opening a window with the directional drilling tool, after starting the drill, it is necessary to check whether the maximum outer diameter and wear rate of the grinding shoe for opening the window are within the design range. If they are not within the design range, window repair work is required.
[0047] S02. Drilling and well cleaning operations: After drilling to the predetermined depth, a well cleaning string with a strong magnet is pulled out and run in. Then, new solids-free mud is introduced into the open hole section, and the well cleaning string is used to absorb and remove iron filings from the mud.
[0048] S03. Run the integrated solids and silicide string; the integrated solids and silicide string includes an inner string and an outer string; the inner string includes a bottom sealing strip guide shoe 13, a first tubing and a first short section, a load indicator, an upper seal, safety slips and a screen pipe hanger; the outer string includes a float shoe 9, a second short section, a liquid-proof lock seal 8, a liquid-proof lock short screen pipe, a filling sleeve 7, a blind pipe short section, a variable thread, a sand-proof screen pipe 6, a choke seal 5, a positioning indicator short section, an open hole packer 4, a top packer, a cementing sleeve 3, a tailpipe 2 and a tailpipe hanger 1.
[0049] S04. Perform the setting and unloading operations on the external tubing string. After the cycle is completed, unload the top drive and drop the ball. When the well inclination of the ball seat position is less than 55°, a metal ball should be dropped; when the well inclination of the ball seat position is greater than 55°, a resin ball should be dropped. After dropping the ball, start the pump to deliver the ball. In the initial stage of starting the pump, deliver the ball at 30% of the displacement, and then gradually reduce the pump speed to deliver the ball at a low speed. If the dropped ball cannot be seated, gradually increase the displacement and observe the pump pressure gauge. When the pump pressure suddenly rises, the pump should be stopped immediately. After observing that the pump pressure is stable, slowly increase the pressure to the set value and stabilize it for 2 to 3 minutes. Then, lower the pressurized load into the drill bit and continue to pressurize it. Compare the theoretical data with the actual retraction difference to confirm that the hanger is engaged. Slowly release the pressure while keeping the pressure release valve open. Then, lift the load a few times. Set the top drive stop torque and slowly rotate forward 2 seconds. Closely observe the torque gauge. Slowly release the torque and observe the number of rotations. After confirming that it is normal, continue to rotate forward. Closely observe and record the number of rotations and torque when the load is released. When the torque rises, immediately stop the rotation and slowly release the torque while retaining the set torque value. Observe and record the number of rotations. Then, lift the load to confirm that the tool is released.
[0050] S05, expand and seal the open hole packer 4, continue to lift until you can see the small tonnage unsealing display, mark on the tubing string as the reference position of the top packer after cementing, then pressurize and record the pumping quantity, each time the fixed pressure value is increased, it needs to be maintained for 2 minutes until there is a pressure drop display at the wellhead, indicating that the packer has started to expand and seal, then stop the pump and control the pressure drop, and record the pumping quantity again.
[0051] S1. Cementing operation: Raise the tubing string to open the cementing sleeve 3 and continue raising it. Start the pump to establish circulation and confirm that the cementing sleeve 3 is open. Then, proceed with the slurry mixing process, the ash injection process, and the displacement process in sequence. After the displacement process is completed, lower the tubing string to permanently close the cementing sleeve 3 and perform a pressure test to confirm.
[0052] S2. Set the top packer; lower the drill pipe weight to set the top packer. After setting, perform a top sealing pressure test through the annulus to remove excess cement and then pull out the drill.
[0053] S3. Verify the integrity of the integrated solid-state pipeline; lift the inner pipeline so that the load indicator is located at the lower end of the throttling sealing cylinder 5, and perform annular pressure testing.
[0054] S4. Lower the filling string. The filling string, from top to bottom, includes a bottom guide shoe, a two-way switch tool, a second oil pipe, a single-closing tool, an upper sealing rod 11, a lower sealing rod 12, a flushing string, and an oil pipe string 10.
[0055] S5. Displace the mud in the open hole section, open the blowout preventer, replace the mud with filtered brine, and record the displacement and pressure.
[0056] S6. Filling preparation: Inject filling fluid with a large-volume positive circulation to displace the annular mud, and lower the filling pipe string to the filling position, connecting the jack, sand-proof circulation elbow and sand-dredging main line.
[0057] S7. Pipeline pressure test, start pump circulation, shut down the jack, and test pressure again.
[0058] S8. Forward circulation test and reverse circulation drill; Open the casing gate valve and conduct forward circulation tests according to different discharge rates. The construction unit is responsible for testing the reverse discharge rate. Construction can only proceed if the reverse discharge rate reaches 75% or higher. Then, conduct a reverse circulation drill. Stop the sand control pump, and the drilling platform and square well enter the reverse circulation process. Start the mud pump to confirm the connection. The drilling platform quickly pulls out the drill string and observes the change in suspended weight. Increase the discharge rate of the mud pump to flush the well and monitor the reverse discharge effect.
[0059] S9. Sand control construction: Connect the construction pipeline and test the pressure. After the pressure test is completed, perform forward circulation filling. When the designed sand filling volume or sand removal pressure is reached, turn on the mud pump and quickly lift the tubing to the reverse circulation position. Use well fluid to reverse circulate and wash the well for more than one week until the outlet is clean and free of sand.
[0060] S10. Pressurize to confirm the condition of the sliding sleeve; lower the tubing to the filling position. If the pressure of the sandless pump tubing is severe, the sliding sleeve will close.
[0061] S11. High-volume reverse circulation well washing: Raise the tubing string to the high-volume reverse circulation well washing position, use well fluid for high-volume reverse circulation well washing for more than one week, and after the operation is completed, pull out the filling tubing string and check the condition of the tools.
[0062] This solution has at least the following beneficial effects:
[0063] When developing oil and gas on offshore platforms, the underground well network is very dense. When casing side-drilling is not feasible, tailpipe side-drilling can be used to develop a single layer. If you drill to the landing point first, then run a small tailpipe for cementing and then drill horizontally, the annulus between the casing and the wellbore will be small, making cementing difficult. The wellbore size in the horizontal section will also make sand control operations difficult.
[0064] like Figure 2 As shown (due to the size and scale of the attached diagram, it has been rotated 90° for clarity; this diagram shows a horizontal well with the casing actually drilled horizontally), after drilling to the landing point on the tailpipe side, drilling continues on the horizontal section until completion. Cementing is performed on the upper part to seal the unstable upper formation, while sand control is achieved by filling the lower part with sand screens and gravel. This method can prevent wellbore collapse and reduced fluid volume caused by continuous development, and also prevent formation sand from entering the electric pump and causing pump jamming. Cementing and sand control operations can be completed in one run of tubing, enabling continuous densification drilling under dense well network conditions. It seals weak formations and prevents sand production during the open period from affecting the operation progress. The process is simple, the operation cycle is short, and the cost is low.
[0065] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for cementing and sand control integrated well completion, characterized in that it comprises the following steps: S1, cementing operation; S2, cementing sliding sleeve (3) opening and pumping; S3, slurry mixing, cementing and displacement; S4, cementing sliding sleeve (3) permanent closing and pressure test.
2. The method according to claim 1, characterized in that it further comprises the following steps before the cementing operation: S01, whipstock windowing operation; S02, drilling and running through the well; S03, running the cementing and sand control integrated string; S04, setting and releasing the outer string; S05, setting the open hole packer (4).
3. The method according to claim 2, characterized in that it further comprises the following steps after the cementing operation: S2, setting the top packer; S3, verifying the integrity of the cementing and sand control integrated string; S4, running the packer string; S5, displacing the slurry in the open hole; S6, preparation for packing; S7, pressure test of the pipeline; S8, positive circulation test and reverse circulation exercise; S9, sand control operation; S10, pressure test to confirm the sliding sleeve status; S11, large displacement reverse circulation.
4. The method according to claim 2, characterized in that the cementing and sand control integrated string comprises the following components: bottom sealing with a leading shoe (13), first tubing and first short joint, load indicator, upper sealing, safety slips and screen hanger; floating shoe (9), second short joint, anti-liquid lock sealing cylinder (8), anti-liquid lock short screen, packing sliding sleeve (7), blind pipe joint, variable buckle, sand control screen (6), throttling sealing cylinder (5), positioning indicator joint, open hole packer (4), top packer, cementing sliding sleeve (3), liner (2) and liner hanger (1). 3. The method of claim 2, wherein: In step S04, the top drive is set to stop rotating torque, and the outer pipe column is rotated and reversed several times to ensure that the tail pipe hanger (1) is properly released, and the number of turns and torque during the release are closely monitored and recorded.
5. The method according to claim 2, characterized in that: In step S05, the open hole packer (4) is inflated, and the pressure is gradually increased and maintained within the set value to ensure that the open hole packer (4) is fully inflated and prevent the wellhead pressure drop.
6. The method according to claim 3, characterized in that: In step S6, the mud engineer is responsible for monitoring the cleanliness of the returned mud and ensuring that the import and export specific gravities are consistent to confirm that the mud is completely replaced.
7. The method according to claim 3, characterized in that: In step S11, the large displacement reverse circulation well flushing is checked to ensure that the filling pipe column is intact and free of any residual sand.