Side drilling wells can choose drilling and grinding-free completion device and method

Abstract

The present invention provides a side-drilling well completion device and method that can be selected without drilling and grinding. The side-drilling well completion device that can be selected without drilling and grinding includes a positioning and straightening device and a removable window opening device that can be selected without drilling and grinding. The positioning and straightening device is located in the wellbore to locate the exact position of the side-drilling well section and straighten the wellbore and casing. The removable window opening device that can be selected without drilling and grinding is located at the casing of the side-drilling oil layer part that needs to be opened. When drilling into the side-drilling well section that needs to branch, the removable window opening device that can be selected without drilling and grinding is opened by remote control to directly open the casing section that needs to be opened by side-drilling, without drilling and grinding the casing at the window opening part. The side-drilling well completion device and method that can be selected without drilling and grinding greatly reduce the drilling cost of the side-drilling well, improve the drilling efficiency, shorten the drilling cycle of the actual side-drilling well and the side-drilling horizontal well, and improve the investment efficiency and return rate. The labor intensity of the operators is reduced, and the operation time and cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and in particular to a side-drilling well completion device and method capable of selectively avoiding drilling and grinding. Background Art

[0002] At present, in the fields of oil and gas extraction, side drilling wells, including side drilling branch wells and multi-branch side branch wells, are highly developed and technically integrated side drilling and horizontal well technologies, mainly aimed at increasing the contact area with the oil layer as much as possible, releasing more energy from the oil and gas layer to improve the final recovery rate. At present, the drilling technology of side drilling branch wells has been solved, but the integrated technology of completion, sand control, and oil production lifting has not yet matured.

[0003] For window side drilling, a steel-beveled whipstock is placed at an appropriate position in the original wellbore. The whipstock is placed in the well with a delivery device and drilling tools. After the whipstock is oriented, it is fixed with slips. A drilling and milling tool (usually a milling cone) is used to support and guide the whipstock to open a window of a certain length in the original well. Then, a branch directional well is drilled sideways to form a new wellbore at the bottom. In this way, the old wellbore (including casing, etc.) at the top can be used, the platform and wellhead equipment can be used more effectively, the cost of re-drilling can be reduced, and its production capacity or drilling function can be restored. Some of the processes for implementing continuous tubing side drilling in cased wells are relatively complicated. First, a set of flexible mechanical milling tools are placed, and the casing is opened in the side drilling layer. After completion, the milling tools are pulled out, and then the continuous tubing with a drill bit is placed for horizontal drilling. The main problem of this technology is that the preliminary preparation work is relatively complicated, and it is necessary to run the pipe string for segment milling and hole expansion many times. The drilling cycle is long and the operation procedure is relatively complicated. At present, milling cones are commonly used in window side drilling abroad, which requires pre-sealing of the lower formation, increasing operation time and operating costs. In China, after the window side drilling is completed, casing milling and cutting or gunpowder perforation are often used to connect the main wellbore and the branch wellbore, which can easily lead to operation failure. It not only consumes a lot of time, increases labor intensity and operating costs, but also has complicated and cumbersome processes. The performance and efficiency of window milling still cannot meet production needs.

[0004] Traditional methods often use mechanical milling and drilling methods. Commonly used window milling devices are hand-drop devices or mechanical milling and drilling. These methods of removing downhole tools are difficult to operate, time-consuming, and easy to damage the casing. They have the disadvantages of long time consumption and high operating costs. In addition, if there is no cement ring protection outside the casing at the window opening point, the casing's pressure bearing capacity is weak, and the casing is prone to curling and tearing during the window opening process, resulting in poor window quality. Window side drilling mainly uses well clearance, pressure testing, bevel drilling, window opening, cement injection, ash sweeping, test drilling, and side drilling. The process is time-consuming and labor-intensive, which complicates the side drilling process. It is also easy to cause downhole accidents such as stuck pipe strings, making the cost and risk of oil well development high, which seriously affects the benefits of oil field development.

[0005] Chinese patent CN103089180A discloses a casing side drilling expansion screen completion method, which is to lower the tail pipe string with the expansion screen into the well to a predetermined position, pressurize and hang the expansion hanger, so that the rubber ring on the expansion hanger is tightly attached to the original well casing to provide a hanging seal for the completion string, eliminating the annular space between the screen and the well wall. However, this method is only applicable to open hole screen side drilling completion in branch well sections, and is not applicable to casing cementing completion in branch well sections.

[0006] Chinese patent CN104265161A discloses a 5.5-inch free section window side drilling process in casing. The process is carried out through well clearing, pressure testing, whipstock, window opening, window repair, and side drilling. The drill tool formed by connecting a drill bit, a spiral drill collar, a single bent screw, a weighted drill pipe, and a drill pipe in sequence is used for side drilling. The drill bit is driven into the formation through the joint action of the bent screw and the bevel surface of the whipstock by sliding drilling, which greatly improves the benefit and efficiency of window side drilling. However, the process method is only used for the process and supporting drilling tools for side drilling wells with 5.5-inch window side drilling in casing with no cement ring at the window opening point, and is not applicable to the wellbore for cementing the branch section of the window side drilling.

[0007] In summary, the traditional method mainly focuses on the sidetracking of casing window opening to ensure the quality of the new wellbore of the sidetracking well and restore the production of the old well, but there is no efficient tool and process method for optional window-free drilling and grinding. For this reason, we invented a new sidetracking well completion device and method that can select no drilling and grinding, which solves the above technical problems. Summary of the invention

[0008] The purpose of the present invention is to provide a side drilling well completion device and method which has reasonable structural design, simple and convenient operation, high efficiency, high safety and strong operability and can select drilling and grinding-free completion.

[0009] The purpose of the present invention can be achieved through the following technical measures: a side-drilling well can select a drilling-free completion device, which includes a positioning and straightening device and a removable drilling-free window opening device. The positioning and straightening device is located in the wellbore, locates the exact position of the side-drilling section, and straightens the wellbore and casing. The removable drilling-free window opening device is located at the casing of the side-drilling oil layer where window opening is required. When drilling into the side-drilling window opening section that requires branching, the removable drilling-free window opening device is remotely controlled to open, and the casing section that needs side-drilling window opening is directly opened, without drilling and grinding the casing at the window opening position.

[0010] The purpose of the present invention can also be achieved by the following technical measures:

[0011] The side drilling well can select the drilling and grinding-free completion device also includes a removable drilling and grinding-free side drilling bottom assembly device, which is connected to the removable drilling and grinding-free window opening device and has the function of automatic positioning and orientation to facilitate the lowering of the completion pipe string, and when the side drilling well branch wellbore is completed by a screen pipe, forward / backwash well construction is performed.

[0012] In the well section where side drilling of a fishbone branch well is required, the side drilling well can select a drilling-free completion device including two or more groups of the removable drilling-free window opening devices, the positioning and centralizing devices, and the removable drilling-free side drilling bottom assembly device.

[0013] The removable window opening device without drilling and grinding is opened by remote control through oil pipe or continuous oil pipe, ball throwing, pressure or sending electric signal.

[0014] The removable drilling and grinding-free window opening device includes a control signal mechanism, a first control circuit, a second control circuit, a third control circuit, a fourth control circuit and a braking mechanism. The control signal mechanism is respectively connected to the first control circuit, the second control circuit, the third control circuit and the fourth control circuit, receives a control signal, and transmits the control signal to the first control circuit. If the first control circuit does not receive the control signal, the control signal is transmitted to the second control circuit, and so on and so forth to the third control circuit and the fourth control circuit. The control circuit that receives the control signal parses the control signal and transmits an action signal to the braking mechanism. The braking mechanism is respectively connected to the first control circuit, the second control circuit, the third control circuit and the fourth control circuit, and turns on the switch under the control of the action signal. The removable drilling and grinding-free window opening device becomes a section of exposed casing, and directly opens the casing section that requires side drilling and window opening.

[0015] The removable window opening device without drilling or grinding comprises a drillable inner cylinder and a magnetizable material fixed in different ways, and the magnetizable material is located at the bottom end of the removable window opening device without drilling or grinding.

[0016] The removable window opening device without drilling or grinding is made of easily grinded material or soluble material.

[0017] The object of the present invention can also be achieved by the following technical measures: a side-drilling well can be completed by a method for selectively free of drilling and grinding, the side-drilling well can be completed by a method for selectively free of drilling and grinding, the method for selectively free of drilling and grinding of a side-drilling well adopts the side-drilling well can be completed by a device for selectively free of drilling and grinding as claimed in claim 1, and is applied to drilling a vertical well section into an inclined well section or a horizontal well section, comprising:

[0018] (1) Drilling the well to the well section where the side drilling window is required, and determining the removable drilling and grinding-free window opening device according to the specific position of the positioning centralizer at the side drilling window opening section from the bottom of the well;

[0019] (2) The casing is lowered to the designed well depth, that is, the side drilling section that needs to be opened is connected, and the lowered pipe string assembly is connected from bottom to top. The removable side drilling bottom assembly device, the removable non-drilling and grinding-free window opening device, and the positioning stabilizer of the side drilling well that can be selected for the non-drilling and grinding completion device are lowered into the main wellbore to ensure that the removable non-drilling and grinding-free window opening device is aligned with the position of the side drilling section that needs to be branched;

[0020] (3) sending a control signal to a control signal mechanism of a removable drilling-free window opening device by means of an oil pipe or a continuous oil pipe, a ball throw, or a pressure blow, and braking a braking mechanism of the removable drilling-free window opening device by means of a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit, thereby controlling the removable drilling-free window opening device to move into a section of exposed casing. At the same time, remotely controlling the removable drilling-free side drilling bottom assembly device to open, so that when drilling into the side drilling section where a branch is required, it is not necessary to drill and grind the casing at the window opening position;

[0021] (4) If step (3) cannot be implemented for various reasons, or the brake mechanism of the removable drilling-free window opening device cannot be opened, lower the spear to salvage the removable drilling-free window opening device, check whether the circulation channel of the spear is unobstructed and whether the slider moves flexibly, accurately calculate the depth of the spear according to the position of the positioning stabilizer, and if the spear cannot reach the specified calculated position, connect the drill pipe, start the pump circulation, and grind until the specified position, lift the pipe string to remove the removable drilling-free window opening device from the wellbore, and use the well clearing gauge to clear the well;

[0022] (5) If step (4) cannot be implemented for various reasons, or the brake mechanism of the removable window opening device without drilling and grinding cannot be salvaged out of the wellbore, it is removed by well washing or drilling and grinding to achieve successful window opening;

[0023] (6) Based on the size relationship between the branch wellbore and the main wellbore, the directional branch wellbore is expanded or drilled in the exposed part of the formation in contact with the removable drilling and grinding-free window opening device. When the branch wellbore size is smaller than the main wellbore size, a small drill bit is used to drill the branch wellbore, and then the casing or screen pipe is lowered to complete the well. When the two sizes need to be the same, the branch hole is expanded and drilled, and the expansion screen pipe of the same size is sent in by continuous oil pipe for suspension sealing and completion.

[0024] The object of the present invention can also be achieved by the following technical measures: a side drilling well can be completed by drilling and grinding-free method, the side drilling well can be completed by drilling and grinding-free method adopts the side drilling well can be completed by drilling and grinding-free device according to claim 1, and is applied to the horizontal well section drilled into the fishbone branch well section or the branch wellbore is completed by casing and needs to be the same as the main wellbore in the horizontal well section, including:

[0025] (1) When drilling into an oil layer, it is not necessary to drill all the way to the bottom of the well. Instead, the drilling tool assembly is used to expand the hole or perform small hole drilling when drilling into the first branch wellbore to directly perform directional drilling of the first branch wellbore;

[0026] (2) After the first branch wellbore is drilled, the drilling tool is pulled out and a completion string is lowered into the first branch wellbore. The completion string is a sand screen, a slotted liner or a direct open hole completion. When the screen section is completed, a removable drill-free window opening device is connected to the part near the horizontal well section;

[0027] (3) Replace the oil, and after the above process is completed, continue to drill the second branch wellbore in the horizontal well section;

[0028] (4) Repeat the steps of drilling the first branch wellbore in the same way to complete the well in the required completion mode. The completion string is a sand screen, a slotted liner or a direct open hole completion. When the lower screen section is completed, a removable drill-free window opening device is connected to the part near the horizontal well section to complete the drilling of the second branch wellbore;

[0029] (5) The same procedure is repeated until the drilling of the fishbone branch wellbores with at least two branch wellbores is completed;

[0030] (6) Complete drilling of the entire main wellbore;

[0031] (7) After drilling, the required completion string is run into the main wellbore, including a removable drill-free side-drilling bottom assembly device, a removable drill-free window opening device, and a positioning stabilizer. The number of removable drill-free window opening devices to be installed is determined according to the number of side-drilling branches, and the number and position of the positioning stabilizers are determined according to the specific conditions of the actual reservoir encountered;

[0032] (8) Sending a control signal to a control signal mechanism of a removable drilling-free window opening device through an oil pipe or a continuous oil pipe, a ball throw, or a pressure method, and using a first control circuit, a second control circuit, a third control circuit, and a fourth control circuit of the removable drilling-free window opening device to brake a brake mechanism of the removable drilling-free window opening device, thereby controlling the removable drilling-free window opening device to move into a section of exposed casing, and at the same time, remotely controlling the removable drilling-free side drilling bottom assembly device to start, so that the removable drilling-free side drilling bottom assembly device has the function of automatic positioning and orientation;

[0033] (9) Control the removable drilling-free window opening device so that the sealing mechanism on the screen section is tightly attached to the original well casing, providing a hanging seal for the completion string; if the branch section adopts the casing cementing and perforating completion method, the sealing mechanism has the function of hanging seal, and cooperates with the casing auxiliary device to complete the cementing cement circulation and effectively seal.

[0034] The side-drilling well completion device and method of the present invention can select the non-drilling and grinding completion device, and relate to a side-drilling well drilling and completion technology that can select the non-drilling and grinding window for the side-drilling well, and particularly a side-drilling horizontal well that uses the original wellbore window to re-drill the old well, so that the old well can be restored and the production capacity can be increased. Therefore, the side-drilling well technology has greater advantages. On the one hand, it can give play to the advantages of high efficiency and high yield of horizontal wells, increase the oil leakage area, tap the potential of remaining oil, improve the recovery rate, and improve the effect of oil field development. On the other hand, a vertical well section can be shared to simultaneously exploit two or more oil layers or the same oil layer in different directions, which can save investment more than horizontal wells while better utilizing reserves. In recent years, the side-drilling branch well technology has gradually become an important advanced technology for oil and gas field development, and has been more and more widely used, with broad market prospects and good economic and social benefits. Therefore, the technology has broad development and application prospects in the future. The present invention realizes that when drilling the window side-drilling well section that needs to branch, it is not necessary to drill and grind the casing of the window opening part, shortens the construction period of the side-drilling well, reduces the operating cost, and achieves the purpose of no restrictions on the size and number of the main wellbore and the side-drilling wellbore. This method can greatly reduce the drilling cost of side-drilling wells, improve drilling efficiency, shorten the drilling cycle of actual side-drilling wells and side-drilling horizontal wells, and improve the return on investment efficiency. It can also reduce the labor intensity of operators and reduce operation time and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A structural diagram of a specific embodiment of the side drilling well completion device of the present invention that can select the non-drilling and grinding completion device when side drilling a vertical well or a directional well;

[0036] Figure 2 It is a structural schematic diagram of a selectively removable drilling and grinding-free completion tool for side drilling in a branch well in a specific embodiment of the present invention;

[0037] Figure 3 It is a schematic diagram of the structure of a selectively removable drilling and grinding-free completion tool for multi-stage sidetracking in a horizontal well in a specific embodiment of the present invention;

[0038] Figure 4 It is a structural schematic diagram of a selectable and removable drilling and grinding-free completion tool for side drilling in a herringbone-shaped branch well in a specific embodiment of the present invention;

[0039] Figure 5 It is a structural schematic diagram of a branch well section in which a sand control screen or liner is run into the well for completion in a specific embodiment of the present invention;

[0040] Figure 6 It is a structural schematic diagram of casing cementing and completion of a branch well section in a specific embodiment of the present invention;

[0041] Figure 7 It is a schematic structural diagram of a removable drilling-free window opening device in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0042] In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings.

[0043] At present, most of the side drilling technology adopts the window side drilling and milling technology, which is easy to damage the cement ring and casing, bringing hidden dangers to the later production, and in serious cases shortening the service life of the horizontal well and the side drilling well. The task of the present invention is to provide a side drilling well that can choose to avoid drilling and grinding completion tools and process methods, which are used for natural fracture reservoirs, heterogeneous strong oil and gas reservoirs, heavy oil reservoirs, fault block reservoirs, coalbed methane and other oil and gas layers suitable for multi-branch exploration and development, so as to achieve the goal of shortening the exploration and development cycle of different oil and gas reservoirs, reducing costs and increasing production.

[0044] like Figure 1 As shown, Figure 1 The structural diagram of the side-drilling well completion device of the present invention is as follows. The side-drilling well completion device includes a positioning and centralizing device 3, a removable drilling and grinding-free window opening device 5, and a removable drilling and grinding-free side-drilling bottom well assembly device 6. For horizontal wells or highly deviated wells, especially for parts with unstable well walls and large well diameter expansion rates, in the well sections where side-drilling of herringbone-shaped branch wells is required, two or more sets of removable drilling and grinding-free window opening devices 5, positioning and centralizing devices 3, and removable drilling and grinding-free side-drilling bottom well assembly devices 6 are also required.

[0045] The positioning and centralizing device 3 has the dual functions of accurately positioning the exact position of the side drilling section and centralizing the wellbore 1 and the casing 2. The number of positioning and centralizing devices is determined according to the specific wellbore structure and the side drilling branch conditions.

[0046] The removable non-drilling and grinding window opening device 5 is remotely controlled to be opened through the oil pipe or continuous oil pipe, ball throwing, pressure or sending an electric signal, so as to control the action of the removable non-drilling and grinding window opening device 5 so that when drilling into the window opening side drilling section that needs branching, the casing section that needs side drilling and window opening is directly opened, and there is no need to drill and grind the casing at the window opening part, which shortens the construction period of side drilling and reduces the operation cost. The removable non-drilling and grinding window opening device 5 has a drillable inner tube fixed by different methods (including pins, shoulder pads, stopper fixing, etc.). Its characteristics are that after the pipe string is lowered, the entire pipe string can be rotated, pressed down, and pulled during the feeding process, and the pipe string can be circulated and rotated. Whether to cement the well is determined according to the needs. Therefore, whether cementing or open hole completion is adopted, a salvage spear or salvage tool can be lowered to salvage the inner tube. The salvage tool is composed of a small drill bit, a slider salvage spear, a large drill bit, a drill pipe female buckle, etc.

[0047] The removable drilling-free side drilling bottom assembly device 6 is conducive to the lowering of the completion string, and when the side drilling branch wellbore is completed by a screen pipe, forward / backwash well construction can be performed.

[0048] like Figure 7 As shown, the control signal mechanism 501 is opened / sent an electrical signal through an oil pipe or a continuous oil pipe, a ball, a pressure, etc., and the control circuit 502-505 is used to brake the brake mechanism 506. A wireless transmitter is placed in the control signal mechanism 501. The wireless transmitter transmits a wireless signal carrying a code and a current state of the switch of the control brake mechanism 506. When the wireless receiving device detects the wireless signal transmitted by the wireless transmitter, the wireless receiving device outputs the received wireless signal to the first control circuit 502. If the first control circuit 502 does not receive it, it outputs it to the second control circuit 503, and so on to the third control circuit 504 and the fourth control circuit 505. The fourth control circuit 505 judges the signal according to the switch code in the received wireless signal. The fourth control circuit 505 analyzes the action state in the received wireless signal and controls the brake mechanism 506 to turn on the switch. The removable drilling-free window opening device 5 is actuated to become a bare casing section, and the casing section that needs side drilling and window opening is directly opened. At the same time, the removable drilling-free side drilling bottom assembly device 6 can be remotely controlled to open. The removable drilling-free side drilling bottom assembly device 6 has the function of automatic positioning and orientation.

[0049] The material of the removable window opening device 5 is made of composite materials such as easy-to-grind materials or soluble materials, and is a metal or special material that is easily soluble, dissolvable, and easy to drill. The material mainly includes metal materials and non-metallic materials. The metal materials include soluble metal materials, such as nano-magnesium powder materials, which make the milling parts more easily dissolved in the downhole fluid; non-metallic materials include polymer degradable materials, nano-carbon element materials, biodegradable materials, etc. Soluble materials, special thermally degradable materials, biodegradable materials, low-melting-point eutectic materials, and easy-to-drill materials. The use of soluble, degradable, decomposable or easy-to-drill materials can be directly dissolved in the wellbore or drilled out more easily than traditional materials. It has the characteristics of simple operation procedures, short construction period, low operation risk, and protection of the wellbore, which can significantly reduce the development cost of a single well and the subsequent maintenance cost, and has significant economic benefits.

[0050] In one embodiment, for large-displacement horizontal wells, if the horizontal section of the horizontal well is long or the number of branches is large, multiple sets of horizontal section compensators, positioning stabilizers and removable drilling-free side drilling bottom hole combination devices are required, wherein the bottom end of the removable drilling-free side drilling bottom hole combination device is connected to a magnetic material, and when the previous drilling stage is completed, the magnetic material is connected to the bottom of the well using a drill pipe connection, and the drilling is completed by releasing the drill pipe when it reaches the bottom of the well, which can reduce the friction resistance of the entire tubing string.

[0051] Open hole completion or casing cementing completion can be performed, and the removable drilling and grinding-free window opening device can be salvaged by lowering the spear, and the circulation channel of the salvage spear can be checked to see if it is unobstructed and the slider can move flexibly. The salvage spear's insertion depth can be accurately calculated according to the position of the positioning stabilizer. If the salvage spear cannot reach the specified calculated position, the drill pipe can be connected to start the pump circulation and grind until it reaches the specified position. The pipe column is lifted to remove the removable drilling and grinding-free window opening device from the wellbore, and the well is cleared using the well clearing gauge. Even if the inner tube of the removable drilling and grinding-free window opening device cannot be salvaged from the wellbore, it can be removed by well washing or drilling and grinding to achieve successful window opening.

[0052] The tool achieves drilling-free completion, relatively effectively protects cement sheath and casing, shortens well construction cycle and completion time, and achieves the goal of unlimited branch wellbore size and number. At the same time, it overcomes the shortcomings of existing technologies that require drilling, grinding and milling to open windows, which easily damages cement sheath and casing. It avoids the risk of drilling casing and causing pipe string jamming, effectively shortens construction time and reduces construction costs.

[0053] The main wellbore can be a vertical well, a directional well or a horizontal well, which saves the cost of the main wellbore, including drilling costs, wellhead equipment costs, surface pipe network costs, platform costs, and processing costs during drilling. Because each multi-branch well only drills one main wellbore, the vertical well section above each branch horizontal well is reduced. A multi-branch well is equivalent to multiple horizontal wells, and the oil leakage area is increased, so the oil well production is greatly increased, which can speed up the recovery of oil and gas, thereby speeding up investment recovery and improving mining efficiency. This reduces costs in many aspects. Due to less drilling, the surface equipment is reduced or the efficiency is improved accordingly, and the efficiency of the platform is also improved. Oil fields that were originally considered uneconomical and marginal oil fields with poor benefits can be put into development. Dead oil areas, or small fault blocks and small sand bodies that were not previously mined, can be mined by drilling multiple wells on the basis of little cost increase, which will greatly increase the recoverable reserves of the oil field.

[0054] like Figure 1 As shown, in the wellbore that needs side drilling, Figure 1 For example, when drilling into a slanted or horizontal well section from a vertical well section, Figure 2 , Figure 3 For example, drilling into a branch well section during a horizontal well section.

[0055] The specific implementation steps are as follows:

[0056] The steps are:

[0057] (1) Whether it is a vertical well or a directional well, the well is dredged to the well section where the side drilling and window opening are required, and the removable drilling and grinding-free window opening device 5 is determined from the bottom of the well 8 at the side drilling section 4 for window opening according to the specific position of the positioning stabilizer 3.

[0058] (2) The casing is lowered to the designed well depth, that is, the side drilling section that needs to be branched is connected, and the lower pipe string assembly is connected from bottom to top, and the removable drill-free side drilling bottom assembly device 6, the removable drill-free window opening device 5, the positioning stabilizer 3 and other pipe string structures are lowered into the main wellbore 1 to ensure that the removable drill-free window opening device 5 is aligned with the position of the side drilling section 4 that needs to be branched.

[0059] (3) Through the use of tubing or continuous tubing, ball throwing, pressure, etc., such as sending an electrical signal to the control signal mechanism 501, the control circuit 502-505 is used to brake the brake mechanism 506, thereby controlling the removable drilling-free window opening device 5 to move into a section of exposed casing. At the same time, the remotely controlled removable drilling-free side drilling bottom assembly device 6 is opened, so that when drilling the window opening side drilling section 4 that needs to be branched, it is not necessary to drill and grind the casing at the window opening position, thereby shortening the construction period of the side drilling well and reducing the operating cost.

[0060] (4) If step (3) cannot be implemented for various reasons, or the brake mechanism 506 of the removable drilling-free window opening device 5 cannot be opened, a salvage spear can be lowered to salvage the removable drilling-free window opening device 5, and the salvage spear circulation channel can be checked to see whether it is unobstructed and whether the slider can move flexibly. The salvage spear insertion depth can be accurately calculated based on the position of the positioning stabilizer. If the salvage spear cannot reach the specified calculated position, the drill pipe can be connected to start the pump circulation and grind until it reaches the specified position. The pipe string can be lifted to remove the removable drilling-free window opening device from the wellbore, and the well can be cleared using a well clearing gauge.

[0061] (5) If step (4) cannot be implemented for various reasons, or the braking mechanism 506 of the removable window opening device 5 cannot be salvaged from the wellbore, it can also be removed by well washing or drilling and grinding to achieve successful window opening.

[0062] (6) According to the size relationship between the branch wellbore and the main wellbore, the directional branch wellbore is expanded or a small wellbore is drilled in the exposed part of the formation in contact with the removable drilling-free window opening device 5. When the branch wellbore size is smaller than the main wellbore size, a small drill bit is used to drill the branch wellbore, and then the casing or screen pipe is lowered to complete the well. Figure 5 As shown, when the two are required to be the same size, the branch hole is expanded and drilled, and the same size expansion screen is sent into the branch hole by continuous tubing for hanging and sealing completion. When the branch wellbore is completed with casing and needs to be the same size as the main wellbore, the side drilling branch well drilling and completion method described below is used for completion.

[0063] by Figure 4 For example, drilling in a horizontal well section enters a fishbone branch well section or a horizontal well section.

[0064] The specific implementation steps are as follows:

[0065] The steps are:

[0066] (1) When drilling into an oil layer, it is not necessary to drill all the way to the bottom of the well 8. Instead, when the drilling tool assembly is used to drill into the first branch wellbore 7, the wellbore can be expanded or small-hole drilling can be performed to directly carry out direction drilling of the first branch wellbore 7.

[0067] (2) After the first branch wellbore 7 is drilled, the drilling tool is removed and a completion string is lowered into the first branch wellbore 7. The string may be a wire-wrapped screen, a slotted screen, a prefabricated screen or other sand-proof screen, or a direct open hole completion. When the lower screen section 10 is completed, a removable drill-free window opening device 5 is connected to the portion near the horizontal well section.

[0068] (3) Replace the oil. After the above process is completed, continue to drill the second branch wellbore 9 in the horizontal well section.

[0069] (4) Repeat the steps of drilling the first branch wellbore to complete the well using the required completion method, which can be sand screen, slotted liner or direct open hole completion, such as Figure 5 As shown, when the lower screen section 10 is completed, the part close to the horizontal well section is connected to the removable drilling-free window opening device 5, thereby completing the drilling of the second branch wellbore 9.

[0070] (5) The same process is repeated until the drilling of the fishbone-shaped branch wellbores with at least two branch wellbores is completed.

[0071] (6) Complete the drilling of the entire main wellbore 1.

[0072] (7) After drilling, the required completion string is lowered into the main wellbore 1, which mainly includes a removable drill-free side drilling bottom hole assembly device 6, a removable drill-free window opening device 5, and a positioning stabilizer 3. The number of removable drill-free window opening devices 5 to be installed is determined according to the number of side drilling branches, and the number and position of the positioning stabilizers are determined according to the specific conditions of the actual drilling reservoir.

[0073] (8) Through the oil pipe or continuous oil pipe, ball throwing, pressure and other methods, such as sending an electrical signal to the control signal mechanism 501, the control circuit 502~505 is used to brake the braking mechanism 506, thereby controlling the removable drilling-free window opening device 5 to move into a section of exposed casing. At the same time, the remotely controlled removable drilling-free side drilling bottom assembly device 6 is opened, and the removable drilling-free side drilling bottom assembly device 6 has the function of automatic positioning and orientation.

[0074] (9) Then, the removable drilling-free window opening device 5 is controlled to make the sealing mechanism 11 on the screen section 10 close to the original well casing, providing a hanging seal for the completion string. If the branch section adopts the casing cementing perforation completion method, the sealing mechanism 11 has the function of hanging seal, and can complete the cementing cement circulation and effectively seal in cooperation with the casing auxiliary device 13.

[0075] The order of the first branch wellbore 7 and the second branch wellbore 9 can be interchanged, that is, drilling can be started from the toe end portion close to the horizontal well section, or drilling can be started from the heel end portion close to the horizontal well section.

[0076] When the branch wellbore is completed with a screen pipe, Figure 5 As shown, when the screen section 10 can pass through a slotted liner, sand control screen, expandable screen, wire-wound screen, and other screen strings lowered by the oil pipe or continuous oil pipe, the sealing mechanism 11 can complete the function of hanging and sealing the screen and the main wellbore 1; when the branch wellbore is completed by casing, such as Figure 6 As shown, the branch cementing section 12 assists the casing through the casing lowering assistant 13 to ensure the smooth lowering of the pipe string, and cooperates with the sealing mechanism 11 to complete the cementing cement circulation and effectively seal.

[0077] The side drilling well in the present invention can select a drilling-free completion device and method, so that the side drilling branch well can achieve unlimited number of branch wells. At the same time, a removable drilling-free completion can be selected, so that when drilling the window side drilling section that needs to branch, it is not necessary to drill and grind the casing of the window opening part. The removable drilling-free device uses soluble, degradable, decomposable or easy-to-drill materials, which can avoid mechanical processes and directly dissolve or quickly remove in the wellbore. The drilling-free completion is achieved, the cement ring and casing are relatively effectively protected, the well construction cycle and completion time are shortened, and the goal of unlimited size and number of branch wells is achieved. At the same time, it also overcomes the shortcomings of the existing technology that drilling, grinding and milling windows are required, which are easy to damage the cement ring and casing. The accuracy requirements of trajectory control are improved, the risk of drilling casing to cause stuck pipe strings is avoided, the construction time is effectively shortened, the well construction cycle is reduced, the construction time and cost are saved, and the construction cost is reduced. The disadvantages of drilling and grinding are overcome, and the operation process is simplified and the wellbore is protected. The present invention can greatly reduce the drilling cost of side-drilling wells, improve drilling efficiency, shorten the drilling cycle of actual side-drilling wells and side-drilling horizontal wells, and improve the return on investment efficiency. It can reduce the labor intensity of operators, reduce operation time and cost, and provide a process technology with reasonable structural design, simple and convenient operation, high efficiency, high safety, and strong operability.

[0078] The above description is only a preferred embodiment of the present invention, and is not intended to limit the patent scope of the present invention. Other equivalent changes that apply the patent spirit of the present invention should all fall within the patent scope of the present invention. That is, in addition to the above embodiment, the present invention can also have other implementation methods, and all technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. The side drilling well can choose the drilling and grinding-free completion method, which is characterized by: The method adopts a side drilling well completion device that can be selected without drilling and grinding, and the side drilling well completion device that can be selected without drilling and grinding includes a positioning and centralizing device and a removable non-drilling and grinding window opening device. The positioning and centralizing device is located in the wellbore, and the exact position of the side drilling section is positioned, and the wellbore and casing are centralized. The removable non-drilling and grinding window opening device is located at the casing of the side drilling oil layer part where the window needs to be opened. When drilling into the side drilling section where the window needs to be branched, the removable non-drilling and grinding window opening device is remotely controlled to open, and the casing section where the side drilling window needs to be opened is directly opened, and there is no need to drill and grind the casing of the window opening part. The method is applied to drilling a vertical well section into a deviated well section or a horizontal well section, and comprises: (1) Drill the well to the well section where the side drilling window is required, and determine the removable drilling and grinding-free window opening device according to the specific position of the positioning centralizer at the side drilling window opening section from the bottom of the well; (2) The casing is lowered to the designed well depth, that is, the sidetracking section that needs to be opened is connected, and the lowered pipe string assembly is connected from bottom to top. The removable sidetracking bottom assembly device, the removable sidetracking window opening device, and the positioning stabilizer of the sidetracking well that can be selected as the sidetracking completion device are lowered into the main wellbore to ensure that the removable sidetracking window opening device is aligned with the position of the sidetracking section that needs to be branched; (3) sending a control signal to the control signal mechanism of the removable non-drilling and grinding window opening device through the oil pipe or continuous oil pipe, ball throwing, or pressure, and braking the braking mechanism of the removable non-drilling and grinding window opening device by using the first control circuit, the second control circuit, the third control circuit, and the fourth control circuit of the removable non-drilling and grinding window opening device, thereby controlling the movement of the removable non-drilling and grinding window opening device to become a section of exposed casing. At the same time, remotely controlling the removable non-drilling and grinding sidetracking bottom assembly device to open, so that when drilling into the sidetracking section where branching is required, it is not necessary to drill and grind the casing at the window opening position; (4) If step (3) cannot be implemented for various reasons, or the brake mechanism of the removable drilling-free window opening device cannot be opened, lower the spear to salvage the removable drilling-free window opening device, check whether the circulation channel of the spear is unobstructed and whether the slider moves flexibly, and accurately calculate the depth of the spear according to the position of the positioning stabilizer. If the spear cannot reach the specified calculated position, connect the drill pipe, start the pump circulation, and grind until it reaches the specified position. Lift the pipe string to remove the removable drilling-free window opening device from the wellbore, and use the well clearing gauge to clear the well; (5) If step (4) cannot be implemented for various reasons, or the brake mechanism of the removable window opening device without drilling and grinding cannot be salvaged from the wellbore, it is removed by well washing or drilling and grinding to achieve successful window opening; (6) Based on the size relationship between the branch wellbore and the main wellbore, the directional branch wellbore is expanded or drilled in the exposed part of the formation in contact with the removable drilling and grinding-free window opening device. When the branch wellbore size is smaller than the main wellbore size, a small drill bit is used to drill the branch wellbore, and then the casing or screen is lowered to complete the well. When the two sizes need to be the same, the branch hole is expanded and drilled, and the same-sized expansion screen is sent in by continuous oil pipe for suspension and sealing completion.

2. The side-drilling well according to claim 1 can select a drilling-free completion method, characterized in that: The side drilling well can select the drilling and grinding-free completion device also includes a removable drilling and grinding-free side drilling bottom assembly device, which is connected to the removable drilling and grinding-free window opening device and has the function of automatic positioning and orientation to facilitate the lowering of the completion pipe string, and when the side drilling well branch wellbore is completed by a screen pipe, forward / backwash well construction is performed.

3. The side-drilling well according to claim 1 can select a drilling-free completion method, characterized in that: In the well section where side drilling of a fishbone branch well is required, the side drilling well can select a drilling-free completion device including two or more groups of the removable drilling-free window opening devices, the positioning and centralizing devices, and the removable drilling-free side drilling bottom assembly device.

4. The side-drilling well completion method according to claim 1 can be selected without drilling and grinding, characterized in that: The removable window opening device without drilling and grinding is opened by remote control through oil pipe or continuous oil pipe, ball throwing, pressure or sending electric signal.

5. The side-drilling well completion method according to claim 1 can be selected without drilling and grinding, characterized in that: The removable drilling and grinding-free window opening device includes a control signal mechanism, a first control circuit, a second control circuit, a third control circuit, a fourth control circuit and a braking mechanism. The control signal mechanism is respectively connected to the first control circuit, the second control circuit, the third control circuit and the fourth control circuit, receives a control signal, and transmits the control signal to the first control circuit. If the first control circuit does not receive the control signal, the control signal is transmitted to the second control circuit, and so on and so forth to the third control circuit and the fourth control circuit. The control circuit that receives the control signal parses the control signal and transmits an action signal to the braking mechanism. The braking mechanism is respectively connected to the first control circuit, the second control circuit, the third control circuit and the fourth control circuit, and turns on the switch under the control of the action signal. The removable drilling and grinding-free window opening device becomes a section of exposed casing, and directly opens the casing section that requires side drilling and window opening.

6. The side-drilling well completion method according to claim 1 is characterized in that: The removable window opening device without drilling or grinding is made of easily grinded material or soluble material.

7. The side drilling well can choose the drilling and grinding-free completion method, which is characterized by: The method adopts a side drilling well completion device that can be selected without drilling and grinding, and the side drilling well completion device that can be selected without drilling and grinding includes a positioning and centralizing device and a removable non-drilling and grinding window opening device. The positioning and centralizing device is located in the wellbore, and the exact position of the side drilling section is positioned, and the wellbore and casing are centralized. The removable non-drilling and grinding window opening device is located at the casing of the side drilling oil layer part where the window needs to be opened. When drilling into the side drilling section where the window needs to be branched, the removable non-drilling and grinding window opening device is remotely controlled to open, and the casing section where the side drilling window needs to be opened is directly opened, and there is no need to drill and grind the casing of the window opening part. The method is applied to a horizontal well section drilled into a herringbone-shaped branch well section or a branch wellbore completed with casing and requiring a horizontal well section with the same size as the main wellbore, comprising: (1) When drilling into an oil layer, it is not necessary to drill all the way to the bottom of the well. Instead, the drilling tool assembly is used to expand the hole or drill a small hole when drilling into the first branch wellbore to directly carry out directional drilling of the first branch wellbore; (2) After the first branch wellbore is drilled, the drilling tool is pulled out and a completion string is lowered into the first branch wellbore. The completion string is a sand screen, a slotted liner or a direct open hole completion. When the screen section is completed, a removable drill-free window opening device is connected to the part near the horizontal well section; (3) Replace the oil, and after the above process is completed, continue to drill the second branch wellbore in the horizontal well section; (4) Repeat the steps of drilling the first branch wellbore in the same way to complete the well in the required completion method. The completion string is a sand screen, a slotted liner or a direct open hole completion. When the lower screen section is completed, a removable drill-free window opening device is connected to the part near the horizontal well section to complete the drilling of the second branch wellbore; (5) This process is repeated in the same manner until the drilling of the fishbone branch wellbores with at least two branch wellbores is completed; (6) Complete drilling of the entire main wellbore; (7) After drilling, the required completion string is run into the main wellbore, including a removable drill-free side-drilling bottom assembly device, a removable drill-free window opening device, and a positioning stabilizer. The number of removable drill-free window opening devices to be installed is determined according to the number of side-drilling branches, and the number and position of the positioning stabilizers are determined according to the specific conditions of the actual reservoir encountered; (8) Sending a control signal to the control signal mechanism of the removable drilling-free window opening device through the oil pipe or continuous oil pipe, ball throwing, or pressure, and using the first control circuit, the second control circuit, the third control circuit, and the fourth control circuit of the removable drilling-free window opening device to brake the braking mechanism of the removable drilling-free window opening device, thereby controlling the removable drilling-free window opening device to move into a section of exposed casing, and at the same time, remotely controlling the removable drilling-free side drilling bottom assembly device to start, so that the removable drilling-free side drilling bottom assembly device has the function of automatic positioning and orientation; (9) Control the removable drilling-free window opening device so that the sealing mechanism on the screen section is tightly attached to the original well casing, providing a hanging seal for the completion string; if the branch section adopts the casing cementing and perforating completion method, the sealing mechanism has the function of hanging seal, and cooperates with the casing auxiliary device to complete the cementing cement circulation and effectively seal.

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