CN114790873A - Multi-branch well bore ultra-short radius windowing sidetrack drilling orientation tool and use method - Google Patents

Abstract

The invention relates to a multi-branch borehole ultrashort radius windowing sidetrack directional tool and a using method thereof. The guide inclined plane of the lower positioning body in the recyclable positioner can be matched with the guide inclined body of the oblique fixer at the bottom of the windowing side drilling window to be stacked. The invention can realize multi-window windowing in the main well bore, reduce the operation cost and achieve the remarkable development effect of cost reduction and efficiency improvement.

Description

Multi-branch well bore ultra-short radius windowing sidetrack drilling orientation tool and use method

Technical Field

The invention relates to a petroleum industry multilateral well bore ultrashort radius windowing sidetracking orientation device and a use method, in particular to a multilateral well bore ultrashort radius windowing sidetracking orientation tool and a use method.

Background

At present, most old oil fields in China enter the middle and later stages of development, the pressure coefficient of a main force block is lower and lower, the exploitation economy is poorer and poorer by adopting a traditional drilling mode, and a sidetrack horizontal well with an inward opening window in an old well barrel is one of yield increasing means with higher economy in the existing oil exploitation. However, the conventional sidetracking horizontal well has a long inclined well section and large displacement before the target, and residual oil around the old well and the near well cannot be effectively used. Aiming at the development difficulty, the ultra-short radius sidetrack horizontal well technology is developed at home and abroad in recent years, a target layer can be rapidly drilled with a curvature radius of 3-5m, a horizontal well hole with a certain length is drilled, the drilling cost is greatly saved, the reservoir exploitation degree is improved, but aiming at a multilayer oil deposit, the single-branch ultra-short radius horizontal well has low reserve control degree in the longitudinal direction, and even if the same oil deposit has a small plane spread range, so the ultra-short radius multi-branch sidetrack horizontal well technology is required to be developed, the economic and effective exploitation of small-scale residual oil between a plane and an interlayer is improved, meanwhile, in the aspect of regulating the streamline of a water-drive oil deposit, the ultra-short radius multi-branch sidetrack horizontal well can realize balanced displacement and exploitation and volume by sidetrack drilling horizontal well holes with different directions and lengths according to the plane oil deposit heterogeneous distribution characteristics, the recovery efficiency is improved.

The existing ultra-short radius sidetracking horizontal well technology is mainly divided into two categories, namely high-pressure water jet injection drilling and flexible steering drilling tool rotary drilling. Chinese patent ZL2008101194691 discloses a radial horizontal drilling device, which utilizes a high-pressure hose to connect a jet drill bit, the jet drill bit jets high-pressure water jet to break rock to form a horizontal borehole, and the technology has the following problems: the horizontal well formed by the jet flow jet rock breaking has small borehole diameter and irregular pore passage, and due to the reason of a hose, the advancing track of the hydraulic jet drill bit is uncontrollable, the formed borehole track is irregular, the borehole track cannot be measured, an applicable well completion technology is lacked, a sand production reservoir cannot prevent sand, the borehole is easy to collapse and close because of no support, and the yield is reduced rapidly.

Aiming at the defects of a high-pressure water jet injection drilling technology, Chinese patents ZL2015104510629, ZL 201146271, ZL2017109462512, ZL2017105827546 and the like disclose a guiding type ultrashort radius horizontal well drilling method, and the drilling principle is basically similar: firstly, setting the whipstock, adopting magnetic positioning to calibrate the depth when setting the whipstock, and determining the normal direction of the inclined plane of the whipstock by a gyroscope to enable the normal direction to be the same as the design azimuth angle of a borehole. After the whipstock is set, a conventional windowing method is adopted for windowing, a deflecting section adopts a guide drilling tool for drilling, the guide drilling tool comprises a guide cylinder and a flexible drilling rod, the guide cylinder is of a human body elbow joint simulating structure and can only be bent in a certain direction in a semi-radial direction with fixed curvature in a unilateral mode, and the flexible drilling rod in the deflecting section is restrained for deflecting drilling. When the guide drilling tool is put in, the gyroscope is adopted to adjust the bending direction of the guide cylinder to be consistent with the normal direction of the inclined plane of the whipstock, and the ultra-short radius deflecting drilling direction is ensured to be the same as the design direction of the well hole. The guide drilling tool is mainly used for drilling construction of an ultra-short radius deflecting well section, and after the deflecting section is finished and reaches a target layer, the guide drilling tool is lifted out, and a horizontal drilling tool is put in to finish horizontal well hole drilling. The technology can finish the deflecting section with the curvature radius of 3-5m, quickly enter a target layer with 90-degree well deflection, can horizontally drill 50-100 m, and basically can meet the technological requirements of ultra-short radius horizontal drilling. However, only a single-branch horizontal well bore can be drilled at the inner side of the same shaft, and an ultra-short-radius multi-branch side drilling horizontal well cannot be implemented, and the technical bottleneck of the method is the lack of a multi-branch well bore windowing side drilling tool.

In order to realize the window sidetracking of the multilateral wellbore, a plurality of whipstocks are required to be set, the prior technical scheme is that salvageable and recyclable whipstocks are adopted, window sidetracking is carried out for a plurality of times in setting at different depths of the same wellbore, and finally all whipstocks are fished out to carry out well completion operation.

The relevant technical devices disclosed by the Chinese patent are as follows:

ZL2014204156245 discloses a reducing recoverable whipstock;

ZL2010105643447 discloses a retrievable orbital ramp;

ZL972230955 discloses a retrievable guide;

ZL2005101352615 discloses a recoverable whipstock and a fishing tool thereof;

ZL2010202320321 discloses a fishable sidetracking integrated deflector;

ZL2010202320321 discloses a suspended positioning type recoverable whipstock;

ZL2016201515245 discloses a hydraulic seat-sealing recoverable whipstock with a self-closing connecting channel.

The working principle of the patent technology is basically similar, and the technical scheme is as follows: and (3) driving a hydraulic setting through descending the running tool to a preset position, anchoring in the casing through slips, and guiding a windowing tool to grind and mill the casing windowing by utilizing a wedge iron on the upper part of the tool. During recovery, a special fishing tool is adopted, after a fishing joint is fished, a lifting force is applied, the shearing pin is cut off, the setting piston retracts, the slips are released, anchoring is released, and the whipstock is recovered.

However, when the technical device is used for multilateral wellbore sidetrack windowing construction, the following problems exist:

the whipstock is required to be provided with a setting and unsealing mechanism, so that the complexity of the tool is increased, the use reliability is reduced, and the risk of recovery failure exists;

after the whipstock is recovered, another new whipstock set is needed to be set at different depths, and a gyroscope is needed to be put into the whipstock to determine the inclined plane direction of the whipstock during each setting of the whipstock, so that the construction period is prolonged, and the construction cost is greatly increased;

after completion of multilateral sidetracking, the lowermost lateral window lacks whipstock guidance and the lateral is unable to be repeatedly run into the completion string.

Therefore, in order to realize ultra-short radius multi-branch sidetracking of the horizontal well, improve the construction efficiency and the construction success rate of multi-window sidetracking, reduce the operation cost, a sidetracking directional tool capable of being used in a matched manner needs to be manufactured, the bottleneck of the prior art is overcome, and the development effect of cost reduction and efficiency improvement is achieved.

Disclosure of Invention

The invention aims to provide a multi-branch well bore ultrashort radius windowing sidetrack directional tool and a using method thereof, which improve the windowing sidetrack construction efficiency and the construction success rate, realize multi-window windowing, reduce the operation cost and achieve the development effect of cost reduction and efficiency improvement.

The technical scheme of the invention is realized as follows:

multilateral borehole ultrashort radius window sidetracking orientation tool includes the slant fixer, and the slant fixer is equipped with leads italic, slant ware back-off rod and slips, works as slant ware back-off rod and slant ware in the slant fixer right the ring and are carried to the outer back of well, lead the inclined plane of leading of italic and can stack with recoverable locator, wherein:

the recyclable positioner mainly comprises an upper positioning body, a righting body and a lower positioning body, wherein the upper positioning body and the lower positioning body are both provided with inclined guide surfaces, and the angle of the inclined guide surface at the lower part of the lower positioning body is the same as that of the inclined guide surface of the inclined guide body in the inclined fixer;

the righting body is internally provided with a righting block, the upper positioning body is connected with the righting body and the lower positioning body through fixing pins, and fishing threads are arranged in the upper positioning body;

the upper positioning body is connected with the reverse buckling rod of the positioner and the upper joint of the positioner in sequence.

The righting body is provided with a righting block mounting groove in the circumferential direction and at least one group of righting blocks in the circumferential direction, a spring mounting hole is formed in a block body of each righting block and is provided with a spring, two side wing edges of each righting block are buckled and pressed below a pressing sheet or a pressing sleeve, and the pressing sheet or the pressing sleeve is fixed in the righting body through a fixing pin.

The manufacturing length of the centralizing body or the number of the centralizing bodies connected into the recoverable locator can be adjusted according to the axial distance between the ultra-short-radius horizontal branch well hole I and the ultra-short-radius horizontal branch well hole II.

The installation direction between the guide inclined plane of the upper positioning body in the recoverable positioner and the guide inclined plane in the lower positioning body is consistent with the azimuth angle of the track of the lateral drilling branch well and can be stacked in a main well, and the angle of the guide inclined plane in the upper positioning body in the lower recoverable positioner is the same as that of the guide inclined plane in the lower positioning body in the other recoverable positioner stacked on the upper positioning body; the oblique fixer is retained in the main well hole below a windowing window of the ultra-short radius horizontal branch well hole.

The upper end of the locator back-off rod is in threaded connection with the locator upper joint, and the lower end of the locator back-off rod is provided with a back-off thread and can be in threaded connection with the back-off thread of the inner circle of the lower end of the upper locating body; fishing threads are arranged above the inner circle step in the middle of the upper positioning body; the excircle of the lower part of the locator back-off rod is provided with a back-off thread, and the locator back-off rod is inserted in the inner circle step of the lower part of the upper locating body and is connected together through the back-off thread.

The outer circle of the upper part of the locator back-off rod is also provided with a righting ring carrying step, and the locator righting ring is installed outside the locator back-off rod above the righting ring carrying step and is fixed with the guide inclined plane of the upper locating body through a locator righting screw; the upper part of the locator back-off rod is in threaded connection with the locator upper joint, and the inner cavity of the upper part of the locator upper joint is provided with drill rod joint threads or oil pipe threads.

The lower positioning body is provided with a center hole, the inner circle of the upper part of the lower positioning body is provided with an inserting step, the inserting step body is uniformly provided with 6 through holes in the circumferential direction, 1 through hole is aligned with the normal direction of the lower guide inclined plane in the circumferential direction, and the lower end of the guide inclined plane in the lower positioning body is a plane.

The outer circle of the lower end of the righting body is an inserting outer circle, 6 counter bores are correspondingly formed in the inserting outer circle upwards corresponding to the 6 through holes in the lower positioning body, and the fixing pin can be inserted into the through hole of the lower positioning body and the counter bores in the righting body; when the inserting excircle of the righting body is inserted into the inserting step of the lower positioning body, the counter bores correspond to the through holes one by one, and the lower positioning body and the righting body are fixed through the fixing pins; the inner circle of the upper end of the righting body is also provided with an inserting step, the circumference of the inserting step is also uniformly provided with 6 through holes, the through holes correspond to the counter bores in the inserting excircle of the lower part of the upper positioning body one by one and can be inserted with fixing pins; a counter bore is formed in the inserting excircle of the lower part of the upper positioning body and is aligned with the normal direction of the guide inclined plane of the upper positioning body in the circumferential direction; the inserting excircle at the lower part of the upper positioning body is arranged below the guide inclined plane.

The setting directions of the slip teeth on the outer walls of the two sets of slip in the inclined fixer are mutually vertical.

The use method is used for the multilateral wellbore ultrashort radius windowing sidetrack directional tool and comprises the following use steps:

A. setting the oblique fixator in a main borehole, grinding and milling a casing by using a windowing milling cone, forming a first window in the casing, and taking out a windowing drilling tool;

B. the side of the ultra-short radius horizontal drilling combined drilling tool is lowered to drill a first ultra-short radius horizontal branch well hole, and the drilling tool is lifted out after drilling is finished;

C. adjusting a normal included angle of a guide slope between a lower positioning body and an upper positioning body in the recoverable positioner according to an azimuth included angle of a well hole between the ultra-short radius horizontal branch well hole I and the ultra-short radius horizontal branch well hole II;

D. c, placing the recyclable positioner downwards, stacking the lower positioning body on the inclined guide body of the inclined fixer, milling the casing pipe by using the windowing milling cone, forming a second window in the casing pipe or continuously forming a next window in different target layers or the same target layer in the casing pipe according to the steps C and D, and taking out the windowing drilling tool;

E. according to the construction design, sidetracking ultra-short radius horizontal branch boreholes in different target layers or sidetracking ultra-short radius horizontal branch boreholes in the same target layer;

F. and (3) running a flexible screen pipe in the main well hole and the ultra-short radius horizontal branch well hole I positioned at the lowest layer to perform sand control completion.

And after the milling of the window of the second ultra-short-radius horizontal branch well hole is finished, the downward ultra-short-radius horizontal drilling combined drilling tool starts deflecting drilling just after going out of the window, an deflecting section is finished by a curvature radius of a meter, and the second ultra-short-radius horizontal branch well hole is continuously drilled when the well deflection reaches 90 degrees to form the second ultra-short-radius horizontal branch well hole.

The method for sidetracking the ultra-short-radius horizontal branch well bore II in the same target layer comprises the steps of lowering the ultra-short-radius horizontal drilling combination drilling tool after the first sidetracking windowing window is finished, finishing a deflecting section with the curvature radius of 3-5 meters when the flexible drill bit just comes out of the window, and continuously drilling to form the ultra-short-radius horizontal branch well bore I when the well deflection reaches 90 degrees; and after the second sidetrack windowing window is finished, continuously drilling by using the windowing milling cone and forming a stable inclined well section with the longitudinal length equal to the longitudinal distance between 2 windows, then taking out the windowing milling cone, then putting the ultra-short radius horizontal drilling combined drilling tool in, finishing the inclined section with the radius of curvature of a meter after reaching the bottom of the stable inclined well section, and continuously drilling and forming an ultra-short radius horizontal branch well bore II when the well inclination reaches 90 degrees.

Compared with the prior art, the invention has the remarkable using effects that:

the inclined fixer does not need to be provided with a special deblocking mechanism, so that the tool is simpler and more reliable in design, and the underground accident rate can be reduced.

The window-opening sidetracking device adopts a recyclable positioner, and the guide inclined plane of the lower positioning body in the recyclable positioner can be matched with the guide inclined body of the inclined fixer at the bottom of the window-opening sidetracking device to be stacked. Before the window sidetracking, according to the design position of the branch well track, the position included angle between the guide inclined plane of the upper positioning body in the recoverable positioner above and the guide inclined body of the inclined fixer below can be preset, and the window sidetracking can be directly arranged in the position. The construction process of measuring the gyroscope is reduced, the method is simple and convenient, and the construction efficiency can be greatly improved.

The recoverable locator does not have setting mechanisms such as anchor tiles and the like, does not need a deblocking mechanism, can be directly salvaged and recovered, has a simple and reliable tool structure, and greatly improves the construction success rate.

The inclined fixer is retained at the lower part of the first branch borehole, so that the effect of guiding the combined drilling tool to descend can be achieved, the reentry capability of the first branch borehole is ensured, and the implementation space of later operation is large.

The formed multiple branch well bores can be used for exploiting one target layer with the same depth in different directions and also can be used for exploiting multiple target layers with different depths, the exploitation mode is more flexible, and the drilling and completion are realizedThe method has higher process applicability, can realize multi-window windowing in the main well, reduces the operation cost, and can achieve the remarkable development effect of cost reduction and efficiency improvement.

In conclusion, the invention has obvious use effect and can generate obvious economic benefit and social benefit.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

fig. 1 is a schematic diagram of the working principle of the present invention.

Fig. 2 is a schematic structural view of the oblique fixer in the window sidetracking directional tool of the present invention.

FIG. 3 is a schematic view of a retrievable locator in the window sidetracking orientation tool of the present invention.

Detailed Description

The drawings are for reference and illustration purposes only and are not intended to limit the scope of the present disclosure. The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the description of the present invention, it is to be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are merely for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention. Further, in the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

Referring to fig. 1 to 3, the multilateral wellbore ultra-short radius windowing and sidetracking directional tool comprises an oblique fixer 1, wherein the oblique fixer 1 is provided with an oblique guiding body 1.4, an oblique guiding rod 1.5 and a slip 1.8, and when the oblique guiding body 1.5 and the oblique guiding ring 1.2 in the oblique fixer 1 are lifted out of a well, the oblique guiding surface of the oblique guiding body 1.4 can be stacked with a recoverable locator 2, wherein:

the recyclable positioner 2 mainly comprises an upper positioning body 2.5, a righting body 2.7 and a lower positioning body 2.11, wherein the upper positioning body 2.5 and the lower positioning body 2.11 are both provided with guide inclined planes, and the angle of the lower guide inclined plane of the lower positioning body 2.11 is the same as that of the guide inclined plane 1.4 of the inclined positioning body in the inclined fixer 1;

a righting block 2.9 is arranged in the righting body 2.7, the upper positioning body 2.5 is connected with the righting body 2.7 and the lower positioning body 2.11 through a fixing pin 2.6, and fishing threads are arranged in the upper positioning body 2.5;

the upper positioning body 2.5 is connected with the positioner back-off rod 2.2 and the positioner upper joint 2.1 in sequence.

The recoverable locator 2 is mainly by lower locating body 2.11, right body 2.7 and last locating body 2.5 grafting and fix through fixed pin 2.6 and become a whole, the half inclined plane structure of lower locating body 2.11 lower part becomes to lead the inclined plane, the angle that the inclined plane was led to lower locating body 2.11 lower part is the same with the angle that leads inclined body 1.4 in the slant fixer 1, can mutually support, realize the windowing of multiple windows in the main well, reduce the operating cost, reach the development effect of cost reduction increase.

On the basis of the first embodiment, the invention also has the following embodiments:

the centralizing body 2.7 is provided with a centralizing block mounting groove in the circumferential direction and at least one group of centralizing blocks 2.9 in the circumferential direction, the block body of the centralizing block 2.9 is provided with a spring mounting hole and is provided with a spring 2.10, two side wing edges of the centralizing block 2.9 are buckled and pressed below a pressing sheet or a pressing sleeve 2.8, and the pressing sheet or the pressing sleeve 2.8 is fixed in the centralizing body 2.7 through a fixing pin 2.6. The pressing sheet is a sheet-shaped body which is pressed on two sides of the righting block mounting groove through a fixing pin cover, the pressing sleeve 2.8 is an annular sleeve which is fixed in a 2.7-ring groove of the righting body on two sides of the righting block mounting groove, and the righting block 2.9 can be fixed in the righting body 2.7 through the two pressing structures. Righting and can setting up the multiunit in the body 2.7 and right 2.9, it has 3 vertical grooves to open at least in week to right the upper middle part excircle of body 2.7, the lower middle part excircle also has 3 vertical grooves to open in week at least, the installation in every groove is right piece 2.9, it has the spring hole to right piece 2.9 bottom design, place spring 2.10 in the spring hole, the top is tight between righting piece 2.9 and tank bottom, right piece 2.9 both ends compress tightly and fasten through fixed pin 2.6 through preforming or pressure cover 2.8. The centralizing block 2.9 is higher than the outer surface of the centralizing body 2.7 under the supporting action of the spring 2.10, and is supported on the inner wall of the shaft to play a role in centralizing in the process of descending. When the card is blocked, the righting block 2.9 can compress the spring 2.10 to contract inwards, and smoothly passes through the blocking position.

The manufacturing length of the centralizing body 2.7 or the number of the centralizing bodies connected in the recoverable locator 2 can be adjusted according to the axial distance between the ultra-short radius horizontal branch well bore I3 and the ultra-short radius horizontal branch well bore II 4. The processing length of the centralizing body 2.7 can be determined according to the axial distance between the ultra-short radius horizontal branch well bore I3 and the ultra-short radius horizontal branch well bore II 4, the length can be increased by increasing the number of the connected centralizing bodies 2.7 in series, and a plurality of groups of centralizing blocks 2.9 can be arranged on the lengthened centralizing body 2.7 in the circumferential direction so as to adjust the distance between the upper positioning body 2.5 and the lower positioning body 2.11 and adjust the longitudinal distances of different sidetracking windows.

The installation direction between the guide slope of the upper positioning body 2.5 in the recoverable positioner 2 and the guide slope of the lower positioning body 2.11 is consistent with the azimuth angle of the track of the lateral branch well and can be stacked in the main well 5, and the angle of the guide slope of the upper positioning body 2.5 in the lower recoverable positioner 2 is the same as that of the guide slope of the lower positioning body 2.11 in the other recoverable positioner 2 stacked on the lower positioning body 2; the oblique fixer 1 is retained in a main borehole 5 below a windowing window of a first 3 ultra-short-radius horizontal branch borehole. The oblique fixer 1 can be used as a supporting tool of a super-short radius horizontal branch well hole of subsequent sidetracking and is retained in a main well hole 5 below a window 3 of the super-short radius horizontal branch well hole.

The upper end of the locator back-off rod 2.2 is in threaded connection with the locator upper joint 2.1, and the lower end of the locator back-off rod 2.2 is provided with a back-off thread and can be connected with the back-off thread of the inner circle at the lower end of the upper locating body 2.5; a salvaging thread is arranged above an inner circular step in the middle of the upper positioning body 2.5, the salvaging thread can be an oil pipe thread or a drill rod joint thread, and the recyclable positioner 2 can be salvaged through an oil pipe column or a drill column connected by a drill rod; the excircle of the lower part of the locator back-off rod 2.2 is provided with a back-off thread, and the locator back-off rod 2.2 is inserted in the inner circle step of the lower part of the upper locating body 2.5 and is connected together through the back-off thread.

A righting ring carrying step is further arranged on the outer circle of the upper portion of the locator back-off rod 2.2, and a locator righting ring 2.3 is mounted outside the locator back-off rod 2.2 above the righting ring carrying step and fixed with a guide inclined plane of the upper locating body 2.5 through a locator righting screw 2.4; the upper part of the locator back-off rod 2.2 is in threaded connection with the locator upper joint 2.1, and the inner cavity of the upper part of the locator upper joint 2.1 is provided with drill rod joint threads or oil pipe threads which can be connected with a drill rod or an oil pipe to feed the tool into the underground. The middle upper part of the locator back-off rod 2.2 is provided with a righting ring carrying step, the locator back-off rod 2.2 above the step is carried by the righting ring, the locator righting ring 2.3 is sleeved outside the locator back-off rod 2.2, the locator righting ring 2.3 is fixed on the guide inclined plane of the upper locating body 2.5 through a locator righting screw 2.4, so that the locator back-off rod 2.2 is kept in the middle, and smooth implementation of back-off and releasing is facilitated.

The lower positioning body 2.11 is provided with a central hole, the inner circle of the upper part of the lower positioning body is provided with an inserting step, the body of the inserting step is uniformly provided with 6 through holes in the circumferential direction, 1 through hole is aligned with the normal direction of the lower guide inclined plane in the circumferential direction, and the lower end of the lower guide inclined plane in the lower positioning body 2.11 is a plane. The flat head structure at the lower end of the guide inclined surface of the lower positioning body 2.11 can prevent self-locking caused by wedging action when being matched with the guide inclined body 1.4 of the inclined fixer 1 or the upper positioning body 2.5 of the recoverable positioner 2.

The excircle of the lower end of the righting body 2.7 is an inserting excircle, 6 counter bores are correspondingly formed in the inserting excircle which upwards corresponds to 6 through holes in the lower positioning body 2.11, and a fixing pin 2.6 can be inserted into the through hole of the lower positioning body 2.11 and the counter bore in the righting body 2.7; when the inserting excircle of the righting body 2.7 is inserted into the inserting step of the lower positioning body 2.11, the counter bores correspond to the through holes one by one, and the lower positioning body 2.11 and the righting body 2.7 are fixed through the fixing pin 2.6; the inner circle of the upper end of the righting body 2.7 is also provided with an inserting step, 6 through holes are uniformly formed in the circumferential direction of the inserting step, the inserting step corresponds to counter bores in an inserting excircle of the lower part of the upper positioning body 2.5 one by one and can be inserted with fixing pins 2.6; a counter bore is arranged in the inserting excircle of the lower part of the upper positioning body 2.5 and is aligned with the normal direction of the guide inclined plane of the upper positioning body 2.5 in the circumferential direction; the inserting excircle at the lower part of the upper positioning body 2.5 is arranged below the guide inclined plane. The upper end of the upper positioning body 2.5 is a guide inclined plane, and the inserting excircle of the lower part is also correspondingly provided with 6 counter bores in the circumferential direction, wherein 1 counter bore is aligned with the normal direction of the guide inclined plane of the upper part in the circumferential direction. When the inserting excircle at the lower part of the upper positioning body 2.5 is inserted into the inserting step of the inner circle at the upper end of the centralizing body 2.7, the counter bores correspond to the through holes one to one, and the fixing pins 2.6 can be inserted for fixing. When the upper positioning body 2.5, the righting body 2.7 and the lower positioning body 2.11 are fixed through the fixing pins 2.6, the upper positioning body 2.5 or the lower positioning body 2.11 can be rotated by 60 degrees in the circumferential direction each time, so that through holes and counter bores in different directions are aligned and installed, and therefore, the included angle between the normal direction of the guide inclined plane of the upper positioning body 2.5 and the normal direction of the guide inclined plane of the lower end of the lower positioning body 2.11 can be selectively adjusted by 0 degree, 60 degrees, 120 degrees, 180 degrees, 240 degrees or 300 degrees, and casing windowing can be performed on different design azimuth angles when different branch wellbores are sidetracked.

The setting directions of the slip teeth of the outer walls of the two sets of slips 1.8 in the oblique fixer 1 are mutually perpendicular, namely: the slip elements in the upper set of slips 1.8 are arranged laterally and the slip elements in the lower set of slips 1.8 are arranged longitudinally and vice versa. The inclined fixer 1 is mainly formed by connecting an inclined guide body 1.4, a hydraulic cylinder sleeve 1.7 and a hydraulic cylinder base 1.17 through threads, a piston 1.10 and a ball seat 1.15 are arranged between the hydraulic cylinder sleeve 1.7 and a central tube 1.11, the excircle of the upper part of the central tube 1.11 is connected with the piston 1.10 through threads, and the ball seat 1.15 and the central tube 1.11 are inserted together. The excircle of ball seat 1.15 lower part is equipped with spacing step, and the design of center tube 1.11 middle and lower parts excircle has the stopping screw thread, is equipped with lock ring 1.14 in the inner chamber of ball seat 1.15 upper end, and lock ring 1.14 suit is on the stopping screw thread of center tube 1.11 outside. The upper part of the ball seat 1.15 is in threaded connection with the locking ring pressing cap 1.13, and the locking ring pressing cap 1.13 is used for limiting the locking ring 1.14 and preventing the backing-off. The ball seat 1.15 outside is an inverted cone structure, and the upper portion excircle of inverted cone structure sets up the rubber ring groove and is equipped with sealing member 1.6, can form sealedly with the inner wall of hydraulic cylinder cover 1.7, and ball seat 1.15 can slide from top to bottom in hydraulic cylinder cover 1.7. The lower part of the ball seat 1.15 is of a hollow step cannula structure, and is inserted into a central hole of the liquid cylinder base 1.17 during assembly and can freely slide in the central hole. Ball seat 1.15 the upper portion of the lower intubate hole is the toper seat, can cooperate and realize sealed with the hitting ball 1.16. At this time, the sealing element 1.6 at the lower part of the piston 1.10, the sealing element 1.6 at the upper part of the ball seat 1.15, the inner wall of the cylinder sleeve 1.7 and the outer wall of the central tube 1.11 form a pressure sealing cavity. A pressure transmission hole 1.12 is arranged in a central tube 1.11 below the piston 1.10, and the pressure transmission hole together form a setting mechanism of the oblique fixer 1. The anchoring mechanism of the oblique fixer 1 is: it has 3 square holes and can place slips 1.8 to open at least in the circumference of the cone corresponding position on hydraulic cylinder cover 1.7 and piston 1.10, and the inner wall of slips 1.8 is arc conical surface structure and cooperatees with the conical body of piston 1.10, fixes both through slips screw 1.9. At least 3 square holes are arranged on the periphery of the position, corresponding to the lower conical surface of the ball seat 1.15, of the hydraulic cylinder sleeve 1.7, and slips 1.8 are also placed in the square holes. The inner wall of the slip 1.8 is an arc conical surface structure and is matched with the conical body of the ball seat 1.15, and the slip and the ball seat are fixed through a slip screw 1.9. The outer surface of the upper slip 1.8 and the lower slip 1.8 is respectively provided with slip teeth which are vertical to each other in the transverse direction or the longitudinal direction, wherein one slip 1.8 is anchored behind the well wall, so that the fixing of the oblique fixer 1 in the axial direction can be ensured, and the other slip 1.8 is anchored behind the well wall, so that the fixation of the oblique fixer 1 in the circumferential direction is ensured, and the supporting stability during the casing windowing operation is facilitated. The middle of the inclined guide body 1.4 is of a through hole structure, the inner cavity of the lower portion and the outer wall are of a double-step structure, small-diameter steps of the outer wall can be inserted into the through hole of the piston 1.10 and sealed through a sealing element 1.6, and the upward working stroke of the piston 1.10 can be limited. The back-off rod 1.5 of the whipstock is inserted into the through hole of the conductive oblique body 1.4, the excircle step at the lower part is designed with a back-off thread, the front end of the back-off thread is provided with an excircle step and can be inserted into the conductive oblique body 1.4 provided with the sealing element 1.6 and tightly extruded at the inner circle step of the conductive oblique body 1.4 to realize sealing. The lower part of the inner circle of the inclined guide body 1.4 is provided with a back-off thread in an inner cavity above the sealing element 1.6, and the back-off thread can be connected with the back-off thread of the inclined device back-off rod 1.5. The middle upper part of the whipstock back-off rod 1.5 is provided with a righting ring carrying step, and the whipstock righting ring 1.2 is sleeved outside the whipstock back-off rod 1.5 above the righting ring carrying step. The whipstock righting ring 1.2 is fixed on the guide inclined plane of the guide inclined body 1.4 through a whipstock righting pin 1.3, so that the whipstock back-off rod 1.5 is ensured to maintain a relatively centered state in the process of descending the well of the whipstock fixer 1. The upper part of the whipstock back-off rod 1.5 is connected with the whipstock upper joint 1.1 through threads, and an inner cavity of the upper part of the whipstock upper joint 1.1 is provided with drill rod joint threads or oil pipe threads which can be connected with a drill string or an oil pipe column and send the whipstock 1 into the underground.

The following description will be given of the method of using the tool for sidetracking in a straight wellbore, i.e., a straight well casing.

The use method of the tool for the ultra-short radius windowing sidetrack drilling orientation of the multilateral wellbore comprises the following steps:

A. setting the oblique fixator 1 in the main borehole 5, milling the casing by using a windowing milling cone, forming a first window in the casing, and starting a windowing drilling tool: firstly, a drill string is connected with the oblique fixer 1 in a main borehole 5 and is lowered to a designed position, after the drill string reaches the designed depth, the normal direction of the oblique guide surface 1.4 of the oblique guide body 1 in the oblique fixer 1 is adjusted through the gyroscope, and the gyroscope is lifted out after the normal direction is consistent with the designed direction of the ultra-short radius borehole track. Before the inclined fixer 1 is set, a pressing ball 1.16 is thrown into a drill string, and the pressing ball 1.16 falls on a conical seat at the middle lower part of a ball seat 1.15 to realize the sealing of the upper space. The hydraulic pressure is applied from the inside of the drill string and is transmitted to a sealing cavity formed by the hydraulic cylinder sleeve 1.7 and a sealing element 1.6 arranged on the outer circle of the ball seat 1.15 and the outer circle of the piston 1.10 through a pressure transmission hole 1.12 on the central pipe 1.11, and the pressure acts on a sealing section formed by the ball seat 1.15, the piston 1.10 and the pressing ball 1.16. Firstly, the slip bolt 1.9 is cut off, the ball seat 1.15 drives the locking ring pressing cap 1.13 to move downwards, the locking ring pressing cap 1.13 pushes the locking ring 1.14 to move downwards on the backstop thread of the central pipe 1.11, and the central pipe 1.11 is locked to prevent withdrawal. And simultaneously, the slip screws 1.9 in the ball seats 1.15 are sheared off, and the inverted cone-shaped structural bodies of the ball seats 1.15 extrude the slips 1.8 outwards and bite into the inner wall of the casing pipe to realize support. The intubate structure of ball seat 1.15 lower part is walked downwards in hydraulic cylinder base 1.17's centre bore, plays on the one hand and rights the effect of centering, and the stopping step on the other hand ball seat 1.15 intubate upper portion plays limiting displacement. Meanwhile, hydraulic pressure acts on a sealing section formed by two groups of sealing elements 1.6 inside and outside the piston 1.10, firstly the piston 1.10 shears the slip screw 1.9 to start to move upwards, the piston 1.10 drives the central pipe 1.11 to move upwards, the distance of the piston 1.10 and the ball seat 1.15 is limited by the retaining thread on the central pipe 1.11 and the locking ring 1.14, and meanwhile, the inverted cone-shaped structural body of the piston 1.10 outwards extrudes the slip 1.8 to bite into the inner wall of the sleeve to realize supporting. The slip teeth on the outer surfaces of the upper slip 1.8 and the lower slip 1.8 are respectively designed to be horizontal or longitudinal, and anchored on the wall of the casing pipe, so that the axial upward fixation of the oblique fixator 1 can be ensured, the circumferential upward fixation of the oblique fixator 1 can be ensured, and the support stability during casing pipe windowing operation is facilitated. After fully setting the anchoring, the drilling string is pushed down to verify the setting reliability, after the setting is successful, the hydraulic pressure in the drilling string is discharged, the drilling string rotates positively, the upper drill rod drives the whipstock back-off rod 1.5 to rotate through the whipstock upper joint 1.1, the whipstock back-off rod 1.5 is released and separated from the guide ramp body 1.4 through the back-off thread at the bottom, the whipstock centering ring 1.2 can ensure that the whipstock back-off rod 1.5 rotates from the middle all the time, and the back-off success rate is improved. After the reversing is successful, the upper joint 1.1 of the whipstock and the reversing rod 1.5 of the whipstock are lifted out of the main borehole 5, and the centering ring on the upper part of the reversing rod 1.5 of the whipstock carries a step to bring the centering ring 1.2 of the whipstock out of the shaft together. And (3) descending a windowing milling cone, grinding and milling the casing pipe under the support and the constraint of the inclined guide body 1.4, windowing in the design direction of the ultra-short radius well hole, and then taking out the windowing drilling tool.

B. The side of the running ultra-short radius horizontal drilling combined drilling tool drills out an ultra-short radius horizontal branch well hole I3, and the drilling tool is lifted out after drilling: the combined drilling tool for the ultra-short-radius horizontal drilling comprises a flexible drill bit, a flexible inclined stabilizer, a flexible drill rod, a conversion joint and a conventional drill rod from bottom to top, and is referred to as 'an ultra-short-radius horizontal drilling flexible drill string and a construction method' with the patent application number of 202011588794. X. When the combined drilling tool reaches the window position of the casing, the drilling tool is slowly lowered, the flexible drill bit is lightly pressed after contacting the inclined surface of the inclined guide body 1.4, the inclined surface of the inclined guide body 1.4 applies lateral reaction force to the flexible drill bit, the lateral reaction force is the same as the design position of the ultra-short radius well track, the flexible drill bit is forced to be bent laterally, the bending direction faces the design position of the ultra-short radius well track, drilling is started, the ultra-short radius horizontal branch well bore I3 is completed, and the ultra-short radius horizontal drilling combined drilling tool is started.

C. Adjusting a normal included angle of a guide slope between a lower positioning body 2.11 and an upper positioning body 2.5 in the recoverable positioner 2 according to an azimuth included angle of a well hole between the ultra-short radius horizontal branch well hole I3 and the ultra-short radius horizontal branch well hole II 4;

D. putting the recoverable positioner 2 in, stacking the lower positioner 2.11 on the inclined guide body 1.4 of the inclined fixer 1, milling the casing by using a windowing milling cone, forming a second window in the casing or continuously forming a next window in different target layers or the same target layer in the casing according to the steps C and D, and taking out a windowing drilling tool;

E. according to the construction design, sidetracking the second ultra-short radius horizontal branch well hole 4 in different target layers or sidetracking the second ultra-short radius horizontal branch well hole 4 in the same target layer: and (3) putting the ultra-short radius horizontal drilling combined drilling tool into the well, sidetracking the ultra-short radius horizontal branch well bore two 4 and the next ultra-short radius horizontal branch well bore, and taking out the drilling tool after drilling.

Now, taking an example that the azimuth included angle between the ultra-short radius horizontal branch wellbore one 3 and the ultra-short radius horizontal branch wellbore two 4 is 180 degrees, the drilling process of the ultra-short radius horizontal branch wellbore two 4 will be described. Firstly, when the recyclable positioner 2 is assembled, the normal directions of the guide inclined surfaces in the lower positioning body 2.11 and the upper positioning body 2.5 are adjusted to form an included angle of 0 degree between the normal directions, and the recyclable positioner is fixed through the fixing pin 2.6. The drill rod is used for connecting the upper connector 2.1 of the positioner, the recoverable positioner 2 is put into a well casing, the inclined guide surface of the lower positioner 2.11 is attached to the inclined guide surface of the inclined guide body 1.4 in the inclined fixer 1 in the well, namely, the included angle between the inclined guide surfaces in the two directions is 180 degrees. At this time, the normal direction of the inclined guide surface of the upper positioning body 2.5 and the normal direction of the inclined guide surface of the inclined guide body 1.4 form an included angle of 180 degrees. The flat head structure of the lower end of the guide inclined plane at the lower part of the lower positioning body 2.11 prevents the guide inclined plane wedged between the guide inclined plane of the guide inclined body 1.4 and the shaft from generating self-locking to bring difficulty to later fishing. The centralizing block 2.9 arranged on the centralizing body 2.7 is tightly propped outwards through the spring 2.10, is higher than the outer surface of the centralizing body 2.7, has the maximum outer diameter larger than the inner wall of the casing pipe, can be supported on the inner wall of the casing pipe, and plays a role in centralizing. The drill column is properly pressed downwards to detect the bottom, after the recoverable positioner 2 is determined to be in place, the drill column is rotated forwards, the upper drill rod drives the positioner reversing rod 2.2 to rotate through the positioner upper connector 2.1, the positioner reversing rod 2.2 is separated from the upper positioner 2.5 release through the reversing thread at the bottom, and the positioner righting ring 2.3 can ensure that the positioner reversing rod 2.2 rotates all the way in the middle, so that the reversing success rate is improved. After the reversing is successful, the upper connector 2.1 of the locator and the reversing rod 2.2 of the locator are lifted out of the shaft, and the centralizing ring on the upper portion of the reversing rod 2.2 of the locator carries a step to bring the centralizing ring 2.3 of the locator out of the shaft together.

And (3) a lower-entering windowing milling cone, a lower milling sleeve and a windowing tool are milled under the support and restriction of the upper positioning body 2.5, and the windowing drilling tool is pulled out after the windowing is finished because the normal direction of the inclined guide surface of the upper positioning body 2.5 is opposite to the normal direction of the inclined guide body 1.4 and the windowing direction forms an included angle of 180 degrees with the direction of the ultra-short-radius horizontal branch well bore I3. And (4) putting the ultra-short radius horizontal drilling combined drilling tool into the well to start drilling, and after finishing the ultra-short radius horizontal branch well hole II 4, taking out the ultra-short radius horizontal drilling combined drilling tool. The longitudinal distance between the windows of the ultra-short radius horizontal branch well bore I3 and the ultra-short radius horizontal branch well bore II 4 can be realized by adjusting the length of the righting body 2.7, and can also be realized by installing different numbers of the righting bodies 2.7. The azimuth included angle between the ultra-short radius horizontal branch well bore I3 and the ultra-short radius horizontal branch well bore II 4 can be achieved by adjusting the normal included angle of the guide inclined plane between the upper positioning body 2.5 and the lower positioning body 2.11.

F. And (3) putting a flexible screen pipe into the main well bore 5 and the ultra-short radius horizontal branch well bore I3 positioned at the lowermost layer to perform sand control completion.

The method for sidetracking the ultra-short radius horizontal branch well bore two 4 in different target layers is characterized in that after the window of the ultra-short radius horizontal branch well bore two 4 is milled, the down-going ultra-short radius horizontal drilling combined drilling tool starts to make deviated drilling just after going out of the window, a deviated section is finished by the curvature radius of 3-5 meters, and the drilling is continued to form the ultra-short radius horizontal branch well bore two 4 when the well deviation reaches 90 degrees. The concrete construction method is as follows: and after the casing windowing window needed by the ultra-short radius horizontal branch well bore II 4 is milled, the ultra-short radius horizontal drilling combined drilling tool is lowered into the ultra-short radius horizontal drilling combined drilling tool, and the ultra-short radius horizontal drilling combined drilling tool comprises a flexible drill bit, a flexible steady-inclination centralizer, a flexible drill rod, a conversion joint and a conventional drill rod from bottom to top. When the combined drilling tool reaches the position of the windowing window, the drilling tool is slowly lowered, the flexible drill bit is slightly pressed after touching the guide inclined plane of the upper positioning body 2.5, the flexible drill bit is forced to bend towards the design position of the ultra-short radius well track, and drilling is started. Namely, the window is just opened, the deflecting section is finished by the curvature radius of 3-5m, and when the well deflection reaches 90 degrees, the horizontal branch well hole is formed by continuously drilling. The ultra-short radius horizontal branch well bore I3 and the ultra-short radius horizontal branch well bore II 4 formed in the way have the longitudinal distance equal to the longitudinal distance between the 2 windows, and can be used for mining the target zones with different depths.

The method for sidetracking the ultra-short-radius horizontal branch well bore two 4 in the same target layer comprises the steps of lowering the ultra-short-radius horizontal drilling combination drilling tool after the first sidetracking windowing window is finished, finishing a deflecting section with the curvature radius of 3-5 meters when the flexible drill bit just comes out of the window, and continuously drilling to form the ultra-short-radius horizontal branch well bore one 3 when the well deflection reaches 90 degrees; and after the second sidetrack windowing window is finished, continuing drilling by using the windowing milling cone and forming a stable inclined well section with the longitudinal length equal to the longitudinal distance between 2 windows, then taking out the windowing milling cone, lowering the ultra-short radius horizontal drilling combined drilling tool again, finishing the inclined section with the curvature radius of 3-5 meters after reaching the bottom of the stable inclined well section, and continuing drilling and forming an ultra-short radius horizontal branch well bore II 4 when the well inclination reaches 90 degrees. The ultra-short radius horizontal lateral wellbore one 3 and the ultra-short radius horizontal lateral wellbore two 4 may also produce the same zone of interest, as described above: and after the first window is finished, a combined drilling tool for ultra-short-radius horizontal drilling is put in, the deviation making section is finished by the curvature radius of 3-5 meters just after the first window is opened, and the first ultra-short-radius horizontal branch well bore 3 is formed by continuously drilling when the well deviation reaches 90 degrees. And after the second sidetrack windowing window is finished, continuing drilling by using the windowing milling cone to form a steady-slope well section with a certain length, wherein the longitudinal length of the steady-slope well section is equal to the longitudinal distance between 2 windows, then starting the windowing milling cone, putting into the ultra-short-radius horizontal drilling combined drilling tool, and finishing the deflecting section with the curvature radius of 3-5 meters only when the well bottom of the steady-slope well section is reached. And when the well deviation reaches 90 degrees, the ultra-short-radius horizontal branch well bore two 4 is formed by continuously drilling, so that the ultra-short-radius horizontal branch well bore one 3 and the ultra-short-radius horizontal branch well bore two 4 are positioned at the same depth, and the same target zone can be produced in different directions.

In the same way, one or more groups of the recoverable localizers 2 can be put in again, and the window sidetracking is carried out to form the ultra-short radius horizontal branch boreholes which have different azimuth angles and different depths and can be used for different destination layers or the same destination layer. After all branch boreholes are drilled, a fishing tool is put in and is connected with the fishing thread of the upper positioning body 2.5 in the recoverable positioner 2, and the recoverable positioner 2 can be separated from the inclined fixer 1 by lifting and the mineshaft can be fished out. And (4) fishing out all the recoverable positioners 2 in sequence, and only leaving the bottommost inclined fixer 1 in the main well hole 5. And then, a flexible sand control screen is put in, the flexible sand control screen can be smoothly put in the ultra-short-radius horizontal branch well bore I3 under the guiding action of the oblique fixer 1 at the bottom, the sand control screen at the upper part is suspended in the main well bore 5 through the tail pipe hanger, and the tail pipe hanger is positioned on the uppermost branch well bore, so that the sand control completion of the main well bore 5 and the first branch well bore, namely the ultra-short-radius horizontal branch well bore I3 in the figure is realized.

The embodiments described above are merely exemplary embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and teaching of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the form and details may be made therein without departing from the spirit and scope of the invention. Any modification, equivalent replacement, improvement and the like made within the spirit and inventive concept of the present invention should be included in the protection scope of the present invention. The scope of protection is therefore not limited to the description above.

Claims (12)

1. Multilateral borehole ultrashort radius sidetracking orientation tool of windowing, including slant fixer (1), slant fixer (1) is equipped with leads italic (1.4), slant buckle bar (1.5) and slips (1.8), characterized by, works as slant buckle bar (1.5) and slant ware in slant fixer (1) are right ring (1.2) and are carried to the back outside the well, lead the inclined plane of leading of italic (1.4) and can stack with recoverable locator (2), wherein: the recyclable positioner (2) mainly comprises an upper positioning body (2.5), a righting body (2.7) and a lower positioning body (2.11), wherein the upper positioning body (2.5) and the lower positioning body (2.11) are both provided with guide inclined planes, and the angle of the guide inclined plane at the lower part of the lower positioning body (2.11) is the same as that of the guide inclined plane of the guide inclined body (1.4) in the oblique fixer (1);

a righting block (2.9) is arranged in the righting body (2.7), an upper positioning body (2.5) is connected with the righting body (2.7) and a lower positioning body (2.11) through a fixing pin (2.6), and fishing threads are arranged in the upper positioning body (2.5);

the upper positioning body (2.5) is connected with the reverse buckling rod (2.2) of the positioner and the upper joint (2.1) of the positioner in sequence.

2. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool according to claim 1, characterized in that the centralizing body (2.7) is provided with a centralizing block mounting groove in the circumferential direction and at least one set of centralizing blocks (2.9) in the circumferential direction, the centralizing block (2.9) is provided with a spring mounting hole in the block body and is provided with a spring (2.10), the two side flanges of the centralizing block (2.9) are buckled and pressed under a pressing sheet or a pressing sleeve (2.8), and the pressing sheet or the pressing sleeve (2.8) is fixed in the centralizing body (2.7) through a fixing pin (2.6).

3. Multilateral wellbore ultrashort radius windowed sidetracking orientation tool according to claim 1 or 2, characterized in that the manufacturing length of the centralizing body (2.7) or the number of connections in the retrievable locator (2) can be adjusted according to the distance in the axial direction between the ultrashort radius horizontal lateral branch wellbore one (3) and the ultrashort radius horizontal lateral branch wellbore two (4).

4. The tool of claim 3, wherein the retrievable locator (2) has a configuration in which the lead-in slant of the upper locator (2.5) and the lead-in slant of the lower locator (2.11) are oriented in the same direction as the azimuth of the track of the lateral bore and can be stacked in the main bore (5), and the angle of the lead-in slant of the upper locator (2.5) of the lower retrievable locator (2) is the same as the angle of the lead-in slant of the lower locator (2.11) of the lower retrievable locator (2) stacked thereon; the oblique fixator (1) is retained in a main well hole (5) below a windowing window of a first ultra-short-radius horizontal branch well hole (3).

5. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool according to claim 1, characterized in that the upper end of the locator back-off rod (2.2) is in threaded connection with the locator upper connector (2.1), the lower end of the locator back-off rod (2.2) is provided with a back-off thread and can be in threaded connection with the back-off thread of the inner circle of the lower end of the upper locating body (2.5); fishing threads are arranged above the inner circular step in the middle of the upper positioning body (2.5); the excircle of the lower part of the locator back-off rod (2.2) is provided with back-off threads, and the locator back-off rod (2.2) is inserted in the inner circle step of the lower part of the upper locating body (2.5) and is connected together through the back-off threads.

6. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool of claim 5, characterized in that the upper excircle of the locator reversing rod (2.2) is further provided with a centering ring carrying step, and the locator centering ring (2.3) is installed outside the locator reversing rod (2.2) above the centering ring carrying step and fixed with the guide slope of the upper locating body (2.5) through a locator centering screw (2.4); the upper part of the locator back-off rod (2.2) is in threaded connection with the locator upper joint (2.1), and the inner cavity of the upper part of the locator upper joint (2.1) is provided with drill rod joint threads or oil pipe threads.

7. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool according to claim 4, characterized in that the lower positioning body (2.11) is provided with a central hole and the upper inner circle is provided with an insertion step, 6 through holes are evenly opened in the circumferential direction of the insertion step body and 1 of the through holes is aligned with the normal direction of the lower guiding bevel in the circumferential direction, and the lower end of the guiding bevel in the lower positioning body (2.11) is a plane.

8. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool of claim 7, characterized in that the outer circle of the lower end of the righting body (2.7) is a plugging outer circle, 6 counter bores are correspondingly formed in the plugging outer circle upwards corresponding to the 6 through holes in the lower positioning body (2.11), and the fixing pin (2.6) can be inserted into the through hole of the lower positioning body (2.11) and the counter bore in the righting body (2.7); when the inserting excircle of the righting body (2.7) is inserted into the inserting step of the lower positioning body (2.11), the counter bores correspond to the through holes one by one, and the lower positioning body (2.11) and the righting body (2.7) are fixed through the fixing pin (2.6); the inner circle of the upper end of the righting body (2.7) is also provided with an inserting step, 6 through holes are uniformly formed in the circumferential direction of the inserting step, the inserting step corresponds to counter holes in an inserting excircle at the lower part of the upper positioning body (2.5) one by one and can be inserted with fixing pins (2.6); a counter bore is arranged in the inserting excircle at the lower part of the upper positioning body (2.5) and is aligned with the normal direction of the guide inclined plane of the upper positioning body (2.5) in the circumferential direction; the inserting excircle at the lower part of the upper positioning body (2.5) is arranged below the guide inclined plane.

9. The multilateral wellbore ultrashort radius windowing sidetrack drilling orientation tool according to claim 1, characterized in that the setting directions of the slips teeth of the outer wall of the two sets of slips (1.8) in the slant holder (1) are perpendicular to each other.

10. A method of use for the multilateral wellbore ultrashort radius windowed sidetracking orientation tool of claim 4, comprising the steps of:

A. setting the oblique fixator (1) in a main borehole (5), milling a casing by using a windowing milling cone, forming a first window in the casing, and starting a windowing drilling tool;

B. the side of the ultra-short radius horizontal drilling combined drilling tool is lowered to drill a first ultra-short radius horizontal branch well hole (3), and the drilling tool is lifted out after drilling is finished;

C. adjusting a normal included angle of a guide slope between a lower positioning body (2.11) and an upper positioning body (2.5) in the recoverable positioner (2) according to an azimuth included angle of a well hole between the ultra-short radius horizontal branch well hole I (3) and the ultra-short radius horizontal branch well hole II (4);

D. putting the recyclable positioner (2) in, stacking the lower positioner (2.11) on the inclined guide body (1.4) of the inclined fixer (1), milling the casing by using a windowing milling cone, forming a second window in the casing or continuously forming a next window in different target layers or the same target layer in the casing according to the steps C and D, and taking out the windowing drilling tool;

E. according to construction design, sidetracking ultra-short radius horizontal branch well bores II (4) in different target layers or sidetracking ultra-short radius horizontal branch well bores II (4) in the same target layer;

F. and (3) putting a flexible screen pipe into the main well hole (5) and the ultra-short radius horizontal branch well hole I (3) positioned at the lowermost layer to perform sand control completion.

11. The method for using the tool for lateral drilling of the ultra-short radius windowed lateral drilling directional tool of the multilateral wellbore of claim 10, wherein the method for lateral drilling of the ultra-short radius horizontal branch wellbore two (4) in different target layers is that after the milling of the window of the ultra-short radius horizontal branch wellbore two (4) is completed, the downward ultra-short radius horizontal drilling combination drilling tool starts to perform the deflecting drilling just after going out of the window, the deflecting section is completed with the curvature radius of 3-5 meters, and the drilling is continued to form the ultra-short radius horizontal branch wellbore two (4) when the well deflection reaches 90 degrees.

12. The method of using the multilateral wellbore ultrashort radius windowing and sidetracking directional tool according to claim 10, wherein the method of sidetracking the ultrashort radius horizontal lateral wellbore two (4) in the same destination zone is to put in the ultrashort radius horizontal drilling combination drilling tool after the first sidetracking windowing window is finished, the flexible drill bit starts to finish the deflecting section with the curvature radius of 3-5 meters just after coming out of the window, and continues to drill to form the ultrashort radius horizontal lateral wellbore one (3) when the well deflection reaches 90 °; and after the second sidetrack windowing window is finished, continuously drilling by using the windowing milling cone and forming a steady-slope well section with the longitudinal length equal to the longitudinal distance between 2 windows, then taking out the windowing milling cone, lowering the ultra-short-radius horizontal drilling combined drilling tool again, finishing the deflecting section with the curvature radius of 3-5 meters after reaching the bottom of the steady-slope well section, and continuously drilling and forming an ultra-short-radius horizontal branch well bore II (4) when the well deflection reaches 90 degrees.

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