A drill string sub to prevent sticking and method of use

Abstract

The present application relates to a kind of drill string short section of preventing sticking and its using method, and the short section short section upper joint, short section body and short section lower joint;The short section body is arranged between the short section upper joint and short section lower joint, and the short section body surface is provided with the rock breaking cutting tooth structure for breaking the cuttings in annulus and hydraulic pulse perforating structure;The short section upper joint is connected with drill string by internal thread, and the short section upper joint is equipped with the rock breaking control device for controlling the hydraulic pulse perforating structure;The short section lower joint is connected with drill string by external thread, and is close to drill bit.Therefore, the present application can be widely used in the field of oil and gas drilling.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas drilling, mainly applied to the drilling short section for preventing annular mud cake and sticking in the oil field, in particular to a drilling string short section for preventing sticking and a using method thereof. BACKGROUND

[0002] The shallow gas layer in the seabed is a common geological phenomenon and also a most dangerous geological factor of marine disaster. According to the causes, it is generally divided into two categories. One is mainly biogenic gas (marsh gas), and its main components are methane, carbon dioxide, hydrogen sulfide, nitrogen, ammonia and the like. The other is oil and natural gas which migrates to the shallow layer through the channels such as deep faults, fissures and unconformity surfaces. However, no matter which kind of gas, they generally exist in the form of interlayer gas and gas in the sediment. The gas in the sediment changes the mechanical properties of the sediment layer soil, reduces the strength, loosens the structure, destroys the original stability of the soil layer and reduces the bearing capacity of the foundation. Under the action of external load, the gas-containing sediment will creep, resulting in subsidence, lateral or rotational sliding, and finally losing balance and tilting and collapsing. Once the stratum collapses, the drilling string will be stuck or buried.

[0003] Meanwhile, a large amount of cuttings will be generated in the process of drilling by the drill bit grinding the stratum. The cuttings are returned to the ground from the annulus between the drill string and the well wall with the drilling fluid. When a large amount of cuttings, especially large cuttings, are accumulated in the annulus, they will form mud cake and adhere to the well wall or drill pipe, resulting in a large friction force between the drill string and the well wall, a large torque borne by the drill string, and drilling accidents such as sticking and torsional fracture of the drill string. Therefore, it is particularly important for drilling operation to break the large cuttings, accelerate the cuttings return and prevent the formation of mud cake.

[0004] The existing technology mainly connects a special drill string short section with a protrusion to stir the dispersed cuttings in the annulus by rotating the drill pipe, so as to prevent the cuttings from gathering and achieve the purpose of preventing mud cake. However, this method has good application effect in hard stratum, but cannot break the formed mud cake and can only stop drilling to remove the fault. SUMMARY

[0005] In view of the above problems, the present application aims to provide a drill string short section for preventing sticking and a using method thereof, which can effectively solve the problem of unsatisfactory cuttings removal effect of the existing technology.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] In a first aspect, the present application provides a drill string short section for preventing sticking, which comprises:

[0008] a short section upper joint, a short section main body and a short section lower joint;

[0009] The short section body is arranged between the short section upper joint and the short section lower joint, and the short section body surface is provided with rock breaking cutting tooth structure and hydraulic pulse perforation structure for breaking the cuttings in the annulus;

[0010] The short section upper joint is connected with the drill string through internal thread, and the short section upper joint is internally provided with rock breaking control device for controlling the hydraulic pulse perforation structure;

[0011] The short section lower joint is connected with the drill string near the drill bit end through external thread.

[0012] Further, the rock breaking cutting tooth structure adopts rock breaking cutting tooth array, which is composed of a plurality of rock breaking cutting tooth line arrays arranged around the short section body surface, and each rock breaking cutting tooth line array is parallel to the axis of the short section body.

[0013] Further, each rock breaking cutting tooth line array includes a plurality of rock breaking cutting teeth arranged at intervals, the rock breaking cutting teeth are barb type structure, including front teeth and rear blades, and the front teeth face counterclockwise direction, and the rear blades face the rotation direction of the drill pipe during normal drilling.

[0014] Further, the blade surface of the front teeth is wider than the rear blades, and the front teeth and the rear blades are composed of three cutting edges with decreasing cutting levels.

[0015] Further, the hydraulic pulse perforation structure adopts hydraulic pulse perforation array, which is composed of a plurality of hydraulic pulse perforation line arrays arranged around the short section body surface, and each hydraulic pulse perforation line array is arranged at intervals between two rock breaking cutting tooth line arrays and parallel to the axis of the short section body.

[0016] Further, the number of the hydraulic pulse perforation line array and the rock breaking cutting tooth line array is eight.

[0017] Further, each hydraulic pulse perforation line array includes a plurality of hydraulic pulse perforations arranged at intervals on the perforation arrangement surface and a water tank connected with each hydraulic pulse perforation in the hydraulic pulse perforation line array;

[0018] Each hydraulic pulse perforation is arranged at a position different from the rock breaking cutting teeth in the rock breaking cutting tooth array, at the center point of the adjacent four rock breaking cutting teeth in the rock breaking cutting tooth array.

[0019] The water tank is arranged in the inner interlayer of the short section body, the water inlet of the water tank is connected with the ground water supply equipment, a groove is arranged beside the water outlet of the water tank, a metal baffle is slidably arranged in the groove through two groups of pulleys and transmission shafts, for shielding each hydraulic pulse perforation, and exposing the hydraulic pulse perforation under the control of the rock breaking control device.

[0020] Further, the short section upper joint is internally provided with an inner interlayer for arranging a single-chip microcomputer and a power supply lithium battery, and the single-chip microcomputer is further connected with the transmission shaft through a cable line extending to the inner interlayer of the short section main body and receives a remote control instruction through a wireless signal receiving device arranged therein to control the transmission shaft to drive the metal baffle to expose the hydraulic pulse perforation.

[0021] Further, the short section upper joint is internally provided with an inner interlayer for arranging a single-chip microcomputer and a power supply lithium battery, and the single-chip microcomputer is further connected with the transmission shaft through a cable line extending to the inner interlayer of the short section main body and receives a remote control instruction through a wireless signal receiving device arranged therein to control the transmission shaft to drive the metal baffle to expose the hydraulic pulse perforation.

[0022] Secondly, the application provides a use method of the drill string short section for preventing sticking, which comprises the following steps:

[0023] 1) installing the drill string short section for preventing sticking at a position close to a drill bit of a drill string between a mud pulse signal generator and a mud pulse signal receiver;

[0024] 2) breaking rock cuttings through the rock breaking tooth structure when normally drilling a formation or back reaming;

[0025] 3) when a mud cake is formed on the surface of the short section main body, remotely controlling the hydraulic pulse perforation structure through a wellhead operation platform to form a jet flow to remove the mud cake on the surface of the short section main body.

[0026] The application has the following advantages due to the above technical scheme:

[0027] 1) The drill string short section for preventing sticking provided by the application has two functions of preventing sticking, can break large rock cuttings of hard formations and assist in destroying a rock cutting bed through the rock breaking tooth structure arranged on the surface of the short section main body when normally drilling a formation or back reaming, and can form a jet flow through the hydraulic pulse perforation structure to remove a mud cake when the mud cake is formed on the surface of the drill string.

[0028] 2) In the hydraulic pulse perforation structure, the metal baffle is arranged in the inner interlayer of the short section main body in a sliding manner, which can effectively prevent the perforation from being blocked by rock cuttings when normally drilling a formation or back reaming.

[0029] 3) The rock breaking tooth array and the hydraulic pulse perforation array can be freely configured according to different formation geological conditions, have high flexibility, and have a wide application range.

[0030] 4) In the rock breaking tooth array, the rock breaking tooth adopts a barb type structure, which can be respectively applied to preventing sticking problems of hard formations and loose formations when rotating clockwise and counterclockwise.

[0031] Therefore, the application can be widely applied to the field of oil and gas drilling. Attached Figure Description

[0032] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0033] Figure 1 This is a schematic diagram of the drill string sub installation provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the drill string sub provided in an embodiment of the present invention;

[0035] Figure 3 This is an exploded structural diagram of the cutting teeth provided in an embodiment of the present invention;

[0036] Figure 4a and Figure 4b These are cross-sectional views of the short section body and exploded structural views of the sliding groove provided in the embodiments of the present invention;

[0037] Figure 5a and Figure 5b These are cross-sectional views of the short section body and its perforation sections provided in the embodiments of the present invention;

[0038] Figure 6 This is a cross-sectional view of the upper joint of the drill string sub provided in an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0040] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0041] Some embodiments of the present application provide a drill string segment for preventing pipe sticking, which can effectively break large rock cuttings by using surface rock breaking cutting teeth, the rock breaking cutting teeth have front teeth and back blades, the front teeth can be used to break rocks during normal drilling, and the back blades can be used to cut and assist in breaking the rock cutting bed during back reaming. Meanwhile, perforation is arranged between the rock breaking cutting teeth, which can use hydraulic pulse to remove the formed mud cake. Thus, the problem of unsatisfactory rock cutting removal effect in the prior art can be effectively solved.

[0042] Meanwhile, some other embodiments of the present application also provide a method for using the drill string segment for preventing pipe sticking.

[0043] Embodiment 1

[0044] As shown in Figure 1 , Figure 2 , the present embodiment provides a drill string segment for preventing pipe sticking, which comprises a segment upper joint 6, a segment main body 7 and a segment lower joint 8. The segment main body 7 is arranged between the segment upper joint 6 and the segment lower joint 8, and the surface of the segment main body 7 is provided with rock breaking cutting tooth structures for breaking rock cuttings in the annulus and hydraulic pulse perforation structures; the segment upper joint 6 is connected to the drill string through internal threads, and the segment upper joint 6 is internally provided with rock breaking control devices for controlling the hydraulic pulse perforation structures; the segment lower joint 8 is connected to the drill string through external threads and is close to the drill bit 3.

[0045] Preferably, the rock breaking cutting tooth structure adopts a rock breaking cutting tooth array, which is composed of a plurality of rock breaking cutting tooth line arrays arranged around the surface of the segment main body 7, and each rock breaking cutting tooth line array is parallel to the axis of the segment main body 7. In field application, different numbers of rock breaking cutting tooth arrays can be arranged according to the actual drilling formation, and preferably, the number of rock breaking cutting tooth line arrays is eight.

[0046] Preferably, as shown in Figure 3 , each rock breaking cutting tooth line array comprises a plurality of rock breaking cutting teeth 9 arranged at intervals. The rock breaking cutting tooth 9 is a barb structure, comprising a front tooth 12 and a back blade 13, and the front tooth 12 of each rock breaking cutting tooth 9 faces the counterclockwise direction, and the back blade 13 of each rock breaking cutting tooth 9 faces the direction of rotation of the drill pipe during normal drilling.

[0047] More preferably, the blade face of the front tooth 12 is wider than the back blade 13, and the front tooth 12 and the back blade 13 each comprise three cutting levels of cutting edges, i.e., a first cutting edge 14, a second cutting edge 15 and a third cutting edge 16, and the sharpness of the cutting edges gradually decreases from the first level to the third level (the cutting level represents the sharpness of the cutting edge: the first level is the sharpest with a thin blade face; the second level is the second; the third level has a relatively blunt blade face).

[0048] Preferably, as shown in Figure 4a andFigure 4b As shown, the hydraulic pulse perforation structure adopts a hydraulic pulse perforation array, which is composed of a plurality of hydraulic pulse perforation line arrays arranged around the surface of the short section body 7, and each hydraulic pulse perforation line array is arranged between two rock cutting tooth line arrays and parallel to the axis of the short section body 7. In field application, different numbers of hydraulic pulse perforation arrays can be arranged according to the actual drilling formation, and preferably, the number of hydraulic pulse perforation line arrays is eight.

[0049] Preferably, each hydraulic pulse perforation line array includes a plurality of hydraulic pulse perforations 10 arranged on the perforation arrangement surface 11 and a water tank 19 arranged in the short section body 7 and connected to each hydraulic pulse perforation 10 in the hydraulic pulse perforation line array. Each hydraulic pulse perforation 10 is arranged in a staggered manner with the rock cutting teeth 9 in the rock cutting tooth array and is located at the center point of the four connected rock cutting teeth 9 in the rock cutting tooth array, that is, the number of hydraulic pulse perforations in each hydraulic pulse perforation line array is one less than the number of rock cutting teeth in the rock cutting tooth line array. The water tank 19 is arranged in the inner interlayer of the short section body 7, the water inlet of the water tank 19 is connected to the ground water supply equipment, a groove 18 is arranged beside the water outlet of the water tank 19, a metal baffle 17 is slidably arranged in the groove 18 through two groups of pulleys 20 and a transmission shaft 21, and the metal baffle 17 is used to shield each hydraulic pulse perforation 19 to prevent the hydraulic pulse perforation from being blocked. The metal baffle 17 is slidably controlled under the control of the rock control device to expose the hydraulic pulse perforation 19.

[0050] Preferably, as shown in Figure 5a , Figure 5b , Figure 6 The inner interlayer of the short section upper joint 6 is provided with a single-chip microcomputer 22 and a power supply lithium battery 23, and the single-chip microcomputer 22 is provided with a wireless signal receiving device for controlling the transmission shaft 21 to drive the metal baffle 17 to slide and expose the hydraulic pulse perforation 19 after receiving the remote control instruction.

[0051] Preferably, the short section upper joint 6 is also provided with a buckle at the inner radial position, and the short section lower joint 8 is provided with a buckle at the outer radial position to prevent the thread from loosening when the drill string short section rotates.

[0052] Embodiment 2

[0053] Based on the drill string short section for preventing sticking provided in the above embodiment, the present embodiment provides a method for using the drill string short section for preventing sticking, which comprises the following steps:

[0054] 1) As shown in Figure 1 , on the wellhead operation platform 1, the drill string short section for preventing sticking 2 is installed at the near-bit 3 of the drill string, and the drill string is also provided with a mud pulse signal generator 4 and a mud pulse signal receiver 5.

[0055] 2) When drilling in normal formation or reverse reaming, the large rock debris is broken by the rock-breaking cutting tooth structure.

[0056] Specifically, when drilling in normal formation, the hydraulic pulse perforation 10 is shielded by the metal baffle 17, and the front teeth 12 of the rock-breaking cutting teeth 9 on the surface of the drill string body 7 are used to break the large rock debris. When reverse reaming, the hydraulic pulse perforation 10 is shielded by the metal baffle 17, and the rear blade 13 of the rock-breaking cutting teeth 9 on the surface of the short section body 7 is used to cut the rock debris, assisting in breaking the rock debris bed.

[0057] 3) When the surface of the short section body 7 has formed a mud cake, the hydraulic pulse perforation structure is remotely controlled by the wellhead operation platform 1 to form a jet to remove the mud cake on the surface of the short section body 7.

[0058] When the surface of the short section body 7 has formed a mud cake, the single-chip microcomputer 22 is remotely controlled by the wellhead operation platform 1 to control the metal baffle 17 to slide into the groove 18 in the interlayer of the drill string body 7, exposing the hydraulic pulse perforation 10, transmitting the control signal to the mud pulse signal receiver 5 through the mud pulse signal generator 4, thereby controlling the hydraulic pulse to form a jet to remove the mud cake on the surface of the short section body 7, further preventing the drill pipe from being stuck.

[0059] The drill string short section for preventing the drill pipe from being stuck has two functions of preventing the drill pipe from being stuck. The rock-breaking cutting teeth on the surface of the drill string body are respectively suitable for breaking the large rock debris in hard formation and assisting in breaking the rock debris bed when drilling in normal formation and reverse reaming, preventing the drill pipe from being stuck. The hydraulic pulse perforation shielded by the metal baffle on the surface of the drill string body can remove the formed mud cake. The array of rock-breaking cutting teeth on the surface of the drill string body and the array of hydraulic pulse perforations can be freely configured according to different formation geological conditions, having high flexibility and wide application range.

[0060] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A drill string segment for preventing sticking, characterized in that, It comprises: a short section upper joint, a short section body and a short section lower joint; The short section body is arranged between the short section upper joint and the short section lower joint, and the surface of the short section body is provided with rock breaking cutting tooth structure and hydraulic pulse perforation structure for breaking the cuttings in the annulus; The short section upper joint is connected with the drill string through internal threads, and the short section upper joint is internally provided with rock breaking control device for controlling the hydraulic pulse perforation structure; The short section lower joint is connected with the drill string near the drill bit through external threads; The rock breaking cutting tooth structure adopts rock breaking cutting tooth array, which is composed of a plurality of rock breaking cutting tooth line arrays arranged around the surface of the short section body, and each rock breaking cutting tooth line array is parallel to the axis of the short section body; Each rock breaking cutting tooth line array comprises a plurality of rock breaking cutting teeth arranged at intervals, the rock breaking cutting teeth are of barb type structure, comprising front teeth and rear blades, and the front teeth face counterclockwise direction, and the rear blades face the rotation direction of the drill pipe during normal drilling; The hydraulic pulse perforation structure adopts hydraulic pulse perforation array, which is composed of a plurality of hydraulic pulse perforation line arrays arranged around the surface of the short section body, and each hydraulic pulse perforation line array is arranged at intervals between two rock breaking cutting tooth line arrays and parallel to the axis of the short section body; Each hydraulic pulse perforation line array comprises a plurality of hydraulic pulse perforations arranged at intervals on the perforation arrangement surface and a water tank connected with each hydraulic pulse perforation in the hydraulic pulse perforation line array; Each hydraulic pulse perforation is arranged in a staggered manner with the rock breaking cutting teeth in the rock breaking cutting tooth array, and is located at the center point of the adjacent four rock breaking cutting teeth in the rock breaking cutting tooth array; The water tank is arranged in the inner interlayer of the short section body, the water inlet of the water tank is connected with the ground water supply equipment, a groove is arranged beside the water outlet of the water tank, a metal baffle is slidably arranged in the groove through two groups of pulleys and a transmission shaft, and the metal baffle is used for shielding each hydraulic pulse perforation and exposing the hydraulic pulse perforation under the control of the rock breaking control device.

2. A drill string segment to prevent sticking as claimed in claim 1 wherein: The width of the blade of the front tooth is wider than that of the rear blade, and the front tooth and the rear blade are both composed of three cutting edges with three cutting levels decreasing.

3. A drill string segment to prevent sticking as claimed in claim 1, wherein: The number of the hydraulic pulse perforation line arrays and the rock breaking cutting tooth line arrays is eight.

4. A drill string segment to prevent sticking as claimed in claim 3 wherein: The inner interlayer of the short section upper joint is internally provided with a single-chip microcomputer and a power supply lithium battery, the single-chip microcomputer is further connected with the transmission shaft through a cable extending into the inner interlayer of the short section body, and receives remote control instructions through the wireless signal receiving device arranged therein, controls the transmission shaft, and drives the metal baffle to move to expose the hydraulic pulse perforation.

5. A drill string segment to prevent sticking as claimed in claim 1, wherein: The short section upper joint is further provided with a buckle at the internal radial position, and the short section lower joint is provided with a buckle at the external radial position, which is used for preventing the thread from loosening when the drill string short section rotates.

6. A method of using the drill string sub of any one of claims 1 to 5 to prevent sticking, characterized in that The method comprises the following steps: A drill string short section for preventing sticking is installed at the near-bit of the drill string between the mud pulse signal generator and the mud pulse signal receiver; During normal drilling or back reaming, the cuttings are broken by the rock breaking cutting tooth structure. When the surface of the short section body has formed a mud pack, the hydraulic pulse perforating structure is remotely controlled through the wellhead operation platform to form a jet to remove the mud pack on the surface of the short section body.

Images