RU2509860C2 - Self-stabilising drilling bits balanced against vibrations and layouts of bottom of drill strings, and systems for their use - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: drilling bit includes an internal cavity interconnected through fluid medium to a drill string, and a variety of calibrating surfaces and cutters, which are arranged on the outer side of the drilling bit. The variety of calibrating surfaces have many holes that allow the fluid medium of the internal cavity of the drill string leave the drilling bit. At least one hole is located approximately at an angle of 90° behind the larger amount of cutters; with that, the variety of holes also includes a hole having another flow cross-section relative from at least one hole for generation of out-of-balance lateral force. The drilling bit is made so that fluid medium is continuously supplied from each hole to create a resultant stabilising effect. Layout of the drill string bottom includes the above drilling bit.

EFFECT: preventing vibrations and other deviations of a drilling bit or layout of the drill string bottom.

8 cl, 5 dwg

Description

FIELD OF THE INVENTION

The present invention relates to systems and methods for preventing vibrations and other deviations of the drill bit and / or the layout of the bottom of the drill string during drilling in the well.

BACKGROUND OF THE INVENTION

Vibrations and deviations of the drill bit are a serious problem in the drilling industry. Oil, gas, water, and other natural resources are often located at a depth of 4,000-10000 feet (1220-3050 m) underground. As a result, one degree deviation of the well can result in a significant increase in drilling distance, time and cost.

In some applications, the driller achieves a vertical well. An even vertical well facilitates the launch of larger casing strings with minimal clearance and allows the use of an additional casing string at some subsequent stage of well construction. A well deviating from the vertical and returning to it may exclude this possibility. In addition, if several wells are drilled from the same platform, deviations can cause drill collisions.

Even in variants of directionally or directionally directed drilling, it is highly desirable to maintain the necessary trajectory, for example, when drilling to project sites under fractured rocks in steeply declining formations or in tectonically active areas.

In addition, with vibrations of the drill bit, the state in which the center of rotation of the bit is shifted from its geometric center, leads to several problems. These problems include non-cylindrical boreholes, deviations in the borehole and excessive bit wear.

Conventional vibration-balanced drill bits tend to reduce vibrations, creating an unbalanced lateral force when the cutters interact with the rock. This unbalanced force should only have a predicted magnitude and direction if the cutting action is smooth and continuous and the cutters are not worn or damaged. None of these conditions are regularly created, since the cutting action is often a discrete process, and not continuous, when the cutters form chipping instead of continuous drilling of the rock. When a rock is removed with spalling, size and direction are both volatile and unpredictable.

Accordingly, there is a need to create a device and method for preventing vibrations and deviations.

DESCRIPTION OF DRAWINGS

For a more complete understanding of the essence and objectives of the present invention, the following is a detailed description with the accompanying drawings, in which the same position denotes the same corresponding parts in several views and which shows the following.

Figure 1 shows a drilling rig in which the present invention can be used.

2 shows a drill bit according to the present invention.

On figa shows the drill bit according to the present invention in the wellbore.

On figa shows a cross section of the drill bit centered on the axis of the wellbore.

3B shows a cross section of a drill bit eccentrically located in a wellbore.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a device and methods for preventing vibrations and other deviations of the drill bit and / or the layout of the bottom of the drill string during drilling in the well.

The method and apparatus presented herein is adapted for use in a range of drilling operations, such as oil, gas and water drilling. The body of the drill bit has a design for inclusion in the composition of drilling rigs, usually used when drilling for oil, gas and water. An example of a downhole drilling system is shown in FIG.

Figure 1 shows a drilling rig in which the present invention can be used. The drilling site may be land or offshore. In this embodiment, the rig drills the wellbore 11 in the subterranean formations by rotary drilling in a well-known manner. Directional drilling can also be used in embodiments of the invention, as described below.

The drill string 12 is suspended in the bore 11 of the well and has a layout 100 of the bottom of the drill string, including a drill bit 105 located at its lower end. Surface rig equipment includes a tower assembly 10 and a platform mounted above the wellbore 11, assembly 10 including a rotor 16, a drill pipe 17, a hook block 18 and a swivel 19. The drill string 12 rotates the rotor 16, receiving power from means not shown and connected to the drill pipe 17 at the upper end of the drill string. The drill string 12 is suspended on the hook block 18 attached to the tackle block (also not shown), through the lead drill pipe 17 and the swivel 19, providing rotation of the drill string relative to the hook block. It is well known that an alternative top drive system can be used.

In this embodiment, the surface drilling rig equipment further includes drilling fluid 26 stored in a tank 27 equipped at the drilling site. The pump 29 delivers the drilling fluid 26 into the drill string 12 through the hole in the swivel 19, causing the drilling fluid to pass downward through the drill string 12 in the direction of arrow 8. The drilling fluid exits the drill string 12 through the holes in the drill bit 105 and then circulates upward through the zone of annular space between the outer surface of the drill string and the wall of the borehole, in the direction indicated by arrow 9. In this well-known method, the drilling fluid lubricates the drill bit 105 and carries drilled rock to the surface, returning to the tank 27 for re-circulation.

The bottom hole assembly 100 of the embodiment shown includes a while logging module 120 while drilling, a measurement module 130 while drilling, a rotary steered system and an engine, and a drill bit 105.

The logging module 120 during drilling is housed in a special known weighted drill pipe and may contain one or a plurality of well-known logging tools. It should also be understood that several logging modules during drilling and / or measurement modules during drilling can be used, for example, such as the shown module 120A. (Text references to module 120 may alternatively also mean module 120A). The logging module during drilling is configured to measure, process and store information and exchange data with equipment on the surface. In the present embodiment, the logging module during drilling includes a pressure gauge.

The measurement module 130 during drilling is also located in a special known weighted drill pipe and may contain one or more devices for measuring the parameters of the drill string and drill bit. The measurement tool while drilling further includes a device (not shown) generating electricity for the downhole system. Such a device may be a generator with a hydraulic turbine driven by the flow of drilling mud, it is clear that you can use other power systems and / or batteries. In the present embodiment, the measurement module during drilling includes one or more measuring devices of the following types: device for measuring axial load on the bit, device for measuring torque on the bit, device for measuring vibration, device for measuring shock load, device for measuring sticking and slipping, device direction measurements and inclinometry device.

It is preferable to use the drilling rig in combination with control of the direction of drilling or directional drilling. In this embodiment, a rotational controlled subsystem 150 is created (FIG. 1). Directional drilling provides a special deviation of the wellbore from the natural trajectory. In other words, directional drilling provides control of the direction of the drill string to move it in the desired direction.

For example, directional drilling is preferred in offshore drilling, as it enables the drilling of many wells from one platform. Directional drilling also provides horizontal drilling through the reservoir. Horizontal drilling provides an increased well length extending across the reservoir, increasing well production.

The directional drilling system can also be used in vertical drilling operations. Often, the drill bit must deviate from the course of the projected drilling path due to the unpredictable nature of the formations in which the penetration is conducted, or the changing forces acting on the drill bit. When such a deviation occurs, a directional drilling system can be used to return the drill bit to the desired course.

A known method of directional drilling involves the use of a rotary controlled system. In this system, the drill string is rotated from the surface, and downhole devices cause drilling the drill bit in the right direction. Rotation of the drill string greatly reduces the chance of sticking or sticking the drill string while drilling. Rotary guided drilling systems for directional boreholes can, in general, be classified into repulsion systems of the entire arrangement or bit positioning system.

In the bit positioning system, the axis of rotation of the drill bit deviates from the local axis of the layout of the bottom of the drill string in the general direction of the new shaft. The well is drilled according to the usual geometry with three contact points formed by the upper and lower points of contact of the centralizer and the drill bit. The angle of deviation of the axis of the drill bit in combination with the final distance between the drill bit and the lower centralizer results in the noncollinearity conditions required for the formation of the curve. There are many ways to achieve this, including fixed curvature at the point of assembly of the bottom of the drill string near the lower centralizer or bending of the drive shaft of the drill bit distributed between the upper and lower centralizer. In their idealized form, the drill bit is not required to go sideways, since the axis of the bit is continuously rotated in the direction of the curved shaft. Examples of rotary guided bit positioning systems and their operation are described in US patent applications No. 2002/0011359; 2001/0052428 and US Pat. Nos. 6,394,193; 6,364,034; 6,244,361; 6,158,529; 6,092,610 and 5,113,953, which are incorporated herein by reference.

In a rotary guided repulsion system of the entire assembly, there is usually no specially identified mechanism for deviating the axis of the bit from the local axis of the layout of the bottom of the drill string; instead, the desired condition for non-collinearity is achieved by applying either one or both of the upper or lower centralizers, an eccentric force, or a bias in the preferred direction with respect to the direction of the borehole. There are also many ways in which this is achieved, including non-rotating (relative to the barrel) eccentric centralizers (displacement-based approaches) and eccentric actuators that apply force to the drill bit to control movement in the desired direction. Directional control is also obtained by creating non-collinearity between the drill bit and at least two other points of contact. In its idealized form, the drill bit requires lateral penetration to make a curved shaft. Examples of rotational controlled repulsion systems of the entire arrangement and their effect are described in US patent No. 5,265,682; 5,553,678; 5,803,185; 6,089,332; 5,695,015; 5,685,379; 5,706,905; 5,553,679; 5,673,763; 5,520,255; 5,603,385; 5,582,259; 5,778,992; 5,971,085, incorporated herein by reference.

In the specific embodiments of the invention described herein, drill bits 105 and bottom-hole assemblies 100 are provided to reduce vibration and / or deviations.

Vibration-balanced bits

Figure 2 shows a drill bit 105 having a rear end 202 and a cutting portion 204. The rear end 202 is adapted for direct or indirect connection to the drill string 12. The cutting portion 204 includes one or more ribs 206a, 206b, 206c, 206d. The ribs 206 include calibrating sections 208 in contact with the walls of the borehole drilled by the cutters 210. Although the cutters 210 are shown only on the rib 206b, the cutters 210 can be performed on several or all of the ribs 206, which is preferred for specific drilling situations.

In embodiments of the present invention, one or more holes 212 are formed on the outside of the drill bit 105. Holes 212 can be provided in calibrating sections 208 or in grooves 214 between ribs 206. Holes 212 allow fluid 26 to escape from drill string 12 from drill bit 12 to achieve stability and reduce vibration. Additional holes can be made in the drill bit 105, for example, at the leading end 216 for lubrication and removal of cuttings, as is known in the art.

In some embodiments, the drill bit 105 comprises a single hole 212. The drilling fluid 26 extends from the hole 212 and contacts the wall of the wellbore 11, creating a lateral force substantially perpendicular to the orientation of the hole 212 and gage section 208. This force counteracts vibration.

In some embodiments, the hole 212 is substantially opposed to most cutters 210. For example, if the cutters 210 are placed longitudinally along the drill bit 105, the hole 212 can be placed rotated about 180 ° from the cutters 210. In this embodiment, the drilling fluid discharged from the hole 212, creates a lateral force pushing the bit in the direction of the cutters 210. This embodiment provides increased contact between the cutters 210 and the wall 11 of the wellbore and / or neutralizes the lateral forces during knowing as a result of contact between the cutters 210 and the wall of the wellbore.

In other embodiments, the opening 212 is rotated approximately 90 ° behind most of the incisors 210. To illustrate this principle, consider the situation shown in FIG. 2A. The drill bit 105 rotates counterclockwise in the wellbore 11. Cutters 210 are close to the impact on the protrusion 218 of the wall of the wellbore 220. If the protrusion 218 is a particularly strong material, it should remain intact at least at the moment of the first contact with the cutters 210. The rotational force on the drill bit 105 should cause the drill bit 105 to move in the negative direction along the y axis, while the calibrating surface 206a is in contact with barrel wall 220 of the well. However, if the hole 212 is located on the gage surface 206a, the drilling fluid 26 should create a force in the positive direction along the y axis, counteracting the tendency of the drill bit 105 to eccentric movement. Moreover, the force in the positive direction along the y axis moves the entire bit 105, while applying additional force to the cutters 210 and facilitating the penetration of the wellbore.

Other configurations of the cutter 210 and the holes 212 may be made within the scope of these inventions. For example, the total force vector created by rotation of the drill bit 105 and contact with a plurality of cutters 210 can be calculated using known formulas and methods. The hole 212 can be configured to counter the vectors of the most probable forces.

Using the hydraulic force of the drilling fluid supply 26 from the hole 212, the drill bits 105 create a more predictable and permanent unbalanced force to reduce and / or prevent the bit from vibrating. The direction of the unbalanced force is known for a given position of the hole. The magnitude of the unbalanced force is a function of the distance between the bore 212 and the wall of the borehole 220, the pressure drop between the drilling fluid 26 in the borehole and the drilling fluid 26 in the drill string 12 and the geometry (i.e., shape and size) of the bore 212. In addition, wear and damage to the cutters 210 should not affect the amplitude and direction of the lateral force.

In some embodiments, the outer portion of the hole 212 is surrounded by a raised annular space or other geometric element to create a higher hydraulic pressure when the drilling fluid 26 exits the hole 212. Such an element and / or the entire calibration section 206 may be coated with a wear-resistant material or made entirely of such a material or surface hardened material, such as a polycrystalline synthetic diamond.

Self-stabilizing drill bit and bottom hole layouts

In another embodiment of the invention, one or more holes 212 are used to stabilize the drill bit 105 and / or bottom hole assembly (BHA) in the wellbore.

3A shows a cross section of a drill bit 105 with three calibrating surfaces 206a, 206b, 206c generally spaced (e.g., 120 °) around the circumference of the drill bit 105 and having holes 212a, 212b, 212c, respectively. Drilling fluid 26 (represented by thick lines) passes from the inside of the drill bit 105 through holes 212a, 212b, 212c.

The drill bit 105 shown in FIG. 3A is generally centered on the axis of the wellbore 11. Accordingly, any hydraulic forces generated by the drilling fluid must compensate for each other. However, if the drill bit 105 moves off-center, as shown in FIG. 3B, the amplitude of the force vector generated by the drilling fluid 26 emerging from the hole 212a should increase with decreasing distance between the hole 212a and the wall of the wellbore 220. At the same time, any force vector created by the openings 212b and 212c should decrease, resulting in a resultant force vector shown by arrow 222 pushing the bit from the wall 220.

In some embodiments, the flow of fluid through one or more orifices is limited by one or more valves (i.e., butterfly valves). One valve may be connected to each hole by a tube or other means. Independent adjustment of each hole by a separate valve is more preferred. Independent adjustment ensures that the volume of drilling fluid 26 passing to a particular hole 212 does not raise the required threshold so that it does not deprive other holes 212 or other holes (for example, holes located on the leading edge 216 of the drill bit 105).

Although in the embodiment of FIG. 3A and 3B show a drill bit 105 with three holes 212, the inventions described herein cover the use of any number of holes 212 to stabilize the drill bit 105 or to lay the bottom of the drill string. For example, a drill bit 105 with one hole should produce an effect similar to a drill bit 105 with three holes. As the drill bit 105 rotates, the force generated by one hole should increase in amplitude when the hole passes through areas in which the drill bit 105 is closer to the wall of the wellbore 220. This increased force should force the drill bit 105 back to the center axis of the shaft. In addition, drill bits and bottom hole layouts with two, three, four, five or six holes, and the like. are included in the scope of the present invention.

The principles described herein can be applied to stabilization surfaces located along the outer part of the bottom of the drill string assembly 100 and to other parts of the drill string 12. The stabilization surfaces act similarly to calibrating surfaces, minimizing movement of the bottom assembly of the drill string and the drill string. In such an embodiment, one or more holes are made in one or more stabilization surfaces to provide the action of the drilling fluid 26 described herein.

Combination of vibration-balanced and self-stabilizing bits

The principles of vibration-balanced and self-stabilizing drill bits described in this document can be combined to produce a bit 105 that provides an unbalanced resultant lateral force to reduce vibration, creating one or more holes to adjust the offset from the central axis of the wellbore 11. In such an embodiment, one of the plurality of holes 212 has a larger bore to create an unbalanced lateral force.

The above description and the accompanying drawings are illustrative and demonstrate some preferred embodiments of the invention. It should be understood, however, that the description is not intended to limit the invention, since many changes, modifications and variations in it can be performed by a person skilled in the art without substantially departing from the scope, ideas and essence of the invention.

Claims (8)

1. A drill bit containing an internal cavity in fluid communication with the drill string, and a plurality of calibrating surfaces and cutters placed on the outer part of the drill bit, characterized in that the plurality of calibrating surfaces have many openings that allow fluid from the inner cavity of the drill string come out of the drill bit, with at least one hole located approximately 90 ° behind most of the cutters, while many holes also contain a hole having another th orifice of the relative at least one hole for the production of an imbalanced side force, wherein the drill bit is configured so that the fluid is continuously supplied from each hole to create the resulting stabilizing effect. 2. The drill bit according to claim 1, wherein the fluid flow is sufficient to repel the drill bit from the wall of the wellbore. 3. The drill bit according to claim 1, containing three calibrating surfaces having holes in communication with the internal cavity. 4. The drill bit according to claim 1, in which the holes are spaced about 120 ° around the circumference of the outer part of the drill bit. 5. A drill bit according to any one of claims 1 to 4, further comprising a valve for adjusting the total fluid flow rate to one or more openings. 6. The layout of the bottom of the drill string containing a drill bit having an internal cavity in fluid communication with the drill string, and a plurality of calibrating surfaces and cutters placed on the outer part of the drill bit, characterized in that the plurality of calibrating surfaces have many holes that allow fluid the medium from the inner cavity of the drill string to exit the drill bit, with at least one hole located approximately behind most of the cutters, with many holes also comprise an opening having a different passage section with respect to at least one opening for producing unbalanced lateral force, the drill bit being configured so that fluid is continuously supplied from the plurality of holes to create a resulting stabilizing force applied to the bottom of the drill string. 7. The arrangement according to claim 6, in which the fluid flow is sufficient to repel the drill bit from the wall of the wellbore, while stabilizing the drill bit in the wellbore. 8. The arrangement according to claim 6, containing many stabilizing surfaces having openings in communication with the internal cavity.

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