JP5538410B2 - Whirling prevention drill bit, well site system and method of use thereof - Google Patents

Description

  The present invention relates to a system and method for preventing whirling and other deflections or deviations of a drill bit and / or bottom assembly while drilling in a well.

  Drill bit whirling and deflection are important issues in the drilling industry. Oil, gas, water and other natural resources are often located 4,000 to 10,000 feet underground (1,219 to 3,048 meters). As a result, even if the well deviation is 1 °, the excavation distance, excavation time and excavation cost may increase significantly as a result.

  In some applications, drillers are seeking vertical wells. Smooth vertical wells facilitate the lowering of large diameter casings with minimal clearance and the possibility of using extra strings of casings at some later stage in well construction operations. Wells that drift away from and return to verticality may ruin this option. In addition, if a large number of wells are drilled from a single platform, this can cause drill string collisions.

  Even for controlled controlled steerability or sloped drilling applications, for example, under broken rocks, in steep downhill formations or in targets in structural geologically active areas It may be highly desirable to maintain the desired pits during excavation.

  In addition, serious problems arise due to the whirling of the drill bit, i.e. the state in which the center of rotation of the bit is offset away from its geometric center. Such problems include non-cylindrical holes, well deflection and excessive bit wear.

  Conventional anti-spin drill bits attempt to reduce run-out by creating an unbalanced or unbalanced lateral force that lacks balance due to the interaction between the cutter and the rock. This unbalanced force has a magnitude and direction that is predictable only when the cutting action is smooth and continuous, and the cutter is not worn or damaged. Because the cutting action is often a discontinuous (intermittent) process rather than a continuous process (for example, when the cutter generates chips instead of continuous cuttings), not all of these conditions occur . When rock is removed by chipping, the size and direction are neither constant nor predictable.

  Accordingly, there continues to be a need for devices and methods for preventing whirling and deflection.

  In one aspect, the present invention includes a drill bit, an internal cavity in fluid communication with the drill string, and a first instrument pad provided outside the drill bit, wherein the first instrument pad is And a first orifice in fluid communication with the internal cavity, wherein the drill bit is configured to allow fluid to flow continuously out of the first orifice.

  In another aspect, the present invention is a well site system comprising a drill string, a kelly coupled to the drill string, and a drill bit, the drill bit being in fluid communication with the drill string. A cavity and a first instrument pad disposed external to the drill bit, the first instrument pad having a first orifice in fluid communication with the interior cavity, A well site system is provided that is configured to continuously flow out of a first orifice.

  In yet another aspect, the present invention provides a method for drilling a curved borehole in an underground formation, comprising the step of attaching a drill bit to the drill string, the drill bit being in fluid communication with the drill string. A cavity and a first instrument pad disposed external to the drill bit, the first instrument pad having a first orifice in fluid communication with the interior cavity, The method further comprises the steps of substantially simultaneously performing rotation of the drill string and pumping of fluid through the drill string and into the drill bit, wherein the method is configured to continuously flow out of the first orifice. Provide a method.

  For a more complete understanding of the nature and desired objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings. Note that the same reference numerals denote corresponding parts throughout the drawings.

It is a figure which shows the well site system which can utilize this invention. It is a figure which shows the drill bit of this invention. It is a figure which shows the drill bit of this invention in a boring hole. It is sectional drawing of the drill bit centered in the boring premises. It is sectional drawing of the drill bit arrange | positioned in a boring hole in the off-center state.

  The present invention provides a system and method for preventing whirling and other deflections of a drill bit and / or bottom assembly while drilling in a well.

  The invention disclosed herein is intended for use in a range of drilling operations, such as oil, gas and water drilling. Thus, the bit body is designed to be incorporated into well field systems commonly used in the oil, gas and water industries. An exemplary well site system is shown in FIG.

  FIG. 1 illustrates a well site system that can utilize the present invention. The well site may be on-shower or off-shower. In this exemplary system, a borehole 11 is formed in the underground formation by rotary excavation in a well-known manner. Embodiments of the present invention can also utilize inclined excavation as described below.

  The drill string 12 is suspended in the boring hole 11, and this drill string has a bottom hole assembly 100, which has a drill bit 105 at its lower end. The outboard system has a platform derrick assembly 10 positioned over the borehole 11, which includes a turntable 16, a kelly 17, a hook 18 and a swivel swivel 19. The drill string 12 is rotated by a turntable 16 and biased by means not shown, which engages a kelly 17 located at the upper end of the drill string. The drill string 12 is suspended from a hook 18 attached to a traveling block (also not shown) via a kelly 17 and a rotating swivel 19, which allows the drill string to rotate relative to the hook. To do. As is well known, a top drive system may be used as a variation.

  In the example of this embodiment, the out-of-well system further includes a drilling fluid or mud 26 stored in a pit 27 configured at the well site. A pump 29 pumps drilling fluid 26 through the port provided in the swivel 19 into the drill string 12 so that the drilling fluid passes through the drill string 12 as indicated by the direction arrow 8. Flows downward. The drilling fluid flows out of the drill string 12 via a port provided in the drill bit 105 and then the annulus between the exterior of the drill string and the borehole wall as indicated by the directional arrows 9. Circulate upward through the area. In this well-known manner, the drilling fluid lubricates the drill bit 105 and carries formation debris to the surface as it is returned to the pit 27 for recirculation.

  The bottom hole assembly 100 of the illustrated embodiment includes a module 120 for logging (physical logging) while drilling, a module 120 for measuring while drilling (MWD), a rotary steering system with a motor, and a drill bit 105. including.

  The LWD module 120 is housed within a specific type of drill collar as is known in the art, and the LWD module may include one or more known types of logging tools. It will also be appreciated that more than one LWD and / or MWD module may be used, for example as shown at 120A. (As a variant, when referring to the module at the 120 position as a whole, this may also mean the module at the 120A position). The LWD module includes the ability to measure, process or store information and communicate with offshore equipment. In this embodiment, the LWD module includes a pressure measurement device.

  The MWD module 130 is also housed in a specific type of drill collar as is known in the art, and the MWD module includes one or more devices that measure the properties of the drill string and drill bit. It is good to have. The MWD tool further includes a device (not shown) that generates power for the downhole system. This is typically a mud turbine generator that is powered by the flow of drilling fluid, but it should be understood that other power and / or battery systems may be used. In this embodiment, the MWD module comprises the following types of measuring devices: a weight measuring device, a torque measuring device, a vibration measuring device, an impact measuring device, a stick-slip measuring device, a direction measuring device, and a gradient measuring device applied to the bit. Including one or more of them.

  A particular advantageous use of well site systems is associated with controlled steering or “tilt drilling”. In this embodiment, a rotational steering subsystem 150 (FIG. 1) is provided. Sloped excavation is the intended departure of a well from the path originally taken by the well. In other words, tilt digging is the manipulation of a drill string that causes the drill string to move in a desired direction.

  Inclined excavation is advantageous, for example, in offshore excavation. This is because such well drilling allows many wells to be drilled from a single platform. Sloped drilling also allows horizontal drilling through the reservoir. Horizontal drilling allows long wells to traverse the reservoir, thereby increasing output from the wells.

  The inclined excavation system can also be used for vertical excavation work. Drill bits often change direction from a planned excavation site due to unexpected properties of the formation being drilled or changes in the force experienced by the drill bit. When such a deviation occurs, the drill bit can be returned to the correct course using an inclined drilling system.

  Known inclined excavation methods include the use of a rotational steering system (“RSS”). In RSS, a drill string ring is rotated from the ground surface, and a drill bit drills in a desired direction by a downhole device. By rotating the drill string, the risk of the drill string becoming hung up or stuck during drilling is greatly reduced. Rotary steerable drilling systems that drill boring holes in the ground are generally “point-the-bit” systems or “push-the-bit” systems. May be classified as any of the systems.

  In the point-the-bit system, the axis of rotation of the drill bit is diverted from the local axis of the bottom hole assembly in the direction of the new hole. The holes are elongated according to the conventional three-point geometry defined by the upper and lower stabilizer contact points and the drill bit. As a result of the combination of the finite distance between the drill bit axis deviation angle and the lower stabilizer of the drill bit, the non-collinear conditions necessary to generate the curve are obtained. There are many ways in which this can be achieved, such as a fixed bend at one point in the bottom hole assembly located near the lower stabilizer or distributed between the upper and lower stabilizers. The use of a drill bit drive shaft bend can be mentioned. The drill bit is not required to cut laterally in its idealized form. This is because the bit axis is continuously rotated in the direction of the curved hole. Examples of point-the-bit rotational steering systems and their operating principles are disclosed in US 2002/0011359, 2001/0052428 and US 6,394,193. No. 6,364,034, No. 6,244,361, No. 6,158,529, No. 6,092,610 and No. 5 No. 113,953, all of which are incorporated herein by reference, the entire contents of which are hereby incorporated by reference.

  In push-the-bit rotational steering systems, there is usually no special mechanism for deflecting the bit axis from the local axis of the bottom hole assembly, instead of the upper or lower stabilizer. The necessary non-collinear condition is achieved by applying an eccentric force or displacement in a direction in which either one or both are preferentially directed with respect to the direction of travel of the hole. Again, there are many ways in which this can be achieved, including non-rotating (relative to the hole) eccentric stabilizer (displacement based) and force the drill bit in the desired steering direction. Use of an eccentric actuator to be added can be mentioned. Again, steering is achieved by creating a non-resonant relationship between the drill bit and at least two other contact points. The drill bit, in its idealized form, needs to be cut laterally to form a curved hole. Examples of push-the-bit rotational steering systems and their operating principles are described in US Pat. Nos. 5,265,682, 5,553,678, and 5,803,185. No. 6,089,332, No. 5,695,015, No. 5,685,379, No. 5,706,905, No. No. 5,553,679, No. 5,673,763, No. 5,520,255, No. 5,603,385, No. 5,582,259 No. 5,778,992 and US Pat. No. 5,971,085, all of which are referenced and cited, and their entire contents are incorporated herein by reference. Part.

  Certain embodiments of the invention described herein provide a drill bit 105 and bottom hole assembly 100 that reduce whirling and / or deviation.

Whirling prevention bit

  FIG. 2 shows the drill bit 105. The drill bit 105 has a trailing end 202 and a cutting portion 204. The trailing end 202 can be directly or indirectly connected to the drill string 12. The cutting portion 204 has one or more ribs 206A, 206B, 206C, 206D. The rib 206 has instrument sections 208 that contact the borehole wall drilled by the cutter 210. Although the cutter 210 is shown only on the ribs 206B, the cutter 210 may be formed on a plurality of ribs 206 or all of the ribs 206 to be advantageous for a particular excavation situation.

  In an embodiment of the present invention, one or more orifices 212 are provided outside the drill bit 105. Orifice 212 may be provided in instrument section 208 or in trough 214 between ribs 206. The orifice 212 allows the fluid 26 from within the drill string 12 to flow out of the drill bit to achieve stability and reduce whirling. Additional orifices may be provided at the leading end 216 for lubrication and debris removal as is known in the art, such as a drill bit 105.

  In some embodiments, the drill bit 105 has a single orifice 212. Drilling fluid 26 flows out of orifice 212 and contacts the wall of borehole 11, thereby creating a lateral force that is substantially perpendicular to the orientation of orifice 212 and instrument section 208. By this force, an effect of preventing wobbling is obtained.

  In some embodiments, the orifice 212 is positioned substantially opposite as viewed from the majority of the cutters 210. For example, if the cutter 210 is disposed longitudinally along the drill bit 105, the orifice 212 may be disposed at approximately 180 ° when viewed from the cutter 210. In such an embodiment, the drilling fluid discharged from the orifice 212 creates a lateral force that pushes the drill bit toward the cutter 210. This embodiment (1) increases the contact between the cutter 210 and the wall of the boring hole 11 and / or (2) cancels out the lateral force caused by the contact between the cutter 210 and the boring hole wall. .

  In other embodiments, the orifice 212 is positioned approximately 90 ° behind the majority of the cutter 210. As an illustration of this principle, consider the situation shown in FIG. 2A. The drill bit 105 rotates in the counterclockwise direction in the boring hole 11. The cutter 210 is about to hit the projection 218 from the borehole wall 220. If the protrusion 218 is a particularly strong material, the protrusion will remain intact at least momentarily upon first contact with the cutter 210. The rotational force applied to the drill bit 105 causes the drill bit 105 to move in the negative y direction until the instrument pad 206A contacts the borehole wall 220. However, when the orifice 212 is provided in the instrument pad 206A, the drilling fluid 26 creates a positive y-direction force, thereby countering the tendency of the drill bit 105 to move off-center. In addition, the positive y-direction force moves the entire bit 105 and thereby exerts additional force on the cutter 210 to help extend the borehole.

  Other configurations for other cutters 210 and orifices 212 are within the scope of the present invention. For example, the resultant vector of forces generated by rotation of the drill bit 105 and contact with the plurality of cutters 210 can be calculated using known equations and techniques. Orifice 212 may be configured to cancel the most likely force vector.

  By utilizing the hydraulic power of the drilling fluid 26 from the orifice 212, the drill bit 105 produces a predictable and constant unbalanced force that reduces and / or prevents bit runout. The direction of the unbalanced force is known if the position of the port is given. The magnitude of the unbalanced force depends on the distance between the orifice 212 and the borehole wall 220, the differential pressure between the drilling fluid 26 in the borehole and the drilling fluid 26 in the drillstring 12, and the geometry of the orifice 212. (For example, dimension shape). Furthermore, wear and damage to the cutter 210 should not affect the magnitude and direction of the lateral force.

  In some embodiments, the exterior of the orifice 212 is surrounded by a raised annulus or other geometric feature to create a large water pressure as the drilling fluid 26 exits the orifice 212. The entire feature and / or instrument section 206 can be coated with an abrasion resistant or surface hardened material, such as polycrystalline diamond (PCD), or it can be made entirely from it.

Self-stabilizing bit and bottom hole assembly

  Another embodiment of the present invention utilizes one or more orifices 212 to stabilize the drill bit 105 and / or bottom hole assembly (BHA) within the borehole.

  FIG. 3A is a cross-sectional view of the drill bit 105 with three instrument pads 206A, 206B, 260C generally spaced from one another (eg, 120 ° in the center) along the circumference of the drill bit 105. Each instrument pad has 212A, 212B, and 212C, respectively. The excavation state 26 (represented by a thick line) flows out of the drill bit 105 through the orifices 212A, 212B, 212C.

  The drill bit 105 shown in FIG. 3A is centered in the boring hole 11 as a whole. Accordingly, the hydraulic forces generated by the drilling fluid cancel each other. However, if the drill bit 15 is moved off-center as shown in FIG. 3B, the magnitude of the force vector generated by the drilling state 26 from the orifice 212A is between the orifice 212A and the borehole wall 220. It will increase as the separation distance decreases. At the same time, the force vector generated by the orifices 212B, 212C decreases, resulting in a net force vector (represented by arrow 222) that pushes away from the drill bit wall 220.

  In some embodiments, the flow rate of fluid to one or more orifices is limited by one or more valves (eg, choke valves). A single valve may be connected to each orifice by tubing or other means. More preferably, each orifice is independently adjusted by a separate valve. With separate and independent adjustments, the amount of drilling fluid 26 flowing to a particular orifice 212 is deprived from other orifices 212 or other ports (eg, ports provided on the leading or leading edge 216 of the drill bit 105). It does not increase beyond the desired threshold.

  Although the embodiment of FIGS. 3A and 3B shows a drill bit 105 with three orifices 212, the scope of the invention described herein is for stabilization of the drill bit 105 or bottom hole assembly. Including the use of fluid by any number of orifices 212. For example, a drill bit 105 with a single orifice produces approximately the same effect as a drill bit 105 with three orifices. As the drill bit 105 is rotated, the force produced by the single orifice increases in magnitude as the orifice passes through the region where the drill bit 105 is located near the borehole wall 220. This increase in force causes the drill bit 105 to be pushed back to the center. Furthermore, drill bits and bottom hole assemblies with two, three, four, five or six orifices and the like are within the scope of the present invention.

  The principles described herein are applicable to stabilization pads provided outside the bottom hole assembly 100 and along other portions of the drill string 12. The stabilization pad acts similarly to the instrument pad to minimize the motion of the bottom hole assembly and drill string. In such embodiments, one or more orifices are added to one or more stabilization pads so that the drilling fluid 26 can operate as described herein.

Combination of anti-rotating bit and self-stabilizing bit

  Combining the anti-swivel bit principle described herein and the self-stabilizing bit principle produces a net unbalanced lateral force that reduces swirl while still remaining from the center of the borehole 11. A bit 105 with one or more orifices that compensates for the drift can be made. In such an embodiment, one of the plurality of orifices 212 has a larger cross-sectional area than the other orifices to produce an unbalanced lateral force.

  The foregoing description and the drawings that form a part of this specification are exemplary in nature and illustrate certain preferred embodiments of the invention. However, it should be recognized and understood that this description should not be construed as limiting the invention. This is because those skilled in the art can devise many variations, modifications and variations of the embodiments without departing from the essential scope, spirit or intent of the present invention.

Claims (7)

A drill bit,
An internal cavity in fluid communication with the drill string;
Multiple cutters,
It has a first instrument pad of the plurality of instruments pads, and
Wherein the plurality of instrument pads, said provided external to the drill bit, the plurality of instruments pads comprises a plurality of orifices in said inner cavity in fluid communication with the plurality of instruments pads, the drill Spaced apart along the periphery of the bit, the plurality of orifices may allow fluid from the internal cavity to flow into the drill bit;
The plurality of orifices further comprises at least one orifice with a larger cross-sectional area than the other orifices to produce an unbalanced lateral force;
The drill bit is configured to achieve the stability of the drill bit and reduce swirl by allowing fluid to flow out of the plurality of orifices continuously.   The drill bit of claim 1, wherein the fluid flow rate is sufficient to push the drill bit away from the borehole wall. The drill bit according to claim 1 or 2 , further comprising a first valve that adjusts a flow rate of the fluid from at least a first orifice of the plurality of orifices . Further comprising, a drill bit according to any one of claims 1 to 3 a first valve for regulating the flow of fluid from the at least first and second orifices of said plurality of orifices. The drill bit of claim 4 , further comprising a second valve that regulates a flow rate of fluid from the second orifice. A well site system,
A drill string,
Kelly coupled to the drill string;
Includes a drill bit, the,
The drill bit is provided with an internal cavity in the drill string in fluid communication with, a plurality of cutters, and a first meter pads of the plurality of instruments pads provided on the outside of the drill bit,
Wherein the plurality of instrument pad is provided with a plurality of orifices in said inner cavity in fluid communication with said plurality of meter pads are arranged at intervals along the circumference of the drill bit, said plurality of orifices Can drain fluid from the internal cavity to the drill bit;
The plurality of orifices further comprises at least one orifice with a larger cross-sectional area than the other orifices to produce an unbalanced lateral force;
The drill bit is configured to achieve the stability of the drill bit and reduce swirl by allowing fluid to flow out of the plurality of orifices continuously. system. A method of drilling a curved borehole in an underground formation,
Attaching a drill bit to a drill string;
The drill bit includes an internal cavity in the drill string in fluid communication with, and a plurality of instruments pads provided on the outside of the drill bit, said plurality of meter pad, the internal cavity in fluid communication with comprising a certain plurality of orifices, said plurality of meter pads are arranged at intervals along the circumference of the drill bit, wherein the plurality of orifices, to flow out of fluid from the internal cavity to the drill bit The plurality of orifices further comprises at least one orifice with a larger cross-sectional area than the other orifices to produce an unbalanced lateral force;
Further, allowing fluid to flow out of the plurality of orifices continuously;
Self-stabilizing the drill bit and reducing whirling during rotation of the drill string by pumping fluid from the drill string to the drill bit and out of the plurality of orifices And a method comprising:

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