Drill pipe with dissolvable layer

Presented herein are apparatus and methods that alleviate incidence of stuck pipes in downhole environments. In some embodiments, the apparatus and methods described herein include a drill pipe for drilling operations including: a dissolvable layer deposited on a portion of an outer surface of the drill pipe; and a tunnel connected to the dissolvable layer.

FIELD

The subject matter described herein relates to apparatuses, methods, and systems for avoiding incidence of stuck pipes in downhole environments.

BACKGROUND

In drilling operations, stuck pipe events are considered to be undesirable incidents. Stuck pipes usually lead to delays and obstructions to operational activities, which often result in significant amount of lost time and incurred costs. Coinciding with the increased number of wells drilled by energy exploration companies each year, stuck pipe incidents consequently have been classified as one of the core challenge to overcome. During stuck pipe incidents, drillers are unable to rotate the drill pipe, nor are they able to move the drill pipe vertically upwards or downwards. Accordingly, millions (if not billions) of dollars are lost every year by companies due to stuck pipe incidents that have occurred during drilling operations.

One contributor to the incidence of stuck pipes is differential sticking, which typically occurs when high-contact forces caused by low reservoir pressures, high wellbore pressures, or both, are exerted over a sufficiently large area of the drill string. A force governing the sticking is a product of the differential pressure between the wellbore and the reservoir, and the area that the differential pressure is acting upon. A relatively low differential pressure applied over a large working area can be just as effective in sticking the pipe as can a high differential pressure applied over a small area. As time passes, if a drill string remains stationary, the area of contact can increase, making it more difficult to free the drill string. For example, the accumulation of consolidated drilling fluid such as drilling mud can form mud cakes which may solidify on the interior of a borehole (for example, on the inner surface of a borehole wall) as well as around the exterior of a drill pipe. When a drill pipe is stationary, the mud that is solidified on the borehole wall may “bridge” the gap between the borehole wall and the drill pipe, and then harden, thereby causing the drill string to become stuck. Another contributor to the incidence of stuck pipes is borehole “pack-off” which occurs when fragments, cuttings, and debris from the drilling process accumulate at the bottom of a borehole around the drill pipe, thereby causing friction and eventual sticking of the drill pipe within the borehole.

SUMMARY

The present disclosed embodiments include apparatuses, systems, and methods for helping drillers to minimize the occurrence of this stuck pipe events.

In one aspect of the present invention, a drill pipe for drilling operations includes a dissolvable layer deposited on a portion of an outer surface of the drill pipe, and a tunnel connected to the dissolvable layer.

In some embodiments, the tunnel is disposed on the outer surface of the drill pipe, thereby fluidly connecting to the dissolvable layer.

In some embodiments, the tunnel is located within a wall of the drill pipe.

In some embodiments, the drill pipe further includes a channel. In some embodiments, the tunnel is fluidly connected to the dissolvable layer through the channel.

In some embodiments, the drill pipe further includes additional channels connecting the tunnel and the dissolvable layer radially.

In some embodiments, the tunnel is accessible from a top of the drill pipe.

In some embodiments, the drill pipe includes a top portion, a center portion and a bottom portion. In some embodiments, outer diameters of the top portion and the bottom portion are greater than an outer diameter of the center portion.

In some embodiments, the dissolvable layer is deposited on the center portion.

In some embodiments, an outer diameter of the dissolvable layer is substantially equal to the outer diameters of the top portion and the bottom portion.

In some embodiments, the dissolvable layer includes a material dissolvable by a dissolving solution.

In some embodiments, the dissolvable layer includes a material selected from the group consisting of CaCO3, plastics, glass fiber, metal mesh, and combinations thereof.

In some embodiments, the dissolvable layer includes CaCO3.

In some embodiments, the dissolving solution includes HCl.

In some embodiments, the drill pipe further includes additional tunnel(s), thereby including 2, 3, 4, 5, or 6 tunnels.

In some embodiments, the drill pipe further includes additional tunnel(s), thereby including 2, 3, 4, 5, or 6 tunnels. In some embodiments, the drill pipe includes additional channel(s), so that the drill pipe has at one channel per tunnel.

In some embodiments, a porosity of the dissolvable layer is within a range from about 10% to about 40%.

In another aspect, a drill pipe for drilling operations includes a dissolvable layer deposited on a portion of an outer surface of the drill pipe, and the dissolvable layer includes CaCO3.

In some embodiments, a thickness of the dissolvable layer is within a range from about 1 mil to about 500 mils.

In another aspect of the present invention, a method includes deploying a drill pipe in a downhole environment, where the drill pipe includes a dissolvable layer deposited on a portion of an outer surface of the drill pipe, and a tunnel connected to the dissolvable layer; initiating a drilling process; stopping the drilling process; and supplying a dissolving solution to the dissolvable layer through the tunnel.

In another aspect of the present invention, a drill pipe system for drilling operations includes at least two drill pipes. In some embodiments, each of the at least two drill pipes include a dissolvable layer deposited on a portion of an outer surface of the at least two drill pipes and a tunnel connected to the dissolvable layer.

In some embodiments, the tunnel is disposed on the outer surface of each of the at least two drill pipes, thereby fluidly connecting to the dissolvable layer.

In some embodiments, the tunnels of the at least two drill pipes fluidly connect to the at least two drill pipes.

The following description is for illustration and exemplification of the disclosure only, and is not intended to limit the invention to the specific embodiments described.

The mention herein of any publication, for example, in the Background section, is not an admission that the publication serves as prior art with respect to any of the present claims. The Background section is presented for purposes of clarity and is not meant as a description of prior art with respect to any claim.

DESCRIPTION OF CERTAIN EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to the present disclosed embodiments, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and/or letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the present embodiments.

Rotary Dynamic System

The present disclosed embodiments include apparatuses, methods, and systems for avoiding stuck pipe and stuck drill string incidents during drilling operations. The apparatuses, methods, and systems use a rotary dynamic system (RDS) that can be attached around the outer diameter of the drill pipe, and that has the ability to rotate continuously, even when the drill string is stationary (for example, when an additional drill pipe is being added to the drill string). The rotary dynamic system may include “layers” that include an outer layer (or sleeve) as well as an inner layer or drill pipe, with the outer layer being rotatable around the inner layer (and the inner layer being rotatable within the outer layer). The rotary dynamic system may include one or more roller, ball, and/or sleeve bearings coupling the outer sleeve to the drill pipe. Roller bearings may include two rings: a first ring that couples to the drill pipe and a second ring that couples to the outer sleeve, with ball, roller, roller ball, or sleeve bearings disposed between the first and second rings, thereby allowing relative rotational motion therebetween.

FIG. 1illustrates an exemplary oil rig10, including a rig floor14, elevated above the ground12. Extending vertically upward from the rig floor14is a derrick16which includes a framework for supporting the oil rig10. The oil rig10may include a drill pipe28that may be coupled via various components to a drill string. The drill string may be disposed in a borehole18that includes a borehole wall24disposed therewithin. The borehole18may include an annulus26defined by the ring-shaped space disposed radially outward of the drill string (and radially inward of the borehole wall24). The drill string may include one or more drill collars29, as well as one or more threaded connections30disposed at the bottom of the drill pipe28. The oil rig10may also include a managed pressure drilling (MPD) system32including one or more rotating control devices (RCD) for maintaining the pressure within the borehole18while one or more pieces of equipment is rotating or operating. The oil rig10may also include a blow-out preventer (BOP)34for preventing blowouts or uncontrolled releases of hydrocarbons at the oil rig10.

FIG. 2illustrates a side view of the oil rig10, including a rotary dynamic system40, according to aspects of the present disclosed embodiments. The oil rig10may include the derrick16, the managed pressure drilling (MPD) system32, the drill pipe28, and the annulus26. In the embodiment ofFIG. 2, the oil rig10may include a rotary dynamic system40disposed within the annulus26defined between the drill pipe28and the borehole wall24. The rotary dynamic system40may be concentric about (that is, rather than adjacent to) the drill pipe28. The rotary dynamic system40may include at least one sensor38disposed along (or within) an outer surface or sleeve60(shown inFIG. 5) of the rotary dynamic system40, as well as a wireline36that may electrically and/or operatively couple the rotary dynamic system40and sensor38to one or more respective power sources and/or control systems located at the surface12, within the borehole18, or at a remote location. The rotary dynamic system40, as illustrated inFIG. 2, may not necessarily be geometrically to scale relative to other components such as the borehole18and the drill pipe28. For example, the rotary dynamic system40may include an outer diameter that is about the same as the outer diameter of a standard drill pipe28, or in other embodiments, that is about one (1) percent, about three (3) percent, about five (5) percent, about eight (8) percent, about twelve (12) percent, about eighteen (18) percent, about twenty-five (25) percent, about forty (40) percent, or about sixty (60) percent greater than the outer diameter of a standard drill pipe28.

Referring still toFIG. 2, in operation, the rotary dynamic system40may freely spin about the drill pipe28such that while the drill pipe28is stationary, the rotary dynamic system40may continue to spin, thereby preventing the hardened mud from caking on the drill pipe28and causing it to get stuck. Stated otherwise, the rotary dynamic system40may rotate independent of the drill pipe28such that the drill string does not become stuck, even while the drill string is stationary.

FIG. 3illustrates a top schematic view of a conventional drill pipe28disposed within a borehole18. The borehole wall24may define a physical outer boundary of the borehole18, and may become caked with mud42and other consolidated drilling fluid and/or downhole debris. The mud cake42accumulates around the interior of the borehole wall24(inner wall of the borehole18), and when the drill pipe28is stationary the mud cake42may bridge from the borehole wall24across a gap48(or annulus) to the drill pipe28. The mud bridging44may then solidify and cause the drill pipe28to couple to the borehole wall24, thereby preventing the drill pipe28from being easily rotated. In situations in which the drill pipe28is not concentric within the borehole18, bridging44may occur more easily since the gap48between the drill pipe28and the nearest surface of the borehole wall24is decreased (that is, when compared to situations in which the drill pipe28is concentric within the borehole18). The drill pipe28does not to be fully encased in mud42to become stuck. For example, in the embodiment ofFIG. 3, the bridging44extends around about 60% of the outer circumference of the drill string or drill pipe28. In other embodiments in which a drill pipe28becomes stuck, the bridging44may extend around from about 5% to about 100%, or from about 10% to about 60%, or from about 15% to about 40%, or from about 20% to about 30% of the outer circumference of the drill pipe28.

FIG. 4illustrates a side schematic view of a conventional drill pipe28disposed within a borehole18, including mud42caked or encased around the borehole wall24. In the embodiment ofFIG. 4, a radial gap48may be disposed between a portion of the drill pipe28and the borehole wall24. In addition, bridging44may partially encase (and overlap with, in the side view ofFIG. 4) the drill pipe28. As discussed above, even if there are one or more radial gaps48between portions of the drill pipe28and the mud42, a partially encased drill pipe28may still become stuck. Stated otherwise, the bridging44may extend around only a portion of the outer circumference of the drill pipe28and still cause a drill pipe28to become stuck.

FIG. 5illustrates a side view of a rotary dynamic system40, according to aspects of the present disclosed embodiments. The rotary dynamic system40may include multiple components coupled to or around a drill pipe28or drill string, or other downhole assemblies and components. The rotary dynamic system40may generally include at least one outer sleeve60concentrically disposed around the drill pipe28, with at least one bearing50,62coupling the outer sleeve60to the drill pipe28such that the outer sleeve60may rotate about the drill pipe28. In one or more embodiments, the rotary dynamic system40may include a first bearing50disposed at the top of the rotary dynamic system40, as well as a second bearing62disposed at the bottom of the rotary dynamic system40. The first bearing50may be coupled to a top end of the outer sleeve60while a second bearing62may be coupled to a bottom end of the outer sleeve60. As such, each of the first and second bearings50,62allow the outer sleeve60to rotate about the drill pipe28.

Referring still toFIG. 5, one or more threaded connections30may be disposed at the bottom of the drill pipe28that is carrying the rotary dynamic system or layer40for connecting the other drill pipes28. The other drill pipes may be located under the rotary dynamic system. The other drill pipe may be connected to the last part of the drill string which is a bottom hole assembly (BHA) or another downhole component. As illustrated inFIG. 5, the rotary dynamic system (RDS)40may be disposed concentrically (or eccentrically) within the borehole wall24or within an annulus26(that is, a ring-shaped space) disposed radially outward of the RDS40and radially attached inward around the drill pipe28. Each of the first and second bearings50,62of the RDS40may also include an inner race54and an outer race46for holding components of each bearing50,62(for example, balls, rollers, et cetera). In other embodiments, the RDS40may include a top drill pipe74coupled via the first bearing50to the outer sleeve60which is coupled to a bottom drill pipe76(and or other downhole component such as a bottom hole assembly (BHA)76) via the second bearing62. In such embodiments, the drill string or drill pipe28may not be disposed within the outer sleeve60. Instead, when the drill string becomes stationary (for example, to add or remove a drill pipe from the drill string), the outer sleeve60may continue to rotate via the first bearing50such that bridging44of the mud cake42does not occur on the outer sleeve60. The bottom hole assembly and/or bottom drill pipe76may also rotate or remain stationary, independent of the outer sleeve60due to the presence of the second bearing62which couples the outer sleeve60to the bottom hole assembly and/or bottom drill pipe76. Each bearing50,62may be affixed to the drill pipe28via two attachment connections. The bearings may work simultaneously for rotating the outer sleeve60.

FIGS. 6 and 7illustrate top views of the first and second bearings50,62respectively. Each of the first and second bearing50,62may include an inner race54that is coupled to the drill pipe28circumferentially surrounding the drill pipe28. The inner race54, which may generally include a ring-shaped geometry, may be coupled to the drill pipe28via compression fit, epoxy, adhesion, welding, brazing, and/or other suitable means. In addition, the inner race54may be formed integrally with the drill pipe28(such that the inner race54and drill pipe28form a single, solitary, or monolithic component). The inner race54may include one or more radial grooves (not shown) circumferentially extending around the exterior of the inner race54such that one or more balls56may roll within the radial grooves (which extend radially inwardly from the outer surface of the inner race54). In other embodiments, the inner race54may include rails extending circumferentially along each axial edge of the inner race54in place of (or in addition to) the radial grooves, thereby allowing the one or more balls56to roll therewithin. Each of the first and second bearings50,62may also include outer rails52extending circumferentially around each bearing, radially outward of the one or more balls56. The outer rails52may include a first outer rail at a first axial end of the bearing50,62and a second outer rail disposed at a second axial end of each bearing50,62. The first and second bearings50,62may also include an outer race46radially outward of the outer rails52. The outer rails52and the outer race46exert axial (both downward and upward) and radially inward forces, respectively, on the one or more balls56while the inner race54(including the radial groove and/or the inner rails) exerts axial (both upward and downward) and radially outward forces on the one or more balls56. As such, the one or more balls56may freely move circumferentially around the first and second bearings50,62, without moving radially or axially. The first and second bearings therefore allow the outer sleeve60to transfer radial and axial forces to the drill pipe28(and vice versa) while simultaneously allowing the outer sleeve60to rotate freely (that is, in a circumferential direction) around the drill pipe28.

Referring still toFIGS. 6 and 7, the first and second bearings50,62may include one or more balls56which may be generally spherically shaped. Each of the first and second bearings50,62may include from about six (6) balls to about thirty (30) balls, or from about eight (8) balls to about twenty-five (25) balls, or from about ten (10) balls to about twenty (20) balls, or from about twelve (12) balls to about eighteen (18) balls, or from about fourteen (14) balls to about sixteen (16) balls. Each of the first and second bearings50,62may include spacers disposed between each ball56such that the one or more balls56do not contact each other. The spacer configuration may include rings joined by linkages, with each ring extending around the circumference of a ball56such that the ball56may role within the ring. Stated otherwise, the spacer configuration may be describes as -o-o-o-o-o-o-o-o- with each “-” representing a linkage and each “o” representing a ring that extends around a circumference of a ball56, holding the ball56while also allowing it to rotate therewithin.

Still referring toFIGS. 6 and 7, each of the first and second bearings50,62may include roller bearings instead of the ball bearings. Roller bearings may include cylindrical rollers in place of the balls56of the ball bearings. Similar to ball bearings, the cylindrical rollers of roller bearings may be disposed radially inward of an outer race46and radially outward of an inner race54. In addition, roller bearings may include one or more sets of rails on the inner and/or outer races54,46to axially contain and/or constrain the cylindrical rollers. Each of the cylindrical rollers of the roller bearings may be rotatably mounted on an axle that is disposed between the one or more sets of rails on the inner and/or outer races54,46. Each axle may be oriented axially (for example, parallel to a centerline of the borehole18and/or drill pipe28). Each roller bearing may contain between about six (6) and about fifty (50) rollers (or sets of rollers), including all sub-ranges therebetween. Roller ball bearings, which include alternating balls56(spherical geometry) and rollers (cylindrical geometry) circumferentially spaced around the bearing between the inner and outer races54,46may also be used. Sleeve bearings (which include concentric cylinders with a predetermined space or tolerance defined between the outer circumference of the inner cylinder and the inner circumference of the outer cylinder) may also be used.

Referring toFIGS. 5-7, the rotary dynamic system40may include first and second bearings50,62that include ball bearings, roller bearings, roller ball bearings, and/or sleeve bearings. Roller bearings may generally be able to accommodate higher stresses than ball bearings since each of the rollers contacts the inner and/or outer races54,46along a contact line whereas each ball in a ball bearing contacts the inner and/or outer races54,46along a single contact point. On the other hand, ball bearings may include lower operational friction, thereby allowing ball bearings to operate with less mechanical losses. Sleeve bearings may accommodate both rotational (that is, circumferential) and axial movement between the inner and outer cylinders while ball bearings, roller bearings, and ball roller bearings allow only rotational (that is, circumferential) movement between the outer sleeve60and drill pipe28. Because different types of bearings include various advantageous and disadvantages, the rotary dynamic system (RDS)40may include multiple types of bearings. For example, in one embodiment, the RDS40may include a first bearing50disposed at the top of the outer sleeve60and a second bearing62disposed at the bottom of the outer sleeve60, where the first bearing50is a ball bearing and the second bearing62(disposed near areas of potentially greater stresses) is a roller bearing. In other embodiments, the RDS40may include a first bearing50that is a sleeve bearing and a second bearing62that is a roller bearing. In other embodiments, the RDS40may include a first bearing50that is a ball bearing and a second bearing62that is a sleeve bearing. In other embodiments, the RDS40may include a first bearing50that is a roller ball bearing and a second bearing62that is either a roller ball bearing or a sleeve bearing. In other embodiments, the RDS40may include a first bearing50that is a roller ball bearing, a ball bearing or a sleeve bearing, as well as a second bearing62that is either a roller bearing, a ball bearing, or a sleeve bearing. The RDS40may also include an outer sleeve60and drill pipe28that are dimensioned such that the two components act as a sleeve bearing (allowing circumferential and axial movement therebetween), even in the absence of other bearings50,62. As such, in some embodiments of the RDS40that include the first and second bearings50,62, the outer sleeve60and drill pipe28may act as a third bearing. The RDS40may include one (1), two (2), three (3), four (4), or more bearings50,62.

Referring still toFIGS. 5-7, each of the bearings50,62may be composed of metallic materials such as steel, stainless steel, carbon steel, austenitic steel, galvanized steel, titanium, aluminum, and/or other suitable metals and metallic alloys. In addition, each of the bearings50,62may be composed of ceramic materials such as ceramic silicon nitride (Si2N4) as well as others such as alumina ceramic (for example, with an alumina purity range from about 75% to about 99%, from about 80% to about 95%, or from about 85% to about 96%), steatite ceramic, zirconia ceramic (for example zirconium dioxide and/or yttria-stabilized zirconia (YSZ), silicon carbide ceramic, cordierite ceramic, mullite ceramic, and other ceramic materials). Roller bearings, ball bearings, roller ball bearings, sleeve bearings, and other types of bearings may be composed entirely of one or more ceramic materials, and may also be partially composed of ceramic materials (for example, the inner and outer races54,46and spacers) and partially composed of metal (for example, the balls and rollers). Ceramic bearings may have the benefit of being more stress and strain resistant (that is, capable of withstanding higher stresses) and may also include lower operational friction. However, ceramic bearings may also be more expensive. Therefore, it may be pragmatic to judiciously include ceramic bearings in the RDS40. In some embodiments, the RDS40may include a first bearing50that is metallic and a second bearing that is ceramic and/or partially ceramic. Each of the bearings50,62described herein including ball bearings, roller bearings, roller ball bearings, sleeve bearings, metallic bearings, ceramic bearings, and hybrid bearings (that is, partially metallic and partially ceramic) may use oil, air, and/or other fluids as lubricating fluids.

Still referring toFIGS. 5-7, each of the first and second bearings50,62may include one or more one-way catches64(shown inFIG. 7). The one or more one-way catches64may be circumferentially spaced around each bearing extending from the inner race54toward the outer race46. In one embodiment, the one or more one-way catches64may be spaced circumferentially around the bearing50,62such that they alternate with the balls56. In other embodiments, the one-way catches64may be located at different axial locations than the balls64(or rollers) such that the balls56or rollers may pass by the one-way catches64while the RDS40is rotating. For example, in one embodiment, the one-way catches64may extend between the inner rails (disposed in the inner race54) and outer rails52. Each one-way catch64may be coupled to the inner race54and may contact (but not be coupled to) the outer race46or outer rails52. The one-way catches64may be contoured (for example, with a concavity or concave surface oriented toward the direction of rotation of the drill pipe28(clockwise in the embodiment ofFIG. 7; counterclockwise in other embodiments)) such that as the drill pipe28rotates, the one-way catches64contact the outer race46(or outer rails52), thereby pushing the outer race46so that it rotates as well (along with the outer sleeve60).

Referring still toFIGS. 5-7, in some embodiments, the outer race46and/or the outer rails52may include notches or grooves that may interface with the one-way catches64when the drill pipe28is rotating. Due to the contouring of the one-way catches64and the ability of the one-way catches64to flex, as the drill pipe stops rotating, the outer race46and outer rails52may pass by the one-way catches64(allowing the outer race46and outer sleeve60to keep rotating). As such, the outer sleeve60may rotate any time the drill pipe28is rotating, but may continue to rotate (at least for a period of time) even when the drill pipe28stops rotating due to the inertial (that is, the rotational momentum) of the outer sleeve60. In the embodiment ofFIG. 7, the bearing62comprises six (6) one-way catches64circumferentially spaced around the bearing62about sixty (60) degrees apart. In other embodiments, each of the first and second bearings50,62may include other numbers and spacing arrangements of one-way catches64.

Referring still toFIGS. 5-7, in other embodiments, each of the first and second bearings50,62may include one or more engagement or lock mechanisms in place of or in addition to the one-way catches64. The engagement or lock mechanisms (not shown) may be used to selectively allow the drill pipe28to couple to or decouple from the outer sleeve60such that the drill pipe28and outer sleeve60may selectively rotate together or independently of one another. Any suitable means may be used as the engagement or lock mechanism including (but not limited to) latches, clutches, splines or teeth, threading, pin connections (and accompanying pin holes), interference fits, gears, as well as other suitable devices. In other embodiments, the RDS40may include motor windings and/or permanent magnets disposed within the outer sleeve60, the first and/or second bearings50,62, and/or the drill pipe28such that the outer sleeve60may be selectively caused to rotate even while the drill pipe28is stationary by electrifying the windings via the wireline36. As such, the outer sleeve60and the drill pipe28may act as a motor (or generator) rotor-stator system. In other embodiments, the RDS40may include one-way catches64, a motor rotor-stator system, and/or one or more engagement or lock mechanisms. In other embodiments, the RDS40may not include one-way catches64, a motor rotor-stator system, and/or any engagement or lock mechanisms. The drill pipe28may include a through-bore58that may be used to circulate drilling fluids such as water, drilling mud, acidizing solution and other fluids while the drill is in operation (that is, while the drill pipe is rotating).

Still referring toFIGS. 5-7, the rotary dynamic system (RDS)40may include one or more sensors disposed on the outer sleeve60(for example, first sensor66), on the drill pipe28(for example, second sensor68), and/or on the bearings50,62(for example, third and fourth sensors70,72). The first, second, third, and fourth sensors66,68,70,72may include electronic transmitters, receivers, and/or transceivers, RFID tags and receivers, proximity sensors, strain gauges, Hall sensors, temperature probes, static pressure transmitters, differential pressure transmitters, moisture sensors, accelerometers, and other types of sensors. The first, second, third, and fourth sensors66,68,70,72may be used to detect the speed (for example, the rotational or angular speed) of the outer sleeve60and/or the drill pipe28on an absolute basis or relative to one another. The first, second, third, and fourth sensors66,68,70,72may also be used to sense the presence of moisture, environmental conditions (such as pressure and temperature), as well as the axial, circumferential, and/or radial position of the outer sleeve60(for example, using the proximity probes or Hall sensors). Data from the first, second, third, and/or fourth sensors66,68,70,72may be transmitted to a control system (either wirelessly or via the wireline36) and used in the operations of the RDS40. The first, second, third, and fourth sensors66,68,70,72may also be used to sense the accumulation of mud, scaling, moisture, and other materials (illustrated inFIG. 5) on the outer sleeve60. In the embodiment ofFIG. 5, deposits are illustrated as having accumulated on the outer surface of the outer sleeve60. The deposits may include scaling, mineral deposits, hardened mud, and/or consolidated drilling fluid.

Referring toFIG. 5, in an alternate configuration, the first and second bearings50,62may be internal to a center portion51of the drill pipe28, rather than longitudinally above and below the drill pipe28, according to aspects of the present disclosed embodiments. In such embodiments, portions of the center portion51may act as the outer race46of the first and second bearings50,62. In some embodiments, the drill pipe28may act as the inner race54of each of the first and second bearings50,62. In such embodiments, the portion of the drill pipe28acting as the inner race54of the first and second bearings50,62may have a smaller outer diameter than the remainder of the drill pipe28. The drill pipe28that includes a drill segment or tool joint may present from about 30 to about 33 feet in length, or from about nine (9) to about eleven (11) meters, or from about eight (8) to about twelve (12) meters in length. The illustrations disclosed herein may not necessarily be to scale.

FIG. 8illustrates a method800of preventing or reducing the incidence of stuck pipes using the rotary dynamic system (RDS)40, according to aspects of the present disclosed embodiments. At step802, the method800may include deploying the RDS40(and accompanying drill pipe28) through a managed pressure drilling (MPD) system32or component thereof (for example, through a lubricator) at or near the wellhead or surface of the borehole18. At step804, the method800may include lowering the RDS40and drill pipe28to a desired depth (for example, for drilling purposes) within the borehole18. At step806, the method800may include initiating drilling operations which may include rotating the drill string or drill pipe28, as well as initiating the circulation of mud (at step808) through the center bore or through-bore58of the drill pipe. At step810, the method800may include engaging or rotating the outer sleeve60. The outer sleeve60may be rotated via the one-way catches64, via one or more locking or engagement mechanisms, via an electrical motor (integrated into the RDS40), and/or via the inherent friction in the RDS40(for example, as the drill pipe28and inner race54rotate (driven by a rotary table or top drive system (TDS)), the balls56or rollers begin to rotate which gradually accelerates the outer sleeve60). As such, the outer sleeve60may rotate as the drill pipe28rotates, even in the absence of a device or system that is actively driving or rotating the outer sleeve60. Step810may occur before steps806, and808, and even before steps802and804.

Referring still toFIG. 8, at step812, the method800may include stopping the drill pipe28from rotating and stopping the circulation of mud and/or drilling fluid (for example, if a new drill pipe needs to be added or removed from the drill string). Prior to step812, the method800may include disengaging the outer sleeve60from the drill pipe28such that the outer sleeve60may continue to rotate freely (for example, due to inertia) about the drill pipe28. In other embodiments, the outer sleeve60may be actively driven (for example, by a motor) after the drill pipe28becomes stationary. At step814, the method800may include adding or removing a drill pipe28from the drill string. At step816, the method800may include determining an angular speed of the outer sleeve via the first, second, third, and/or fourth sensors66,68,70,72in order to determine if an action should be taken to accelerate the outer sleeve60(for example, if the outer sleeve60has decelerated or become stationary). In one embodiment, a timer may be initiated when the outer sleeve60becomes stationary so as to provide a timeframe for which the mud hardening may occur (such that mud hardening (and a resulting stuck pipe) may be avoided). If the outer sleeve60has been stationary for a predetermined period of time, the control system and/or operator may command the RDS40to accelerate the drill pipe28and/or outer sleeve60so as to avoid or reduce the likelihood of a stuck pipe incidence.

In some embodiments, the outer sleeve60of the RDS40may include a cleaning solution unit including a nozzle (not shown) for spraying a cleaning solution, a container (not shown) for the cleaning solution, and a nozzle gate (not shown). For example, the cleaning solution may prevent the mud cake and/or assist the removal of the mud cake. In some embodiments, the cleaning solution may include acid. When necessary, the nozzle gate may open and the nozzle may spray the cleaning solution stored in the container. In some embodiments, the outer sleeve60of the RDS40may include a sensor (for example, an optical sensor, a moisture sensor, a touch sensor, and/or other types of sensors) to determine whether the cleaning solution should be sprayed. The sensor may activate the opening of the nozzle gate and the spraying action of the nozzle remotely. In some embodiments, the cleaning solution unit may be located on the outer surface of the outer sleeve60. The nozzle and the container may be embedded in the outer sleeve60, so that the nozzle does not protrude from the outer sleeve60. For example, only a tip of the nozzle may be exposed when the nozzle gate is open. In some embodiments, the outer sleeve60may include a plurality of cleaning units. The cleaning units may be distributed throughout the entire outer sleeve60. The cleaning units may be spaced evenly. In some embodiments, the container may be connected to two or more nozzles.

Still referring toFIG. 8, at step818, the method800may include initiating (or re-initiating) a rotation of the outer sleeve60(for example, if the outer sleeve60has stopped rotating due to friction). At step818, the method800may also include rotationally accelerating the outer sleeve in situations in which the outer sleeve60has decelerated but has yet to fully stop rotating. At step820, the method800may include re-initiating the rotation of the drill pipe28. At step822, the method800may include re-initiating the circulation of mud or drilling fluid through the drill pipe28. At step824, the method800may include repeating any of steps802-822as needed to avoid allowing the drill pipe28and/or outer sleeve60from remaining stationary for more than a predetermined length of time. In some embodiments, the predetermined length of time may be from about thirty (30) seconds to about two (2) hours, or from about one (1) minute to about one-hundred (100) minutes, or from about two (2) minutes to about eighty (80) minutes, or from about three (3) minutes to about sixty (60) minutes, or from about four (4) minutes to about forty (40) minutes, or from about five (5) minutes to about thirty (30) minutes, or from about seven (7) minutes to about twenty-five (25) minutes, or from about ten (10) minutes to about twenty (20) minutes, or from about thirteen (13) minutes to about seventeen (17) minutes. The method800may include performing any of steps802-824in a different order than what is shown inFIG. 8, as well as omitting and/or repeating any of802-824. In addition, one or more steps of method800may be performed concurrently with at least one other step of method800.

In one mode of operation of the rotary dynamic system (RDS)40, the drill pipe28may be stationary while the outer sleeve60rotates. In another mode of operation, the outer sleeve60may be stationary while the drill string or drill pipe28rotates. In another mode of operation, both the outer sleeve60and the drill pipe28may be rotating simultaneously with the drill pipe28rotating faster than the outer sleeve60. In another mode of operation, both the outer sleeve60and the drill pipe28may be rotating simultaneously with the drill pipe28rotating slower than the outer sleeve60. In another mode of operation, both the outer sleeve60and the drill pipe28may be stationary. In one or more embodiments, the outer sleeve60may become stuck after a stationary prolonged period in which case the drill pipe28may be rotatable within the outer sleeve60. As the drill pipe28rotates, mud or drilling fluid may be circulated therethrough, exiting the drill string at the threaded connection30, and circulating back toward the surface through the annulus26. As the circulating mud and drilling fluid passes the stuck outer sleeve60(that is, as it flows through the annulus26), it may dislodge the outer sleeve60, thereby unsticking the outer sleeve60. The drilling action of the drill pipe28may also cause the outer sleeve to become loosened as vibrational and gravitational effects propagate through the borehole18as a result of the drilling action. Thus, even in situations where the outer sleeve60becomes stuck, having the ability to rotate the drill pipe28and circulate drilling fluid may aid in quickly unsticking the outer sleeve60.

When deployed in operation, the outer sleeve60of the rotary dynamic system40of the present disclosed embodiments may continue to rotate for a period of time after the drill pipe28has become stationary (for example, if a new drill pipe needs to be added or removed from the drill string). In such cases, the outer sleeve60may continue rotating the entire time the drill pipe28is stationary. In other cases, the outer sleeve60may stop rotating after the drill pipe28has become stationary, but before the drill pipe28begins rotating again. In these cases, even if the outer sleeve60stops rotating, it may allow operators to “buy time” such that the outer sleeve60is not stationary long enough for caking or bridging to occur, thereby preventing the drill pipe28from becoming stuck. Therefore, by allowing the outer sleeve60to continue to passively rotate after the drill pipe28has become stationary, the rotary dynamic system40of the present disclosed embodiments may enable a high percentage of stuck pipe incidents to be avoided, even in cases where the outer sleeve60eventually stops rotating.

In operation, the outer sleeve60does not need to extend through the full longitudinal length of the drill pipe28in order to significantly reduce the likelihood of a stuck pipe incident. In some embodiments, the diameter of the drill pipe28may be reduced to accommodate the outer sleeve60such that the outer diameter of the outer sleeve60is approximately (for example, within about five (5) percent) of the original drill pipe28outer diameter. In other embodiments, the RDS40may include a drill pipe28that includes an outer diameter that is not modified in any way, in which case the outer sleeve60may include an outer diameter that is about one (1) to about sixty (60) percent larger than the outer diameter of the drill pipe28, as discussed above with respect toFIG. 2. In one or more embodiments, the outer sleeve60continues to rotate on its own after the drill pipe28becomes stationary and then subsequently becomes actively driven by one or more of the mechanisms disclosed herein. The rotary dynamic system (RDS)40of the present disclosed embodiments may aid in mitigating differential sticking resulting from the stationary periods, by preventing the bridging action caused by muds cakes or filter cakes around the drill string or drill pipe28. By disposing an outer sleeve60around the drill pipe28that is free to rotate thereabout, the RDS40of the current embodiments shields the drill pipe28(or portions thereof) from being subject to the bridging action of mud cake accumulation within the borehole18. In addition, by allowing or causing the outer sleeve60to continue to rotate about the drill pipe28(for example, while the drill pipe28is stationary due to the addition or removal of a drill pipe28to or from the drill string) bridging action may be avoided on the outer sleeve60as well. The rotational speeds of each of the downhole components including the outer sleeve60, the first and second bearings50,62, the drill pipe28, the top drill pipe74, and the bottom drill pipe76may all be selectively varied (independently or in concert with each other) so as to avoid the various downhole components from becoming stuck.

Extended Surface System with Helical Reamer

FIG. 9illustrates an extended surface system80, according to aspects of the present disclosed embodiments. The extended surface system80may include a drill pipe28with a helical reamer (or helical reaming features) wrapping around an outer surface of the drill pipe28in a spiral fashion. The extended surface system80may be disposed within the borehole18(shown inFIG. 1) with an annulus26(for example, a radial gap) disposed between the drill pipe28and the borehole wall24. A threaded connection30and/or bottom hole assembly (BHA) may be disposed at (or coupled to) the bottom of the drill pipe28for constructing the drill string. The extended surface system80may include one or more spiral notches78that wrap around the drill pipe28extending radially outward further than one or more spiral spacings82, which also wrap around the drill pipe28. The one or more spiral notches78alternate with the one or more spiral spacings82along a longitudinal (or axial) length of the drill pipe28. Each of the spiral notches78and the one or more spiral spacings82may extend around the drill pipe28through the entire axial length of the drill pipe28, or through only a center portion84(for example, a threaded portion84) of the axial length of the drill pipe28. In one or more embodiments, an outer diameter of the threaded portion84of the drill pipe28remains constant throughout the longitudinal length of the threaded portion84.

Referring still toFIG. 9, the extended surface system80may include a first torque sensor92disposed at the top of the drill pipe28as well as a second torque sensor94disposed at the bottom end of the drill pipe28. Each of the first and second torque sensors92,94may include torque sensors that work in connection with each other to sense the respective positions of the two torque sensors92,94relative to each other. As torque is applied to the drill pipe28(for example, via a surface rotary system or top drive system (TDS), or externally via friction from mud and debris), the drill pipe28may torsionally flex (that is, flex in a torsional or circumferential direction) thereby causing the position of the second torque sensor94to be rotated slightly from the position of the first torque sensor92, or vice versa. As additional torque is applied to the drill pipe28, the drill pipe28will torsionally flex more. Each of the first and second torque sensors92,94may include proximity sensors, RFID tags, and/or magnetic teeth that may be used to sense the phase shift or angular offset between the first and second sensors torque92,94. A control system of the oil rig10communicatively coupled to the first and second sensors torque92,94(which may be located, for example, at the surface) may then compute the torque that is applied to the drill pipe28, which is directly proportional to the angular offset. In other embodiments, the first and second torque sensors92,94may include strain gauges and/or Hall sensors (in addition to, or in place of, the torque sensors) in order to sense the resistive torque acting on the drill pipe28either or directly, or indirectly (for example, as a function of the rotational speed and the applied torque from a rotary table and/or top drive system (TDS)).

During drilling operations, as debris, rock fragments, cuttings, drilling fluid (such as drilling mud) and/or other substances and objects accumulate in the annulus26at the bottom of the borehole18, the friction acting on the drill pipe28may increase to the point where the drill pipe28would ordinarily become stuck. The extended surface system80of the present disclosed embodiments may be used to un-stick the drill pipe28and/or prevent the incidence of stuck drill pipes28. As the drill pipe28rotates during drilling operations, drill or rock fragments may be trapped between the drill pipe28and the borehole wall24. The one or more spiral notches78may help to axially raise and/or lower the fragments (as the extended surface system80acts like a screw), thereby freeing the drill pipe28from being stuck by the accumulated debris. As such, the extended surface system80(including helical reaming features) may act as a spiral elevator or lifter to remove accumulated debris from the bottom of the borehole18. In other embodiments, the helical reaming features (that is, the one or more spiral notches78) may act as grinders or reamers and may grind the debris such that it becomes pulverized, fragmented further, and/or fractured into smaller pieces, again resulting in the drill pipe becoming unstuck.

Still referring toFIG. 9, the one or more spiral notches78(as well as the one or more spiral spacings82) may include a wear-resistant coating79disposed thereon, the wear-resistant coating79being composed of materials and/or alloys such as TiN, ZrN, TiC, Ti—Al, CrN, Ni—Cr—B—Si—C alloys, tungsten carbide, ceramic coatings, metallic coatings, composite coatings (for example, coatings that include multiple layers made up of different materials such as binders, environmental barrier coatings (EBC), thermal barrier coatings (TBC), et cetera), and other suitable materials and combinations thereof. The wear-resistance coating(s)79may be applied to the surface as thin films and/or sprays via cold-spray, plasma spray, arc vapor deposition, atomic layer deposition (ALD), high-powered pulsed magnetron sputtering (HPPMS), mid-frequency/dual magnetron sputtering (MF/DMS), glancing angle of incidence deposition (GLAD), sintering, and/or other suitable methods. The wear-resistant coating(s)79may include a thickness from about 1 micron to about 800 microns, or from about 2 microns to about 500 microns, or from about 3 microns to about 300 microns, or from about 4 microns to about 200 microns, or from about 5 microns to about 130 microns, or from about 10 microns to about 90 microns, or from about 15 microns to about 70 microns, or from about 25 microns to about 60 microns, or from about 30 microns to about 55 microns, and/or other subranges therebetween. The wear-resistant coating(s)79may include a hardness (using the Vickers Pyramid Number (Hv)) from about 40 Hv to about 2500 Hv, or from about 100 Hv to about 2000 Hv, or from about 200 Hv to about 1600 Hv, or from about 300 Hv to about 12000 Hv, or from about 500 Hv to about 800 Hv, and/or other subranges therebetween.

Referring still toFIG. 9, in one embodiment, the one or more spiral notches78may be disposed around the drill pipe28such that a single spiral notch78wraps continuously around drill pipe28. In another embodiment, multiple spiral notches78(for example two (2), three (3), four (4), five (5), six (6), or more than six (6)) may wrap around the drill pipe28such that they alternate. For example a first spiral notch78A may wrap around the drill pipe28such that it alternates with a second spiral notch78B along an axial length of the drill pipe28, in embodiments that include two (2) spiral notches78A,78B. In such embodiments, the one or more spiral spacings82would correspondingly include a first spiral spacing82A that alternates with a second spiral spacing82B along the axial length of the drill pipe28, in the spaces between the first and second spiral notches78A,78B. In one or more embodiments, one or more of the spiral notches78,78A,78B may include at least one gap (thereby causing the spiral notches78,78A,78B to be non-continuous or segmented), allowing debris to become dislodged via (or through) the at least one gap (not shown). The one or more gaps may be preferentially spaced both circumferentially and axially throughout the threaded portion84of the drill pipe28. The edge or edges of the spiral notches78adjacent to the one or more gaps may also be used as grinding features for grinding up debris and/or rock fragments. In one embodiment, as the torque on the drill pipe28increases (for example due to the accumulation of debris in the borehole18), the first and second sensors92,94may send a signal to the control system that the drill pipe28is beginning to get stuck or has already become stuck (as increased torque may be predictive or indicative of a stuck drill pipe28). The control system may then cause the drill pipe28to rotate in an opposite direction, thereby lowering or raising the debris in the annulus26jammed between the drill pipe28and the borehole wall24, and serving to loosen up the drill pipe28, and/or unjam the debris. Drilling operations may then be reinitiated in the original direction of rotation once the drill pipe28has become unstuck. Because, the rotational action of the drill string in the opposite direction of the normal drilling operation may disconnect the drill pipes28from each other because the threaded connection30may be unscrewed, it is important to monitor the torque on drill string during reverse-direction drilling operations to ensure an unscrewing torque is not exceeded.

FIG. 10illustrates a perspective view of the extended surface system80, according to aspects of the present embodiments. The extended surface system80includes the drill pipe28including a hollow interior or through-bore58as well as the one or more spiral notches78, and the one or more spiral spacing82wrapped there-around.

FIG. 11illustrates an enlarged perspective view of a gripping surface90that may be used instead of, or in addition to, the one or more spiral notches78and the one or more spiral spacings82, to help grip and remove debris that becomes stuck between the drill pipe28and the borehole wall18. The gripping surface90may be disposed around the drill pipe28(for example, via epoxy, glue, fusion, sintering, adhesion, compression fit, welding, brazing, latches, and/or other suitable mechanisms), and in one embodiment, may grip the exterior surface of the drill pipe28with a pre-determined or selected amount of torque or friction. In such embodiments (which may use a loose compression fit), the gripping surface90will generally rotate with the drill pipe28due to the predetermined friction or compression of the gripping surface90around the drill pipe28. As the external torque or friction acting on the drill pipe28(for example, due to mud caking or bridging) increases, the gripping surface90may become temporarily stuck to the mud cake42(shown inFIGS. 3 and 4). In such cases, the drill pipe28may still be rotatable within the gripping surface90if a torque exceeding the predetermined torque (or friction amount) is applied to the drill pipe28. The rotation of the drill pipe28within the gripping surface90may help to loosen up the gripping surface90, especially if pressurized drilling fluids are present as a result of the rotation of the drill pipe28. The gripping surface90may include a plurality of crisscrossing, intersecting, and/or interlocking elements including a first plurality of wires86(for example, metallic wires) disposed radially outward of (and crisscrossing with) a second plurality of wires88, where the first plurality of wires86is oriented at a different angle than the second plurality of wires88. The first and second pluralities of wires86,88may intersect at an angle from about 45 degrees to about 90 degrees, or from about 50 degrees to about 80 degrees, or from about 55 degrees to about 75 degrees, or from about 60 degrees to about 70 degrees, and/or other subranges therebetween.

FIG. 12illustrates a schematic side view of the extended surface system80, according to aspects of the present disclosed embodiments. Each of the one or more spiral notches78may be oriented at a first angle96from a radial direction104. The first angle may be from about one (1) degree to about forty-five (45) degrees, or from about two (2) degrees to about thirty-five (35) degrees, or from about three (3) degrees to about thirty (30) degrees, or from about four (4) degrees to about twenty-five (25) degrees, or from about five (5) degrees to about twenty (20) degrees, or from about six (6) degrees to about fifteen (15) degrees, or from about seven (7) degrees to about ten (10) degrees, or from about three (3) degrees to about seven (7) degrees, or from about four (4) degrees to about six (6) degrees, and/or other subranges therebetween. A notch spacing98defined between each of the spiral notches78(for example, the axial height of the spiral spacings82) may be from about one (1) to about ten (10) times a thickness of each spiral notch78, or from about one-and-a-half 1.5 to about eight (8) times the thickness of each spiral notch78, or from about two (2) to about six (6) times the thickness of each spiral notch78, or from about two-and-a-half (2.5) to about five (5) times the thickness of each spiral notch78, or from about three (3) to about four (4) times the thickness of each spiral notch78, and/or other subranges therebetween. A protrusion height102may be defined as the difference between the radius of each spiral notch78and the outer radius of the drill pipe28. The protrusion height102may be dimensioned such that the notch spacing98is from about one (1) to about twenty (20) times the protrusion height102, or from about two (2) to about fifteen (15) times the protrusion height102, or from about three (3) to about ten (10) times the protrusion height102, or from about four (4) to about nine (9) times the protrusion height102.

FIG. 13illustrates a side view of a hybrid system100combining features of the helical reamer (or extended surface system80) ofFIG. 9with the rotary dynamic system40ofFIG. 5, according to aspects of the present disclosed embodiments. The hybrid system100may include the first and second bearings50,62of the rotary dynamic system40as well as the one or more spiral notches78and the one or more spiral spacings82of the extended surface system80. The hybrid system may also include the first, second, third, and fourth sensors66,68,70,72, as well as the first and second torque sensors92,94. The one or more spiral notches78may extend around each of the first and second bearings50,62. In other embodiments, the one or more spiral notches78may extend around the center portion84(or threaded portion84) of the drill pipe28, but not around the one or more spiral notches78. In operation, the hybrid system100functions such that both the helical reaming features (that is, the spiral notches78) and the first and second bearings50,62act to prevent the incidence of stuck pipes. In particular, the spiral notches78help to grind up and unjam debris stuck in the annulus26between the drill pipe28and the borehole wall24, while the first and second bearings50,62allow the drill pipe20to rotate within the outer sleeve60, thereby allowing for the continuous circulation of fluids (for example, water, mud and/or other drilling fluids), and thereby reducing the likelihood of the drill pipe28becoming permanently stuck.

FIG. 14illustrates an enlarged, perspective side view of the extended surface system80, according to aspects of the present disclosed embodiments. In the embodiment ofFIG. 14, a helical transition plate106is disposed around the outer circumference of the drill pipe28, radially inward of the one or more spiral notches78. The helical transition plate106may be joined to each of the one or more spiral notches78and the drill pipe28via any suitable mechanism including compression fit, epoxy, welding, brazing, glue, fusion, sintering, adhesion, and/or latches. In one or more embodiments, the helical transition plate106may be monolithic, solitary, and/or integral with the one or more spiral notches78(that is, they may be formed as a single piece or component). Because the one or more spiral notches78may undergo high stresses due to contact with debris that gets jammed between the drill pipe28and the borehole wall24, the helical transition plate106aids in distributing the stresses and transferring of forces between the one or more spiral notches78and the drill pipe28over a wider area, thereby reducing the likelihood that the spiral notches78will break off of (or become detached from) the drill pipe28. The helical transition plate106may be composed of aluminum, galvanized steel, stainless steel, brass, bronze, copper, carbon steel, austenitic steel, other metallic materials and alloys thereof, composite materials such as metal matrix composites and polymer matrix composites, thermoplastics, polymer materials such as polyether ether ketone (PEEK), other suitable materials, and combinations thereof. A width of the helical transition plate106may be approximately equal to the width of the spiral spacing82(for example, within about ten (10) percent or within about twenty (20) percent of the width of the spiral spacings82). The width of the helical transition plate106may also be between about twice the width of the spiral notches78, or about three (3) times the width of the spiral notches78, or from about one-and-a-half (1.5) to about five (5) times the width of the spiral notches78.

FIG. 15illustrates a method1500of operating the extended surface system80with helical reaming features, according to aspects of the present disclosed embodiments. At step1502, the method1500may include installing helical reaming features (for example, the one or more spiral notches78and the wear resistant coating79) on or around the drill pipe28. At step1504, the method1500may include deploying the drill pipe28in a downhole environment (for example, in the borehole18). At step1506, the method1500may include initiating drilling operations which may include rotating the drill pipe28and circulating drilling fluid (and/or other fluids) therethrough. At step1508, the method1500may include measuring at least one of: the rotational speed of the drill pipe28, the torque or friction acting on the drill pipe28, the rotational acceleration of the drill pipe28, and/or the angular position of the drill pipe28, via at least one of the first, second, third, and fourth sensors66,68,70,72, and/or via the first and/or second torque sensors92,94.

Referring still toFIG. 15, at step1510, the method1500may include reversing the direction of rotation of the drill pipe28if the control system determines that the drill pipe28is stuck or beginning to become stuck (for example, due to the accumulation of debris in the borehole18and/or annulus26). The rotational action of the drill string in the opposite direction of the normal drilling operation may disconnect the drill pipes28from each other because the threaded connection30may be unscrewed. Reversing the direction of rotation of the drill pipe28may be monitored closely to ensure the threaded connections30do not become unscrewed. The control system may determine that the drill pipe28is stuck or beginning to become stuck by sensing a high torque acting on the drill pipe28(that is, torque above a first predetermined threshold), or by sensing a low rotational speed (or acceleration) of the drill pipe28(that is, a rotational speed below a second predetermined threshold). At step1512, the method1500may include iterating operations of the drill pipe28from a forward direction to a reverse direction, and vice versa, as needed to unstick the drill pipe28and/or to unjam any debris jammed between the drill pipe28and the borehole wall24(thereby causing the torque acting on the drill pipe28to fall below the first predetermined threshold and/or causing the rotational speed of the drill pipe28to increase above the second predetermined threshold). At step1514, the method1500may include measuring the speed of acceleration of the drill pipe28, and/or the torque or strain acting on the drill pipe28via the first, second, third, and/or fourth sensors66,68,70,72, and/or via the first and/or second torque sensors92,94. At step1516, the method1500may include reinitiating drilling operations once the high torque or friction acting on the drill pipe28has been reduced or eliminated thereby indicating that the drill pipe28has become unstuck or loosened. Steps1502-1516of method1500may be performed in different orders or sequences than what is shown inFIG. 15. In addition, one or more steps may be repeated or omitted. In other embodiments, one or more of steps1502-1516may be performed concurrently with at least one other step of method1500.

The extended surface system80of the present disclosed embodiments may be utilized statically such that the helical reaming features (that is, the spiral notches78, the spiral spacings82, and the wear resistant coatings79) are disposed directly onto the drill pipe28(thereby causing the extended surface system80with helical reaming features to rotate, move and/or become stationary in unison with the drill pipe28). In such embodiments, the control system may rotate or drive the drill pipe28when necessary. In other embodiments, the extended surface system80may be used dynamically in connection with the rotary dynamic system40disclosed herein. In other embodiments, the extended surface system80may include one or more gripping surfaces90disposed around the drill pipe28, and allowing the drill pipe28to rotate therewithin when a predetermined external torque (for example, from the accumulation of mud or debris around the drill pipe28) acts on the gripping surface90. The helical reaming features and grinding surfaces of the drill pipe28(including the spiral notches78and other surfaces covered with wear-resistant coatings or materials79) may be used to grind the drill cuttings and/or debris as much as possible to completely eliminate them, or to make them smaller and therefore easier to extract out of the borehole via the drilling fluid. In some embodiments, the extended surface system80may include small rollers (not shown) in the helical reaming features and/or the grinding surfaces. The small rollers may store chemicals that help reduce or eliminate the cuttings and/or debris. The small rollers may release the chemicals when the cuttings press hard on the outer surface of the rollers. For example, the rollers may be squeezed by the cuttings, and then supply the stored chemicals.

The helical reaming features of the extended surface system80of the present disclosed embodiments may be used, simultaneously, as grinders to break down large rock fragments, as well as debris extraction tools to lift pieces out of the borehole via the spiral elevator functionality. Therefore, the extended surface system80and features thereof have the ability to act as a spiral elevator or lifter for the purpose of eliminating or extracting cuttings from the borehole18up to the surface. By deploying the extended surface system80with helical reaming features of the present disclosed embodiments into downhole environments such as boreholes18, the incidence of stuck drill pipes28resulting from accumulated debris at the bottom of the borehole18may be reduced or eliminated, thereby resulting in minimization of oil rig downtime and substantial cost savings.

Drill Pipe with Dissolvable Layer

The present disclosed embodiments include apparatuses, methods, compositions, and systems for alleviating stuck pipe and stuck drill string incidents during drilling operations. The apparatuses, methods, compositions, and systems may use a drill pipe with a dissolvable layer. The dissolvable layer may be placed on an outer surface of the drill pipe. When the drill pipe is stuck in a borehole, a dissolving solution may be delivered to the dissolvable layer of the drill pipe, thereby dissolving the dissolvable layer. The removal of a portion of the dissolvable layer may assist movement of the drill pipe. For example, the dissolution may reduce the outer diameter of the dissolvable layer, creating space between the drill pipe and the borehole. Additionally or alternatively, the dissolution may eliminate the surface where mud cake has accumulated.

FIG. 16illustrates a schematic side view of a drill pipe120with a dissolvable layer125, according to aspects of the present embodiments. In some embodiments, the dissolvable layer125is deposited on the outer surface134(shown inFIG. 17) of the drill pipe120. The outer diameter of the top portion122of the drill pipe120may be greater than the outer diameter of the center portion124of the drill pipe120. The outer diameter of the bottom portion126of the drill pipe120may also be greater than the outer diameter of the center portion124of the drill pipe120. The outer diameter of the dissolvable layer125may be substantially similar (for example, within 1%, 5%, or 10% of) to the outer diameter of the top portion122before the dissolution process. The outer diameter of the dissolvable layer125may be substantially similar (for example, within 1%, 5%, or 10% of) to the outer diameter of the bottom portion126before the dissolution process. The drill pipe120may further include a threaded connection128.

FIG. 17illustrates a schematic side view of a drill pipe120without a dissolvable layer125exposing tunnels132, according to aspects of the present embodiments. The tunnels132are accessible from the top130of the drill pipe120. The tunnels132may extend longitudinally along the length of the center portion124. Through the tunnels132, a dissolving solution may be delivered to the dissolvable layer124. As the tunnels132are connected to the top130of the drill pipe120, the dissolving solution may be introduced from the top130of the drill pipe to the dissolvable layer125. The drill pipe120may include a plurality of tunnels132, so that the dissolving solution can be distributed to the dissolvable layer125rapidly. The tunnels132may be parallel to each other. The tunnels132may extend axially toward the bottom portion126of the drill pipe120. In some embodiments, the tunnels132are in contact with the dissolvable layer125. In some embodiments, each of the tunnels132is designed to deliver the dissolving solution to only a specific portion of the dissolvable layer125. In some embodiments, the tunnels132may fluidly connect more than one drill pipes120. For example, when the drill string includes at least two drill pipes120, the tunnels132in each drill pipe120are aligned so that the dissolving solution may be delivered from the top of the first drill pipe120to the bottom of the second drill pipe120.

FIGS. 18 and 19show schematic views of a drill pipe120with a dissolvable layer125within a borehole, according to aspects of the present embodiments. The drill pipe120may be caked with mud138. The mud cake may bridge from the wall136of the borehole to the outer surface140of the dissolvable layer125. When the drill pipe120is not concentric within the borehole due to the differential pressure between the wellbore and the reservoir, bridging may occur where the gap142between the drill pipe120and the wall of the borehole is small. For example, when there is a high differential pressure between the drilling fluid hydrostatic circulated in the borehole via the drill string and the existing rock formation pressure, the drill string may be forced to rest against the borehole wall24, sinking into the mud cake (filter cake) and causing the drill string to stick to it. Since the dissolvable layer125is the outermost layer140, the dissolution of the dissolvable layer125may remove mud bridges138thereon. Additionally and/or alternatively, the removal of the dissolvable layer125provides space between the drill pipe120and the borehole136, so that the drill pipe120may be moved radially within the borehole. In some embodiments, only a portion of the dissolvable layer is removed. In some embodiments, the dissolution process releases gas, thereby increasing the pressure in the borehole. In some embodiments, the dissolution of the dissolvable layer125provides a slippery medium, assisting rotational movements of the drill pipe120.

FIG. 20depicts an alternative embodiments of a drill pipe120with a dissolvable layer125within a borehole, according to aspects of the present embodiments. In some embodiments, the tunnels146may not directly be in contact with the dissolvable layers125. The tunnels146may be connected to the dissolvable layer125via one or more channels148. In some embodiments, the channels148extend radially from the tunnels146to the dissolvable layer125, which is radially inward of the dissolvable layer125and radially outward of the tunnels146. In some embodiments, the drill pipe125includes a plurality of the channels148.FIG. 21shows the drill pipe without the dissolvable layer125. InFIG. 21, the drill pipe120is not concentric within the borehole. For example, a portion of the drill pipe120(for example, the right side inFIG. 21) is in contact with the borehole. The contacting portion may be bridged with mud. In contrast, the drill pipe120may be positioned concentrically in the borehole after removing the dissolvable layer125and the mud bridge inFIG. 21.

In some embodiments, the dissolvable layer125may include a material dissolvable by a dissolving solution. In some embodiments, the dissolvable layer125includes CaCO3. In some embodiments, the dissolvable layer125includes plastics, such as phenolic resins, glass fibres or a metal mesh, such as or aluminium.

In some embodiments, the dissolvable layer125may include CaCO3, and the dissolving solution may include hydrochloric acid (HCl). When the dissolvable layer125including CaCO3reacts with the dissolving solution including HCl, CO2will be released as shown in the below chemical reaction Formula 1.
CaCO3(s)+HCl(aq)→Ca2+(aq)+Cl−(aq)+H2O(l)+CO2(g)   Chemical Reaction Formula 1

In some embodiments, a porosity of the dissolvable layer125is within a range from about 10% to about 40%. In some embodiments, a porosity of the dissolvable layer125is within a range from about 10% to about 30%. In some embodiments, a porosity of the dissolvable layer125is within a range from about 10% to about 20%. In some embodiments, a porosity of the dissolvable layer125is within a range from about 20% to about 40%. In some embodiments, a porosity of the dissolvable layer125is within a range from about 30% to about 40%.

In some embodiments, a molarity of the dissolving solution is within a range from about 1 M to about 30 M. In some embodiments, a molarity of the dissolving solution is within a range from about 1 M to about 20 M. In some embodiments, a molarity of the dissolving solution is within a range from about 1 M to about 10 M. In some embodiments, a molarity of a dissolving solution is within a range of about 1 M to about 5 M. In some embodiments, a molarity of the dissolving solution is within a range from about 5 M to about 30 M. In some embodiments, a molarity of the dissolving solution is within a range from about 10 M to about 30 M. In some embodiments, a molarity of the dissolving solution is within a range from about 20 M to about 30 M.

In some embodiments, a thickness of the dissolvable layer125is within a range from about 1 mil to about 500 mils, where a mil is a thousandth of an inch. In some embodiments, a thickness of the dissolvable layer125is within a range from about 2 mils to about 300 mils. In some embodiments, a thickness of the dissolvable layer125is within a range from about 5 mils to about 150 mils. In some embodiments, a thickness of the dissolvable layer125is within a range from about 10 mils to about 100 mils. In some embodiments, a thickness of the dissolvable layer125is within a range from about 15 mils to about 80 mils. In some embodiments, a thickness of the dissolvable layer125is within a range from about 20 mils to about 60 mils. In some embodiments, a thickness of the dissolvable layer125is within a range from about 30 mils to about 40 mils. In some embodiments, a thickness of the dissolvable layer125may be less than a thickness of the tool joint of the drill pipe120. In some embodiments, an outer diameter of the dissolvable layer125may be less than an outer diameter of the tool joint of the drill pipe120.

In some embodiments, the drill pipe120may include one tunnel. In some embodiments, the drill pipe120may include two tunnels146spaced 180° apart. In some embodiments, the drill pipe120may include three tunnels146spaced 120° apart. In some embodiments, the drill pipe120may include four tunnels146spaced 90° apart. In some embodiments, the drill pipe120may include five tunnels146spaced 72° apart. In some embodiments, the drill pipe120may include six tunnels146spaced 60° apart. In some embodiments, the tunnel(s)146may be positioned on an outer surface of the drill pipe120. In some embodiments, the tunnel(s)146extend axially from a top portion122to a bottom portion126of the drill pipe120. In some embodiments, the tunnel(s)146may be helix shaped. In some embodiments, the tunnel(s)146may be zigzag shaped. In some embodiments, the tunnel(s)146may be sinusoidal shaped. In some embodiments, the tunnel(s)146may be vertical sine wave shaped.

In some embodiments, the tunnel(s)146may be located within a wall of the drill pipe120. In other words, the tunnel(s)146may not be exposed to or in contact with the dissolvable layer125. In some embodiments, the tunnel(s) may be annulus shaped, and may be disposed between inner and outer walls of the drill pipe125. In some embodiments, the tunnel(s)146extend axially within the wall of the drill pipe125. In some embodiments, the tunnel(s) may be helix shaped within the wall of the drill pipe125. Such a drill pipe125may include channel(s)148connecting the tunnel(s)146and the dissolvable layer125. In some embodiments, the channel(s)148connect the tunnel(s)146and dissolvable layer125radially. In some embodiments, the drill pipe120may include at least one channel148for each tunnel146. In some embodiments, the drill pipe120may include one, two, three, four, five, six, seven, eight, nine, and/or more than nine channel(s)148for each tunnel146. Each channel148may include a larger diameter at a radially inner end and a smaller diameter at a radially outer end. In some embodiments, the larger diameter of the channel(s)148may be within a range from about 1 mil to about 500 mils. In some embodiments, the channels148may be equally positioned and spaced along the entire length of the drill pipes120.

FIG. 22illustrates a method1600of preventing or reducing the incident of stuck pipes using a drill pipe120with a dissolvable layer125. At step1602, the method1600may include deploying the drill pipe including the dissolvable layer125and the tunnel146for accessing the dissolvable layer125at or near surface of the borehole. At step1604, the method1600may include lowering the drill pipe120to a desired depth (for example, for drilling purposes) within the borehole18. At step1606, the method1600may include initiating drilling operations, as well as initiating the circulation of mud (at step1608) through the center bore or through-bore58of the drill pipe120. At step1610, the method1600may include stopping the drill pipe120and stopping the circulation of mud and/or drilling fluid (for example, if a new drill pipe needs to be added or removed from the drill string). At step1610, the method1600may include delivering a dissolving solution to remove the dissolvable layer125as well as the mud cake created on the dissolvable layer125. In some embodiments, the dissolving solution may be supplied by a circulating system of the drilling rig system. The dissolving solution may be pumped to the tunnels132from the top130of the drill pipe120. The method1600may include allowing the dissolvable layer to dissolve for a predetermined length of time.

In some embodiments, the predetermined length of time may be from about 1 minute to about 60 minutes. In some embodiments, the predetermined length of time may be from about 1 minute to about 30 minutes. In some embodiments, the predetermined length of time may be from about 1 minute to about 15 minutes. In some embodiments, the predetermined length of time may be from about 1 minute to about 10 minutes. In some embodiments, the predetermined length of time may be from about 1 minute to about 5 minutes. In some embodiments, the predetermined length of time may be from about 2 minutes to about 4 minutes.

In some embodiments, a flow rate of a dissolving solution to a dissolvable layer may be substantially similar to (for example, within about 1% of, within about 5% of, and/or within about 10% of) the flow rate of the circulation fluid.

The drill pipe120and dissolvable layer125of the present disclosed embodiments may remain fluidly connected to a source of dissolving solution, even if the drill pipe120becomes stuck. The pressure release associated with the dissolving of the dissolvable layer125may aid in further loosening up a stuck drill pipe120. In addition, excess dissolving solution may act to chemically break-up or dissolve mud accumulated around the drill pipe120. Excess dissolving solution may also be beneficial by acting to stimulate the matrix or formation. By selectively flowing dissolving fluid through the tunnels146in a sequential manner, (for example, through a first tunnel during a first stuck pipe incident, then through a second tunnel during a second stuck pipe incident, et cetera) the drill pipe120and dissolvable layer125of the present embodiments may allow operators to unstick pipes several times, without having to remove the drill pipe120from the borehole18, and/or without having to deploy any special tooling downhole.

Elements of different implementations described may be combined to form other implementations not specifically set forth previously. Elements may be left out of the processes described without adversely affecting their operation or the operation of the system in general. Furthermore, various separate elements may be combined into one or more individual elements to perform the functions described in this specification.

Other implementations not specifically described in this specification are also within the scope of the following claims.

Certain Definitions

In order for the present disclosure to be more readily understood, certain terms are first defined below. Additional definitions for the following terms and other terms are set forth throughout the specification.

An apparatus, system, or method described herein as “comprising” one or more named elements or steps is open-ended, meaning that the named elements or steps are essential, but other elements or steps may be added within the scope of the apparatus, system, or method. To avoid prolixity, it is also understood that any apparatus, system, or method described as “comprising” (or which “comprises”) one or more named elements or steps also describes the corresponding, more limited apparatus system, or method “consisting essentially of” (or which “consists essentially of”) the same named elements or steps, meaning that the apparatus, system, or method includes the named essential elements or steps and may also include additional elements or steps that do not materially affect the basic and novel characteristic(s) of the system, apparatus, or method. It is also understood that any apparatus, system, or method described herein as “comprising” or “consisting essentially of” one or more named elements or steps also describes the corresponding, more limited, and closed-ended apparatus, system, or method “consisting of” (or “consists of”) the named elements or steps to the exclusion of any other unnamed element or step. In any apparatus, system, or method disclosed herein, known or disclosed equivalents of any named essential element or step may be substituted for that element or step.

As used herein, the term “longitudinally” generally refers to the vertical direction, and may also refer to directions that are co-linear with or parallel to the centerlines40of the rotary dynamic system40, drill pipe28, or borehole18. Angles that are defined relative to a longitudinal direction may include both negative and positive angles. For example, a 30-degree angle relative to the longitudinal direction may include both an angle that is rotated clockwise 30 degrees from the vertical direction (that is, a positive 30-degree angle) as well as an angle that is rotated counterclockwise 30 degrees from the vertical direction (that is, a negative 30-degree angle). The word “longitudinally” may be used interchangeably with the word “axially.”

As used herein, the term “downhole environment” may describe locations within a borehole and may describe environmental conditions typically experienced within boreholes during operation.

As used herein, “a” or “an” with reference to a claim feature means “one or more,” or “at least one.”

As used herein, the term “substantially” refers to the qualitative condition of exhibiting total or near-total extent or degree of a characteristic or property of interest.

EQUIVALENTS

It is to be understood that while the disclosure has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention(s). Other aspects, advantages, and modifications are within the scope of the claims.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the present embodiments, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the present embodiments is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.