Patent Application
20220112770
Wellbores may be drilled into a surface location or seabed for a variety of exploratory or extraction purposes. For example, a wellbore may be drilled to access fluids, such as liquid and gaseous hydrocarbons, stored in subterranean formations and to extract the fluids from the formations. Wellbores used to produce or extract fluids may be lined with casing around the walls of the wellbore. A variety of drilling methods may be utilized depending partly on the characteristics of the formation through which the wellbore is drilled.
The wellbores may be drilled by a drilling system that drills through earthen material downward from the surface. Some wellbores are drilled vertically downward, and some wellbores have one or more curves in the wellbore to follow desirable geological formations, avoid problematic geological formations, or a combination of the two.
In some aspects, a downhole tool includes a directional pad configured to contact a wellbore wall at a pad contact location and a drill bit having at least one active cutting element. The at least one active cutting element contacts the wellbore wall at a cutting element contact location, and a contact distance between the pad contact location and the cutting element contact location being 3 in. (7.6 cm) or less.
According to some aspects, a downhole tool includes a directional pad configured to contact a wellbore wall at a pad contact location and a drill bit having at least one active cutting element. A contact ratio between a bit diameter and a contact length between the pad contact location and the at least one active cutting element being greater than 3:1.
According to further aspects, a downhole tool includes a directional pad configured to contact a wellbore wall at a pad contact location and a drill bit having at least one active cutting element. A directional pad angle between the contact location and the at least one active cutting element relative to the longitudinal axis is greater than 0° and less than or equal to 5°.
Additional aspects include a downhole tool having a directional pad configured to contact a wellbore wall at a pad contact location and a drill bit having a first active cutting element and a second active cutting element. The first active cutting element is located further uphole than any other cutting element and the second active cutting element is located further uphole than any other cutting element except the first active cutting element. An angle between the first active cutting element and the second active cutting element being greater than 0° and less than or equal to 5°.
This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Rather, additional features and aspects of embodiments of the disclosure will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of such embodiments. The features and aspects of such embodiments may be realized and obtained by means of the instruments and combinations particularly pointed out in the appended claims. These and other features will become more fully apparent from the following description and appended claims, or may be learned by the practice of such embodiments as set forth hereinafter.
In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more particular description will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. For better understanding, the like elements have been designated by like reference numbers throughout the various accompanying figures. While some of the drawings may be schematic or exaggerated representations of concepts, at least some of the drawings may be drawn to scale. Understanding that the drawings depict some example embodiments, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
This disclosure generally relates to devices, systems, and methods for a downhole directional drilling tool.
The drill string 105 may include several joints of drill pipe 108 a connected end-to-end through tool joints 109. The drill string 105 transmits drilling fluid through a central bore and transmits rotational power from the drill rig 103 to the BHA 106. In some embodiments, the drill string 105 may further include additional components such as subs, pup joints, etc. The drill pipe 108 provides a hydraulic passage through which drilling fluid is pumped from the surface. The drilling fluid discharges through selected-size nozzles, jets, or other orifices in the bit 110 for the purposes of cooling the bit 110 and cutting structures thereon, and for lifting cuttings out of the wellbore 102 as it is being drilled.
The BHA 106 may include the bit 110 or other components. An example BHA 106 may include additional or other components (e.g., coupled between to the drill string 105 and the bit 110). Examples of additional BHA components include drill collars, stabilizers, measurement-while-drilling (“MWD”) tools, logging-while-drilling (“LWD”) tools, downhole motors, underreamers, section mills, hydraulic disconnects, jars, vibration or dampening tools, other components, or combinations of the foregoing.
In general, the drilling system 100 may include other drilling components and accessories, such as special valves (e.g., kelly cocks, blowout preventers, and safety valves). Additional components included in the drilling system 100 may be considered a part of the drilling tool assembly 104, the drill string 105, or a part of the BHA 106 depending on their locations in the drilling system 100.
The bit 110 in the BHA 106 may be any type of bit suitable for degrading downhole materials. For instance, the bit 110 may be a drill bit suitable for drilling the earth formation 101. Example types of drill bits used for drilling earth formations are fixed-cutter or drag bits. Swarf or other cuttings formed by use of a mill may be lifted to surface, or may be allowed to fall downhole. The bit 110 may be guided by a directional drilling assembly 112.
As shown in
In some embodiments, the second pad 317 is a discrete component attached to the directional pad housing 330. In other embodiments, the second pad 317 is integrally formed with the directional pad housing 330 (see
The directional pad 316 may engage or contact the wall 318 of the wellbore 302 at a pad contact location 336. Cutting elements 337 located on the bit 310 may engage the formation 301, degrading or cutting the formation 301 to form the wellbore 302. Some of the cutting elements 337 are active cutting elements 337, meaning that they actively engage and remove the formation 301, or cut a path through the formation 301. At least one of the active cutting elements 337 may be at a position defining a final active cutting element contact location 338. In some embodiments, a contact length 340 between the pad contact location 336 and the final cutting element contact location 338 may directly influence the DLS achievable using the directional drilling assembly 312. In other words, a shorter contact length 340 may increase the DLS, and a longer contact length 340 may decrease the DLS.
In some embodiments, the bit 310 may rotate independently of, or relative to, the directional pad housing 330. In other words, the bit 310 may be driven by a downhole motor (not shown), such as a mud turbine or a Moineau pump. The directional pad 316 may retain an absolute angular orientation (e.g., relative to a gravitational force and/or a cardinal direction such as magnetic north). As the wellbore 302 advances, the directional pad 316 may slide along the wellbore wall 318, constantly pushing the bit 310 opposite the pad contact location 336. Thus, the directional drilling assembly 312 may form a dog leg by slide drilling. The direction of the dog leg may be changed by rotating the directional pad housing 330. Moreover, the magnitude of DLS can be adjusted by adjusting by switching between the drilling modes from sliding to rotating.
At least a portion of a downhole tool (such as a downhole motor drive shaft, not shown) extends from the downhole end 332 of the directional pad housing 330 to form the bit connection 328. The bit connection 328 may extend a connection length 342, thereby moving (e.g., extending) the directional pad housing 330, and potentially the directional pad 316, away from the bit 310. In some embodiments, including an overhang 334 extending or protruding past the downhole end 332 of another portion of the directional pad housing 330 may allow the directional pad 316 to be positioned closer to the drill bit 310, without interfering with the bit connection 328. In this manner, the contact length 340 may be decreased, thereby increasing the DLS.
In
The bit 410 may include a plurality of cutting elements 437. Some of the cutting elements 437 may be active cutting elements 437. Active cutting elements 437 are cutting elements that actively degrade and remove a volume of the formation 401 while the bit 410 rotates and weight on bit is applied downhole. Thus, a cutting element that is uphole of a cutting element at a greater or equal radial distance may not be considered an active cutting element 437 as the volume that could be removed by that cutting element may be removed by the time the cutting element is moved to the location of the removed rock. Rather, such a cutting element may instead be used to protect gauge, stabilize the bit, or for backreaming, rather than for active cutting while advancing the drill bit 410.
A final active cutting element 437-1 may be the uphole-most active cutting element 437. Accordingly, the final active cutting element 437-1 may be located further uphole than every other active cutting element 437 of the plurality of cutting elements 437. In some examples, the final active cutting element 437-1 element may be the furthest uphole cutting element 437. In other examples, one or more cutting elements 437, which are not active, may be uphole of the final active cutting element 437. For instance, one or more cutting elements 437 may be used for backreaming when the bit 410 is removed from the borehole.
The final active cutting element 437-1 may engage the formation 401 at a final cutting element contact location 438 and remove a volume of rock from the formation 401. The final cutting element contact location 438 may be at approximately the center (e.g., longitudinal center for cylindrical shaped cutters) of the final active cutting element 437-1, measured lengthwise down a longitudinal axis 446 of the directional drilling assembly 412. Thus, the contact length 440 may be the distance between the pad contact location 436 and the final cutting element contact location 438. In the illustrated embodiment, the contact length 440 may be the distance between the downhole-most location where the directional pad 416 contacts the wall 418 and the center of the final active cutting element 437-1.
In some embodiments, the contact length 440 may be in a range having a lower value, an upper value, or lower and upper values including any of 0.25 in. (0.6 cm), 0.5 in. (1.3 cm), 0.75 in. (1.9 cm), 1.0 in. (2.5 cm), 1.25 in. (3.2 cm), 1.5 in. (3.8 cm), 1.75 in. (4.4 cm), 2.0 in. (5.1 cm), 2.25 in. (5.7 cm), 2.5 (6.4 cm), 2.75 in. (7.0 cm), 3.0 in. (7.6 cm), 4.0 in. (10.2 cm), 5.0 in. (12.7 cm), 6.0 in. (15.2 cm), 7.0 in. (17.8 cm), 8.0 in. (20.3 cm), or any value therebetween. For example, the contact length 440 may be greater than 0.25 in. (0.6 cm). In other examples, the contact length 440 may be less than 8.0 in. (2.3 cm). In still other examples, the contact length 440 may be any value in a range between 0.25 in. (0.6 cm) and 8.0 in. (2.3 cm). In other examples, the contact length 440 may be less than 6.0 in. (15.2 cm). In still other examples, the contact length 440 may be less than 3.0 in. (7.6 cm). In at least some embodiments, contact lengths 440 of less than 3.0 in. (7.6 cm) may be critical to achieve a desired DLS increase of the directional drilling assembly 412.
In some embodiments, the maximum DLS achievable by the directional drilling assembly 412 may be in a range having a lower value, an upper value, or lower and upper values including any of 1° per 100 ft. (30 m), 2° per 100 ft. (30 m), 3° per 100 ft. (30 m), 4° per 100 ft. (30 m), 5° per 100 ft. (30 m), 6° per 100 ft. (30 m), 7° per 100 ft. (30 m), 8° per 100 ft. (30 m), 9° per 100 ft. (30 m), 10° per 100 ft. (30 m), or any value therebetween. Some analysis has further been done to show that the maximum DLS achievable by the directional assembly 412 may even exceed 10° per 100 ft. (30 m), and may even be up to 20° per 100 ft. (30 m), up to 25° per 100 ft. (30 m), up to 40° per 100 ft. (30 m), or even up to 60° per 100 ft. (30 m).
Accordingly, the maximum DLS may be greater than 1° per 100 ft. (30 m), greater than 10° per 100 ft. (30 m), greater than 20° per 100 ft. (30 m), greater than 30° per 100 ft. (30 m), or greater than 40° per 100 ft. (30 m). In the same or other examples, the maximum DLS may be less than 60° per 100 ft. (30 m), less than 50° per 100 ft. (30 m), less than 40° per 100 ft. (30 m), less than 25° per 100 ft. (30 m), less than 20° per 100 ft. (30 m), or less than 10° per 100 ft. (30 m). In still other examples, the maximum DLS may be any value in a range between 1° per 100 ft. (30 m) and 25° per 100 ft. (30 m), or any value in a range between 1° per 100 ft. (30 m) and 60° per 100 ft. (30 m).
Similar to the directional drilling assembly 312 of
In some embodiments, an overhang distance 448 between the downhole end of the directional pad 416 and the downhole end 432 of the other portion of the directional pad housing 430 may be the same as, or less than, the distance 442 between the downhole end 432 and an uphole end of the drill bit 410. For instance, the overhang 434 may extend across an entirety of a shank portion of the bit connection 428. The shank portion of the bit connection 428 may remain outside the bit 410 when made-up to the drill bit 410 as described herein. In these or other embodiments, the contact length 440 may be zero or close to zero (e.g., less than the diameter of the final active cutting element 437-1). In some embodiments, the contact length 440 may be a percentage of a connection distance 442. The connection distance 442 may be the distance between the downhole end 432 of the other portion of the directional pad housing 430 and the uphole end of the drill bit 410. In some embodiments, the connection length 442 corresponds to the length of the shank portion of the bit connection 428.
The overhang distance 448 may be related to the connection length 442 by an overhang percentage. In some embodiments, the overhang percentage (i.e., percentage of the overhang distance 448 to the connection length 442) may be in a range having a lower value, an upper value, or lower and upper values including any of 10%, 25%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 100%, or any value therebetween. For example, the overhang percentage may be greater than 10%. In other examples, the overhang percentage may be less than 100%. In still other examples, the overhang percentage may be any value in a range between 10% and 100%.
The bit 410 has a bit diameter, which may also be referred to as the gauge diameter. The bit diameter is twice the bit radius 450 shown in
The directional pad 416 of
In some embodiments, the bit 410 is rotated relative to the directional pad housing 430 by the downhole tool 444. For example, the downhole tool 444 may include a drive shaft such as a drive shaft from a downhole motor, such as a turbine or a positive displacement motor (e.g., a Moineau pump). The directional pad housing 430 may maintain a desired a rotational orientation during drilling, including an orientation relative to the force of gravity, and/or an orientation relative to magnetic or true north. For instance, the directional pad housing 430 may be used for slide drilling. In some embodiments, the directional pad housing 430 and the directional pad 416 may be rotationally fixed relative to the longitudinal axis 446. In other embodiments, the directional pad housing 430 may be rotated, thereby changing the direction of the dog leg of the directional drilling assembly 412. In some embodiments, the directional pad 416 may be a singular directional pad 416. In other words, the directional pad housing 430 may have a single (e.g., only one) directional pad 416. Where the directional pad housing 430 has one or more directional pads 416, the directional pad housing 430 may include one or more other or second pads 417 having a different configuration. The second pads 417 may not materially contribute to the directional tendencies of the directional pad housing 430. For instance, the second pads 417 may have radial reach (and optionally reduced axial reach) relative to the directional pads 416, such that the second pads 417 can act more like a stabilizer while the directional pad(s) 416 steer the directional drilling assembly 412.
In some embodiments, the bit 410 may include a box connection 454. The box connection 454 may be a hollow portion inside of the bit 410 configured to connect to the downhole tool 444 at a pin connection coupled to the bit connection 428. In some examples, the box connection 454 and the bit connection 428 may connect via threads 456, where the box connection 454 has the female end of the threaded connection 456, and the bit connection 428 has the male end of the threaded connection 456. The threaded connection may be single shoulder connection, such as an API connection. In some embodiments, the threaded connection is a double shoulder connection or premium connection, such as a proprietary connection or licensed connection. When the drill bit 410 is made-up to the downhole tool 444, fluid flowing through a central bore 458 of the downhole tool 444 (e.g., in the drive shaft) may flow into the drill bit 410 and through one or more ports or nozzles in the body of the drill bit 410. The threaded connection 456 may allow sufficient room in the drill bit body to allow the ports or nozzles that will provide total flow sufficient to clean and cool the cutting structure of the drill bit 410 while drilling formation.
In some embodiments, the contact length 640 may be less than 3 in. (7.6 cm), and the directional pad angle 662 may be between 0.0° and 5.0° or between 0.5° and 3.5°. The combination of contact length 640 and directional pad angle 662 may further increase the DLS and/or improve control over the accuracy or precision of the DLS.
In some embodiments, the active gauge cutting element(s) 737-1 is located farther uphole than every other cutting element of the plurality of cutting elements (or farther uphole than every other active cutting element of the plurality of cutting elements), including the active adjacent-to-gauge cutting element(s) 737-2. The active adjacent-to-gauge cutting element(s) 737-2 are located farther uphole than every other cutting element of the plurality of cutting elements except the active gauge cutting element(s) 737-1. In some embodiments, an active gauge cutting element 737-1 and an active adjacent-to-gauge cutting element 737-2 are located on the same blade of the bit 710. In other embodiments, a blade may include one, but not both, of an active gauge cutting element 737-1 and an active adjacent-to-gauge cutting element 737-2.
The active gauge cutting element 737-1 has a first cutting element radius 764-1 relative to a longitudinal axis 746 of the bit 710. The active adjacent-to-gauge cutting element 737-2 has a second cutting element radius 764-2 relative to the longitudinal axis 746. In some embodiments, the second cutting element radius 764-2 may be different than the first cutting element radius 764-1. In this manner, a cutting element angle 766 is formed between the first cutting element 737-1 and the second cutting element 737-2. In some embodiments, the cutting element angle 766 may be in a range having a lower value, an upper value, or lower and upper values including any of 0.05°, 0.1°, 0.5°, 1.0°, 1.5°, 2.0°, 2.5°, 3.0°, 3.5°, 4.0°, 4.5°, 5.0°, or any value therebetween. For example, the cutting element angle 766 may be greater than 0.05°. In other examples, the cutting element angle 766 may be less than 5.0°. In still other examples, the cutting element angle 766 may be any value in a range between 0.0° and 5.0°, between 0.1° and 4°, or between 1° and 3°.
In some embodiments, the second cutting element radius 764-2 may be smaller than the first cutting element radius 764-1. Thus, a negative cutting element angle 766 is formed. In other words, the gauge of the bit may have a negative, or inward, taper in a downhole direction. A negative cutting element angle 766 may enable the upper cutting elements, on the gauge of a drill bit, to more fully engage the formation (e.g., formation 301 of
In some embodiments, the cutting element angle 766 may be the same as the directional pad angle (e.g., directional pad angle 662 of
The bit 810 has a bit diameter 850. In some embodiments, a bit ratio may be the ratio of the bit diameter 850 to the box length 868. In some embodiments, the bit ratio may be between 2.5 and 5. For instance, the bit ratio may be 8.5:2 (17:4), 8:2.5 (16:5), 8.75:2.75 (35:11), 8.5:2.75 (34:11), 3:1, or any other ratio of bit diameter 850 to box length 868. In some embodiments, the bit ratio may be greater than 3:1 or less than 4.5:1. In some embodiments, the box length 868 may be at least partially dependent on the bit diameter 850. A longer box length 868 may be stronger, and a larger bit diameter 850 may incur greater forces on the box connection 854, thereby impacting the bit ratio. In some embodiments, however, the type of formation (e.g., formation 301 of
In some embodiments, the bit may include redundant or backup final active cutting elements 937-1. In some embodiments, a bit having multiple blades may have multiple, redundant cutting elements 937 located in the same radial and longitudinal position on each of two or more different blades. Cutting elements 937 located in the same longitudinal position on different blades are redundant because they cut the same rotational path. In this manner, placing multiple final active cutting elements 937-1 in the same radial and longitudinal position on multiple blades provides redundancy that can help improve the life of the final active cutting elements 937-1, which may experience greater wear than other cutting elements, as they can each actively remove a reduced total volume.
As may be seen in the composite cutting profile 970, if redundant or backup final active cutting elements 937-1 are placed on every blade of the bit (and if the blades do not include trailing cutters at other positions), none of the other cutting elements 937 may be at a position in the cutting profile 970 that overlaps the position of the final active cutting element 937-1. Placing redundant or backup final active cutting elements 937-1 on some but fewer than each of the blades (e.g., half, one-third, one-quarter, every other blade, and so forth), may allow some overlap of the positions of active cutting elements with the final active cutting element(s) 937-1 on the cutting profile 970.
The first final active cutting element 1037-1 and the second final active cutting element 1037-2 may overlap in the cutting profile 1070 and may thus be located on different blades of the bit, or at leading and trailing positions on a single blade. Thus, in at least some embodiments, the first final active cutting element 1037-1 and the second final active cutting element 1037-2 may have overlapping cutting paths. In this manner, the cutting element angle (e.g., cutting element angle 766) may be fine-tuned along a length of the bit.
While the connection 1128 is shown as having eight flats that define the keyed features 1174, the connection 1128 of the motor, drive shaft, or bias unit may have any suitable feature. In other embodiments, for instance, the bit connection 1128 may include 1, 2, 3, 4, 5, 6, 7, or more than 8 flats or other keyed features 1174. In some embodiments, the keyed features may include protrusions, recesses, slots, or holes that can be engaged by the assembly tool. Any suitable keyed features 1174 may be evenly spaced around a circumference of the connection 1128. In other embodiments, the keyed features 1174 may be unevenly spaced around the circumference of the connection 1128. For example, a larger slot or flat may correspond to a specific location on the assembly tool 1171, thereby aligning the connection 1128 with the assembly tool 1171.
The connection 1128 may be a pin connection that is coupled to a box connection (e.g., box connection 454 of
To securely fasten the bit to the connection 1128 via the threaded connection 1156, the bit is rotated relative to the bit connection 1128 (or vice versa). The assembly tool 1171 may clamp onto the connection 1128 to restrict or even prevent the drive shaft or other downhole tool from rotating while the bit is fastened to the connection 1128. In the illustrated embodiment, the assembly tool has an upper portion 1176 and a lower portion 1178. The upper portion 1176 and the lower portion 1178 may have generally U-shaped radial cross-sectional areas to clamp around the connection 1128. The upper portion 1176 may have an upper cut-out 1180 that mates with a portion of one or more of the directional pad 1116, the directional pad housing 1130, or the keyed features 1174. For instance, the upper cut-out 1180 may be sized to pass over the connection 1128 and the directional pad 1116. One or more portions of the upper cut-out 1180 may then be sized and position to restrict rotation of the directional pad 1116 or directional pad housing 1130 when positioned as shown in
The upper portion 1176 and the lower portion 1178 may connect at an interface 1184. The interface 1184 may be used to clamp or otherwise secure the upper portion 1176 and the lower portion 1178 together (e.g., with a compressive force). The interface 1184 may be a bolted connection, a threaded connection, or any other connection or interface that aligns or secures the upper portion 1176 to the lower portion 1178 in the closed configuration shown in
In some embodiments, the connection 1228 includes two slots spaced around the outer surface of the connection 1228, which slots cooperatively define a surface or connection feature allowing the assembly tool 1271 to hold the connection 1228 in place while a bit 1210 can be rotated and secured thereto, or rotated around the bit 1210 while the bit 1210 is held in place. In contrast to the flats 1174 shown in
The connection 1228 may be a pin connection that is coupled to a box connection (e.g., box connection 454 of
To securely fasten the bit 1210 to the connection 1228 via the threaded connection, the bit 1210 is rotated relative to the bit connection 1228 (or vice versa). The assembly tool 1271 may fit around the connection 1228, and optionally into the keyed features 1274, to restrict or even prevent the drive shaft or other downhole tool from rotating while the bit 1210 is fastened to the connection 1228. In the illustrated embodiment, the assembly tool has an outer portion 1276 and an inner portion 1278. The inner portion 1278 may fit within the outer portion 1276, and is optionally rotationally secured therein using one or more pins 1279 or other fasteners. In some embodiments, there may be a single portion, rather than separate inner and outer portions 1276, 1278. As further shown, one or more openings 1280 may be formed in the outer portion 1276 and optionally the inner portion 1278. These openings may be used as a grip so that the assembly tool 1271 can be held in place. Of course, other mechanisms such as grips, keyed features, or the like may be used to otherwise hold the assembly tool 1271 in place.
The inner portion 1278 may have a cut-out 1280 that mates with a portion of one or more of the directional pad 1216, the directional pad housing 1230, or even keyed features (e.g., flats) of the connection 1228. For instance, the cut-out 1280 may be sized to pass over the connection 1228 and the directional pad 1216. One or more portions of the cut-out 1280 may then be sized and position to restrict rotation of the directional pad 1216 or directional pad housing 1230 when positioned as shown in
The embodiments of the downhole directional drilling tool have been primarily described with reference to wellbore drilling operations; the downhole directional drilling tool described herein may be used in applications other than the drilling of a wellbore. In other embodiments, downhole directional drilling tool according to the present disclosure may be used outside a wellbore or other downhole environment used for the exploration or production of natural resources. For instance, downhole directional drilling tool of the present disclosure may be used in a borehole used for placement of utility lines. Accordingly, the terms “wellbore,” “borehole” and the like should not be interpreted to limit tools, systems, assemblies, or methods of the present disclosure to any particular industry, field, or environment.
One or more specific embodiments of the present disclosure are described herein. These described embodiments are examples of the presently disclosed techniques. Additionally, in an effort to provide a concise description of these embodiments, not all features of an actual embodiment may be described in the specification. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous embodiment-specific decisions will be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one embodiment to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary skill having the benefit of this disclosure.
The articles “a,” “an,” and “the” are intended to mean that there are one or more of the elements in the preceding descriptions. It should be understood that references to “one embodiment” or “an embodiment” of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. For example, to simplify the discussion herein, some features are described with respect to particular embodiments. However, any features that are not mutually exclusive can be combined or interchanged. For instance, features of
Numbers, percentages, ratios, or other values stated herein are intended to include that value, and also other values that are “about” or “approximately” the stated value, as would be appreciated by one of ordinary skill in the art encompassed by embodiments of the present disclosure. A stated value should therefore be interpreted broadly enough to encompass values that are at least close enough to the stated value to perform a desired function or achieve a desired result. The stated values include at least the variation to be expected in a suitable manufacturing or production process, and may include values that are within 5%, within 1%, within 0.1%, or within 0.01% of a stated value.
A person having ordinary skill in the art should realize in view of the present disclosure that equivalent constructions do not depart from the spirit and scope of the present disclosure, and that various changes, substitutions, and alterations may be made to embodiments disclosed herein without departing from the spirit and scope of the present disclosure. Equivalent constructions, including functional “means-plus-function” clauses are intended to cover the structures described herein as performing the recited function, including both structural equivalents that operate in the same manner, and equivalent structures that provide the same function. It is the express intention of the applicant not to invoke means-plus-function or other functional claiming for any claim except for those in which the words ‘means for’ appear together with an associated function. Each addition, deletion, and modification to the embodiments that falls within the meaning and scope of the claims is to be embraced by the claims.
The terms “approximately,” “about,” and “substantially” as used herein represent an amount close to the stated amount that still performs a desired function or achieves a desired result. For example, the terms “approximately,” “about,” and “substantially” may refer to an amount that is within less than 5% of, within less than 1% of, within less than 0.1% of, and within less than 0.01% of a stated amount. Further, it should be understood that any directions or reference frames in the preceding description are merely relative directions or movements. For example, any references to “up” and “down” or “above” or “below” are merely descriptive of the relative position or movement of the related elements.
The present disclosure may be embodied in other specific forms without departing from its spirit or characteristics. The described embodiments are to be considered as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. Changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
This application claims the benefit of, and priority to, U.S. Patent Application No. 62/805,977 filed on Feb. 15, 2019, which is incorporated herein by this reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/018227 | 2/14/2020 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 62805977 | Feb 2019 | US |
