Patent Application
20200392807
This application is related to the U.S. non-provisional utility patent application titled “COMPACT DOWNHOLE TOOL”, attorney docket number NSC100/4-013US, filed concurrently herewith and hereby incorporated by reference in its entirety herein.
The present disclosure relates generally to parts used in downhole assemblies and, more particularly, to a slip with internal buttons for use in a downhole assembly.
During drilling or reworking of wells, tubing or other pipe (e.g., casing) in the wellbore may be sealed at a particular location, such as for pumping cement or other fluids down the tubing, and forcing fluid out into a formation. Various downhole tools have been designed to effect this sealing or to isolate a particular zone of the wellbore. Many such downhole tools used for sealing a wellbore employ slips to contact casing in the wellbore with sufficient friction under pressure to hold the downhole tool in place and maintain the seal in the wellbore for the desired application.
Multiple slips may be arranged around an exterior surface of a cylindrically-shaped downhole tool, and are pushed outward by a cone in the downhole tool that moves the slips to be in contact with a surface of the wellbore, such as the wall of the wellbore, or casing within a wellbore, when the downhole tool is set. Typical slips may be equipped with buttons on the exterior surface to increase the friction between the slip and the surface of the wellbore.
Various types of downhole tools may also employ an elastomeric member and spherical element with a cone and slip arrangement to effect a seal in the wellbore, such as packers, bridge plugs, and frac plugs. In a frac plug, the slips hold the elastomeric member of the frac plug in place against the wellbore when the frac plug is set and may enable the frac plug to withstand a certain amount of pressure or flow rate while maintaining the seal in the wellbore and holding the frac plug in place. Certain frac plugs may further be enabled to remain in the wellbore and held in place by slips during production from the well.
In one aspect, a slip haying internal buttons is disclosed. The slip may include an outer surface enabled to engage a wellbore surface, and an inner surface enabled to be engaged by a setting cone of a downhole tool. In the slip, the inner surface may include at least one inner button enabled to contact the setting cone when the setting cone engages the inner surface.
In any of the disclosed embodiments of the slip, the outer surface may include at least one outer button enabled to contact the wellbore surface.
In any of the disclosed embodiments of the slip, the inner button may include a material that has a higher coefficient of friction than the coefficient of friction of the inner surface of the slip when in contact with the setting cone.
In any of the disclosed embodiments or the slip, the inner surface of the slip in the downhole tool may be parallel to the setting cone.
In any of the disclosed embodiments of the slip, an exposed surface of the inner button facing the setting cone may be non-parallel with the setting cone.
In any of the disclosed embodiments of the slip, the setting cone may include a metal and the inner button may include a non-metal. In the slip, the inner button may include a composite material including at least one non-metal. In the slip, the inner button may include a metal.
In any of the disclosed embodiments of the slip, the inner button may be substantially cylindrical in shape.
In any of the disclosed embodiments of the slip, the inner button may be shaped substantially as a polygonal prism.
In any of the disclosed embodiments of the slip, an exposed surface of the inner button that faces a surface of the setting cone may be non-parallel with the surface of the setting cone.
In any of the disclosed embodiments of the slip, an exposed surface of the inner button that faces a surface of the setting cone may be parallel with the surface of the setting cone.
In any of the disclosed embodiments of the slip, the wellbore surface may be a casing.
In another aspect, a downhole tool is disclosed. The downhole tool may include a setting cone enabled to engage a plurality of slips located circumferentially about the setting cone when the downhole tool is set. In the downhole tool, the slips may further include an external surface enabled to engage a casing when the downhole tool is set, and an internal surface enabled to engage the setting cone when the downhole tool is set. In the downhole tool, at least one of the slips may further include the internal surface of the slip including at least one internal button enabled to contact the setting cone when the downhole tool is set.
In any of the disclosed embodiments of the downhole tool, the external surface of the slip may include at least one exterior button enabled to contact the casing.
In any of the disclosed embodiments of the downhole tool, the internal button may include a material that has a higher coefficient of friction than the coefficient of friction of the internal surface of the slip when in contact with the setting cone.
In any of the disclosed embodiments of the downhole tool, the setting cone may include a metal, and the internal button comprises a non-metal.
In any of the disclosed embodiments of the downhole tool, the internal button may include a composite material including at least one non-metal. In the downhole tool, the internal button may include a metal.
In any of the disclosed embodiments of the downhole tool, the internal surface of the slip may be parallel to the setting cone.
In any of the disclosed embodiments of the downhole tool, an exposed surface of the internal button that faces a surface of the setting cone may be non-parallel with the surface of the setting cone.
In any of the disclosed embodiments of the downhole tool, an exposed surface of the internal button that faces a surface of the setting cone may be parallel with the surface of the setting cone.
In any of the disclosed embodiments of the downhole tool, the internal button may be substantially cylindrical in shape.
In any of the disclosed embodiments of the downhole tool, the internal button may be shaped substantially as a polygonal prism.
In yet another aspect, a method for engaging downhole tools in wellbores is disclosed. The method may include running a downhole tool to a depth in a casing. In the method, the downhole tool may include a setting cone enabled to engage a plurality of slips located circumferentially about the setting cone when the downhole tool is set. The method may further include setting the downhole tool in the casing, including causing the plurality of slips to engage a setting cone. In the method, the slips may further include an outer surface enabled to engage the casing when the downhole tool is set, and an inner surface enabled to engage the setting cone when the downhole tool is set. In the method, at least one of the slips may be an inner button slip that may further include the inner surface of the slip including at least one inner button. In the method, causing the plurality of slips to engage the setting cone may further include forcing the plurality of slips against the setting cone. In the method, the plurality of slips may include the at least one inner button slip, while the inner button may contact the setting cone as the plurality of slips engage the casing.
In any of the disclosed embodiments of the method, the plurality of slips engaging the setting cone may further include at least one outer button located at the outer surface of the slip engaging the casing.
In any of the disclosed embodiments of the method, the inner button may further include a material that has a higher coefficient of friction than the coefficient of friction of the inner surface of the slip when in contact with the setting cone.
In any of the disclosed embodiments of the method, the setting cone may include a metal, while the inner button may include a non-metal.
In any of the disclosed embodiments of the method, the inner button may include a composite material including at least one non-metal. In any of the disclosed embodiments of the method, the inner button may include a metal.
In any of the disclosed embodiments of the method, the inner surface of the slip may be parallel to the setting cone in the downhole tool.
In any of the disclosed embodiments of the method, an exposed surface of the inner button that faces a surface of the setting cone may be non-parallel with the surface of the setting cone.
In any of the disclosed embodiments of the method, an exposed surface of the inner button that faces a surface of the setting cone may be parallel with the surface of the setting cone.
In any of the disclosed embodiments of the method, the inner button may be substantially cylindrical in shape.
In any of the disclosed embodiments of the method, the inner button may be shaped substantially as a polygonal prism.
For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
In the following description, details are set forth by way of example to facilitate discussion of the disclosed subject matter. It should be apparent to a person of ordinary skill in the field, however, that the disclosed embodiments are exemplary and not exhaustive of all possible embodiments.
Throughout this disclosure, a hyphenated form of a reference numeral refers to a specific instance of an element and the un-hyphenated form of the reference numeral refers to the element generically or collectively. Thus, as an example (not shown in the drawings), device “12-1” refers to an instance of a device class, which may be referred to collectively as devices “12” and any one of which may be referred to generically as a device “12”. In the figures and the description, like numerals are intended to represent like elements.
As noted above, slips are parts in downhole tools, such as packers, bridge plugs, and frac plugs, among others, that may be used for anchoring against a surface of a wellbore, typically by using a cone-shaped member to force the slips against the surface of a wellbore. The gripping force that the slips are capable of exerting can be a key factor in the design and implementation of the downhole tool. The frictional performance of the slip may be determinative for the strength of the seal formed by the downhole tool and the amount of pressure that the seal and the downhole tool can withstand. Seals and downhole tools that can withstand higher pressures or higher flow rates are desirable because they enable wider ranges of operating conditions for well operators. Accordingly, slips having hard external or exterior buttons, such as ceramic buttons, have been used to improve the coefficient of friction between the slip and the casing, thereby improving the frictional force applied by the slip.
As will be disclosed in further detail herein, a slip with internal buttons for use in a downhole assembly, such as in a downhole tool, is disclosed. The slip with internal buttons for use in a downhole assembly disclosed herein may enable an increased frictional force between the slip and a setting cone in a downhole tool, for example. Accordingly, the slip with internal buttons for use in a downhole assembly disclosed herein may enable an improved design for a downhole tool, such as by using a single setting cone with slips in the downhole tool instead of a pair of setting cones with respective pairs of slips, which may enable a substantially more compact downhole tool for a given frictional force, which is desirable. The slip with internal buttons for use in a downhole assembly disclosed herein may be implemented using a variety of materials for the slip body and or the internal buttons, as disclosed herein.
Referring now to the drawings,
As shown in
Although a frac plug 100 is shown incorporating slips 104, it will be understood that other types of downhole tools, such as bridge plugs, packers or other sealing devices, may incorporate slips 104 having internal buttons.
Referring now to
Also shown in
In some instances, internal button 222 may accordingly enable a more compact design in a given downhole tool or assembly, such as by enabling the use of a single set of cone 106/slips 104 instead of a plurality of sets, for example, to achieve the same downhole slip performance (see also
As shown, external buttons 110 and internal button 222 may be formed as cylindrically shaped parts that are mounted in corresponding holes formed in slip 104. Additionally, the exposed surfaces of external buttons 110 or internal button 222 or both may be non-parallel with their respective engaging surfaces, such that external buttons 110 or internal button 222 have an edge that can bite in the respective engaging surface when set to further increase frictional force. It is noted that in various embodiments, internal button 222 may cause at least some plastic deformation in cone 106 when set, such as an indentation that corresponds to the shape of internal button 222 and helps to hold internal button 222, and also slip 104, in place when set. In some embodiments, cone 106 may be formed from a metal, such as steel, while internal button 222 may be formed from a hard material, such as a ceramic. It is noted that a body of slip 104 may be formed from any of various materials, including metals or rubbers, resin, epoxy, or other polymers. In particular, the body of slip 104 may be a composite material having a matrix phase as noted with an inclusion phase that may include various inclusions, such as fibers, filaments, and particles, or various combinations thereof.
In certain embodiments, slip 104 may be made using a filament-reinforced composite material, such as an epoxy with glass fiber filaments, among other types of composite matrix and inclusion combinations. In particular embodiments, the glass fiber is wound as a continuous filament on a mandrel from which individual parts for slip 104 may be cut. One example of a filament-reinforced slip part is disclosed in U.S. patent application Ser. No. 15/981,592 titled “Filament Reinforced Composite Material with Load-Aligned Filament Windings” filed on May 16, 2018, which is hereby incorporated by reference.
Referring now to
Method 300 may begin at step 302 by running a downhole tool to a depth in a wellbore, where the downhole tool comprises a setting cone enabled to engage a plurality of slips located circumferentially about the setting cone when the downhole tool is set. At step 304, the downhole tool is set in the wellbore, including causing the plurality of slips to engage the setting cone, and where at least one of the slips is an inner button slip. At step 306, the plurality of slips are forced against the setting cone, including the at least one inner button slip, where the inner button contacts the setting cone as the outer surface of the plurality of slips engages the wellbore.
Referring now to
In
The non-parallel surface of internal buttons 422 or external buttons 410 may be realized using different methods. As shown in
In this manner, internal buttons 422 may increase the frictional force by which slip 404 is held in place by frustoconical member 406 when frac plug 400 is set, which may enable the relatively low ratio of tool length to tool diameter, such as by allowing frac plug 400 to have a single frustoconical member 406, instead of a plurality of cones and a respective plurality of sets of slips.
The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to include all such modifications, enhancements, and other embodiments thereof which fall within the true spirit and scope of the present disclosure.
