Patent Application
20160237530
Various types of materials are used in equipment, operations, etc. for exploration, development and production of resources from geologic environments. For example, equipment may be used in one or more of a sensing operation, a drilling operation, a cementing operation, a fracturing operation, a production operation, etc.
A method can include producing stock material via equal-channel angular pressing where the stock material includes an alloy that includes an average grain size less than approximately 500 nanometers and machining the stock material into at least one part of borehole tool. A method can include producing stock material via cryomilling spray-atomized particles where the stock material includes an alloy that includes a grain size less than approximately 500 nanometers and forming the stock material into at least one part of a borehole tool. A degradable apparatus can include a shaped material that includes an aluminum alloy that has an average grain size less than about 500 nanometers. Various other apparatuses, systems, methods, etc., are also disclosed.
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.
Features and advantages of the described implementations can be more readily understood by reference to the following description taken in conjunction with the accompanying drawings.
The following description includes the best mode presently contemplated for practicing the described implementations. This description is not to be taken in a limiting sense, but rather is made merely for the purpose of describing the general principles of the implementations. The scope of the described implementations should be ascertained with reference to the issued claims.
As an example, a material or materials may be processed to form processed material. In such an example, the processed material may be machined, formed, etc. to produce a part or parts. As an example, a part may be a component or a portion of a component. A part may be included in equipment, which may be suitable for use in an environment such as, for example, a downhole environment. As an example, equipment may be drilling equipment, cementing equipment, fracturing equipment, sampling equipment, or other type of equipment. As an example, equipment may be borehole equipment. As an example, a tool may be a borehole tool, for example, suitable to perform a function or functions in a downhole environment in a borehole.
As to cementing equipment, such equipment may be used in one or more downhole cementing operations. As an example, cement may be placed adjacent to a liner. As an example, a liner may be a string of casing in which the top does not extend to the surface but instead is suspended from inside another casing string. As an example, a liner hanger may be used to attach or hang one or more liners from an internal wall of another casing string.
As an example, a method may include operating one or more components of a liner hanger system. As an example, a lower completion may be a portion of a well that is at least in part in a production zone or an injection zone. As an example, a liner hanger system may be implemented to perform one or more operations associated with a lower completion, for example, including setting one or more components of a lower completion, etc. As an example, a liner hanger system may anchor one or more components of a lower completion to a production casing string.
In the example of
Prior to introducing cement into an annulus between a bore and a casing, calculations may be performed to estimate an amount of cement sufficient to fill the annulus, for example, for purposes of sealing off a casing segment. Accuracy of an estimate as to the amount of cement as well as issues in a process of introducing cement may, for example, result in occasional voids or gaps (e.g., regions where cement is lacking).
As an example, a string may include one or more tools such as, for example, a logging while drilling (LWD) tool, which may carry one or more transmitters and one or more receivers. For example, the SONICSCOPE™ tool marketed by Schlumberger Ltd. (Houston, Tex.) carries a wideband multipole transmitter and wideband receivers. The multipole transmitter provides for transmission of high-frequency monopole energy (e.g., for compressional and shear slowness in fast formation), low-frequency monopole energy (e.g., for Stoneley waves) and quadrupole energy (e.g., for shear slowness in slow formations). The wideband receivers provide for digitization of sensed signals and inter-receiver sampling to address aliasing. As an example, a tool may include circuitry to sense information as to regions proximate to a bore. As an example, a tool may include circuitry to determine one or more cement-related parameters (e.g., extent of cement, cement quality, voids, etc.). As an example, a controller may include an interface to receive information from one or more sensors.
As mentioned, a liner may be a casing (e.g., a completion component). As mentioned, a liner may be installed via a liner hanger system. As an example, a liner hanger system may include various features such as, for example, one or more of the features of the assembly 150 of
As shown in
As an example, an assembly may include a liner top packer with a polished bore receptacle (PBR), a coupling(s), a mechanical liner hanger, a hydraulic liner hanger, a hydraulic liner hanger, a liner(s), a landing collar with a ball seat, a landing collar without a ball seat, a float collar, a liner joint or joints and/or a float shoe and/or a reamer float shoe.
As an example, a method can include a liner hanger setting procedure. Such a procedure may include positioning a liner shoe at a depth at which a hanger is to be set, dropping a setting ball from a ball dropping sub of a cementing manifold, gravitating or pumping the ball down to a ball catch landing collar, reducing the pump rate when the ball is expected to seat, increasing pressure, which pressure may act through setting ports of a hanger body and set slips on to a casing, and while holding the hanger setting pressure, setting the liner hanger by slacking off the liner weight on the hanger slips, where a loss of weight may be indicated on a weight gauge as the liner hanger sets.
In the foregoing example, it may be desirable that the ball (see, e.g., the ball 162) has properties suited for one or more operation or operations. Properties may include mechanical properties and may include one or more other types of properties (e.g., chemical, electrical, etc.). As an example, it may be desirable that the ball degrades. For example, a ball may be manufactured with properties such that the ball degrades when exposed to one or more conditions. In such an example, where the ball acts to block a passage, upon degradation, the passage may become unblocked. As an example, a ball or other component (e.g., a plug, etc.) may degrade in a manner that facilitates one or more operations. As an example, a component or a portion of a component may degrade in stages. For example, consider a plug that degrades from a first size to a second smaller size. In such an example, the second smaller size may allow the plug to move (e.g., from a first seat to a second seat, etc.). As an example, a plug tool may be a degradable tool. As an example, a plug tool may be degradable in part. For example, consider a plug tool with a degradable seat or degradable seats. In such an example, a plug may be seated in a degradable seat that upon degradation of the seat, the plug may pass through the seat (e.g., become unplugged with respect to that seat). As an example, a system can include a plug tool that is degradable at least in part and one or more degradable plugs (e.g., balls, cylinders, etc.).
Resource recovery from a geologic environment may benefit from application of one or more enhanced recovery techniques. For example, a geologic environment may be artificially fractured to increase flow of fluid from a reservoir to a well. As an example, consider hydraulic fracturing where fluid pressure is applied to a subterranean environment to generate fractures that can act as flow channels. Hydraulic fracturing may be planned in advance, for example, to develop a region, which may be referred to as a drainage area. Hydraulic fracturing may be analyzed during or post-fracturing. As an example, hydraulic fracturing may occur in stages where a later stage may be planned at least in part based on information associated with one or more earlier stages.
In
As an example, a model can include constructs that model, for example, a matrix, a well, natural fractures, hydraulic fractures, activated fractures and a stimulated inter-hydraulic fracture region. In the example of
As an example, a method can includes a delivery block for delivering fluid to a subterranean environment, a monitor block for monitoring fluid pressure and a generation block for generating fractures via fluid pressure. As an example, the generation block may include activating one or more fractures. As an example, the generation block may include generating and activating fractures. As an example, activation may occur with respect to a pre-existing feature such as a fault or a fracture. As an example, a pre-existing fracture network may be at least in part activated via a method that includes applying fluid pressure in a subterranean environment. The foregoing method may be referred to as a treatment method or a “treatment”. Such a method may include pumping an engineered fluid (e.g., a treatment fluid) at high pressure and rate into a reservoir via one or more bores, for example, to one or more intervals to be treated, which may cause a fracture or fractures to open (e.g., new, pre-existing, etc.).
As an example, a fracture may be defined as including “wings” that extend outwardly from a bore. Such wings may extend away from a bore in opposing directions, for example, according in part to natural stresses within a formation. As an example, proppant, such as grains of sand of a particular size, may be mixed with a treatment fluid to keep a fracture (or fractures) open when a treatment is complete. Hydraulic fracturing may create high-conductivity communication with an area of a formation and, for example, may bypass damage that may exist in a near-wellbore area. As an example, stimulation treatment may occur in stages. For example, after completing a first stage, data may be acquired and analyzed for planning and/or performance of a subsequent stage.
Size and orientation of a fracture, and the magnitude of the pressure to create it, may be dictated at least in part by a formation's in situ stress field. As an example, a stress field may be defined by three principal compressive stresses, which are oriented perpendicular to each other. The magnitudes and orientations of these three principal stresses may be determined by the tectonic regime in the region and by depth, pore pressure and rock properties, which determine how stress is transmitted and distributed among formations.
Where fluid pressure is monitored, a sudden drop in pressure can indicate fracture initiation of a stimulation treatment, as fluid flows into the fractured formation. As an example, to break rock in a target interval, fracture initiation pressure exceeds a sum of the minimum principal stress plus the tensile strength of the rock. To determine fracture closure pressure, a process may allow pressure to subside until it indicates that a fracture has closed. A fracture reopening pressure may be determined by pressurizing a zone until a leveling of pressure indicates the fracture has reopened. The closure and reopening pressures tend to be controlled by the minimum principal compressive stress (e.g., where induced downhole pressures exceed minimum principal stress to extend fracture length).
After performing fracture initiation, a zone may be pressurized for furthering stimulation treatment. As an example, a zone may be pressurized to a fracture propagation pressure, which is greater than a fracture closure pressure. The difference may be referred to as the net pressure, which represents a sum of frictional pressure drop and fracture-tip resistance to propagation (e.g., further propagation).
As an example, a method may include seismic monitoring during a treatment operation (e.g., to monitor fracture initiation, growth, etc.). For example, as fracturing fluid forces rock to crack and fractures to grow, small fragments of rock break, causing tiny seismic emissions, called microseisms. Equipment may be positioned in a field, in a bore, etc. to sense such emissions and to process acquired data, for example, to locate microseisms in the subsurface (e.g., to locate hypocenters). Information as to direction of fracture growth may allow for actions that can “steer” a fracture into a desired zone(s) or, for example, to halt a treatment before a fracture grows out of an intended zone.
Referring to the operation 250 of
In an operation such as the operation 250 of
In a system such as the system 300 of
As an example, at least a portion of a borehole tool may be broken via interaction with a tool where at least some of resulting pieces are degradable. For example, a tool may apply force (e.g., drilling force or other force) to a plug, a plug tool, etc. such that the applied forces causes breaking into pieces of at least a portion of the plug, at least a portion of the plug tool, etc. In such an example, the pieces may be relatively large and degrade to relatively small pieces (e.g., which may pass through one or more openings, etc.).
As an example, processing may promote grain-boundary strengthening (e.g., Hall-Petch strengthening). Such processing can strengthen a material, for example, by changing average crystallite (grain) size. As an example, grain boundaries can impede dislocation movement, for example, the number of dislocations within a grain can have an effect on how easily dislocations can traverse grain boundaries and travel from grain to grain. Thus, as an example, by changing grain size via processing, dislocation movement and, for example, yield strength may be tailored. As an example, processing may include heat treatment after plastic deformation. As an example, processing may include controlling a rate or rates of solidification to alter grain size of a material.
As an example, processing may alter strength, ductility or strength and ductility. The strength of a material may be defined as the material's ability to withstand an applied load without failure. Strength may characterize a material, for example, via calculations of stresses, strains, stresses and strains, etc. For example, consider predicting response of a structure under loading and its susceptibility to various failure modes, which can take into account material properties such as its yield strength, ultimate strength, Young's modulus, and Poisson's ratio. Mechanical macroscopic properties (e.g., geometric properties) such as length, width, thickness, boundary constraints, abrupt changes in geometry, etc. may be considered when determining strength of a material.
Ductility pertains to deformation under tensile stress (e.g., measurable by stretching material). Malleability pertains to deformation under compressive stress (e.g., measurable by hammering or rolling material). Ductility and malleability are mechanical properties that pertain to plasticity (e.g., extent to which a material can be plastically deformed without fracture).
As an example, a subgrain may be defined to be a part of a grain that is slightly disoriented from other parts of the grain. Depending on the processing of the material, subgrains can form within the grains of the material. As an example, a higher density of subgrain may provide for a higher yield stress of the material due to the increased subgrain boundaries. Strength of metal may vary reciprocally with subgrain size (e.g., analogous to Hall-Petch phenomenon). Subgrain boundary strengthening may include a breakdown point of around a subgrain size of about 100 nanometers (e.g., the size where smaller subgrains may decrease yield strength).
As an example, a material may include one or more calcium-magnesium (Ca—Mg) alloys, calcium-aluminum (Ca—Al) alloys, calcium-zinc (Ca—Zn) alloys, magnesium-lithium (Mg—Li) alloys, aluminum-gallium (Al—Ga) alloys, aluminum-indium (Al—In) alloys, and aluminum-gallium-indium alloys (Al—Ga—In). As an example, a material may include about 80 weight percent aluminum, about 10 weight percent gallium and about 10 weight percent indium.
An alloy can include crystalline, amorphous or mixed structure (e.g. partially crystalline, partially amorphous). Features characterizing the structure can include grains, grain boundaries, phases, inclusions, etc. As an example, one or more features may be of the order of macroscopic, micron or submicron scale, for instance nanoscale. Shape, size, shape and size, etc. may be characteristics that can influence mechanical properties and, for example, reactivity.
As an example, a reactive material may include an element that tends to form positive ions when its compounds are dissolved in a liquid solution and whose oxides form hydroxides rather than acids with water. As an example, a material may disintegrate. For example, consider an alloy that loses structural integrity and becomes dysfunctional for instance due to grain-boundary embrittlement or dissolution of one of its elements. As an example, a byproduct of degradation from grain boundaries may not necessarily include an ionic compound such as a hydroxide and may include a metallic powder residue (e.g., consider severely embrittled aluminum alloys of gallium and indium).
As an example, a material may be electrically conductive and may include a metallic luster. As an example, a material may possess a relatively high mechanical strength in tension, shear and compression (e.g., exhibit a relatively high hardness).
Regarding alloying elements in an alloy, consider, for example, carbon (C) in iron (Fe) (e.g., in a steel, etc.). As an example, one or more of lithium (Li), magnesium (Mg), calcium (Ca), and aluminum (Al) may be included in a material that includes an alloy or alloys. Such metals or elements may, for example, act as metallic solvents, like iron in steels, or alloying elements, in dilute or high concentrations, like carbon in steels or chromium in stainless steels.
As an example, a material may be degradable and, for example, an alloy may be degradable (e.g., a degradable alloy). As an example, a material may degrade when subject to one or more conditions (e.g., over time). For example, consider one or more environmental conditions and/or “artificial” conditions that may be created via intervention, whether physical, chemical, electrical, etc. As an example, conditions can include temperature, pressures (e.g., including loads and forces), etc.
As an example, a degradable alloy may degrade at least in part due to formation of internal galvanic cells, for example, between structural heterogeneities (e.g. phases, internal defects, inclusions, etc.). As an example, a degradable material may resist passivation or, for example, formation of one or more stable protective layers.
As an example, a degradable alloy can include one or more alloying elements “trapped” in “solid solution”. For example, consider aluminum, which may be impeded from passivating or building a resilient protective layer (e.g., aluminum oxide such as Al2O3).
As an example, a material can include concentrations of one or more solute elements, for example, trapped in interstitial and in substitutional solid solutions. As an example, concentrations, which may be spatially heterogeneous, of such one or more solute elements, may be controlled through chemical composition, processing, etc. As an example, consider rapid cooling where solubility is higher than at ambient temperature or temperature of use.
As an example, a material may include one or more elements or phases that liquate (e.g., melt, etc.) once elevated beyond a certain temperature, pressure, etc., which for alloys may be predictable from phase diagrams, from thermodynamic calculations (e.g., as in the CALPHAD method), etc.
As an example, a material may “intentionally” fail via liquid-metal embrittlement, for example, as in an alloy that includes gallium and/or indium. As an example, a degradable material may include an alloy or alloys and possess phases that may be susceptible to creep (e.g., superplastic) deformation (e.g., under intended force, etc.), possess phases that are brittle (e.g., which may rupture in response to impact, etc.).
As an example, a degradable material may include a calcium alloy such as, for example, calcium-lithium (Ca—Li), calcium-magnesium (Ca—Mg), calcium-aluminum (Ca—Al), calcium-zinc (Ca—Zn), calcium-lithium-zinc (Ca—Li—Zn), etc. As an example, in a calcium-based alloy, lithium may be included in concentrations, for example, between about 0 to about 10 weight percent (e.g., to enhance reactivity, etc.). As an example, concentrations ranging from about 0 to about 10 weight percent of one or more of aluminum, zinc, magnesium and silver may enhance mechanical strength.
As an example, a material may include one or more magnesium-lithium (Mg—Li) alloys, for example, enriched with tin, bismuth and/or one or more other low-solubility alloying elements.
As an example, a material can include one or more alloys of aluminum. As an example, a material may include one or more of an aluminum-gallium (Al—Ga) alloy and an aluminum-indium (Al—In) alloy. As an example, a material may include one or more of an aluminum-gallium-indium (Al—Ga—In) and an aluminum-gallium-bismuth-tin (Al—Ga—Bi—Sn) alloy.
As an example, a material can include aluminum, gallium and indium. For example, consider a material with an alloy of about 80 weight percent aluminum, about 10 weight percent gallium and about 10 weight percent indium. Such a material may include Vickers microhardness (500 g) of about 32 (#1), 34 (#2), 34 (#3), 30 (#4), 35 (#5), 36 (#6) and 33 (average) and estimated strength of about 100 (MPa), 15 (ksi) and 1.5 (normalized).
As an example, a component may be formed of material that provides a desired degradation rate and desired mechanical properties (e.g., strength, etc.). As an example, a degradation rate may depend upon one or more conditions (e.g., temperature, pressure, fluid environments), which may be exist in an environment and/or may be achieved in an environment (e.g., via one or more types of intervention).
As an example, a method may produce a material such as, for example, a stainless steel, a nickel alloy (for HP & HT applications), or a degradable material.
As an example, a nickel alloy may be suitable for use in a harsh environment. For example, a harsh environment may be classified as being a high-pressure and high-temperature environment (HPHT). A so-called HPHT environment may include pressures up to about 138 MPa (e.g., about 20,000 psi) and temperatures up to about 205 degrees C. (e.g., about 400 degrees F.), a so-called ultra-HPHT environment may include pressures up to about 241 MPa (e.g., about 35,000 psi) and temperatures up to about 260 degrees C. (e.g., about 500 degrees F.) and a so-called HPHT-hc environment may include pressures greater than about 241 MPa (e.g., about 35,000 psi) and temperatures greater than about 260 degrees C. (e.g., about 500 degrees F.). As an example, an environment may be classified based in one of the aforementioned classes based on pressure or temperature alone. As an example, an environment may have its pressure and/or temperature elevated, for example, through use of equipment, techniques, etc. For example, a SAGD operation may elevate temperature of an environment (e.g., by 100 degrees C. or more).
As an example, a degradable material may be suitable for use in an operation that may include stages. For example, consider a cementing operation, a fracturing operation, etc. As explained with respect to
As an example, a method can include subjecting a material or materials to severe plastic deformation (SPD). As an example, a method can employ one or more metalworking techniques that involve introducing very large strains that may provide for complex stress state or high shear, resulting in a high defect density and equiaxed ultrafine grain (UFG) sizes (e.g., with a dimension less than about 500 nm or, for example, less than about 300 nm) and/or nanocrystalline (NC) structures (e.g., with a dimension less than about 100 nm).
As an example, a method can include equi-channel angular processing (ECAP). As an example, a method can include cyromilling. As an example, a method can include ECAP and cyromilling.
As an example, a method can include raising alloy strength. As an example, a method can include increasing pressure rating of a piece of equipment.
As an example, a method can include processing a nickel-chromium alloy 625 (e.g., INCONEL® 625, etc.). For example, consider the following material with percent mass given in parenthesis for INCONEL® 625: nickel (58.0 minimum), chromium (20.0-23.0), iron (5.0 maximum), molybdenum (8.0-10.0), niobium (e.g., plus tantalum) (3.15-4.15), carbon (0.10 maximum), manganese (0.50 maximum), silicon (0.50 maximum), phosphorus (0.015 maximum), sulfur (0.015 maximum), aluminum (0.40 maximum), titanium (0.40 maximum), and cobalt (1.0 maximum). As an example, a method can include processing a nickel-chromium alloy to more than double its strength. In such an example, the processed alloy may be used in a piece of equipment to increase the pressure rating of the piece of equipment. As an example, a method can include processing a NiCrMo alloy and using the processed alloy in equipment in an HPHT application (e.g., consider a sampling bottle formed at least in part of a processed alloy).
As an example, a material may be processed to form a degradable component or a portion of a component that is degradable. For example, a method may include processing material that includes a degradable alloy to strengthen the material. In such an example, the resulting material may be used, for example, as a component or as a portion of a component in a stage or stages of a fracturing operation. As an example, such a material may be used as a component or as a portion of a component in a tensile-loaded application, for example, consider a bridge plug, etc. As an example, a bridge plug may be a tool, for example, a bridge plug tool. Such a tool may include one or more seats, which may, for example, provide for seating of one or more plugs.
As an example, a method may include processing to manufacture one or more abrasion-subjected parts. In such an example, the processing may increase part longevity. For example, consider a part such as a drill-stem stabilizer, which may be used in a deep well, in a deviated well, etc.
As an example, a method can include processing that may result in material with enhanced mechanical properties. For example, consider processing that forms nanostructures. In such an example, the material may exhibit more controlled and enhanced operational limits. As an example, a material produced via a method that implements one or more processing techniques may “homogenize” grain size and grain shape. As an example, a material with more homogeneous grains may behave in a manner that is more amenable to modeling. For example, when compared to a material with less homogenous grains, the material with more homogenous grains may behave in a more predictable manner. Such a material may be implemented in one or more operations (e.g., as a component or as part of a component). As an example, consider an operation where a component or a part of a component is to degrade where a priori knowledge of degradation mechanics may allow the operation to be performed with greater reliability, greater success, less risk, in a more timely manner, with greater scheduling certainty, etc.
As an example, a material produced via a method that includes ECAP may be of a size that includes a cross-sectional dimension of the order of inches. For example, consider a material with a cross-sectional dimension of the order of about 10 inches or less. As an example, a material produced via a method that includes ECAP may form stock that can be machined into a spherical form, a plug form, a plug tool form, a seat form, a valve form, or other borehole tool form, etc. In such an example, the resulting component may include grains of relatively homogenous size and shape. Where the material is degradable in an environment, the degradation mechanics may be predictable via one or more models, for example, more so than a material produced without ECAP that includes a less homogeneous grain size and shape and, for example, larger grain sizes.
As an example, a method can include casting. As an example, a method can include forming a material from chips. As an example, a method can include forming a material from powder. As an example, a method can include forming a material from powder and chips. As an example, a method can include forming a near-net strengthened ball. As an example, a method can include forming a near-net strengthened dart. As an example, a method can include increasing strength of a material via processing that increases homogeneity of the material. As an example, a method can include processing that enhances degradability, for example, uniformity of degradation (e.g., CPL/PSG/WS).
As an example, a method can include reducing porosity in an alloy through severe plastic deformation (SPD). As an example, such an alloy may be a degradable alloy.
As an example, a method can include increasing strength and ductility of an alloy. As an example, such an alloy may be a degradable alloy.
As an example, a method can include developing more uniform properties of an alloy. As an example, such an alloy may be a degradable alloy.
As an example, a method can include increasing thermal stability of an alloy. As an example, such an alloy may be a degradable alloy.
As an example, a method can include abetting strain hardening through dislocation strengthening. As an example, such an alloy may be a degradable alloy.
As an example, a method can include increasing volume fraction of low sigma coincidence lattices (e.g., low ΣCSLs) or coherent boundaries in an alloy with LSFE/TWIP properties, for example, for CRAs deployed in a hostile downhole environment (e.g., a harsh environment).
As an example, a method can include increasing residual stress in a treated downhole component, for example, to mitigate effects of tensile loading in a hoop direction due to existing compressive residual stress.
As an example, a method can include ECAP. As an example, ECAP can include pressing a billet through a single abrupt angle contained within a die. As an example, a die may include multiple sections such that multiple abrupt angles exist within the die.
In ECAP, a level of imposed strain may be dependent on an angle φ between two portions of a channel of a die and, for example, to a lesser extent by an angle ψ marking an outer arc of curvature where the two portions of the channel intersect. For example, given a channel angle of φ=90 degrees, imposed strain may be of the order of about 1 for a single pass through the channel. As an example, repetitive pressings may be undertaken to impose larger strains.
Equal-channel angular pressing (ECAP) can fabricate ultrafine-grained metals and alloys. ECAP can impose strain where one or more of a slip system and a shearing pattern may be factors that can be selected, adjusted, etc. that can influence ECAP. As an example, ECAP may include a die with a die geometry. As an example, ECAP may include one or more pressing regimes.
As an example, ECAP can provide for microstructural refinement during a pressing operation. As an example, features of microstructures produced by ECAP may include single crystals, polycrystalline materials with both a single phase and multi-phases, and metal-matrix composites.
As an example, ECAP may be applied to form ultrafine grains in metals and alloys, which may enhance their mechanical and functional properties. As an example, a method can include controlling a range of microstructural parameters such as, for example, grain boundary misorientations, crystallographic texture and distributions of one or more second phases.
As an example, a method can include cryomilling. As an example, an alloy may be spray atomized. As an example, spray-atomized powder may be produced with a particle size of less than about 150 microns. In such an example, the powder may be mechanically milled in liquid nitrogen, for example, to reduce the micron-sized grains in the atomized powders to nanocrystalline size. At atmospheric pressure, liquid nitrogen boils at about −196 degrees C. (e.g., about 77 K or about −321 degrees F.).
As an example, a method may include applying a milling treatment. In such an example, nano-grained cryomilled particulates may be subsequently hot isostatic pressed (e.g., “HIPped”) and extruded at apposite temperature to produce a bulk alloy.
As an example, the material 704 may be stock material, for example, a bar, a rod, etc. In the example method 700, the resulting material 705, 706 or 707 may be processed material, for example, as a processed bar or a processed rod. As an example, the processed material may be machined. As an example, the processed material may be machined to form a part. As an example, a part may be a ball, a plug, a plug tool, a portion of a tool, etc.
As an example, the channel 803 may include an entry portion and an exit portion where the forward punch 805 is received at least in part by the entry portion of the channel 803 and where the backward punch 807 is received at least in part by the exit portion of the channel 803. As an example, a method can include controlling at least one of a force applied to a forward punch and force applied to a backward punch.
As an example, a material such as 5083 Al (4.4Mg, 0.7Mn, 0.15Cr, balance Al) may be spray-atomized. The resulting spray-atomized powder may have a particle size less than about 150 microns, which may be mechanically milled in liquid nitrogen (e.g., cryomilling), for example, to reduce the micron-sized grains in the atomized powder to nanocrystalline size. The nanograined cryomilled particulates may be subsequently hot isostatic pressed (hipped) and extruded at a temperature of about 473 K to produce the bulk ultra-fine grain (UFG) 5083 Al alloy.
While the foregoing example mentions 5083 Al, other types of material or materials may be subjected to atomization and cryomilling and optionally one or more additional processes. As an example, a method that includes cryomilling may produce cryomilled material with a reduced grain size. Such material may be further processed, optionally via ECAP. As an example, a cryomilled material or cryomilled materials may be processed to form a component, a part of a component, etc.
As an example, a method such as the method 1000 of
As an example, a method can include mixing a first alloy and a second alloy to form a mixture, cold working the mixture to form a cold worked mixture and then age hardening the cold worked mixture to form an age hardened mixture. In such an example, the first and the second alloys may be aluminum alloys. For example, consider 5083 Al and 7075 Al. In such an example, the alloys may be formed individually with nanostructure size grains and mixed to form a mixture. The mixture may be subjected to cold working to increase strength. Then, via age hardening, the strength may be further increased. For example, the 5083 Al grain size may be relatively stable during age hardening while the 7075 Al grain size may change and increase strength. In such an example, a method can harness thermal stability to provide for enhanced strength and ductility.
Aluminum alloy 5083 (5083 Al) includes magnesium and traces of manganese and chromium. It tends to be quite resistant to attack by seawater and industrial chemicals. Aluminum alloy 7075 (7075 Al) includes zinc as a primary alloying element with a composition of approximately: 5.6-6.1 weight percent zinc, 2.1-2.5 weight percent magnesium, 1.2-1.6 weight percent copper, and less than about one-half of a percent of silicon, iron, manganese, titanium, chromium, and other metals. It may be produced in various tempers (e.g., 7075-0, 7075-T6, 7075-T651, etc.).
As an example, a method may include processing a mater below its incipient melting temperature. For example, consider an alloy with an incipient melting temperature of about 340 degrees C. Such a material may be processed at a lesser temperature where such processing introduces severe plastic deformation (SPD).
As mentioned, a material may be formed of a plurality of alloys. For example, consider the data of Table 1 below, which indicates application of sever plastic deformation for materials that include one or more of 5083 Al and 7075 Al. In such an example, the resulting properties indicate that a method can include tailoring, for example, to meet one or more desired properties of at least a portion of a borehole tool. For example, consider the 25/75, 50/50 and 75/25 examples of 5083/7075, which provide for different ultimate tensile strengths (UTS), as presented in units ksi. Table 1 also shows data for percent elongation (% e), which may be considered a measure of ductility. Accordingly, as shown in Table 1, severe plastic deformation may be applied to a mixture of alloys to tailor strength and/or ductility.
As an example, a material may be a composite material that includes at least one alloy. As an example, such a material may include ceramic, polymer, carbon, etc. As an example, a material may include graphene, fiber structures, nanotube structures, etc. As an example, a composite material may include components therein that act to pin grain boundaries.
As an example, a material may be processed to generate a processed material with directionality. For example, such a material may include oriented grains, oriented fibers, nano-sheets, etc. As an example, a material may be processed via a single pass through an ECAP die or, for example, multiple passes. In such an example, depending on orientation, number of passes, etc., directionality may be imparted as to structure (e.g., grain structure orientation, fiber orientation, nano-sheet orientation, etc.).
As an example, a material may be embedded with a material that is one or more of active, passive, chemical, functionalized, etc. As an example, an embedded material may alter thermal conductivity, electrical conductivity, etc. of a bulk phase of the material. As an example, an embedded material may operate at a grain boundary or grain boundaries.
As an example, a process material may be formed as part of a cable. For example, consider a power cable for an electric submersible pump. In such an example, the processed material may be armor, a strength member, a barrier, an insulator, etc.
As an example, a component formed from processed material may be a bridge plug. A bridge plug may be a downhole tool (e.g., a type of plug tool) that can be located and set to isolate a lower part of a wellbore. As an example, a bridge plug may be permanent, degradable, retrievable, etc. As an example, a bridge plug may be tailored to enable a lower wellbore to be permanently sealed from production or temporarily isolated, for example, from a treatment conducted on an upper zone.
A part, a component, etc. constructed of a processed material or processed materials may include be a fluid sampling bottle, a pressure housing, a pump shaft, a cable (e.g., wireline, a power cable, etc.), a bridge plug tool, a projectile (e.g., a drop ball, a dart, etc.), a drill stem stabilizer, etc.
As an example, a method can include subjecting a material to severe plastic deformation. For example, such a method may employ ECAP, high pressure torsion (HPT), surface mechanical attrition (SMAT), cryomilling of spray atomized powders and subsequent consolidation through hot isostating processing (“HIPing”), extrusion, etc. Such techniques may enhance mechanical properties through grain refinement. As an example, a metallic material may be processed to produce processed material suitable for use in a downhole application. For example, consider a downhole environment that may be corrosive (e.g., sour hostile environments). As an example, a material may be an alloy that may be characterized as having low stacking fault energy (e.g., consider NiCrMo alloys such as 718, 625+, C276, C22HS).
As an example, a method can include employing one or more techniques that introduce severe plastic deformation (SPD), which may, for example, augment mechanical properties of one or more oilfield metallic materials (e.g., which may increase part rating) and enhance and/or control response toward corrosion (e.g., including environmental cracking resistance, an effect especially evident in materials having low stacking fault energy (LSFE)).
As an example, a method may employ ECAP to increase residual stress, refine grains and develop a nano to ultrafine grained microstructure, which may, for example, increase strength via Hall-Petch strengthening and, for example, alter ductility by abetting grain boundary sliding, which may make a processed alloy a high strain rate superplastic that may enhance formability and working. As an example, ECAP may be applied to abet strain hardening through dislocation strengthening. As an example, a method can include introducing deformation twins and annealing twins (e.g., though post processing heat treatment), which may increase volume fraction of low sigma coincidence lattice (low ΣCSLs') and/or coherent boundaries. In such an example, a material (e.g., a treated alloy) may exhibit improved mechanical/environmental resistance in hostile environments.
As an example, a method may employ cryomilling of one or more spray atomized powders and subsequent consolidation through HIPing and/or extrusion. Such a method may be a powder metallurgy route to synthesize ultrafine grained metallic materials dispersion hardened due to the presence of nitrides and carbides of milled alloy due to treatment in liquid nitrogen.
As an example, a method can include refining grains and developing a nano to ultrafine grained microstructure with one or more of increased strength via Hall-Petch strengthening and increased ductility by abetting grain boundary sliding. As an example, a treated alloy may be a high strain rate superplastic, which enhanced formability and workability.
As an example, a method can include increasing residual stresses in a treated alloy. In such an example, when subjected to stress in hoop direction, the treated alloy (e.g., processed material) may be better able to mitigate the effect of tensile loading due to existing compressive residual stress.
As an example, a method can include abetting strain hardening through dislocation strengthening and introducing deformation twins and annealing twins (e.g., though post processing heat treatment), thus increasing the volume fraction of low sigma coincidence lattice (low ΣCSLs') and/or coherent boundaries, improving both mechanical and environmental resistance of the treated alloy in hostile environments (e.g., for alloys like NiCrMo).
As an example, a method can include dispersion strengthening of a treated material or materials (e.g., as cryomilled), for example, through introduction of nitrides, carbides, etc. Such a method may introduce second phase particles of treated spray atomized alloy powder.
As an example, a method can include increasing thermal stability of bulk alloy synthesized through a powder metallurgy route by introduction of second phase particles (e.g., drag).
As an example, a material may be a degradable material. As an example, a method can include increase strength and ductility of one or more alloys that may be or include at least one degradable alloy. As an example, a method can include increasing thermal stability of a degradable material. As an example, a method can include reducing porosity in a cast alloy, for example, via a technique that introduces severe plastic deformation. In such an example, the cast alloy may be or include a degradable alloy.
As an example, a method can include making a centralizer using processed material. For example, a centralizer may exhibit enhanced wear resistance that can reduce surface damage and corrosion fatigue on a borehole assembly (e.g., BHA), for example, thereby increasing BHA lifetime. As an example, via improved abrasion wear resistance of a centralizer, reliability may be improved, for example, when drilling over extended deviated lengths.
As an example, a method can include making a sampling bottle. In such an example, a C22HS, a high strength C alloy of about 180 ksi yield strength may be processed using at least one technique that introduces severe plastic deformation. As an example, refinement of grains may augment strength of a material several fold through Hall-Petch strengthening. As an example, cold working may be employed (e.g., optionally without a change of shape of severe plastic deformation processed stock material). Through such an example method, an alloy of strength exceeding several hundred ksi (e.g., more than about 300 ksi) may be produced. Such a material may exhibit enhanced survivability in an environment (e.g., NACE VII or beyond; see, e.g., MR0175/ISO 15156-3 Annex E).
As an example, a high strength corrosion resistant wire may be formed via a process that includes subjecting a material or materials to severe plastic deformation. As an example, a material may be used to form wire for use in a wireline or a slickline. As an example, a corrosion resistant alloy (CRA) processed via a method that employs severe plastic deformation may exhibit increased strength (e.g., several fold). In such an example, the CRA may be drawn into corrosion resistant wire.
As an example, a method can include forming a high strength degradable alloy via severe plastic deformation. For example, consider processing through milling in cryogenic temperatures and subsequent consolidation to produce bulk alloy. As an example, properties of a degradable cast alloy may be augmented (e.g., several fold) by reducing porosities and imperfections (e.g., which may be inherent in a casting process) and, for example, by obtaining a more uniform fine grained microstructure. As an example, uniform deformation and enhanced ductility may be exhibited by a processed alloy, for example, due to grain boundary sliding of the fine grains formed abetting possible high strain rate super-plasticity (e.g., consider ease of forming into one or more parts for deploying downhole). As an example, a method can enhance strength and load bearing of a material through Hall-Petch strengthening, for example, for use of the material in one or more applications (e.g., high pressure reservoir applications, stimulation applications, etc.).
As an example, where machining of stock material occurs, machine swarf (e.g., chips, etc.) may be processed. Swarf, also known as chips or by other process-specific names (such as turnings, filings, or shavings) may be pieces of material resulting from machining or similar subtractive (material-removing) manufacturing processes. As an example, a method can include recycling swarf. As an example, a method can include processing swarf from processed stock that is machined to form one or more components. In such an example, the processed stock may be a degradable material that is used to form one or more degradable components (e.g., parts, etc.). The swarf may be processed to form processed stock and then machined to form one or more parts. As an example, swarf may be subjected to cryomilling and/or one or more other processes.
As shown, the system 1301 includes a casing 1310, a centralizer 1315, cement 1320 and a microannulus 1330 disposed between the casing 1310 and the cement 1320 (see, e.g., cross-section along line A-A). As shown, the centralizer 1315 is disposed with respect to the casing 1310 and the microannulus 1330. The centralizer 1315 includes biasing members 1316 (e.g., springs such as bow springs) that join end pieces. Another example of a centralizer is shown in
As an example, a centralizer may be a bow-spring centralizer that includes a strip shaped like a hunting bow and attached to a tool or to an outside of casing. As an example a bow-spring centralizer may be used to bias a casing toward a center of a bore, for example, prior to and during a cementing operation. As an example, a centralizer may be a tool fitted with a hinged collar and springs (e.g., biasing members) that can bias a casing, a liner, etc. toward a center of a bore, for example, to help ensure efficient placement of a cement sheath around a casing string. As an example, if a casing string is cemented off-center, risk may be increased that a channel of drilling fluid or contaminated cement may be left where the casing contacts the formation, creating an imperfect seal.
As an example, a hydraulic centralizer may be a type of tool-string centralizer, optionally used in through-tubing applications, which can employ hydraulic force to energize centralizer arms or bows. Such a centralizer may provide positive center positioning for cementing in vertical and deviated wells drilled using casing-drilling and liner-drilling technology.
As an example, a hydraulic centralizer may be placed on an outer diameter of a portion of a casing string, for example, to create standoff between the casing and a borehole for casing or liner drilling. As an example, a hydraulic centralizer may include helical blades, for example, to enhance one or more of circulation, borehole cleaning, and cementing. As an example, an optional tungsten carbide hard facing on the blades may be provided for wear resistance while drilling abrasive formations.
As an example, a processed material may be machined or otherwise formed as a centralizer or as a part of a centralizer. As an example, one or more blades, one or more springs (e.g., bow springs), etc. may be formed using a processed material (e.g., processed via a severe plastic deformation process). As an example, a centralizer may be optionally formed from ECAP processed material. For example, consider a method that includes generating stock processed material with a cross-sectional dimension sufficient to machine at least a portion of a centralizer therefrom. In such an example, a bore may be machined into the stock processed material and, for example, surface protrusions may be machined (e.g., consider a hydraulic centralizer).
As shown, the system 1302 includes an example of a sampling bottle 1350 with a sample chamber 1352 (e.g., for reservoir fluid) and a chamber for fluid such as water and glycol. A sampling bottle can include various fittings, valves, etc. As an example, a sampling bottle may include one or more additional chambers such as, for example, a gas chamber (e.g., a nitrogen chamber). As an example, a sampling bottle may include an outer dimension (e.g., outer diameter) less than about five inches (e.g., optionally less than about four inches). In such an example, a part of the sampling bottle may be formed from ECAP processed material. For example, consider a method that includes generating stock processed material with a cross-sectional dimension sufficient to machine at least a portion of a sampling bottle therefrom. In such an example, a bore may be machined into the stock processed material and, for example, appropriate apertures, openings, fittings, etc. may be machined.
As shown in
As an example, a plug tool may include an outer dimension (e.g., outer diameter) less than about six inches. In such an example, a part of the plug tool may be formed from ECAP processed material. For example, consider a method that includes generating stock processed material with a cross-sectional dimension sufficient to machine at least a portion of a plug tool therefrom. In such an example, a bore may be machined into the stock processed material and, for example, appropriate apertures, openings, fittings, etc. may be machined.
As an example, a borehole tool may be a tool that is part of a borehole assembly (e.g., “BHA”) or borehole system. As an example, a BHA may be a lower portion of the drillstring, including (e.g., from a bottom up in a vertical well) a bit, a bit sub, optionally a mud motor, stabilizers, a drill collar, a heavy-weight drillpipe, a jarring devices (e.g., jars) and crossovers for various threadforms. As BHA may provide force for a bit to break rock (e.g., weight on bit), survive a hostile mechanical environment and provide a driller with directional control of a borehole. As an example, an assembly may include one or more of a mud motor, directional drilling and measuring equipment, measurements-while-drilling tools, logging-while-drilling tools or other borehole tools.
As an example, a method can include producing stock material via equal-channel angular pressing and machining the stock material into at least one part. In such an example, the stock material can include an aluminum alloy. For example, consider an aluminum alloy that includes gallium.
As an example, a method may include machining stock material produced via ECAP to form at least one degradable part. As an example, a part may be a frac plug, which may optionally be a degradable frac plug. As an example, a frac plug may be a layered plug, optionally including at least one degradable layer. As an example, a frac plug may include a core and one or more layers where at least one of the layers is degradable and optionally where the core is degradable. As an example, degradable layers, a degradable core, etc. may differ in properties in a manner that effects degradability (e.g., with respect to one or more conditions). As an example, a method may include machining stock material produced via ECAP to form at least part of a borehole tool. For example, consider forming a plug tool or a portion of a plug tool such as a seat or seats of a plug tool that may be dimensioned to seat a plug or plugs.
As an example, a degradable frac plug may include an aluminum alloy that includes gallium and indium where the aluminum alloy has been processed using a technique or techniques that subject the alloy to severe plastic deformation, for example, to generate the frac plug with an average grain size less than about 500 nanometers (e.g., consider less than about 300 nanometers).
As an example, a method that includes ECAP may produce stock material with a cross-sectional dimension less than about 6 inches. In such an example, the method can include machining at least one sphere that has a diameter less than about 6 inches.
As an example, a method can include machining that generates swarf and processing the swarf to form additional stock material where such processing may include ECAP, cryomilling or ECAP and cryomilling.
As an example, a method can include producing stock material via cryomilling spray-atomized particles and forming the stock material into at least one part. In such an example, the stock material can include an aluminum alloy. As an example, consider an aluminum alloy that includes gallium and, for example, indium.
As an example, a method that includes cryomilling spray-atomized particles may generate stock material that can form at least one part. As an example, consider a frac plug, which may be, for example, a degradable frac plug. In such an example, the stock material may include an aluminum alloy that includes gallium and indium. As an example, a method may include forming at least part of a borehole tool using cryomilled spray-atomized particles. For example, consider forming a plug tool or a portion of a plug tool such as a seat or seats of a plug tool that may be dimensioned to seat a plug or plugs.
As an example, a method that includes cryomilling spray-atomized particles may generate stock material such as stock powder. In such an example, the method may include forming at least one part by pressing the stock powder into the at least one part.
As an example, an apparatus can include a shape and material that includes an aluminum alloy that has an average grain size less than about 500 nanometers or, for example, less than about 300 nanometers. In such an example, the apparatus may be a degradable apparatus. As an example, such an apparatus may be a degradable plug. In such an example, the degradable plug may include aluminum and gallium and, for example, indium.
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes an alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool. As an example, a borehole tool may be a tool such as, for example, a tool operable in a downhole operation. For example, consider a plug as a tool, a plug tool, a centralizer, a sampling bottle, a wireline, a slickline, etc.
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes at least one aluminum alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool.
As an example, an alloy may include one or more of the following group 13 elements: aluminum, gallium and indium.
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes at least one magnesium alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool. As an example, an alloy may include at least one of the following group 2 elements: magnesium and calcium.
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes at least one alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool where the at least one part is a degradable part. For example, consider a degradable plug, a degradable plug tool, a degradable seat of a plug tool, a degradable centralizer, a degradable portion of a centralizer (e.g., collar portion, biasing member, flow guide portion, etc.).
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes at least one alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool where the at least one part includes a frac plug. As an example, stock material may be of dimensions sufficient to machine multiple frac plugs. For example, consider a piece of stock material with a length greater than or equal to about ten inches and a cross-section dimension of about five inches. Such a piece of stock material may be machined to form two frac plugs, for example, two spherical frac plugs with diameters of about five inches or less.
As an example, a frac plug may be a degradable frac plug, for example, where stock material is degradable (e.g., when subjected to one or more conditions, which may exist in a downhole environment, naturally and/or artificially). As an example, a degradable frac plug may be made of or include an aluminum alloy that includes gallium and indium.
As an example, a method can include producing stock material via equal-channel angular pressing where the stock material includes at least one alloy that includes an average grain size less than approximately 500 nm and machining the stock material into at least one part of borehole tool. In such an example, the stock material may be produced with a cross-sectional dimension less than about 6 inches. In such an example, the method may include machining at least one sphere that includes a diameter less than about 6 inches.
As an example, a method may include machining stock material produced via ECAP where the machining generates swarf and processing the swarf to form additional stock material.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes an alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool. In such an example, the method may include at least one of mixing the particles with at least one other material, consolidating at least the particles via hot isostatic pressing and consolidating at least the particles via vacuum hot pressing.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes at least one aluminum alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool. As an example, an aluminum alloy may include gallium and/or indium.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes at least one magnesium alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool. As an example, an alloy may include calcium.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes at least one alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool where the at least one part includes a frac plug.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes at least one alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool where the at least one part includes a degradable part. In such an example, the degradable part may include an aluminum alloy that includes gallium and indium.
As an example, a method can include producing stock material via cryomilling spray-atomized particles where the stock material includes at least one alloy that includes a grain size less than approximately 500 nm and, for example, less than approximately 300 nm, and forming the stock material into at least one part of a borehole tool wherein the producing produces the stock material as stock powder. In such an example, the method may include pressing the stock powder into the at least one part.
As an example, a degradable apparatus can include a shaped material that includes an aluminum alloy having an average grain size less than about 500 nanometers and, for example, optionally less than about 300 nanometers. As an example, such a material may include an aluminum alloy that includes gallium. As an example, a material may include an aluminum alloy that includes gallium and indium. As an example, the degradable apparatus may be a borehole tool or a part of a borehole tool.
As an example, one or more methods described herein may include associated computer-readable storage media (CRM) blocks. Such blocks can include instructions suitable for execution by one or more processors (or cores) to instruct a computing device or system to perform one or more actions. As an example, equipment may include a processor (e.g., a microcontroller, etc.) and memory as a storage device for storing processor-executable instructions. In such an example, execution of the instructions may, in part, cause the equipment to perform one or more actions (e.g., consider the equipment 120 and the controller 122 of
According to an embodiment, one or more computer-readable media may include computer-executable instructions to instruct a computing system to output information for controlling a process. For example, such instructions may provide for output to sensing process, an injection process, drilling process, an extraction process, an extrusion process, a pumping process, a heating process, etc.
According to an embodiment, components may be distributed, such as in the network system 1410. The network system 1410 includes components 1422-1, 1422-2, 1422-3, . . . 1422-N. For example, the components 1422-1 may include the processor(s) 1402 while the component(s) 1422-3 may include memory accessible by the processor(s) 1402. Further, the component(s) 1402-2 may include an I/O device for display and optionally interaction with a method. The network may be or include the Internet, an intranet, a cellular network, a satellite network, etc.
Although only a few examples have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the examples. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures. It is the express intention of the applicant not to invoke 35 U.S.C. §112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the words “means for” together with an associated function.
This application claims the benefit of and priority to a U.S. Provisional Patent Application Ser. No. 61/891,202, filed 15 Oct. 2013, which is incorporated by reference herein.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2014/060561 | 10/15/2014 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61891202 | Oct 2013 | US |
