Patent Publication Number: US-2021181043-A1

Title: Strain magnification

Description:
FIELD 
     The present application is directed to a strain magnification patch. More specifically, this application is directed to a strain magnification patch for use with downhole tools. 
     BACKGROUND 
     Downhole tools operable in the oil and gas industry are exposed to extreme environments including high heat and high pressures. During drilling operations, a strain measurement can be important in determining other measurements including Weight on Bit (WOB), bending, and torque. However, downhole tools designed to operate in extreme environments are robust, and thus strain measurements provided are often low resolution. Electric magnification of these strain measurements further magnifies noise within the measurement, reducing the measurements usefulness. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present application are described, by way of example only, with reference to the attached Figures, wherein: 
         FIG. 1  is a diagrammatic view of a drilling string having a strain magnification patch disposed within a wellbore, according to the present disclosure; 
         FIG. 2  is an isometric view of a drill string shank having a strain magnification patch, according to the present disclosure; 
         FIG. 3  is an isometric view of a strain magnification patch, according to the present disclosure; 
         FIG. 4  is an isometric view of a strain magnification patch having a continuous width, according to the present disclosure; 
         FIG. 5  is an isometric view of a strain magnification patch having a narrow middle section, according to the present disclosure; 
         FIG. 6  is an isometric view of a strain magnification patch having narrow end section, according to the present disclosure; and 
         FIG. 7  is an isometric view of a strain magnification patch having narrow middle section formed from a second material, according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments of the disclosure are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the disclosure. 
     It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed compositions and methods may be implemented using any number of techniques. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated herein, but may be modified within the scope of the appended claims along with their full scope of equivalents. 
     Disclosed herein is an apparatus for strain magnification of downhole tools in a wellbore environment, which can include any or all of the following features or aspects in any given example. A strain magnification device can include a patch operable to couple with a downhole tool. The patch can have a stiff section and a weak section having a strain gauge coupled thereto. The weak section can be more deformable relative to the stiff section, thus magnifying the strain experienced by the downhole tool. The weak section can be thinner and/or narrower than the stiff section, thereby providing increased deformation relative to the stiff section and accordingly magnifying the measurable strain experienced by the downhole tool. 
     In other instances, the weak section of the path can be formed from a different material than the stiff section. The weak section material can have a lower Young&#39;s Modulus (E) compared with a material of the stiff section. The weak section can be operable to magnify the measurable strain experienced by the downhole tool. 
     The present disclosure further provides a downhole tool having a strain magnification system coupled therewith. In at least one instance, the downhole tool can have a groove and/or recess formed therein operable to receive a strain magnification patch. The strain magnification patch can have a stiff section and a weak section having a strain gauge coupled thereto. The weak section can be deformable relative to the stiff section, thus magnifying the measurable strain experienced by the downhole tool. 
       FIG. 1  illustrates a drilling process according to the present disclosure. A drilling process  100  can include one or more drilling tools  11  and related equipment disposed on a surface  102  (or a boat/platform in off-shore based-operations). The one or more drilling tools  11  can be coupled with the distal end  12  of a drill string  10 . A drill bit  16  can be disposed at the distal end  12  of the drill string  10  and operable to form a wellbore  14  in a subterranean formation  50 . The wellbore  14  can be formed according to a desired well plan having one or more vertical, curved, and/or horizontal portions extending through one or more subterranean formations  50 . 
     A strain magnification device  18  can be operable coupled with the drill string  10  and/or drill bit  16  (or drill shank). The strain magnification device  18  can be included in the drill bit  16  and/or independent of a drill bit. It at least one instance, the strain magnification device  18  could be coupled to an independent drill string sub that can be coupled at any joint within the drill string  10 , specifically above and/or below a mud motor. The strain magnification device  18  can further be disposed directly on to a mud motor, a measurement-while-drilling (MWD) device, and/or any other bottom hole assembly (BHA) component where it is desirable to measure strain. The strain magnification device  18  can be operable to mechanically increase the measureable strain experienced by the one or more drilling tools  11  during the drilling process  100  without requiring the introduction of a weakness into the one or more drilling tools. The strain magnification device  18  can provide at least a portion being deformable relative to the remaining portion, thus providing a higher resolution strain measurement. The strain magnification device  18  can include a strain gauge coupled with the deformable portion, thus allowing a strain measurement to be taken during the drilling operation  100 . 
       FIG. 2  illustrates a drill shank having a strain magnification patch disposed thereon. The drill shank  200  is shown coupled with a strain magnification patch  202  and is operable to magnify the strain experienced by the drill shank  200  in a downhole environment. As illustrated, the drill shank  200  has a groove  204  operable to receive the string magnification patch therein. The groove  204  can be sized and shaped to substantially correspond to the size and shape of the strain magnification patch  202 , thereby allowing the drill shank  200  to have a substantially smooth exterior surface  206 . In other instances, the strain magnification patch  202  can be coupled to the exterior surface  206  of drill shank  200  and thus extend above the exterior surface  206 . 
     The strain magnification patch  202  can be coupled with the groove  204  and/or exterior surface  206  by brazing, welding, fastening, adhesive, etc. In at least one instance, the strain magnification patch  202  can be bolted to the drill shank via one or more threaded fasteners (e.g. screws and/or bolts). In other instances, the strain magnification patch  202  can be welded and/or brazed to the drill shank  200 . The coupling between the strain magnification patch  202  and the drill shank  202  must be operable to withstand the temperatures and/or pressures experienced by the drill shank  200  in a downhole environment. 
       FIG. 3  illustrates a strain magnification patch couplable with one or more downhole tools. The magnification patch  202  has a stiff section  208  and a weak section  210 . The stiff section  208  can be any desirable size and shape and/or any desirable material. In at least one instance, the stiff section  208  can be made of substantially the same material as the drill shank  200 . The weak section  210  can be deformable relative to the stiff section  208 , thereby magnifying the strain experienced by drill shank  200 . 
     The strain magnification patch  202  can be made of two different materials. The stiff section  208  can be formed from a first material and the weak section  210  can be formed from a second material. The second material has a higher elasticity than the first material. This elasticity may be measured using Young&#39;s modulus, such that the first material can have a higher Young&#39;s modulus (E) compared with the second material. As a result, the second material is more deformable, or more elastic, relative to the first material and provides a more measurable strain experienced by the drill shank  200 . This more measurable strain may be considered a magnification of the strain as disclosed herein. 
     The stiff section  208  can be made from substantially the same material as the drill shank  200  (shown in  FIG. 3 ). In at least one instance, the drill shank  200  and the stiff section  208  can be formed from materials, including, but not limited to, stainless steel, nickel, nickel alloys, Inconel, tungsten, heavy metal alloy, a steel alloy, molybdenum, ceramics (e.g. alumina, silicon carbide, zirconia), and/or intermetallics (e.g. NiAl). The weak section  210  can be formed from any material having a lower Young&#39;s modulus (E) than the stiff section  208 . In at least one instance, the weak section  210  can be formed from materials including, but not limited to, Aluminum (Al), Aluminum alloys, elastomers, natural and/or synthetic rubbers, bronze, Titanium (Ti), Titanium alloys, Copper (Cu), Copper alloys, polymers, brass, and/or any other material having a Young&#39;s modulus lower than the stiff section  208 . 
     The strain magnification patch  202  can be formed from a single material across the stiff section  208  and the weak section  210 . The weak section  210  can have a reduced stiffness relative to the stiff section  208 . The stiffness can be defined by the modulus and the cross-sectional area of the weak section  210 . Thus, the weak section  210  can have a thinned and/or reduced shape profile relative to the stiff section  208 , thereby reducing the overall stiffness of the weak section  210  relative to the stiff section  208  when formed from substantially similar and/or the same material. The thinned and/or reduced shape profile of the weak section  210  can reduce the cross-sectional area of the weak section  210  can be reduced relative to the stiff section, thereby increasing the measurable strain experienced by the drill shank  200 . 
     The weak section  210  can incorporate a holed pattern and/or skeletal mesh to increase the measurable stain therein. The skeletal mesh pattern can contain an open network of void space (e.g. apertures) that will concentrate strain to the remaining ligaments surrounding the strain gauge. Such network can be made via additive manufacturing ( 3 D printing) and/or a continuous material skin can be made completely around the open network to attach the stain gauge and/or the skin can be selectively placed in the location where it is desirable to attach the strain gauge. Several small holes can be drilled through the material to create several apertures therein, thus forming the weak section. The apertures will act similar to the void space in the skeletal network. Both an aperture pattern and/or skeletal mesh can be used with or without a thinned and/or reduced shape profile. 
     The strain magnification patch  202  can have any shape and/or arrangement operable to provide to at least one section having an increased measurable strain. The weak section having an increased measurable strain can provide significant information regarding the downhole tools and the load experienced without requiring electrical magnification that similarly magnifies the noise. The increased measurable strain provided by the weak section further allows increased resolution of the strain measurement from the drill shank  200 . 
     The strain magnification patch can include a strain gauge  212  coupled with the weak section  210  and operable to detect strain based on the deformation (and/or change in length) of the material when under tension and/or compression. The weak section  210  can provide the drill shank  200  (and/or downhole tool) with a section and/or material operable to change length, thus providing a higher resolution strain measurement, without requiring any weakening of the drill shank  200  and/or downhole tool. 
     The drill shank  200  can implement one strain magnification patch  200 , or multiple strain magnification patches  200 . In at least one instance, the drill shank implements two strain magnification patches  200 , as shown in  FIG. 3 . 
       FIG. 4  illustrates a strain magnification patch having a substantially uniform shape. The strain magnification patch  400  can have a substantially uniform shape across a stiff section  402  and a weak section  404 . The substantially uniform shape can include a substantially uniform width  406  across the strain magnification patch  400 . While the width  406  can be substantially uniform, lengths  408 ,  410 , and/or  412  can vary between the stiff section  402  and the weak section  404 . Further the thickness (or depth) of the strain magnification patch  400  may or may not be consistent between the stiff section  402  and the weak section  404 . 
     The strain magnification patch  400  can have two stiff sections  402  disposed at opposing distal ends  414 ,  416 . The weak section  404  can be disposed between the two stiff sections  402 . The weak section  404  can be formed from a softer material (e.g. a material with a lower Young&#39;s modulus) relative to the two stiff sections  402 . The two stiff sections  402  can be formed from the same material. 
     The weak section  404  can be sized sufficiently to be operably coupled with a strain gauge. The strain gauge can be operable to measure strain experienced by the stain magnification patch  400  and a downhole tool coupled therewith. The weak section  404  being a softer material than stiff section  402  and/or the downhole tool can provide a high resolution strain measurement to the strain gauge. 
       FIG. 5  illustrates a strain magnification patch having a narrow center section. The strain magnification patch  500  can have a narrow center section  502  operable to magnify the measurable strain experienced by the strain magnification patch  500  and/or a downhole tool through a reduced stiffness. The strain magnification patch  500  can be formed from a single material that has a center section  502  having a necked section  504  of the material. The necked section  504  can magnify the measurable strain due to the cross-sectional area relative to the modulus of the material implemented within the strain magnification patch  500 . 
     The strain magnification patch  500  can have two stiff sections  506  disposed at opposing distal ends  508 ,  510 . A weak section  512  can be disposed between the two stiff sections  506 . The weak section  512  can correspond with the necked section  504 . 
       FIG. 6  illustrates a strain magnification patch having a narrow end section. The strain magnification patch  600  can have a stiff section  602  and a weak section  604 . The weak section  604  can be deformable relative to the stiff section  602 , thereby magnifying strain experienced by the strain magnification patch  600  and/or a downhole tool. The strain magnification patch  600  can be formed from a single material that in which the weak section  602  can have a necked section  606  and/or narrowed section of the material. The necked section  602  can magnify the measurable strain due to the cross-sectional area relative to the modulus of the material implemented within the strain magnification patch  600 . The stiffness of the necked section  602  can be defined by the relationship between cross-sectional area and modulus of material, thus magnifying the measurable strain. 
     The necked section  606  can be disposed at a distal end  608  of the strain magnification patch  600 . In at least one instance, the necked section  606  can be a transition between the stiff section  602  and the weak section  604 . In other instances, the necked section  606  and the weak section  604  can collectively become narrower as it approaches the distal end  608 . The weak section  604  can have a width  610  approximately equal to a fraction of a width  612  of the stiff section  602 , or the width  610  can be approximately equal to the width  612  of the stiff section  602 . 
       FIG. 7  illustrates a strain magnification patch having a narrow center section formed from a second material. The strain magnification patch  700  can have a stiff section  702  and a weak section  704 . The stiff section  702  can be formed from a first material and the weak section  704  can be formed from a second material. The second material can have a lower Young&#39;s modulus compared with the first material. The weak section  704  can be a narrow center section  706  operable to magnify the measurable strain experienced by the strain magnification patch  700  and/or a downhole tool. 
     The strain magnification patch  700  can be formed from any two materials sufficient to provide an increase in measurable strain by the second material relative to the first material, thus providing a higher resolution strain measurement. The first material and second material on the stiff section  702  and weak section  704 , respectively, can be any two materials with the second material having a lower Young&#39;s modulus than the first. 
     While  FIGS. 3-7  detailed various arrangements of a strain magnification patch, it is within the scope of this disclosure to implement any size and/or shape strain magnification patch operable to mechanically increase the measurable strain experienced by a tool through material selection and/or size shape. 
     Further, while the present disclosure is generally directed to downhole tools, it is within the scope of this disclosure to implement a strain a magnification patch with any tool for which an experienced strain measurement is useful. 
     The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size and arrangement of the parts within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms used in the attached claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the appended claims. 
     Statement Bank: 
     STATEMENT 1: A downhole tool comprising a housing having a strain magnification patch coupled thereto, the strain magnification patch comprising a first section, a second section coupled with the first section, the second section having a lower stiffness relative to the first section, and a strain gauge coupled to the second section, wherein the second section has a higher elasticity than the second section, whereby strain experienced by the housing produces a magnified strain measurement as measured by the strain gauge due to the higher elasticity of the second section. 
     STATEMENT 2: The downhole tool of STATEMENT 1, wherein the first section and the second section are formed from the same material 
     STATEMENT 3: The downhole tool of STATEMENT 1 or STATEMENT 2, wherein the first section and the second section are formed from different materials, the second section formed of a material having a Young&#39;s modulus (E) less than a Young&#39;s Modulus (E) of the adjacent first section. 
     STATEMENT 4: The downhole tool of any one of preceding STATEMENTS 1-3, wherein the first section is divided into two adjacent first sections, the second section disposed between the two adjacent first sections. 
     STATEMENT 5: The downhole tool of any one of preceding STATEMENTS 1-4, wherein the first section has a first width and the second section has a second width, the first width and the second width are substantially the same. 
     STATEMENT 6: The downhole tool of any one of preceding STATEMENTS 1-5, wherein the first section has a first width and the second section has a second width, the second width smaller than the first width. 
     STATEMENT 7: The downhole tool any one of preceding STATEMENTS 1-6, wherein the second section is formed at one end of the first section, the second section having a width narrower than a first section width. 
     STATEMENT 8: The downhole tool any one of preceding STATEMENTS 1-7, wherein the second section includes a plurality of apertures formed in a predetermined pattern and/or a skeletal mesh. 
     STATEMENT 9: A strain magnification system, comprising a tool string disposed within a wellbore formed in a subterranean formation, the tool string having a strain magnificent patch coupled thereto, the strain magnification patch comprising a first section, a second section, a second section coupled with the first section, the second section having a lower stiffness relative to the first section, and a strain gauge coupled to the second section, wherein the strain experienced by the tool is magnified in a strain measurement measured by the strain gauge due to the higher elasticity of the second section. 
     STATEMENT 10: The strain magnification system of STATEMENT 9, wherein the housing has a groove formed therein, the groove operable to receive the strain magnification patch therein. 
     STATEMENT 11: The strain magnification system of STATEMENT 9 or STATEMENT 10, wherein the first section and the second section are formed from the same material. 
     STATEMENT 12: The strain magnification system any one of preceding STATEMENTS 9-11, wherein the first section and the second section are formed from different materials. 
     STATEMENT 13: The strain magnification system any one of preceding STATEMENTS 9-12, wherein second section is formed of a material having a lower Young&#39;s modulus (E) than a material of the first section. 
     STATEMENT 14: The strain magnification system any one of preceding STATEMENTS 9-13, wherein the first section is divided into two adjacent first sections, the second section disposed between the two adjacent first sections. 
     STATEMENT 15: The strain magnification system any one of preceding STATEMENTS 9-14, wherein the first section has a first width and the second section has a second width, the first width and the second width are substantially the same. 
     STATEMENT 16: The strain magnification system any one of preceding STATEMENTS 9-15, wherein the first section has a first width and the second section has a second width, the second width smaller than the first width. 
     STATEMENT 17: The strain magnification system any one of preceding STATEMENTS 9-16, wherein the second section contains a plurality of apertures formed in a predetermined pattern and/or skeletal mesh. 
     STATEMENT 18: The strain magnification system any one of preceding STATEMENTS 9-17, wherein second section is a narrow portion formed at one end of the first section. 
     STATEMENT 19: The strain magnification system any one of preceding STATEMENTS 9-18, wherein at least a portion of the tool string and the first section are formed from the same material. 
     STATEMENT 20: A method for measuring strain in a downhole tool, the method comprising introducing a tool string into a wellbore formed in a subterranean formation, wherein the tool string includes a strain magnification patch having a first section and a second section coupled to the first section, the second section having a lower stiffness relative to the first section, and a strain gauge coupled to the second section, and measuring a strain experienced by the tool string within the wellbore, wherein the strain experienced by the tool string is concentrated in the second section, thereby producing a more measurable strain measurement.