CUTTER FORCES AND WEAR SEVERITY DETERMINATION FOR A DRILL BIT FOR DRILLING A WELLBORE

Abstract

A method comprises determining an input drill bit response to a drill bit for drilling a wellbore based on at least one operational attribute during drilling of the wellbore and predicting a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit response.

Description

BACKGROUND

Wellbores may be drilled into a subsurface formation using a drill bit having a number of cutters. It can be challenging to know a cutter wear severity of a given cutter during drilling of the wellbore.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the disclosure may be better understood by referencing the accompanying drawings.

FIG. 1 an elevation view (partially cross sectional) of an example well system, according to some implementations.

FIG. 2 is a block diagram of an example computer, according to some implementations.

FIG. 3 is a graphical representation of a cutter of a drill bit, according to some implementations.

FIG. 4 is a graph defining an example relationship between the cutter wear volume and energy of a cutter of a drill bit, according to some implementations.

FIG. 5 is a graphical representation of a cutter of a drill bit, according to some implementations.

FIG. 6 is a flowchart of example operations for determining a cutter wear severity for cutters of a drill bit during drilling of a wellbore, according to some implementations.

FIG. 7 is a graph of weight on bit (WOB) contributed from primary cutters, backup cutters, Depth of Cut Controllers (DOCCs) and blades at a bit wear level 5, according to some implementations.

FIG. 8 is a graph of a ratio of WOB from the primary cutters to WOB at the bit wear level 1 to 10, according to some implementations.

FIGS. 9-10 are graphs of an example of a scaled cutter axial force distribution and cutter torque distribution at different depths of cut (DOC) across the different cutters of a new drill bit, according to some implementations.

FIG. 11-12 are graphs of an example of a scaled cutter axial force distribution for a given depth of cut for a worn drill bit, according to some implementations.

FIGS. 13-14 are graphs of an example of a predicted cutter axial force and drag force, respectively, for a nose cutter, according to some implementations.

FIG. 15 is a graph of examples of how the cutter wear severity changes with drilling depth, according to some implementations.

FIG. 16 is graph of examples of the calculated cutter dull severity distribution compared with the actual measured cutter dull severity distribution after drilling a well.

FIGS. 17-18 are flowcharts of example operations for determining a cutter wear severity for each of the cutters of a drill bit during drilling of a wellbore, according to some implementations.

DESCRIPTION

The description that follows includes example systems, methods, techniques, and program flows that embody aspects of the disclosure. However, it is understood that this disclosure may be practiced without these specific details. In some instances, well-known instruction instances, protocols, structures, and techniques have not been shown in detail in order not to obfuscate the description.

In contrast to conventional approaches, example implementations may include estimation of cutter forces and cutter wear severity on cutters of a drill bit in real time while the wellbore is being drilled using the drill bit. Accordingly, example implementations may determine such severity at a cutter level. This is in contrast to conventional approaches that are limited to determining severity across the entire drill bit. Accordingly, example implementations may estimate a cutter wear severity for each cutter of a drill bit during drilling of a wellbore. For example, a cutter wear severity for each cutter of the drill bit may be estimated or determined along a drilling depth of the wellbore using drill bit response data.

For example, in some implementations, the following may be pre-calculated before drilling operation for an assumed drill bit wear level and a depth of cut for a given rock strength: 1) a ratio of primary cutter weight on bit (WOB) to drill bit WOB, 2) a ratio of primary cutter torque on bit (TOB) to drill bit TOB, 3) a scaled cutter axial force distribution, and 4) a scaled cutter torque distribution. At a given drilling depth, a bit response (that may include WOB, TOB, rate of penetration (ROP), and drill bit rotation speed (e.g., rotations per minute (RPM)), etc.) may be determined. For example, sensors in the drill bit may be used to determine these responses. Some implementations may calculate a cutter axial force, a drag force, a cutter power, a cutter energy, a cutter wear volume, a cutter wear depth, and a cutter wear severity based on this bit response (as further described below). The cutter wear severity may then be used to monitor the bit drilling performance. If the bit drilling performance is below a threshold, drilling may be stopped to bring the drill string to the surface of the wellbore to replace the current drill bit with a new drill bit. The drill string may then be lowered back down into the wellbore to resume drilling.

Example Well System

FIG. 1 an elevation view (partially cross sectional) of an example well system, according to some implementations. In particular, FIG. 1 is a schematic diagram of a well system 100 that includes a drill string 180 having a drill bit 112 disposed in a wellbore 106 for drilling the wellbore 106 in the subsurface formation 108. While depicted for a land-based well system, example embodiments can be used in subsea operations that employ floating or sea-based platforms and rigs. The drill bit 112 is an example drill bit for which simulation of abrasive wear and damage as described herein can be performed.

The well system 100 may further include a drilling platform 110 that supports a derrick 152 having a traveling block 114 for raising and lowering the drill string 180. The drill string 180 may include, but is not limited to, drill pipe, drill collars, and down hole tools 116. The down hole tools 116 may comprise any of a number of different types of tools including measurement while drilling (MWD) tools, logging while drilling (LWD) tools, mud motors, and others. A kelly 115 may support the drill string 180 as it may be lowered through a rotary table 118. The drill bit 112 may include roller cone bits, polycrystalline diamond compact (PDC) bits, natural diamond bits, any hole openers, reamers, coring bits, and the like. As the drill bit 112 rotates, it may crush or cut rock to create and extend a wellbore 106 that penetrates various subterranean formations. The drill bit 112 may be rotated by various methods including rotation by a downhole mud motor and/or via rotation of the drill string 180 from the surface 120 by the rotary table 118. Attributes of drilling the wellbore may be adjusted to increase, decrease, and/or maintain the rate of penetration (ROP) of the drill bit 112 through the subsurface formation 108. Attributes may include weight-on-bit (WOB) and rotations-per-minute (RPM) of the drill string 180. In some embodiments, the drill bit 112 may become dull and lose efficiency, thus requiring more WOB and/or RPM to maintain a target ROP. A pump 122 may circulate drilling fluid through a feed pipe 124 to the kelly 116, downhole through interior of the drill string 180, through orifices in the drill bit 112, back to the surface 120 via an annulus surrounding the drill string 180, and into a retention pit 128.

The well system 100 includes a computer 170 that may be communicatively coupled to other parts of the well system 100. The computer 170 can be local or remote to the drilling platform 110. A processor of the computer 170 may perform simulations (as further described below). In some embodiments, the processor of the computer 170 may control drilling operations of the well system 100 or subsequent drilling operations of other wellbores.

An example of the computer 170 is now described. FIG. 2 is a block diagram of an example computer, according to some implementations. FIG. 2 depicts a computer 200 that includes a processor 201 (possibly including multiple processors, multiple cores, multiple nodes, and/or implementing multi-threading, etc.). The computer 200 includes a memory 207. The memory 207 may be system memory or any one or more of the above already described possible realizations of machine-readable media. The computer 200 also includes a bus 203 and a network interface 205.

The computer 200 also includes a simulation processor 211 and a controller 215. The simulation processor 211 and the controller 215 can perform one or more of the operations described herein. For example, the simulation processor 211 can perform data processing and simulation operations as further described below. The controller 215 may perform various control operations to a wellbore operation based on the simulations. For example, the controller 215 can modify a drilling operation based on the simulations.

Any one of the previously described functionalities may be partially (or entirely) implemented in hardware and/or on the processor 201. For example, the functionality may be implemented with an application specific integrated circuit, in logic implemented in the processor 201, in a co-processor on a peripheral device or card, etc. Further, realizations may include fewer or additional components not illustrated in FIG. 2 (e.g., video cards, audio cards, additional network interfaces, peripheral devices, etc.). The processor 201 and the network interface 205 are coupled to the bus 203. Although illustrated as being coupled to the bus 203, the memory 207 may be coupled to the processor 201.

Nonlinear Cutter Wear Model

Some implementations may include a nonlinear cutter wear model for at least one of step wear of a cutter and nonlinear velocity of a cutter during drilling. To illustrate, FIG. 3 is a graphical representation of a cutter of a drill bit, according to some implementations. In FIG. 3, a cutter 300 includes a cutting element 301 and a body 303. In some implementations, the cutting element 301 may be composed of diamond. The body 303 may be composed of other less costly material (such as carbide).

As shown, a critical cutter energy (Ec) may be defined as the energy associated with a wear depth of the cutter 300 substantially equaling the chamfer size. A critical wear depth (Wc) may be defined as the depth wherein the cutting element 301 is worn away to a point where the body 303 is starting to be in contact with the formation being drilled.

To further illustrate, FIG. 4 is a graph defining an example relationship between the cutter wear volume and energy of a cutter of a drill bit, according to some implementations. FIG. 4 depicts a graph 400 that includes an x-axis that is the energy (E) 402 of a cutter and a y-axis that is the cutter wear volume (V) 404 of the drill bit. The graph 400 includes a line 405 that starts at an Ec 403 (when V is zero). A first part 407 of the line 405 is based on (a constant), Ka (the rock abrasive factor), and Kb (the diamond cutter wear resistance factor). A second part 409 of the line 405 is based on, Ka, Kb, and Kc (the carbide body element wear resistance factor).

In some implementations, the nonlinear cutter wear model for a cutter of a drill bit may be defined as follows. If E is less than Ec, V=0 (as shown in the graph 400 of FIG. 4). However, if E is not less than Ec, a determination is made of whether the cutter wear depth (Wd) is less than Wc. If Wd is less than We, the cutter wear volume (V) may be defined by Equation (1):

$\begin{array}{cc}V=\mu \mathrm{Ka}\mathrm{Kb}\left(E-\mathrm{Ec}\right)& \left(1\right)\end{array}$

However, if Wd is not less than We, V may be defined by Equation (2):

$\begin{array}{cc}V=\mu \mathrm{Ka}\mathrm{Kb}\mathrm{Kc}\left(E-\mathrm{Ec}\right)& \left(2\right)\end{array}$

Also, as part of the nonlinear cutter wear model, a nonlinear velocity of the drill bit may be determined. A critical velocity (Vc) may be defined as the last cone cutter's velocity of the drill bit. Vc may be fixed in a simulation for a drill bit (even when drilling parameters are changed.

Cutter power (Pt) may be defined as follows. If the velocity (Vel) of the cutter is less than or equal to Vc, P may be defined by Equation (3):

$\begin{array}{cc}\mathrm{Pt}=F*\left({\mathrm{Vel}}^m\right)& \left(3\right)\end{array}$

• • wherein F is the force and m is a constant (0.5-0.75). However, if Vel is not less than Vc, P may be defined by Equation (4):

$\begin{array}{cc}\mathrm{Pt}=F*\left(\mathrm{Vel}\right)& \left(4\right)\end{array}$

Additionally, cutter energy (E) may be defined by Equation (5):

$\begin{array}{cc}E=\mathrm{Pt}*T& \left(5\right)\end{array}$

• • wherein T is time required to drill a subsection.

Additionally, a cutter wear severity may be defined based on a cutter wear depth. To illustrate, FIG. 5 is a graphical representation of a cutter of a drill bit, according to some implementations. FIG. 5 depicts a cutter 500 having a cutter wear depth and at a back rake angle (BRa). A cutter wear depth may be a function of back rake angle, cutter diameter, chamfer size, cutter shape and cutter wear volume. A cutter wear severity (Sc) may be defined by Equation (6):

$\begin{array}{cc}\mathrm{Sc}=8\left(\mathrm{Cutter}\mathrm{Wear}\mathrm{Depth}/\mathrm{Diameter}\right)& \left(6\right)\end{array}$

If Sc=4, cutter wear depth=0.5 diameter. Therefore, Sc=4 may be defined as the maximal cutter wear. If Sc>4, the cutter may be considered lost.

Example Operations

Example operations are now described. Example operations for determining a cutter wear severity based on input drill bit response are described.

Example Operations for Determining Cutter Wear Severity

Example operations for determining cutter wear severity are now described. FIG. 6 is a flowchart of example operations for determining a cutter wear severity for cutters of a drill bit during drilling of a wellbore, according to some implementations. Operations of a flowchart 600 of FIG. 6 are described in reference to the well system 100 of FIG. 1 and the computer 200 of FIG. 2. Operations of the flowchart 600 start at block 602.

At block 602, an input drill bit response is determined. For example, the drill bit response may include at least one of WOB, TOB, ROP, rotation speed, etc. of the drill bit. With reference to FIG. 2, the processor 201 may retrieve these measurements from one or more sensors positioned at the surface and/or downhole in the wellbore. The energy input to bit may include the primary cutters, backup cutters, Depth of Cut Controllers (DOCCs) and blades. However, the energy input to primary cutters may need to be determined. Accordingly, an estimation of how much at least one of WOB or TOB is applied to the primary cutters may be determined. To illustrate, FIG. 7 is a graph of weight on bit (WOB) contributed from primary cutters, backup cutters, Depth of Cut Controllers (DOCCs) and blades at a bit wear level 5, according to some implementations. In particular, FIG. 7 includes a graph 700 having lines for the primary cutters, the backup cutters, and the DOCCs and blades. FIG. 8 is a graph of a ratio of WOB from the primary cutters to WOB at the bit wear level 1 to 10, according to some implementations. In particular, FIG. 8 includes a graph 800.

In some implementations, WOB ratio may be determined based on Equation (7):

$\begin{array}{cc}\lambda w=\mathrm{WOB\_p}/\mathrm{WOB}*100\%& \left(7\right)\end{array}$

In some implementations, TOB ratio may be determined based on Equation (8):

$\begin{array}{cc}\lambda t=\mathrm{TOB\_p}/\mathrm{TOB}*100\%& \left(8\right)\end{array}$

Both λw and λt may depend on depth of cut (DOC) and bit wear level. These ratios may be pre-calculated once bit is designed and saved for subsequent use. Returning to FIG. 6, operations of the flowchart 600 continues at block 604.

At block 604, cutter forces (for at least one cutter of the drill bit) are determined based on the input drill bit response. With reference to FIG. 2, the processor 201 may make this determination. In some implementations, the processor 201 may retrieve pre-calculated scaled cutter axial and torque forces distributions for a given DOC and a bit wear level for the current bit used in drilling. In some implementations, the cutter forces being determined may be the axial force and the drag force for the at least one cutter.

The processor 201 may then determine the axial forces coefficient (fa) based on the Equation (9):

$\begin{array}{cc}\mathrm{\eta a}=\mathrm{WOB}/{\sum }_1^n{F}_a^i& \left(9\right)\end{array}$

The processor 201 may then determine an axial force (Fa) for each cutter based on Equation (10):

$\begin{array}{cc}\mathrm{Fa}=\eta a*F_a^i& \left(10\right)\end{array}$

$F_a^i$

is scaled cutter axial force of cutter i

The processor 201 may also determine a torque coefficient (ηd) based on Equation (11):

$\begin{array}{cc}\eta d=\mathrm{TOB}/{\sum }_1^n{T}_d^i& \left(11\right)\end{array}$

The processor 201 may then determine a torque (Td) for each cutter based on Equation (12):

$\begin{array}{cc}\mathrm{Td}=\eta d*T_d^i& \left(12\right)\end{array}$

$T_d^i$

is scaled cutter torque of cutter i

The processor 201 may determine a drag force (Fd) for each cutter based on Equation (13):

$\begin{array}{cc}\mathrm{Fd}=\mathrm{Td}/\mathrm{Rc}& \left(13\right)\end{array}$

• • wherein Rc is the cutter radial location on the drill bit. Accordingly, the processor 201 may determine the cutter forces for a given cutter of the drill bit (which may be a combination of the axial force and the drag force for the given cutter).

To further illustrate, FIGS. 9-10 are graphs of an example of a scaled cutter axial force distribution and cutter torque distribution at different depths of cut (DOC) across the different cutters of a new drill bit, according to some implementations. FIGS. 11-12 are graphs of an example of a scaled cutter axial force distribution and cutter torque distribution at different depths of cut (DOC) across the different cutters of a used drill bit, according to some implementations.

FIGS. 13-14 are graphs of an example of a predicted cutter axial force and drag force, respectively, for a nose cutter, according to some implementations.

At block 606, cutter power (for the at least one cutter of the drill bit) is determined based on the cutter forces. With reference to FIG. 2, the processor 201 may make this determination. In some implementations, the processor 201 may determine cutter power (Pc) based on Equations (14)-(16):

$\begin{array}{cc}\mathrm{Pa}=\mathrm{Fa}*\mathrm{Va}& \left(14\right)\end{array}$ $\begin{array}{cc}\mathrm{Pt}=\mathrm{Fd}*\mathrm{Vc}& \left(15\right)\end{array}$

$\begin{array}{cc}\mathrm{Pc}=\mathrm{Pa}+\mathrm{Pt}& \left(16\right)\end{array}$

• • wherein Va and Vc are axial velocity and cutting velocity, respectively. Nonlinear cutter power may apply to equation (15), according to some implementations.

At block 608, cutter energy (for the at least one cutter of the drill bit) is determined based on the cutter power. With reference to FIG. 2, the processor 201 may make this determination. In some implementations, the processor 201 may determine cutter energy (Ec) based on Equation (17):

$\begin{array}{cc}\mathrm{Ec}=\mathrm{Pc}*T& \left(17\right)\end{array}$

• • wherein T is the time required to drill a subsection.

At block 610, cutter wear volume (for the at least one cutter of the drill bit) is determined based on the cutter response. With reference to FIG. 2, the processor 201 may make this determination. In some implementations, the processor 201 may determine cutter wear volume (Vc) based on Equation (18):

$\begin{array}{cc}\mathrm{Vc}=\mathrm{Vw}=\mu \mathrm{Ka}\mathrm{Kb}\mathrm{Kc}\mathrm{Ec}& \left(18\right)\end{array}$

At block 612, cutter wear depth (for the at least one cutter of the drill bit) is determined based on the cutter wear volume. With reference to FIG. 2, the processor 201 may make this determination.

At block 614, cutter wear severity (for the at least one cutter of the drill bit) is determined based on the cutter wear depth. With reference to FIG. 2, the processor 201 may make this determination. To illustrate, FIG. 15 is a graph of examples of how the cutter wear severity changes with drilling depth, according to some implementations. FIG. 16 is graph of examples of the calculated cutter dull severity distribution compared with the actual measured cutter dull severity distribution after drilling a well.

FIGS. 17-18 are flowcharts of example operations for determining a cutter wear severity for each of the cutters of a drill bit during drilling of a wellbore, according to some implementations. Operations of a flowchart 3100 of FIG. 31 and a flowchart 3200 of FIG. 32 are described in reference to the well system 100 of FIG. 1 and the computer 200 of FIG. 2. Also, operations of the flowchart 3100 of FIG. 31 and the flowchart 3200 of FIG. 32 continue between each other through transition points A, B, and C. Operations of the flowcharts 3100-3200 start at block 3102.

At block 3102, the following are pre-calculated for the bit currently in use at each bit wear level and at each depth of cut: 1) WOB, 2) TOB, 3) scaled cutter axial force and cutter torque for each cutter, 4) ratios of primary cutter WOB and TOB to bit WOB and TOB. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3104, a bit response (including WOB, TOB, RPM and ROP) by a drill bit is retrieved based on data derived from drilling a section of a well using the drill bit. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3106, cutter number k is initialized to 1. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3108, bit wear level is retrieved (assuming bit wear level at the start=0). For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3110, WOB and TOB to the primary cutters (WOBp and TOBp, respectively) are determined. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3112, scaled cutter axial force distributions and axial coefficient (ηA) are retrieved. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3114, cutter axial force (Fa) for each cutter of the drill bit is determined. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3116, scaled cutter torque distributions and torque coefficient (TB) are determined. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3118, cutter torque (Td) for each cutter is determined. For example, with reference to FIG. 2, the processor 201 may perform this operation. Operations of the flowchart 3100 continue at transition point A, which continues at transition point A of the flowchart 3200.

From transition point A of the flowchart 3200, operations continue at block 3202.

At block 3202, cutter energy for each cutter is determined based on cutter axial force and drag force. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3204, cutter wear volume for each cutter is determined based on the cutter energy. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3206, cutter wear depth for each cutter is determined based on the cutter wear volume. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3208, cutter wear severity for each cutter is determined based on the cutter wear depth. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3210, a determination is made of whether cutter number k is less than or equal to the total number of cutter, N. For example, with reference to FIG. 2, the processor 201 may perform this operation. If k is less than or equal to N, operations of the flowchart 3200 continue at block 3212. If k is not less than or equal to N, operations of the flowchart 3200 continue at block 3214.

At block 3212, a bit wear level is determined based on the cutter wear severity. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3214, the cutter number k is incremented. For example, with reference to FIG. 2, the processor 201 may perform this operation. Operations of the flowchart 3200 continue at transition point B, which continues at transition point B of the flowchart 3100. From the transition point B, operations of the flowchart 3100 continue at block 3108.

At block 3216, cutter wear severity for each of the different cutters of the drill bit is output. For example, with reference to FIG. 2, the processor 201 may perform this operation.

At block 3218, a determination is made of whether at least one cutter wear severity exceeds a severity threshold. For example, with reference to FIG. 2, the processor 201 may perform this operation. If at least one cutter wear severity does not exceed a severity threshold, operations of the flowchart 3200 continue at transition point C, which continues at transition point C of the flowchart 3100. From the transition point C, operations of the flowchart 3100 continue at block 3102. If at least one cutter wear severity does not exceed a severity threshold, operations of the flowchart 3200 continue at block 3220.

At block 3220, a drilling operation for drilling of the wellbore is modified (e.g., replace the drill bit). For example, with reference to FIG. 2, the processor 201 may perform this operation. Operations of the flowchart 3200 continue at transition point C, which continues at transition point C of the flowchart 3100. From the transition point C, operations of the flowchart 3100 continue at block 3102.

While the aspects of the disclosure are described with reference to various implementations and exploitations, it will be understood that these aspects are illustrative and that the scope of the claims is not limited to them. Many variations, modifications, additions, and improvements are possible.

Plural instances may be provided for components, operations or structures described herein as a single instance. Finally, boundaries between various components, operations and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific illustrative configurations. Other allocations of functionality are envisioned and may fall within the scope of the disclosure. In general, structures and functionality presented as separate components in the example configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure.

Example Implementations

Example implementations are now described.

Example Implementation #1: A method comprising: determining an input drill bit response to a drill bit for drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and predicting a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit response.

Example Implementation #2: The method of Example Implementation #1, further comprising: determining cutter forces on the at least one cutter based on the input drill bit energy; determining a cutter power of the at least one cutter based on the cutter forces; determining a cutter energy of the at least one cutter based on the cutter power; determining a cutter wear volume of the at least one cutter based on the cutter energy; and determining a cutter wear depth of the at least one cutter based on the cutter wear volume, wherein predicting the cutter wear severity of the at least one cutter comprises predicting the cutter wear severity based on the cutter wear depth.

Example Implementation #3: The method of any one of Example Implementations #1-2, further comprising: determining whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, stopping drilling of the wellbore; tripping the drill string to a surface of the wellbore; replacing the drill bit with a new drill bit; and lowering the drill string

Example Implementation #4: The method of any one of Example Implementations #1-3, further comprising: adjusting the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

Example Implementation #5: The method of any one of Example Implementations #1-4, wherein the bit response comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

Example Implementation #6: A method comprising: determining an input drill bit response to a drill bit while drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and predicting a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit energy.

Example Implementation #7: The method of Example Implementation #6, further comprising: determining cutter forces on the at least one cutter based on the input drill bit response, wherein predicting the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter forces on the at least one cutter.

Example Implementation #8: The method of any one of Example Implementations #6-7, further comprising: determining a cutter power of the at least one cutter based on the cutter forces, wherein predicting the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter power of the at least one cutter.

Example Implementation #9: The method of any one of Example Implementations #6-8, further comprising: determining a cutter energy of the at least one cutter based on the cutter forces, wherein predicting the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter energy of the at least one cutter.

Example Implementation #10: The method of any one of Example Implementations #7-9, further comprising: determining a cutter wear volume of the at least one cutter based on the cutter forces, wherein predicting the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear volume of the at least one cutter.

Example Implementation #11: The method of any one of Example Implementations #6-10, further comprising: determining a cutter wear depth of the at least one cutter based on the cutter forces, wherein predicting the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear depth of the at least one cutter.

Example Implementation #12: The method of any one of Example Implementations #6-11, further comprising: determining whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, stopping drilling of the wellbore; tripping the drill string to a surface of the wellbore; replacing the drill bit with a new drill bit; lowering the drill string; and resuming drilling of the wellbore using the new drill bit.

Example Implementation #13: The method of any one of Example Implementations #6-12, further comprising: adjusting the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

Example Implementation #14: The method of any one of Example Implementations #6-13, wherein the operational attribute comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

Example Implementation #15: A non-transitory, computer-readable medium having instructions stored thereon that are executable by a processor, the instructions comprising: instructions to determine an input drill bit response to a drill bit while drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and instructions to predict a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit energy.

Example Implementation #16: The non-transitory, computer-readable medium of Example Implementation #15, wherein the instructions comprise, instructions to determine cutter forces on the at least one cutter based on the input drill bit response, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter forces on the at least one cutter.

Example Implementation #17: The non-transitory, computer-readable medium of any one of Example Implementations #15-16, further comprising: instructions to determine a cutter power of the at least one cutter based on the cutter forces, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter power of the at least one cutter.

Example Implementation #18: The non-transitory, computer-readable medium of any one of Example Implementations #15-17, further comprising: instructions to determine a cutter energy of the at least one cutter based on the cutter forces, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter energy of the at least one cutter.

Example Implementation #19: The non-transitory, computer-readable medium of any one of Example Implementations #15-18, further comprising: instructions to determine a cutter wear volume of the at least one cutter based on the cutter forces, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear volume of the at least one cutter.

Example Implementation #20: The non-transitory, computer-readable medium of any one of Example Implementations #15-20, further comprising: instructions to determine a cutter wear depth of the at least one cutter based on the cutter forces, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear depth of the at least one cutter.

Example Implementation #21: The non-transitory, computer-readable medium of any one of Example Implementations #15-20, further comprising: instructions to determine whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, instructions to stop drilling of the wellbore; instructions to trip the drill string to a surface of the wellbore to replace the drill bit with a new drill bit; and instructions to resume drilling of the wellbore using the new drill bit after lowering the drill string back down into the wellbore.

Example Implementation #22: The non-transitory, computer-readable medium of any one of Example Implementations #15-21, further comprising: instructions to adjust the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

Example Implementation #23: The non-transitory, computer-readable medium of any one of Example Implementations #15-22, wherein the operational attribute comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

Example Implementation #24: An apparatus comprising: a processor; and a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to, determine an input drill bit response to a drill bit while drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and predict a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit energy.

Example Implementation #25: The apparatus of Example Implementation #24, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine cutter forces on the at least one cutter based on the input drill bit response, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter forces on the at least one cutter.

Example Implementation #26: The apparatus of any one of Example Implementations #24-25, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine a cutter power of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter power of the at least one cutter.

Example Implementation #27: The apparatus of any one of Example Implementations #24-26, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine a cutter energy of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter energy of the at least one cutter.

Example Implementation #28: The apparatus of any one of Example Implementations #24-27, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine a cutter wear volume of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear volume of the at least one cutter.

Example Implementation #29: The apparatus of any one of Example Implementations #24-28, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine a cutter wear depth of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear depth of the at least one cutter.

Example Implementation #30: The apparatus of any one of Example Implementations #24-29, wherein the instructions comprise instructions executable by the processor to cause the processor to, determine whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, stop drilling of the wellbore; trip the drill string to a surface of the wellbore to replace the drill bit with a new drill bit; and resume drilling of the wellbore using the new drill bit after lowering the drill string back down into the wellbore.

Example Implementation #31: The apparatus of any one of Example Implementations #24-30, wherein the instructions comprise instructions executable by the processor to cause the processor to, adjust the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

Example Implementation #32: The apparatus of any one of Example Implementations #24-31, wherein the operational attribute comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

Claims

1. A method comprising:

determining an input drill bit response to a drill bit for drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and

predicting a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit response.

2. The method of claim 1, further comprising:

determining cutter forces on the at least one cutter based on the input drill bit energy;

determining a cutter power of the at least one cutter based on the cutter forces;

determining a cutter energy of the at least one cutter based on the cutter power;

determining a cutter wear volume of the at least one cutter based on the cutter energy; and

determining a cutter wear depth of the at least one cutter based on the cutter wear volume,

wherein predicting the cutter wear severity of the at least one cutter comprises predicting the cutter wear severity based on the cutter wear depth.

3. The method of claim 1, further comprising:

determining whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and

in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, stopping drilling of the wellbore; tripping the drill string to a surface of the wellbore; replacing the drill bit with a new drill bit; and lowering the drill string.

4. The method of claim 1, further comprising:

adjusting the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

5. The method of claim 1, wherein the bit response comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

6. A non-transitory, computer-readable medium having instructions stored thereon that are executable by a processor, the instructions comprising:

instructions to determine an input drill bit response to a drill bit while drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and

instructions to predict a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit response.

7. The non-transitory, computer-readable medium of claim 6, wherein the instructions comprise,

instructions to determine cutter forces on the at least one cutter based on the input drill bit response, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter forces on the at least one cutter; and

instructions to determine a cutter power of the at least one cutter based on the cutter forces, wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter power of the at least one cutter.

8. The non-transitory, computer-readable medium of claim 7, further comprising:

instructions to determine a cutter energy of the at least one cutter based on the cutter forces,

wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter energy of the at least one cutter.

9. The non-transitory, computer-readable medium of claim 8, further comprising:

instructions to determine a cutter wear volume of the at least one cutter based on the cutter forces,

wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear volume of the at least one cutter.

10. The non-transitory, computer-readable medium of claim 9, further comprising:

instructions to determine a cutter wear depth of the at least one cutter based on the cutter forces,

wherein the instructions to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear depth of the at least one cutter.

11. The non-transitory, computer-readable medium of claim 6, further comprising:

instructions to determine whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and

in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, instructions to stop drilling of the wellbore; instructions to trip the drill string to a surface of the wellbore to replace the drill bit with a new drill bit; and instructions to resume drilling of the wellbore using the new drill bit after lowering the drill string back down into the wellbore.

12. The non-transitory, computer-readable medium of claim 6, further comprising:

instructions to adjust the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

13. The non-transitory, computer-readable medium of claim 6, wherein the operational attribute comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.

14. An apparatus comprising:

a processor; and

a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to, determine an input drill bit response to a drill bit while drilling a wellbore based on at least one operational attribute during drilling of the wellbore; and predict a cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore based on the input drill bit response.

15. The apparatus of claim 14, wherein the instructions comprise instructions executable by the processor to cause the processor to,

determine cutter forces on the at least one cutter based on the input drill bit response,

wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter forces on the at least one cutter.

16. The apparatus of claim 15, wherein the instructions comprise instructions executable by the processor to cause the processor to,

determine a cutter power of the at least one cutter based on the cutter forces,

wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter power of the at least one cutter.

17. The apparatus of claim 16, wherein the instructions comprise instructions executable by the processor to cause the processor to,

determine a cutter energy of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter energy of the at least one cutter;

determine a cutter wear volume of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear volume of the at least one cutter; and

determine a cutter wear depth of the at least one cutter based on the cutter forces, wherein the instructions executable by the processor to cause the processor to predict the cutter wear severity of at least one cutter of the drill bit during drilling of the wellbore is based on the cutter wear depth of the at least one cutter.

18. The apparatus of claim 14, wherein the instructions comprise instructions executable by the processor to cause the processor to,

determine whether the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold; and

in response to the cutter wear severity of the at least one cutter of the drill bit exceeds a wear severity threshold, stop drilling of the wellbore; trip the drill string to a surface of the wellbore to replace the drill bit with a new drill bit; and resume drilling of the wellbore using the new drill bit after lowering the drill string back down into the wellbore.

19. The apparatus of claim 14, wherein the instructions comprise instructions executable by the processor to cause the processor to,

adjust the at least one operational attribute to reduce cutter wear severity during the drilling of the wellbore.

20. The apparatus of claim 14, wherein the operational attribute comprises at least one of a weight on bit, a torque on bit, a rate of penetration, or a rotation speed of the drill bit during drilling of the wellbore.