Control of a downhole device using NMR measurements.

Description

1 / 26 Control of a downhole device using NMR measurements. CROSS-REFERENCE TO RELATED REQUESTS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 492,387, entitled DOWNHOLE TOOL STRING MOVEMENT SENSOR SYSTEM, filed March 27, 2023, disclosure of which is hereby incorporated herein by reference. FUNDAMENTALS OF THE INVENTION

[0002] This disclosure relates generally to downhole devices and, more specifically, to the control of downhole devices using nuclear magnetic resonance (NMR) measurements.

[0003] This section is intended to introduce the reader to various aspects of the technique that may be related to several aspects of the present techniques, which are described and / or claimed below. It is believed that this discussion will be useful in providing the reader with fundamental information to facilitate a better understanding of the various aspects of the present disclosure. Consequently, it should be understood that these statements should be read in this context, and not as admissions of the prior art.

[0004] Hydrocarbon production from a drilled well into a geological region is a remarkably complex undertaking. In many cases, decisions involved in hydrocarbon exploration and production can be informed by measurements from downhole logging tools that are carried deep into the wellbore. The measurements can be used to infer properties or characteristics of the geological region surrounding the wellbore.

[0005] One type of wellbore logging tool uses nuclear magnetic resonance (NMR) to measure the response of nuclear spins in formation fluids to applied magnetic fields. In general, it is advantageous to obtain NMR measurements accurately and relatively quickly. Improving the accuracy of NMR measurements, such as removing noise or artifacts from the measurements, Petition 870250107764, dated 11 / 25 / 2025, page 9 / 40 2 / 26 NMR helps oil and gas organizations or companies make decisions about oil and gas, such as determining where to drill or not. While it can be advantageous to acquire NMR measurements quickly, this can reduce the accuracy of the NMR measurements. SUMMARY OF THE INVENTION

[0006] A summary of certain aspects disclosed in this document is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief overview of these certain aspects and that these aspects are not intended to limit the scope of this disclosure. Indeed, the disclosure may encompass a variety of aspects that may not be set forth below.

[0007] Another aspect of the present disclosure relates to a system. The system includes one or more processors and one or more memories comprising instructions stored on a non-transient, computer-readable medium and executable by one or more processors to receive NMR measurements acquired by a downhole device that translates across a geological region. The instructions, when executed, also cause the processor to determine a plurality of NMR-based parameters based on the NMR measurements. Furthermore, the instructions, when executed, cause the processor to determine a porosity fraction with an NMR-based parameter that exceeds a threshold based on the plurality of NMR-based parameters. Additionally, the instructions, when executed, cause the processor to generate an operational tuning output based on the porosity fraction.Furthermore, when executed, the instructions cause the processor to modify a well log operation based on the operational adjustment output.

[0008] Another aspect of the present disclosure relates to a non-transient, computer-readable medium comprising computer-executable instructions which, when executed, cause a processor to receive NMR measurements acquired by a downhole device which translates Petition 870250107764, dated 11 / 25 / 2025, page 10 / 40 3 / 26 through a geological region. The instructions also cause the processor to determine T1 relaxation times based on NMR measurements. Additionally, the instructions cause the processor to determine a porosity fraction with a T1 relaxation time that exceeds a threshold based on the T1 relaxation times. Furthermore, the instructions, when executed, cause the processor to generate an operational adjustment output based on the porosity fraction. Even additionally, the instructions cause the processor to modify a translation rate of a well logging operation based on the operational adjustment output.

[0009] Another aspect of this disclosure relates to a method. The method includes receiving, by means of one or more processors, NMR measurements acquired by a downhole device traversing a geological region. The method also includes determining, by means of the one or more processors, T1 relaxation times based on the NMR measurements. Furthermore, the method includes determining, by means of the one or more processors, a porosity fraction having a T1 exceeding a T1 threshold based on the T1 relaxation times. Still further, the method includes determining, via the one or more processors, the porosity fraction that exceeds a porosity fraction threshold; still further, the method includes generating, via the one or more processors, an operational tuning output based on the porosity fraction that exceeds the porosity fraction threshold.Furthermore, the method includes adjusting, via one or more processors, the rate of penetration (ROP) of a logging device during drilling (LWD) based on the operational adjustment output. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] These and other features and advantages of this disclosure will become better understood when the following detailed description is read with reference to the attached drawings, in which similar characters represent similar parts in all drawings, where:

[0011] FIG. 1 is a partial cross-sectional view of a device Petition 870250107764, dated 11 / 25 / 2025, p. 11 / 40 4 / 26 of a suspended well bottom in an underground formation, according to one aspect of this disclosure;

[0012] FIG. 2 illustrates a block diagram of a surface control system that is coupled to a downhole device, according to an aspect of the present disclosure;

[0013] FIG. 3 is a flowchart of a method for determining an operational adjustment output for controlling downhole devices based on NMR measurements, according to an aspect of this disclosure;

[0014] FIG. 4 is a flowchart of a method for determining an operational adjustment output for controlling downhole devices based on T1 measurements, according to an aspect of this disclosure;

[0015] FIG. 5 shows a graph of normalized total polarization versus rate of penetration (ROP), according to an aspect of the present disclosure; and

[0016] FIG. 6A shows a first graph of a T1 distribution that visually indicates the fraction of porosity having a T1 that exceeds a T1 threshold, in accordance with an aspect of the present disclosure;

[0017] FIG. 6B shows a second graph of a T1 distribution showing an example of the operational adjustment output that visually indicates the fraction of porosity having a T1 that exceeds a T1 limit, in accordance with an aspect of the present disclosure;

[0018] FIG. 6C shows a third graph of a T1 distribution showing an example of the operational adjustment output that visually indicates the porosity fraction having a T1 that exceeds a T1 limit, in accordance with an aspect of the present disclosure; and

[0019] FIG. 6D shows a fourth graph of a T1 distribution showing an example of the operational adjustment output that visually indicates the fraction of porosity having a T1 that exceeds a T1 limit, in accordance with an aspect of the present disclosure. DETAILED DESCRIPTION Petition 870250107764, dated 11 / 25 / 2025, p. 12 / 40 5 / 26

[0020] One or more specific embodiments of this disclosure will be described below. In an effort to provide a concise description of these embodiments, all the features of an actual implementation may not be described in the descriptive report. It should be noted that in the development of any such actual implementation, as in any engineering or design undertaking, numerous implementation-specific decisions must be made to achieve the specific objectives of the developers, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Furthermore, it should be noted that such a development endeavor may be complex and time-consuming, but nevertheless, it would be a routine design, manufacturing, and production task for people of ordinary skill in the art who have the benefit of this disclosure.

[0021] When presenting elements of various modalities of this disclosure, the articles "a," "an," "the" are intended to mean that there is one or more of the elements. The terms "which includes," "which comprises," and "which has" are intended to be inclusive and mean that there may be additional elements beyond those listed. Any examples of operational parameters and / or environmental conditions are not exclusive of other parameters / conditions of the disclosed modalities.

[0022] In the present context, the term “about” or “approximately” is intended to mean that the stated values ​​are not exact and the actual value may vary from those stated in a way that does not materially alter the operation in question. For example, the term “about” or “approximately,” as used in this document, is intended to convey a suitable value that is within a specific tolerance (e.g., ±10%, ±5%, ±1%, ±0.5%), as would be understood by a person skilled in the art.

[0023] As generally discussed above, oil and gas organizations can use NMR measurements to inform oil and gas decisions, such as where to drill. In general, to obtain NMR measurements, a device of Petition 870250107764, dated 11 / 25 / 2025, page 13 / 40 6 / 26 A downhole drilling tool (e.g., a downhole drilling tool) with an NMR system subjects a region of a geological region to a strong magnetic field, which polarizes the atomic nuclei (e.g., the proton nucleus in 1H). The polarized nuclei are then manipulated by a series of radio frequency pulses from an antenna, and information about the formation response is recorded and analyzed to obtain various NMR-based parameters, such as formation porosity, T1 relaxation time(s) (e.g., T1), T2 relaxation times (e.g., T2), T1 / T2 ratios, a quantity (e.g., relative or absolute) of bound and free fluid, permeability, and the like. NMR measurements are sensitive to the motion or translation (e.g., axial translation where the downhole device moves along the longitudinal length of a well) of the downhole device.Although certain techniques can correct for downhole device motion (e.g., translation rate) using a known pipe velocity or downhole device rate of penetration (ROP), these techniques may be limited to relatively slower ROPs.

[0024] In general, the translation rate (e.g., ROP of a logging device during drilling or cable velocity of a cable well logging device) of a downhole device can affect the NMR measurements obtained, acquired, or measured by the downhole device, and the NMR-based parameters determined using the NMR measurements. For example, when the translation rate of the downhole device is relatively high (e.g., the translation rate is 30 m / h or greater, 40 m / h or greater, 50 m / h or greater, 60 m / h or greater, and 70 m / h or greater), the movement of the downhole device can increase the error in the NMR measurements or in the NMR-based parameters.Certain conventional techniques include applying a correction (e.g., a profiling speed correction based on a translation rate, such as a measured ROP value or a cable speed value) to NMR processing when the translation rate is relatively high. However, currently it is... Petition 870250107764, dated 11 / 25 / 2025, page 14 / 40 7 / 26 It is recognized that uncertainty in the translation rate correction (e.g., ROP correction) can be relatively high when certain NMR-based parameters (e.g., T1) are relatively high (e.g., T1 is greater than 1 second (s), 2 s or more, 3 s or more, 4 s or more, 5 s or more, 6 s or more, 7 s or more, 8 s or more, 9 s or more, 10 s or more). As used herein, “T1” refers to the T1 relaxation time. Consequently, when both T1 and the translation rate are relatively high, it can be difficult to accurately correct for the ROP effect. It should be noted that while the disclosure below generally describes the use of T1, it should be noted that the disclosed techniques can also apply to other NMR-based parameters that are related to T1, such as T2 and the T1 / T2 ratio.

[0025] Consequently, this disclosure is directed to techniques for improving the accuracy of NMR parameters (e.g., NMR-based parameters such as T1, T2, and / or porosity) by adjusting the translation rate of a downhole device (e.g., the ROP or cable velocity) using T1 or T2 and the T1 / T2 ratio. For example, a processor can determine NMR-based parameters using NMR measurements while a downhole device, including an NMR sensor, acquires the NMR measurements. In turn, the processor can determine an operational adjustment output that can alert the user that the NMR measurements may have a relatively high error (e.g., 2% or more, 5% or more, 10% or more, or 15% or more).Additionally or alternatively, the operational adjustment output may notify a user (e.g., a downhole device operator) of a translation rate (e.g., a ROP) that provides NMR measurements with an appropriate error (e.g., error of 10% or less, 5% or less, 2% or less, 1% or less, or 0.5% or less). At least in some cases, the processor may determine the translation rate (e.g., the ROP or cable speed) of the downhole device. In turn, the processor may determine an adjustment to the translation rate or other logging operations. Petition 870250107764, dated 11 / 25 / 2025, page 15 / 40 8 / 26 of the well (for example, generating an alert on a display, providing visual indications in a well logging, or adjusting the translation rate of an LWD or wireline device) based on the current translation rate of the downhole device and the NMR-based parameter. In this way, the NMR-based parameter can be used as feedback to control the operation of the downhole device. Thus, disclosure techniques can improve the accuracy of NMR measurements while the downhole device is acquiring NMR measurements, adjusting and / or notifying users about an appropriate ROP and / or ROP range to provide NMR measurements with a relatively low error, thereby improving the efficiency of oil and gas operations that utilize NMR measurements.

[0026] Bearing the foregoing in mind, FIG. 1 illustrates a drilling system 10 that can utilize the systems and methods of this disclosure. The drilling system 10 can be used to drill a well 12 in a geological region 14. In the drilling system 10, a drilling rig 18 can rotate a drill string 20 within the well 12. As the drill string 20 rotates, a drilling fluid pump 22 can be used to pump drilling fluid, which may be referred to as “mud” or “drilling mud,” down through the center of the drill string 20 and back up around the drill string 20, as shown by the reference arrows 24. At the surface, the return drilling fluid can be filtered and transported back to a mud well 26 for reuse. The drilling fluid can travel down to the bottom of the drill string 20, known as the bottom composition (BHA) 28.Drilling fluid can be used to rotate, cool and / or lubricate a drill bit 30 which may be a part of BHA 28. The fluid can exit the drill string 20 through the drill bit 30 and carry fragments and drilling cuttings away from the bottom of the well 12 back to the surface.

[0027] BHA 28 may include drill bit 30 along with various Petition 870250107764, dated 11 / 25 / 2025, p. 16 / 40 9 / 26 downhole tools, such as an NMR 32 tool. BHA 28 can then transport the NMR 32 tool through geological region 14 via well 12. As described in more detail in this document, the NMR 32 tool can be any suitable downhole tool that emits electromagnetic waves within well 12 (e.g., a downhole environment). Downhole tools, which may include the NMR 32 tool, can collect a variety of information related to geological region 14 and the drilling status in well 12. For example, downhole tools can be log-drilling (LWD) tools that measure physical properties of geological region 14, such as density, porosity, resistivity, lithology, and so on.Similarly, downhole tools can be measuring tools during drilling (MWD) that measure certain drilling parameters, such as temperature, pressure, drill bit orientation, and so on.

[0028] As discussed further below, the NMR 32 tool may receive power from an electrical power device or from an electrical energy storage device, such as an auxiliary power supply 34 or another electrical power source to power the tool. In some embodiments, the NMR 32 tool may include a power source (e.g., a turbine / alternator configuration) within the NMR 32 tool, such as a battery system or a capacitor to store sufficient electrical energy to emit and / or receive electromagnetic waves.

[0029] Communications 36, such as control signals, can be transmitted from a data processing system 38 to the NMR tool 32, and communications 36, such as data signals related to the results / measurements of the NMR tool 32, can be returned to the data processing system 38 from the NMR tool 32. The data processing system 38 can be any electronic data processing system that can be used to execute the systems and methods. Petition 870250107764, dated 11 / 25 / 2025, page 17 / 40 10 / 26 of this disclosure. For example, the data processing system 38 may include a processor 40, which can execute instructions stored in memory 42 and / or storage 44. The memory 42 and / or storage 44 of the data processing system 38 may be any suitable manufactured article that can store instructions. The memory 42 and / or storage 44 may be read-only memory (ROM), random access memory (RAM), flash memory, an optical storage medium, or a hard disk drive, to cite some examples. A display 46, which may be any suitable electronic display, may display images generated by the processor 40.The data processing system 38 may be a local component of the drilling system 10 (i.e., on the surface), within the NMR tool 32 (i.e., inside the well), a device located near the drilling operation, and / or a remote data processing device located away from the drilling system 10 to process inside-the-well measurements in real time or some time after the data have been collected. In some embodiments, the data processing system 38 may be a portable computing device (e.g., tablet computer, smartphone, or laptop computer) or a remote server of the drilling system 10.In some embodiments, the NMR 32 tool can store and process data collected in BHA 28 or send the data to the surface for processing via communications 36 described above, including any suitable telemetry (e.g., pulsed electrical signals across the geological region 14 or mud pulse telemetry using drilling fluid).

[0030] It should be noted that although the above discussion refers to a drilling system, other downhole equipment or systems may employ the systems and methods of this disclosure. For example, a downhole tool with an acoustic tool carried by smooth cable, spiral tubing, wire rope, or other distribution systems may utilize the disclosed systems and methods. Petition 870250107764, dated 11 / 25 / 2025, page 18 / 40 11 / 26

[0031] The operation of the drilling system 10 can be controlled by a processor of the data processing system 38. For example, Figure 2 illustrates a block diagram of the data processing system 38 that is communicatively coupled to the NMR tool 32. In the illustrated embodiment, the NMR tool 32 includes a processor 50, memory 52, an NMR acquisition system 54, and storage 56. In some embodiments, the processor 50 may be an ASIC (application-specific integrated circuit), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a digital signal processor (DSP), and the like. In general, the drilling system 10 communicates with the data processing system 38 by means of a data cable, rangefinder, or other suitable techniques. For example, the drilling system 10 can communicate NMR measurements obtained by an NMR sensor of the drilling system 10.In turn, a surface control system processor can determine certain parameters (e.g., T1, T2, porosity, T1 / T2 ratio, water saturation, permeability) based on NMR measurements. In such embodiments, the NMR acquisition system 54 may include an emission source (e.g., an antenna) to acquire, obtain, or measure NMR signals.

[0032] As described herein, the data processing system 38 can generate an operational adjustment output that can adjust the operation of the drilling system 10 and / or inform an operator about an adjustment. To illustrate this, FIG. 3 provides a flowchart of a method 70 that can be implemented by a processor 40 of the data processing system 38 or by the NMR tool 32 to modify well logging operations (e.g., generate an alert on a display, provide visual indications on a well profile, or adjust the translation rate of an LWD device or a wireline device), drilling operations, and similar operations of the drilling system 10 based on NMR measurements taken by an NMR sensor of the NMR tool 32. Although the method 70 has been described as being performed by the processor 40, it should be noted that Petition 870250107764, dated 11 / 25 / 2025, page 19 / 40 12 / 26 Any suitable processing device can perform method 80, such as the NMR tool processor 50 32.

[0033] In block 72, the processor receives NMR measurements obtained, measured, or otherwise acquired by a downhole device. In general, the NMR 32 tool can activate one or more antennas to obtain the NMR measurements. In some embodiments, the antennas of the NMR 32 tool can use a pulse sequence to obtain the NMR measurements. As a non-limiting example, the antennas can use one or more Carr-Purcell-Meiboom-Gill (CPMG) sequences and burst sequences to acquire the NMR measurements (e.g., an NMR dataset). The phrase “CPMG” refers to a way of acquiring NMR echoes that give rise to relaxation information (e.g., T1-based information and / or T2-based information) at a given time hold (polarization).The term “bursts” is used to refer to additional CPMG echo trains that are relatively shorter and repeated multiple times to build the signal-to-noise ratio for intermediate and shorter time constants, which also builds the T1-based information in NMR measurements. In some modes, neither the bursts nor the main CPMG echo trains are pure CPMGs. In some modes, NMR measurements can be generated using sequences at multiple frequencies (e.g., an antenna operating frequency).

[0034] In block 74, processor 40 determines NMR-based parameters, such as a T1 relaxation time, using NMR measurements. For example, processor 40 can determine a T1 distribution using multiple T1 relaxation times determined from NMR measurements. As described here, NMR-based parameters may include other T1-related parameters, such as a T2 relaxation time (e.g., T2) and a T1 / T2 ratio. In general, NMR-based parameters are data corresponding to the amount and relaxation rate of nuclear spins of one or more components (e.g., a rock formation, fluids, and the like). Petition 870250107764, dated 11 / 25 / 2025, page 20 / 40 13 / 26 along the wellbore region. In some embodiments, the 40 processor can determine a porosity fraction based on NMR parameters. For example, the 40 processor can determine a porosity fraction based on T1 relaxation times that exceed a T1 relaxation time threshold, as described in more detail in relation to FIG. 4.

[0035] In an embodiment where processor 40 uses a pulse sequence, such as a CPMG echo train sequence, processor 40 can determine the NMR-based parameter as described below. For example, NMR measurements obtained using a general CPMG measurement can be described as: = ff f(T1,T2)K(tw,tB,T1,T2)dT1dT2(1) where T1 and T2 are the longitudinal and transverse relaxation times of the sample, respectively, and f(T1, T2) represents the fraction of the signal with particular T1-T2 values. The K function is a direct model to describe the behavior of the NMR signal and is also known as the kernel function. For the one-th echo in a CPMG measurement, it can be expressed as Kn= Mo {1 - exp R)}exp (-nr) (2) where tw is the waiting time after the end of the previous measurement (also known as polarization time) and te is the echo spacing. M0 represents the magnetization size at thermal equilibrium, which is proportional to the formation porosity in NMR well logging after proper calibration. The distribution function f(T1, T2) can be obtained by repeating the CPMG measurements while changing tW (and, additionally or alternatively, the number of echoes, which determines the length of the CPMG measurement) and applying inversion to the two-dimensional data obtained. As described here, it may be desirable to use a porosity fraction based on the T1 distribution that exceeds a T1 threshold to adjust the translation rate of a downhole device.

[0036] In block 76, processor 40 generates an adjustment output. Petition 870250107764, dated 11 / 25 / 2025, page 21 / 40 14 / 26 operational based on the NMR-based parameter. In general, the operational adjustment output may include an alert or control signal that causes, or may be used to cause, an adjustment in the operation of the drilling system 10 to reduce an error level in the NMR measurement by the NMR tool 32. In general, the adjustment corresponds to a reduced and / or recommended translation rate (e.g., ROP or cable speed). For example, in an embodiment where the operational adjustment output includes an alert, the alert may include information informing the user whether the translation rate of the drilling system 10 should be reduced. For example, the alert may include a notification displayed on a computing device such as a laptop, mobile device, tablet, or other.In some embodiments, the notification may indicate that the translation rate of the drilling system 10 may produce NMR measurements with an error that exceeds an error limit (e.g., provided as user input and / or stored as reference data accessible by the processor 40). In some embodiments, the notification may include a suggested translation rate and / or translation rate range to provide NMR measurements with adequate error (e.g., an error below an error limit).

[0037] In some embodiments, processor 40 can generate operational tuning output based on a comparison between an NMR-based parameter and a threshold NMR-based parameter. As described in more detail in relation to FIG. 4, processor 40 can determine a porosity fraction of geological region 14 that has an NMR-based parameter (e.g., T1) that exceeds an NMR-based threshold (e.g., a T1 threshold, a T2 threshold, a T1 / T2 threshold). For example, processor 40 can determine a porosity fraction that has a T1 above a T1 threshold of geological region 14 (e.g., a depth range, a volume range, a fraction, or a subsection). In some embodiments, the T1 threshold can be 4 s, 5 s, 6 s, 7 s, 8 s, 9 s, 10 s, or greater than 10 s. Processor 40 can compare the porosity fraction or porosity percentage with a Petition 870250107764, dated 11 / 25 / 2025, page 22 / 40 15 / 26 porosity threshold, such as a porosity fraction threshold (e.g., 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9) or a porosity percentage threshold (e.g., 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%). If processor 40 determines that the porosity fraction with value T1 exceeding the threshold T1 exceeds the porosity fraction threshold, processor 40 may generate an operational adjustment output that includes a warning and / or control signal to reduce the rate of translation (e.g., ROP) of the drilling system 10.

[0038] In some embodiments, the processor 40 can determine a porosity fraction based on NMR parameters. As described herein, an error in NMR measurements can change (e.g., increase or decrease) based on the NMR-based parameter and the rate of movement of the devices (e.g., the NMR tool) of the drilling system 10. It should be noted that the disclosed techniques are not limited to drilling systems but can also be applied to other downhole systems, such as wire rope systems using a wire rope tool. For example, and as described in more detail in FIG. 5, an error in NMR measurements can be relatively high (e.g., 5% or more, 6% or more, 7% or more, 10% or more, 15% or more, and so on) when the T1 relaxation time of the formation region is relatively high (e.g., 2 seconds (s) or more, 3 s or more, 4 s or more, 5 s or more, 6 s or more, 7 s or more, or 8 s or more).Furthermore, the error in NMR measurements can be relatively high when the downhole device's movement speed (e.g., ROP) is relatively high (e.g., 30 meters per hour (m / h) or more, 40 m / h or more, 50 m / h or more, 60 m / h or more, or 70 m / h or higher). Consequently, it may be advantageous to reduce the downhole device's speed or provide an alert indicating that the speed is relatively high or exceeds a limit. Thus, the processor 40 can determine an appropriate reduction in the drilling system's ROP 10 and / or an ROP range that corresponds to a smaller error range (e.g., 5% or less, 4% or less, 3% or less, 2% or less, 1% or less). Petition 870250107764, dated 11 / 25 / 2025, p. 23 / 40 16 / 26 less, 0.5% or less, 0.1% or less).

[0039] In some embodiments, processor 40 can determine the translation rate adjustment using reference data, such as a table, a graph, and the like. For example, processor 40 can provide the NMR-based parameter and / or well velocity as input to a table that stores relationships between NMR-based parameters (e.g., T1 relaxation times, well device velocities, and translation rate adjustments) and determines the corresponding correction. In some embodiments, the reference data can be stored in memory 42, storage 44, or another suitable storage component (e.g., cloud storage). For example, the reference data can include data stored in a table that indicates a relative and / or absolute translation rate adjustment corresponding to a porosity fraction with a T1 exceeding a T1 threshold.

[0040] In block 78, processor 40 modifies, adjusts, or alters a well logging operation (e.g., an operation associated with drilling system 10) based on the operational adjustment output, such as, for example, issuing an alert or a control signal that modifies the operation of drilling system 10 or another well operation system. In some embodiments, the operational adjustment output may adjust a translation rate of well logging operations, such as a rate of penetration (ROP) of a drilling logging device (LWD) and the like. In an embodiment where the operational adjustment output includes an alert, the operational adjustment output may cause a display (e.g., display 46) to display an alert that includes information or instructions for an operator to reduce the rate of penetration (ROP) of drilling system 10.In some modes, the alert may indicate a ROP range, thus informing the operator about a suitable ROP range that provides NMR measurements with a specific accuracy. For example, the alert may inform a user that the drilling system's ROP 10 should be reduced to an ROP within 10%. Petition 870250107764, dated 11 / 25 / 2025, page 24 / 40 17 / 26 of a first ROP range (e.g., between approximately 60 m / h and approximately 40 m / h, between approximately 50 m / h and approximately 30 m / h, between approximately 40 m / h and approximately 30 m / h, between approximately 30 m / h and 20 m / h) to reduce the error of the NMR measurements to below an error threshold (e.g., 15% or less, 10% or less, 8% or less, 5% or less, 2% or less, 1% or less, or 0.5% or less).

[0041] In some modes, the alert may indicate a predicted error in the NMR measurement corresponding to the current ROP. For example, processor 40 may determine a predicted error based on NMR-based parameters (e.g., T1) and / or the current ROP. Processor 40 may output operational adjustment output that causes an alert to display the predicted error, which may help the user determine a corrective action, such as a more appropriate translation rate (e.g., ROP value or cable speed) and / or translation rate range (e.g., ROP range or cable speed range).Additionally or alternatively, the operational adjustment output indicates other information that may assist the user in determining corrective action (e.g., whether to manually adjust the translation rate), such as the NMR measurement within the geological region (e.g., a proportion of T1 values ​​that exceed a T1 threshold), such as the accuracy of the NMR measurement at the current ROP, or the penetration rate of the drilling system 10.

[0042] In some embodiments, the operational adjustment output can adjust the drilling system operation 10 automatically. For example, the operational adjustment output can reduce the current ROP of the downhole device to an ROP within a suitable ROP range (i.e., having an error within a particular or acceptable range).

[0043] As described above, processor 40 can generate an operational adjustment output based on NMR-based parameters of the geological region to improve the accuracy of NMR measurements by the NMR tool 32. To illustrate this, FIG. 4 shows a flowchart of a method 80 that Petition 870250107764, dated 11 / 25 / 2025, page 25 / 40 18 / 26 can be implemented by a processor 50 of the NMR tool 32 and / or processor 40 of the data processing system 38 generating the operational tuning output using a T1 threshold. Although method 80 has been described as being performed by processor 40, it should be noted that any suitable processing device can perform method 80, such as processor 50 of the NMR tool 32. Furthermore, although method 80 is described based on a T1 threshold, it should be noted that other NMR-based parameter thresholds can be used, such as a T1 / T2 ratio threshold, a T2 threshold, a water permeability ratio, or other values ​​indicating a T1 distribution.

[0044] As shown, processor 40 receives an NMR 82 measurement. In general, the NMR 82 measurement corresponds to a specific region within geological region 14, such as a depth range or area within the geological region. Furthermore, processor 40 can receive the NMR 82 measurement in a manner generally similar to that described in relation to block 72 of FIG. 3. In block 84, processor 40 determines T1 based on the NMR 82 measurements. In general, processor 40 can execute block 84 in a manner generally similar to that described in relation to block 74 of FIG. 3. It should be noted that although method 70 is described in relation to T1, processor 40 can use T2, T1 / T2, and other NMR-based parameters, as described herein.

[0045] In block 86, processor 40 determines a porosity fraction of geological region 14 having a T1 that exceeds a T1 limit (e.g., 2 seconds (s), 3 s, 4 s, 5 s, 6 s, 7 s, or more than 8 s). In other words, processor 40 can determine a porosity fraction having a T1 exceeding the T1 limit (or other NMR-based parameter limit). A non-limiting example where the T1 limit is 5 seconds is shown in... Eq. 3: -' —ΨΤοΐαΙ (3) Petition 870250107764, dated 11 / 25 / 2025, p. 26 / 40 19 / 26 where φTοίαι and φτ1>3ε correspond to the total porosity and the fraction of porosity with T1 greater than 5 seconds, respectively.

[0046] Equation 3 can be expressed in terms of the T1 distribution as follows: _^^1maxT1dt $5= fI11ma%T1dt11min (4)

[0047] This porosity fraction with a T1 above 5 s (or “high T1 indicator”) is then used in conjunction with a translation rate threshold (e.g., an ROP threshold, a logging speed threshold) that indicates the maximum logging speed above which a translation rate correction (e.g., an ROP correction) is used. As described herein, if the translation rate exceeds the translation rate threshold, the translation rate correction may provide inaccurate results due to the simultaneous presence of sufficient porosity at long T1 and high ROP. When the high T1 indicator is above an empirically determined cutoff, such as 0.25, the expected long T1 response may increase the uncertainty in the correction result, and therefore it may be desirable to keep logging below a maximum logging speed.This indicator can help regulate translation rates (e.g., ROP or logging speed) so that NMR measurements with a relatively high T1 are more accurate, avoiding relatively high uncertainties in a translation rate correction (e.g., ROP correction) when both ROP and T1 are relatively high. Furthermore, the indicator can improve efficiency (e.g., by determining a logging speed that provides measurements with adequate accuracy) by indicating a translation rate threshold corresponding to an error range. In this way, it can reduce the need for a user or the drilling system 10 to use an unnecessarily slow logging speed (e.g., an operator might operate the drilling system 10 assuming that T1 is at the highest measured T1 through the well), thereby improving the efficiency of drilling operations and / or... Petition 870250107764, dated 11 / 25 / 2025, page 27 / 40 20 / 26 well logging, as described here.

[0048] If processor 40 determines that the portion of geological region 14 having a T1 measurement exceeds a T1 threshold, processor 40 may proceed to block 88 and generate an operational adjustment output 90. In general, processor 40 may execute block 88 in a manner generally similar to that described in relation to block 76 of FIG. 4. However, if processor 40 determines that the portion of geological region 14 does not exceed the T1 threshold, processor 40 may return to block 84 for a subsequent NMR measurement.

[0049] As described herein, processor 40 can use reference information to determine an ROP based on NMR measurements and / or an actual ROP of the drilling system 10. To illustrate an example, FIG. 5 shows a graph of normalized total polarization (e.g., y-axis) versus ROP (e.g., x-axis). The graph in FIG. 5 includes multiple traces 100, 102, 104, 106, 108, and 110 corresponding to different values ​​of T1. For example, trace 100 corresponds to T1 = 1s; trace 102 corresponds to T1 = 2s; trace 104 corresponds to T1 = 4s; trace 106 corresponds to T1 = 6s; trace 108 corresponds to T1 = 8s; and trace 110 corresponds to T1 = 10s. In general, the graph describes an amount of correction to be applied in NMR data processing based on the ROP value and the T1 value.

[0050] In general, the graph in FIG. 5 shows that the amount of correction increases with increasing ROP and T1 values. The graph includes traces 112, 114, 116, 118, 120, and 122 corresponding to different T1 values ​​at a relatively higher temperature (e.g., 80°C) than traces 100, 102, 104, 106, 108, and 110. In general, the graph in FIG. 5 illustrates that the amount of ROP correction applied for a given T1 increases with increasing ROP. Thus, it is now recognized that if a measured translation rate (e.g., measured based on the addition of piping and / or with a device that measures a rate corresponding to the translation rate) has an error, the error in the ROP correction (e.g., a correction applied to the analysis of Petition 870250107764, dated 11 / 25 / 2025, p. 28 / 40 21 / 26 NMR measurements as described here) may also increase. Consequently, to reduce the error in NMR measurements based on an ROP correction with a relatively high error, it may be advantageous to determine an ROP that would reduce the error below an error threshold. At least in some embodiments, the processor 40 may issue a visual recommendation (e.g., via an alert) indicating a recommended ROP value based on the measured T1 values ​​that has an appropriate error (e.g., an error within a threshold). At least in some cases, the processor 40 may receive and utilize temperature information (e.g., acquired by a sensor placed in a suitable location on a downhole device) to determine an ROP adjustment (e.g., by reducing the translation rate).For example, processor 40 can compare a measured temperature (e.g., a magnetic temperature or other temperature associated with an NMR sensor) to a temperature threshold. If the temperature exceeds the tempered threshold, processor 40 can determine that the uncertainty of the ROP correction is relatively larger, as generally illustrated in the graph in FIG. 5. As such, processor 40 can use the relationship information indicated in traces 112, 114, 116, 118, 120, and 122 to determine the ROP. Thus, processor 40 can use the measured ROP, the temperature, and the measured T1 relaxation time to determine the ROP adjustment.

[0051] As described herein, the operational adjustment output 90 can cause a display to show an indication that assists the user in determining whether to reduce the drilling system ROP 10. To illustrate this, FIGS. 6A, 6B, 6C, and 6D illustrate a T1 distribution that includes a porosity fraction indicator 130. The graphs in FIGS. 6A, 6B, 6C, and 6D each include an x-axis indicating a T1 relaxation time and a y-axis indicating a porosity fraction of the corresponding T1 value. In general, each graph in FIGS. 6A, 6B, 6C, and 6D shows a distribution of T1 relaxation times derived from NMR measurements of a geological region (by Petition 870250107764, dated 11 / 25 / 2025, page 29 / 40 22 / 26 example, a location along the geological region). Furthermore, each graph shows a dashed line corresponding to the logarithmic mean of the T1 distribution. As shown, the 130 porosity fraction indicator is a shaded portion of each graph. Additionally or alternatively, the 130 porosity fraction indicator may include a separate graph, a number, or other visualization indicating a given porosity fraction of a T1 distribution.

[0052] In some embodiments, the visualization may change when the porosity fraction corresponding to the porosity fraction indicator 130 exceeds one or more thresholds. For example, the porosity fraction indicator 130 may be configured to change color from green to yellow when the porosity fraction with a relaxation time of T1 that exceeds a threshold (e.g., 5 s) is greater than a first threshold (e.g., 0.2, 0.25, 0.3, or 0.4 when the porosity threshold is a porosity fraction threshold, or 20%, 25%, 30%, or 40% when the porosity threshold is a porosity percentage threshold). Furthermore, the porosity fraction indicator 130 can be configured to change color from yellow to red when the porosity fraction with a T1 relaxation time exceeding a threshold (e.g., 5 s) is greater than a second threshold (e.g., 0.3, 0.35, 0.40, 0.45, 0.50).It is worth noting that any suitable visual indication can be used, such as markers, alerts, colors, text, or patterns. Furthermore, such visual indications can be triggered when the T1 relaxation time and / or the porosity fraction is above or below a threshold or within threshold ranges. For example, operational adjustment output 90 can cause display 46 to show an image of a first marker (e.g., using display 46) with a first color (e.g., yellow) when the porosity fraction is greater than 0.25 and the ROP is greater than 20 m / h. Additionally, operational adjustment output 90 can cause display 46 to show an image of a second marker (e.g., using display 46) with a second color (e.g., red) when the porosity fraction is... Petition 870250107764, dated 11 / 25 / 2025, pages 30 / 40 23 / 26 greater than 0.25 and the ROP greater than 30 m / h. In this way, the operational adjustment output can help operators identify when to adjust the translation rate of a downhole device (e.g., LWD device or well logging device).

[0053] The specific embodiments described in this document have been illustrated by way of example, and it should be understood that these embodiments may be subject to various modifications and alternative forms. It should further be understood that the claims are not intended to be limited to the specific forms disclosed, but rather to cover all modifications, equivalents and alternatives that fall within the spirit and scope of this disclosure.

[0054] The techniques presented and claimed herein are referenced and applied to material objects and concrete examples of a practical nature that demonstrably improve the present technical field and, as such, are not abstract, intangible, or purely theoretical. Furthermore, if any claims appended to the end of this descriptive report contain one or more elements designated as “means for (performing) a function...” or “step for (performing) a function...” it is intended that such elements be interpreted in accordance with Title 35 of the USC § 112(f). However, for any claims containing elements designated in any other way, it is intended that such elements not be interpreted in accordance with Title 35 of the USC § 112(f).

[0055] Additional aspects of the invention are provided by the subject matter of the following clauses:

[0056] 1. A system comprising: one or more processors; and one or more memories comprising instructions stored in a non-transient, computer-readable medium and executable by one or more processors for: receiving NMR measurements acquired by a downhole device that translates across a geological region; determining a plurality of NMR-based parameters based on the NMR measurements; Petition 870250107764, dated 11 / 25 / 2025, page 31 / 40 24 / 26 determine a porosity fraction with an NMR-based parameter that exceeds a threshold based on the plurality of NMR-based parameters; generate an operational adjustment output based on the porosity fraction; and modify a well logging operation based on the operational adjustment output.

[0057] 2. The system of any previous clause, in which the plurality of NMR-based parameters comprises T1 relaxation times.

[0058] 3. The system of any previous clause, in which the plurality of NMR-based parameters comprises relaxation times T2 and a ratio T1 / T2.

[0059] 4. The system of any previous clause, in which the operational adjustment output is configured to decrease a translation rate of the downhole device.

[0060] 5. The system of any previous clause, wherein the operational adjustment output comprises an alert indicating the porosity fraction having an NMR-based parameter that exceeds a threshold T1.

[0061] 6. The system of any previous clause, in which the threshold T1 is approximately 5 s.

[0062] 7. The system of any preceding clause, in which the instructions are configured to cause one or more processors to generate the operational adjustment output based on a translation rate of the downhole device.

[0063] 8. The system of any preceding clause, wherein the well logging operation comprises a rate of penetration of a logging device during drilling (LWD).

[0064] 9. A non-transient computer-readable medium comprising computer-executable instructions which, when executed, are configured to cause a processor to: receive NMR measurements acquired by a downhole device translating through a Petition 870250107764, dated 11 / 25 / 2025, pp. 32 / 40 25 / 26 geological region; determine T1 relaxation times based on NMR measurements; determine a porosity fraction with a T1 relaxation time that exceeds a threshold based on T1 relaxation times; generate an operational adjustment based on the porosity fraction; and modify a translation rate of a well logging operation based on the operational adjustment output.

[0065] 10. The non-transient, computer-readable means of any preceding clause, wherein the instructions, when executed, are configured to cause one or more processors to generate operational tuning output based on the porosity fraction and a temperature measurement.

[0066] 11. The non-transient, computer-readable means of any preceding clause, wherein the translation rate comprises a cable speed of a cable well logging device.

[0067] 12. The non-transient computer-readable means of any preceding clause, wherein the instructions, when executed, are further configured to cause one or more processors to determine a rate of translation of the downhole device; determine an error corresponding to the NMR measurements based on the rate of translation of the downhole device and the T1 relaxation times; and generate the operational adjustment output based on the error.

[0068] 13. The non-transient computer-readable medium of any preceding clause, wherein the translation rate comprises a penetration rate (ROP) of an LWD device.

[0069] 14. The non-transient, computer-readable means of any preceding clause, wherein the relaxation threshold of T1 is approximately 5 s.

[0070] 15. The non-transient, computer-readable means of any preceding clause, wherein the operational adjustment output is configured to generate a visual indication of a T1 relaxation threshold in a well logging operation. Petition 870250107764, dated 11 / 25 / 2025, pp. 33 / 40 26 / 26

[0071] 16. A method comprising receiving, by means of one or more processors, NMR measurements acquired by a downhole device that translates through a geological region; determining, by means of one or more processors, T1 relaxation times based on the NMR measurements; determining, by means of one or more processors, a T1 porosity fraction having a T1 exceeding a threshold based on the T1 relaxation times; determining, by means of one or more processors, that the porosity fraction exceeds a porosity fraction threshold; generating, by means of one or more processors, an operational adjustment output based on the porosity fraction exceeding the porosity fraction threshold; and adjusting, by means of one or more processors, a rate of penetration (ROP) of a drilling logging device (LWD) based on the operational adjustment output.

[0072] 17. The method of any previous clause, where the porosity fraction threshold is 25%.

[0073] 18. The method of any preceding clause, further comprising: determining, by means of one or more processors, a current ROP of the LWD device; and generating, by means of one or more processors, the operational adjustment output based on the current ROP and the T1 relaxation times.

[0074] 19. The method of any preceding clause, wherein the operational adjustment output is set to indicate a rate of penetration (ROP) range of the downhole device that reduces an error in the NMR measurements below an error threshold.

[0075] 20. The method of any preceding clause claim, comprising: determining a rate of translation of the downhole device; determining an error corresponding to the NMR measurement based on the rate of translation of the downhole device; and generating the operational adjustment output based on the error. Petition 870250107764, dated 11 / 25 / 2025, pp. 34 / 40

Claims

1 / 4 CLAIMS 1. A system, characterized in that it comprises: one or more processors; and one or more memories comprising instructions stored on a non-transient computer-readable medium and executable by the one or more processors for: receiving NMR measurements acquired by a downhole device traversing a geological region; determining a plurality of NMR-based parameters based on the NMR measurements; determining a porosity fraction having an NMR-based parameter that exceeds a threshold based on the plurality of NMR-based parameters; generating an operational tuning output based on the porosity fraction; and modifying a well logging operation based on the operational tuning output.

2. System according to claim 1, characterized in that the plurality of NMR-based parameters comprises T1 relaxation times.

3. System according to claim 1, characterized in that the plurality of NMR-based parameters comprises T2 relaxation times and a T1 / T2 ratio.

4. System according to claim 1, characterized in that the operational adjustment output is configured to decrease the translation rate of the downhole device.

5. System according to claim 1, characterized in that the operational adjustment output comprises an alert indicating the porosity fraction having the NMR-based parameter that exceeds a threshold of T1.

6. System, according to claim 5, characterized by the fact that the T1 threshold is approximately 5 s.

7. System according to claim 1, characterized in that the instructions are configured to cause one or more processors to generate the operational tuning output based on a translation rate of the downhole device.

8. System according to claim 1, characterized in that the well logging operation comprises a rate of penetration of a logging device during drilling (LWD).

9. Non-transient computer-readable medium, characterized in that it comprises computer-executable instructions which, when executed, are configured to make a processor: receive NMR measurements acquired by a downhole device translating through a geological region; determine T1 relaxation times based on the NMR measurements; determine a porosity fraction having a T1 relaxation time that exceeds a T1 threshold based on the T1 relaxation times; generate an operational tuning output based on the porosity fraction; and modify a translation rate of a well logging operation based on the operational tuning output.

10. Non-transient computer-readable medium according to claim 9, characterized in that the instructions, when executed, are configured to cause one or more processors to generate operational tuning output based on the porosity fraction and a temperature measurement.

11. Non-transient computer-readable medium according to claim 9, characterized in that the translation rate comprises a cable speed of a steel wire rope well logging device.

12. Non-transient computer-readable medium, according to Petition 870250087250, dated 09 / 26 / 2025, page 17 / 20 3 / 4, claim 9, characterized in that the instructions, when executed, are configured to make one or more processors: determine a translation rate of the downhole device; determine an error corresponding to the NMR measurements based on the translation rate of the downhole device and the T1 relaxation times; and generate the operational adjustment output based on the error.

13. Non-transient computer-readable medium according to claim 11, characterized in that the translation rate comprises a rate of penetration (ROP) of a wire rope well logging or LWD device.

14. Non-transient computer-readable medium according to claim 9, characterized in that the T1 relaxation threshold is approximately 5 s.

15. Non-transient computer-readable medium according to claim 9, characterized in that the operational adjustment output is configured to generate a visual indication of a T1 relaxation threshold in a well log.

16. Method, characterized in that it comprises: receiving, via one or more processors, NMR measurements acquired by a downhole logging device translating through a geological region; determining, via the one or more processors, T1 relaxation times based on the NMR measurements; determining, via the one or more processors, a T1 porosity fraction having a T1 exceeding a T1 threshold based on the T1 relaxation times; determining, via the one or more processors, the porosity fraction that exceeds a porosity fraction threshold; generating, via the one or more processors, an operational adjustment output based on the porosity fraction that exceeds the porosity fraction threshold; Petition 870250087250, dated 09 / 26 / 2025, page 18 / 20 4 / 4 and adjusting, via the one or more processors, a rate of penetration (ROP) of a logging device during drilling (LWD) based on the operational adjustment output.

17. Method according to claim 16, characterized in that the porosity fraction threshold is 0.

25.

18. Method, according to claim 16, characterized in that it further comprises: determining, via one or more processors, a current ROP of the LWD device; and generating, via one or more processors, the operational adjustment output based on the current ROP and the T1 relaxation times.

19. Method, according to claim 16, characterized in that the operational adjustment output is configured to indicate the rate of penetration (ROP) range of the downhole device that reduces an NMR measurement error below an error threshold.

20. Method according to claim 16, characterized in that it further comprises: determining a translation rate of the downhole device; determining an error corresponding to the NMR measurement based on the translation rate of the downhole device; and generating the operational adjustment output based on the error. Petition 870250087250, dated 09 / 26 / 2025, pp. 19 / 20

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