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US-12618317-B2 - Methods for predicting and adapting to high frequency torsional oscillation

US12618317B2US 12618317 B2US12618317 B2US 12618317B2US-12618317-B2

Abstract

An accurate and elegant model is provided to characterize HFTO. For Type 1 HFTO, the model can predict frequency of the HFTO based on the distance between a reference location on the bottomhole assembly (e g., the end of the drill bit) and a point 40% up the motor. In short BHA strings there is the fundamental frequency while in longer BHA the first harmonic is used. For Type 2 HFTO, the model can predict frequency of the HFTO based on distance between a reference location on the bottomhole assembly (e.g., the end of the drill bit) and the first slick contact point, which is optionally in the middle of a long flex joint.

Inventors

  • Ashley Bernard Johnson

Assignees

  • SCHLUMBERGER TECHNOLOGY CORPORATION

Dates

Publication Date
20260505
Application Date
20230303

Claims (7)

  1. 1 . A method comprising: measuring frequency of high frequency torsional oscillation (HFTO) in a bottomhole assembly (BHA); using a model correlating frequency of the HFTO to distance relative to a reference location on the BHA to identify a position of a HFTO node in the BHA; when the HFTO node is at a contact point in a curve of a drilled wellbore, reducing dogleg severity or sending a recommendation to reduce dogleg severity; when the HFTO node is at a contact point in a lateral of the drilled wellbore, back reaming or sending a recommendation to back ream; when the HFTO node is in a motor of the BHA, changing drilling parameters or sending a recommendation to change drilling parameters; and after drilling, performing post event analysis and re-designing the BHA for a subsequent well, the redesigned BHA including at least one of different or additional wear band placement, replacement of heavy weight drill pipe with drill collars or vice versa, or changing a distance between components such that the HFTO node is located away from a sensitive component.
  2. 2 . The method of claim 1 , wherein: the model includes a linear function that relates characteristic frequency for the HFTO to a length representing distance from the reference location on the BHA to a first significant node of the HFTO.
  3. 3 . The method of claim 1 , further comprising: using the model to determine a type of the HFTO.
  4. 4 . The method of claim 3 , wherein the drilling parameters are dependent on determining a first type of HFTO that occurs above the motor.
  5. 5 . The method of claim 1 , wherein the model is correlated from experimental data representing different types of HFTO.
  6. 6 . The method of claim 1 , wherein the model is further based on an acoustic velocity.
  7. 7 . The method of claim 1 , wherein the model is further based on a constant.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a National Stage Entry of International Appl. No. PCT/US2023/063646, filed Mar. 3, 2023, which claims priority from U.S. Provisional Appl. No. 63/268,803, filed on Mar. 3, 2022, herein incorporated by reference in its entirety. BACKGROUND The dynamics of present-day drilling systems are complex. The bottomhole assembly (BHA), typically a long slender beam with a very high aspect ratio, suffers a myriad of instabilities. High-frequency torsional oscillation (HFTO), in which the BHA vibrates at frequencies above a few Hz, has been identified as a cause of damage to the drilling system. These damages can include cracks in collars, washouts, damage to electronic components, as well as over torqued joints or the back off of tool components. Using high-speed data recorders, HFTO characteristics can be measured in drill bits. Examples include torsional oscillations at about 56 Hz, as well as other harmonics. Modelling may also be done to predict possible resonant frequencies. By adding additional memory logging tools into the BHA, the constraints that impact these vibration characteristics can be better understood. For instance, although there are multiple frequencies of torsional oscillations (from low frequency Stick Slip (f˜0.2 Hz) to frequencies in excess of 300 Hz) which may appear in the same run, these different oscillations can also be mutually exclusive. Stringers can also trigger HFTO and the presence of HFTO can be seen as a marker for passing these hard formation boundaries. SUMMARY Methods and systems are provided that predict a position of a node for vibration in a drill string, which involves accessing a model that is based on vibration frequency and distance relative to a reference location on the drill string and using measured vibration frequency as input to the model to determine a location of the node in the drill string. In embodiments, the model can include a linear function that relates characteristic frequency for the vibration to a length representing distance from the reference location on the drilling tool to a first significant node of the vibration. In embodiments, the reference location on the drill string can be an end of the drill bit of the drill string. In embodiments, the vibration can be high frequency torsional oscillation. In embodiments, the model can be defined by correlating experimental data representing different types of high frequency torsional oscillation. In embodiments, the methods and systems can further involve taking action in real time to mitigate effects of the vibration based on the location of the node. For example, the action can involve i) reducing or increasing dogleg severity, ii) back reaming, iii) changing drilling parameters, or iv) sending a request to change dogleg severity, back ream, or change drilling parameters. In embodiments, the methods and systems can further involve using the location of the node in changing a design of the drill string to change at least one of frequency or location of the node. For example, the change in design can involve i) using the location of the node in identifying one or more wear bands placement locations, ii) replacing at least one heavy weight drill pipe with a collar or vice versa, or iii) changing a distance between components of the drill string and thereby moving a node to a less sensitive location. In another aspect, methods and systems are provided that access a model that is based on vibration frequency and distance relative to a reference location on the bottomhole assembly and using the model in conjunction with design of the bottomhole assembly to predict vibration frequency in the bottomhole assembly. In yet another aspect, methods are provided that measure frequency of high frequency torsional oscillation (HFTO) in a bottomhole assembly (BHA) and using a model that correlates frequency of the HFTO to distance relative to a reference location on the bottomhole assembly to identify a position of a HFTO node in the BHA. When the node is at a contact point in a curve of a drilled wellbore, the method involves reducing dogleg severity or sending a recommendation to reduce dogleg severity. When the node is at a contact point in a lateral of the drilled wellbore, the method involves back reaming or sending a recommendation to back ream. And when the node is in a motor of the BHA, the method involves changing drilling parameters or sending a recommendation to change drilling parameters. This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS In order to describe the manner in which the above-recited and other features of the disclosure can be obtained, a more part