Drill Bit Gamma Ray Sensors for Inclination Estimation

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Solution Overview

Problem

Existing drill bits lack accurate tilt and inclination measurements during drilling due to sensors being positioned away from the drill bit, leading to inaccuracies in formation evaluation and drilling operations.

Innovation Solution

Integration of gamma ray sensors within the drill bit, placed proximate to the formation and in a common plane perpendicular to the drill bit's longitudinal axis, to detect naturally-occurring gamma rays and estimate the drill bit's inclination, with an electronic circuit for signal processing and communication to a control unit for real-time data analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If sensors are positioned away from the drill bit in the BHA, then the device complexity is reduced and ease of manufacture is improved, but the measurement precision of tilt and inclination is degraded

Engineering Contradiction:
Improvetilt and inclination measurement accuracyVSAvoidsensor positioning complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the measurement function by placing multiple gamma ray sensors at different positions on the drill bit surface, allowing each sensor to independently measure gamma ray intensity from different directions. This segmentation enables accurate inclination determination through comparative analysis of multiple sensor readings.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from traditional BHA-based inclination measurement to bit-based measurement by positioning sensors on the drill bit surface in a common plane perpendicular to the longitudinal axis. This dimensional repositioning provides direct measurement of drill bit orientation relative to the formation, eliminating the inaccuracies associated with remote BHA sensing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If gamma ray sensors are integrated within the drill bit proximate to the formation, then the measurement precision of formation characteristics is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveformation evaluation accuracyVSAvoiddrill bit manufacturing ease
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent merges the gamma ray sensing function with the drill bit structure by integrating sensors directly onto the drill bit surface. This consolidation eliminates the need for separate BHA sensor assemblies and their associated complex mounting structures, simplifying the overall system while achieving superior measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The drill bit structure itself serves as the mounting platform for the gamma ray sensors, with the bit body providing mechanical support and positioning. The sensors are positioned on the drill bit surface to directly contact or near-contact the formation, allowing the drill bit to perform both its cutting function and its sensing function simultaneously.

Inventive Principle:
Principle #25Self-service

3Reliability

If multiple gamma ray sensors are positioned in a common plane perpendicular to the drill bit longitudinal axis, then the reliability of inclination estimation is improved, but the device complexity increases

Engineering Contradiction:
Improveinclination estimation reliabilityVSAvoidsensor array complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs asymmetric positioning of gamma ray sensors on the drill bit surface, with sensors placed at specific locations in a common plane perpendicular to the longitudinal axis. This asymmetric arrangement optimizes the measurement geometry for determining drill bit inclination by maximizing the differential gamma ray signal response to changes in bit orientation.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The system uses feedback from multiple gamma ray sensor readings to continuously estimate and monitor drill bit inclination. The processed signals from sensors positioned in a common plane provide real-time feedback on bit orientation, enabling dynamic adjustment of drilling parameters to maintain optimal inclination.

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Provides accurate and real-time inclination measurements, enabling precise control of drilling parameters such as weight-on-bit and rotational speed, enhancing drilling efficiency and extending drill bit and assembly life by differentiating between various rock formations.

Implementation Method 1

two or more gamma ray sensors in the drill bit for detecting naturally-occurring gamma rays from the formation during drilling of the wellbore

Methodology Applied
Scientific EffectGamma ray detection: Radiation

Data Source

PatentEP2561184B1Apparatus and methods for estimating tool inclination using bit-based gamma ray sensors
Publication Date: 2019.07.03 BAKER HUGHES CO
  • EP2561184B1 patent drawingFigure 1
  • EP2561184B1 patent drawingFigure 2
  • EP2561184B1 patent drawingFigure 3

AI summary

A drill bit made according to one embodiment may include a bit body having a longitudinal axis, a plurality of gamma sensors placed in the bit body, at least two gamma ray sensors in the plurality of sensors are spaced-apart from each other along the longitudinal axis of the bit body, wherein each such sensor in the plurality of sensors is configured to detect gamma rays from the formation during drilling of the wellbore and to provide signals representative of the detected gamma rays, and a circuit configured to process at least partially the signals from each of the at least two gamma ray sensors for estimating an inclination of the bit body relative to the longitudinal axis.