Downhole Caliper Tool Flexible Wire Mesh for Wellbore Shape Measurement
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Solution Overview
Problem
Conventional downhole caliper tools face challenges in accurately measuring the size and shape of wellbores due to limitations in mechanical durability and fluid interaction, leading to inaccuracies in predicting downhole issues and drilling efficiency.
Innovation Solution
The development of downhole caliper tools with a flexible wire mesh caliper and advanced sensor modules that include piezoelectric, electromagnetic, and magnetostrictive sensors, which expand radially to contact the wellbore and provide precise measurements despite harsh drilling conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional wireline calipers with rigid pads are used to measure wellbore diameter, then the measurement mechanism is simple and robust, but the tool cannot accurately adapt to varying wellbore shapes and is prone to mechanical failure under harsh drilling conditions
Solution Approach 1:
The patent employs a flexible wire mesh caliper structure that can radially expand and contract to conform to varying wellbore shapes. The wire mesh acts as a flexible sensing element that maintains structural integrity while adapting to elliptical, spiral, or irregular wellbore cross-sections, thereby improving measurement accuracy without compromising reliability under harsh drilling conditions
Solution Approach 2:
The caliper tool incorporates movable collars that can shift position to dynamically adjust the radial expansion of the wire mesh. This dynamic mechanism allows the tool to adapt to different wellbore diameters and shapes in real-time, enhancing both measurement precision and reliability by preventing mechanical stress concentration
2Measurement precision
If conventional ultrasonic calipers are used to measure wellbore dimensions, then contact with the wellbore is required for measurement, but fluid accumulation and cuttings buildup around the tool can interfere with measurement accuracy
Solution Approach 1:
The wire mesh structure inherently provides fluid bypass pathways that prevent drilling fluid and cuttings from accumulating around the sensing elements. The porous nature of the wire mesh allows continuous fluid flow through the tool, eliminating the harmful accumulation effect that plagues conventional ultrasonic calipers while maintaining accurate dimensional measurements
3Reliability
If the caliper structure is made rigid to withstand high temperatures and pressures, then durability improves, but the ability to smoothly contact and respond to wellbore wall variations is reduced
Solution Approach 1:
The patent utilizes composite construction combining rigid collars for structural support and temperature/pressure resistance with a flexible wire mesh for smooth wellbore wall contact. This composite approach allows different parts of the tool to perform specialized functions - the rigid collars withstand harsh environmental conditions while the flexible mesh conforms to wellbore irregularities, achieving both durability and ease of operation
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
These tools offer improved accuracy and durability, enabling real-time monitoring of wellbore dimensions and preventing issues like washout, ellipticity, and spiral-hole conditions, while withstanding high temperatures and pressures, and providing 3D representation of wellbore morphology.
Implementation Method 1
The sensor module includes piezoelectric, electromagnetic, and magnetostrictive sensors
Implementation Method 2
The sensor module includes piezoelectric, electromagnetic, and magnetostrictive sensors
Implementation Method 3
The sensor module includes piezoelectric, electromagnetic, and magnetostrictive sensors
Data Source
AI summary
Tools and methods are described to measure dimensions of wellbores. Downhole caliper tools include a downhole collar and an uphole collar having a running position and a sensing position. The uphole collar is farther from the downhole collar in the running position than in the sensing position. A caliper sensor assembly includes: a sensor module defining tracks extending parallel to an axis of the caliper tool, the sensor module positioned towards an uphole end of the caliper tool relative to the uphole collar; and a caliper disposed between the downhole collar and the uphole collar including: a flexible mesh extending from the downhole collar to the uphole collar. Movement of the uphole collar from the running position to the sensing position axially compresses and radially expands the flexible mesh. The annular sensor module can measure dimensions of the flexible mesh relative to the axis of the caliper tool.