Sensing Subassembly Shock Mitigation for Perforating Guns

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The detonation of perforating guns in wellbores generates mechanical shock waves that can damage sensors and other components, leading to inaccurate data collection and potential system failure due to excessive exposure to these forces.

Innovation Solution

A sensing subassembly with a shock protection apparatus is used, featuring a shock mitigating member between the sensor and the housing, which attenuates or reflects mechanical waves, ensuring the sensor remains functional and accurate during perforating events.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a sensor is directly exposed to the wellbore environment for accurate mechanical wave measurement, then measurement precision is improved, but the sensor becomes vulnerable to damage from high-intensity shock waves generated by perforating guns

Engineering Contradiction:

Improvemechanical wave measurement accuracyVSAvoidsensor durability under shock wave exposure

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

A shock isolating member is introduced as an intermediary element between the sensor and the housing exterior. This mediator allows the sensor to detect mechanical waves through the housing while simultaneously protecting it from direct exposure to high-intensity shock waves generated by perforating guns, thus resolving the contradiction between measurement accuracy and sensor durability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The shock isolating member is pre-installed between the sensor and housing to provide beforehand cushioning against incoming shock waves. This protective measure is in place before the perforating operation occurs, allowing the sensor to withstand the intense mechanical forces without damage while still functioning for measurement purposes

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If the sensor is fully protected from shock waves using a shock isolating member, then reliability is improved, but transmission of mechanical waves to the sensor may be attenuated, reducing measurement precision

Engineering Contradiction:

Improvesensor protection from shock damageVSAvoidmechanical wave detection accuracy

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The shock isolating member is designed with specific material and structural parameters that allow it to selectively filter mechanical wave energies. It is configured to attenuate high-intensity shock waves above certain thresholds while transmitting lower-intensity measurement waves, thus changing the parameter of wave transmission to simultaneously achieve protection and measurement accuracy

Inventive Principle:

Principle #35Parameter changes

3Reliability

If the sensor housing is made more robust to withstand shock waves, then reliability is improved, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvehousing resistance to shock wavesVSAvoidhousing structural complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Rather than making the housing itself more robust and complex, a shock isolating member is introduced as a mediator between the exterior environment and the sensor interior. This approach achieves the same protective function with a simpler housing design, reducing manufacturing complexity while maintaining reliability

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The protective function is segmented from the housing structure itself and implemented as a separate shock isolating member. This segmentation allows the housing to remain simple while the dedicated isolating component provides the necessary shock resistance, reducing overall device complexity

Inventive Principle:

Principle #1Segmentation

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

The shock protection apparatus effectively reduces the transmission of mechanical waves to the sensor, preventing damage and ensuring reliable data collection, thereby enhancing the accuracy and longevity of the sensing equipment.

Implementation Method 1

a shock mitigating member disposed between at least one end of the sensor and the housing, wherein the shock mitigating member is configured to attenuate at least a portion of a mechanical wave between the housing and the sensor

Methodology Applied

Scientific EffectShock wave attenuation: Shock Wave

Implementation Method 2

shock mitigating member is configured to attenuate at least a portion of a mechanical wave

Methodology Applied

Scientific EffectMechanical wave reflection: Reflection

Data Source

PatentUS9926777B2Protection of electronic devices used with perforating guns

Publication Date: 2018.03.27 HALLIBURTON ENERGY SERVICES INC

AI summary

In an embodiment, a sensing subassembly for use with a downhole tool comprises a housing, a cavity extending into the housing, a sensor disposed at least partially within the cavity, a shock mitigating member disposed between at least one end of the sensor and the housing, and at least one seal member disposed between the sensor and the housing. At least a portion of the sensor is in fluid communication with an exterior of the housing, and the shock mitigating member is configured to attenuate at least a portion of a shock wave between the housing and the sensor.