Downhole Nuclear Tool Sleeve Stabilizer Design

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing downhole drilling technologies face challenges in accurately measuring formation characteristics while minimizing interference and damage, particularly in reducing stand-off effects and enhancing measurement accuracy for nuclear measurements during drilling operations.

Innovation Solution

A downhole tool string component with a tubular body and sleeve design, incorporating a pulse neutron generator and detectors, where the neutron source is partially disposed within a pocket under a stabilizer blade, and the detectors are axially aligned to minimize neutron penetration into the bore and maximize interaction with the formation, with a network for synchronization and data transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the neutron source is disposed within the tubular body, then the structure is simpler and more compact, but the neutron penetration into the bore increases causing interference and potential damage

Engineering Contradiction:

Improvestructural complexityVSAvoidneutron penetration into bore

Core Design Contradiction:

Device complexityVSObject-affected harmful factors

Solution Approach 1:

The neutron source is segmented into two distinct locations: partially within a pocket formed in the inner surface of the sleeve (for formation interaction) and partially within the tubular body (for structural integration). This segmentation allows the system to achieve both compact structure and reduced bore penetration by distributing the source function across two spatial zones.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The sleeve acts as an intermediary structure between the tubular body and the formation. It provides a pocket that positions the neutron source optimally while the stabilizer blade configured as a key-way structure serves as a mediator to further control neutron direction and reduce unwanted penetration into the bore while maintaining formation interaction.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Measurement precision

If the detectors are placed closer to the formation, then measurement accuracy improves, but the stand-off effects increase and interfere with measurements

Engineering Contradiction:

Improveformation measurement accuracyVSAvoidstand-off effects

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The stabilizer blade is configured as a key-way structure that can be positioned to minimize the distance between the detectors and the formation wall. This dynamic positioning capability allows the system to reduce stand-off effects adaptively, bringing detectors closer to the formation for improved measurement accuracy while maintaining operational flexibility.

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If the stabilizer blade is made larger to improve stabilization, then the tool string interference increases and drilling efficiency decreases

Engineering Contradiction:

Improvetool string stabilityVSAvoiddrilling efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The stabilizer blade is segmented into a key-way configured structure that provides stabilization functionality only where needed. This segmentation allows the blade to be smaller in overall size while maintaining effective stabilization, thereby reducing interference with the drill bit and improving drilling efficiency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The key-way configuration of the stabilizer blade concentrates the stabilization function in specific localized areas rather than requiring a large blade surface. This local quality approach provides adequate tool string stability while minimizing the blade's overall footprint and its potential to interfere with drilling operations.

Inventive Principle:

Principle #3Local quality

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

This configuration allows for accurate secondary nuclear measurements during drilling, reducing drilling interference, enhancing measurement accuracy, and enabling real-time analysis for drilling recommendations, thereby improving drilling efficiency and safety.

Implementation Method 1

a pulse neutron generator and detectors disposed within a stabilizer assembly

Methodology Applied

Scientific EffectPulse neutron generation:

Implementation Method 2

at least one nuclear detector disposed within a stabilizer assembly associated with one of the tool string components

Methodology Applied

Scientific EffectNuclear radiation detection:

Data Source

PatentUS7897914B2Downhole nuclear tool

Publication Date: 2011.03.01 SCHLUMBERGER TECH CORP

AI summary

In one aspect of the invention, a downhole tool string component comprises a tubular body with a first and a second tool joint adapted to connect to adjacent tool string components, and a central bore adapted to pass drilling mud between the joints. A sleeve circumferentially disposed about an outer surface of the tubular body. The sleeve is rigidly attached to the outer surface at first and second sleeve ends and forming at least three stabilizer blades. A nuclear source and at least one nuclear detector are disposed within a gap formed between the inner surface of the sleeve and the outer surface of the tubular body.