NMR Frequency Location via Frequency Decomposition

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Solution Overview

Problem

Conventional methods for determining the preferred nuclear magnetic resonance (NMR) frequency in varying temperature environments, such as downhole drilling, are time-consuming and inefficient, as they require searching for optimal frequency settings.

Innovation Solution

An ex-situ apparatus and method using processors and electromagnetic transmitter-receiver pairs to generate pulsed magnetic fields and record free induction decay signals, which are then transformed via frequency decomposition to quickly determine the preferred NMR frequency providing the maximum signal-to-noise ratio, applicable in both laboratory and downhole settings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional searching methods are used to locate the preferred NMR frequency at varying temperatures, then the NMR measurements can be obtained, but the process becomes time-consuming and inefficient

Engineering Contradiction:

ImproveNMR frequency determination accuracyVSAvoidTime to locate preferred NMR frequency

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating and storing the relationship between temperature and preferred NMR frequency in a lookup table before actual measurements. Instead of searching for the optimal frequency during field operations, the system pre-computes frequency offsets for various temperatures and stores them for rapid retrieval, eliminating the time-consuming search process during actual NMR surveys.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical searching process with an electronic/computational system. Instead of manually or iteratively testing different frequencies to find the optimal one, the system uses a processor to automatically calculate the preferred frequency based on temperature sensor readings and a pre-stored lookup table, substituting physical trial-and-error with computational determination.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If temperature-controlled equipment is used to maintain stable NMR frequency, then measurement consistency is improved, but equipment complexity and cost increase

Engineering Contradiction:

ImproveNMR measurement consistencyVSAvoidTemperature control equipment requirements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by adjusting the NMR frequency parameter based on temperature variations rather than attempting to maintain constant temperature. The system senses temperature changes and correspondingly adjusts the operating frequency using a lookup table that provides pre-calculated frequency offsets, allowing the NMR system to adapt to temperature changes without requiring temperature stabilization equipment.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent inverts the conventional approach by instead of controlling temperature to maintain frequency stability, it controls frequency to maintain measurement accuracy despite temperature variations. Rather than stabilizing the environmental parameter (temperature), the system stabilizes the operational parameter (frequency) by adapting it to temperature changes.

Inventive Principle:

Principle #13The other way round (Inversion)

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 approach allows for rapid determination of the preferred NMR frequency, reducing the need for temperature-controlled equipment and enhancing the efficiency of NMR data acquisition in geological formations, thereby shortening the drilling process and improving exploration operations.

Implementation Method 1

an electromagnetic transmitter to generate a pulsed magnetic field

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

nuclear magnetic resonance (NMR) sensor probes... measurements made by the NMR sensor probe can be used to provide information about the surrounding formation

Methodology Applied

Scientific EffectNuclear magnetic resonance:

Data Source

PatentUS9228431B2Frequency location apparatus, methods, and systems

Publication Date: 2016.01.05 HALLIBURTON ENERGY SERVICES INC

AI summary

In some embodiments, an ex-situ apparatus and a system, as well as a method and an article, operate to transmit wideband modulated pulses to generate an externally-projected oscillating magnetic field in a material body, to record one or more raw echo free induction decay (REFID) signals during echo acquisition periods following some of the second modulated pulses, and to transform the acquired REFID signals via frequency decomposition to determine a preferred nuclear magnetic resonance frequency associated with a maximum amplitude of decomposed frequency components. Additional apparatus, systems, and methods are described.