Annular Density Estimation via Monte Carlo Simulation

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Solution Overview

Problem

The challenge in subterranean well monitoring is accurately estimating material density in the annular space to prevent particulate material from mixing with extracted fluids, which affects production efficiency and increases maintenance costs due to non-uniform distribution of gravel and precipitation of drilling fluid particulates forming a cement-like substance that couples pipes together, making removal difficult.

Innovation Solution

A system using a logging tool with a radiation source and detectors to gather data, which is processed by computer processors to perform Monte Carlo simulations and principal component analysis to estimate material density in real-time, allowing for effective monitoring and maintenance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a radiation source and detectors are used to measure material density in the annular space, then measurement capability is provided, but the device complexity increases

Engineering Contradiction:
Improvematerial density estimationVSAvoidlogging tool configuration
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The logging tool is divided into functional modules: a radiation source module, a detector module with multiple detectors positioned at different locations, and a processing module. Each module performs a specific function, allowing the complex measurement system to be managed through modular components that can be independently optimized and maintained.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Monte Carlo simulations serve as an intermediary computational model that bridges the physical measurement data from detectors and the final density estimation. The simulations create a library of hypothetical detector responses for various material densities, enabling the system to interpret complex detector signals without requiring direct inverse modeling of the measurement physics.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If Monte Carlo simulations and principal component analysis are performed to estimate density, then measurement accuracy is improved, but processing time and computational resources increase

Engineering Contradiction:
Improvedensity estimation accuracyVSAvoiddata processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary Monte Carlo simulations offline to create a comprehensive library of hypothetical detector responses for a range of material densities and annular space configurations. This pre-computed library is stored and later used during field operations, allowing rapid density estimation by comparing actual detector readings against the pre-generated simulation library without performing time-consuming simulations in real-time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system transforms the complex density estimation problem into a parameter matching problem by using principal component analysis to reduce the dimensionality of the simulation data. Instead of comparing entire simulation datasets, the system compares extracted principal components and key parameters, significantly reducing computational requirements while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the annular space is monitored continuously for density changes, then production problems are detected early, but the complexity of the monitoring system increases

Engineering Contradiction:
Improveproduction monitoringVSAvoidcontinuous monitoring system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system uses the well's own production fluids and existing annular space geometry as the measurement medium, eliminating the need for separate test fluids or additional infrastructure. The radiation source and detectors utilize the natural attenuation and scattering properties of the materials already present in the well, allowing the system to monitor itself without external intervention or complex auxiliary systems.

Inventive Principle:
Principle #25Self-service

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

Enables continuous, real-time estimation of material density, preventing particulate mixing and facilitating optimal maintenance by accurately identifying density variations and potential issues before they cause production disruptions.

Implementation Method 1

radiation detectors being configured to detect scattered photons resulting from interaction of the material in the annular space with radiation from the radiation source

Methodology Applied
Scientific EffectScattering: Scattering

Data Source

PatentUS10192007B2System and method for estimating material density
Publication Date: 2019.01.29 BAKER HUGHES OILFIELD OPERATIONS LLC
  • US10192007B2 patent drawing
  • US10192007B2 patent drawing
  • US10192007B2 patent drawing

AI summary

A method implemented using one or more computer processors for estimating the density of a material in an annular space includes receiving detector data representative of scattered photons resulting from interaction of a material in an annular space with radiation from a radiation source and detected by a plurality of radiation detectors. The technique further includes performing a set of Monte Carlo simulations. The method further includes performing a principal component analysis on the set of Monte Carlo simulations to generate a principal component analysis model of the detector data. The method also includes estimating the density of the material at one or more locations within the annular space based upon the principal component analysis model and the detector data.