In-situ Hydrate Composition Analysis via Releasing Agent

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for determining the composition of hydrates in subterranean reservoirs are inadequate, as they rely on sampling which is prone to contamination and does not accurately represent the in-situ conditions, leading to challenges in identifying hydrate characteristics and potential energy sources.

Innovation Solution

A method involving the injection of a releasing agent into the subterranean reservoir, followed by incremental pressure reduction and stabilization, using a formation testing tool to evaluate the composition of released fluids and gases, allowing for in-situ characterization of hydrate composition and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hydrate-bearing cores are brought to the surface for composition analysis, then the composition can be determined, but the surrounding temperatures and pressures fall outside the thermodynamic stability zones causing hydrate dissociation and composition change

Engineering Contradiction:
Improvehydrate composition determinationVSAvoidhydrate composition stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

A releasing agent is introduced as an intermediary substance that facilitates hydrate dissociation at controlled conditions. The releasing agent allows the hydrate to break down and release its guest molecules in a controlled manner, enabling composition analysis without the need to bring cores to surface conditions where dissociation would occur uncontrollably

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical approach of physically transporting cores to the surface with an in-situ chemical analysis method. Instead of mechanically bringing the core to surface conditions, the system uses chemical releasing agents and pressure control to achieve dissociation and analysis while the core remains in the borehole, substituting a chemical-controlled process for a mechanical transport process

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If gas samples are collected in a borehole for surface analysis, then the hydrate composition can be determined, but obtaining an uncontaminated sample is difficult

Engineering Contradiction:
Improvehydrate composition determinationVSAvoidsample contamination
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The releasing agent selectively extracts the guest molecules from the hydrate structure in a controlled manner. By using the releasing agent to facilitate dissociation, the system extracts only the hydrate's guest molecules for analysis, leaving behind the hydrate structure and avoiding contamination from other borehole fluids or materials

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The releasing agent serves as an intermediary that mediates between the hydrate and the sampling system. It enables the selective release of guest molecules without direct contact between the sample and potential contaminants in the borehole environment, ensuring sample purity while facilitating retrieval

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If pressure is reduced to dissociate hydrate for composition monitoring, then the composition can be determined, but the process requires multiple incremental steps and stabilization periods

Engineering Contradiction:
Improvehydrate composition determinationVSAvoidpressure testing duration
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

Pressure reductions are performed in predetermined incremental steps with stabilization periods at each level. This preliminary structuring of the pressure reduction process allows systematic monitoring of gas release at different pressure thresholds, enabling composition determination through a methodical approach that balances accuracy with time efficiency

Inventive Principle:
Principle #10Preliminary action

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 accurate and uncontaminated determination of hydrate characteristics and composition within the subterranean reservoir, distinguishing productive from non-productive hydrate deposits, and understanding the mechanisms of hydrate formation, thereby improving exploration and production strategies.

Implementation Method 1

The only know method for determining the composition of a hydrate found in a subterranean reservoir is to monitor the composition of gases released by the dissociation of the hydrate

Methodology Applied
Scientific EffectHydrate dissociation: Phase Change

Implementation Method 2

determining an initial pressure within a subterranean reservoir; reducing the pressure within the subterranean reservoir; stabilizing the pressure in the subterranean reservoir

Methodology Applied
Scientific EffectPressure measurement:

Data Source

PatentUS9291051B2Reservoir pressure testing to determine hydrate composition
Publication Date: 2016.03.22 CONOCOPHILLIPS CO

AI summary

The present invention relates to a method and system for identifying one or more characteristics within a subterranean reservoir of natural gas.