Non-Condensable Gas Barrier for In Situ Solvent Extraction

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Solution Overview

Problem

In situ hydrocarbon extraction from tar sands or oil sands is inefficient due to the high viscosity and specific gravity of heavy oil or bitumen, which makes it difficult to extract, and the geological characteristics of the overburden layer can lead to wasted heat and water flooding of the extraction chamber, reducing the efficiency of the condensing solvent process.

Innovation Solution

Control the location of solvent condensation in the gravity drainage chamber by accumulating non-condensable gases as a thermal barrier, with a vapour density lower than the solvent vapour, to restrict vertical heat flow and chamber growth, while allowing horizontal growth, thereby optimizing the extraction process and maintaining the integrity of the bitumen layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the chamber grows vertically to extract all hydrocarbon up to the overburden layer, then extraction completeness is improved, but heat is wasted on the overburden with no hydrocarbon present

Engineering Contradiction:

Improveextraction completenessVSAvoidheat waste

Core Design Contradiction:

ProductivityVSLoss of energy

Solution Approach 1:

A non-condensable gas barrier layer is introduced as an intermediary between the condensing solvent and the overburden layer. This barrier layer blocks heat transfer to the overburden while allowing the extraction chamber to maintain contact with hydrocarbon-bearing formations, thus preventing energy waste without compromising extraction completeness.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent applies different thermal properties to different regions of the extraction chamber. The barrier layer creates a localized thermal insulation zone at the chamber-overburden interface, while other regions of the chamber continue to experience efficient heat transfer for hydrocarbon extraction. This selective thermal management optimizes both energy efficiency and extraction completeness.

Inventive Principle:

Principle #3Local quality

2Productivity

If the chamber grows vertically to the overburden layer, then extraction completeness is improved, but water flooding occurs when the overburden is porous and water-saturated

Engineering Contradiction:

Improveextraction completenessVSAvoidchamber stability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The non-condensable gas barrier layer serves as a physical barrier that prevents water from the porous overburden from entering the extraction chamber. This intermediary layer maintains chamber integrity and prevents water flooding while allowing the chamber to grow to the overburden for complete hydrocarbon extraction.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The barrier layer is established in advance to prevent the harmful effect of water intrusion. By maintaining this protective layer before water flooding can occur, the system proactively prevents chamber instability and extraction failure, ensuring reliable operation throughout the extraction process.

Inventive Principle:

Principle #9Preliminary anti-action

3Loss of energy

If non-condensable gases are allowed to accumulate as a barrier layer, then thermal efficiency is improved and vertical heat flow is restricted, but chamber growth is constrained vertically

Engineering Contradiction:

Improvethermal efficiencyVSAvoidvertical chamber growth

Core Design Contradiction:

Loss of energyVSLength of moving object

Solution Approach 1:

The patent changes the thermal parameters of the chamber-overburden interface by introducing the non-condensable gas barrier layer. This parameter change restricts vertical heat flow to improve thermal efficiency while the chamber continues to grow horizontally, maintaining effective extraction volume without unnecessary vertical expansion.

Inventive Principle:

Principle #35Parameter changes

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 enhances the thermal efficiency of the condensing solvent process, prevents heat loss to the overburden, and avoids water flooding, allowing for continued horizontal extraction and maximizing hydrocarbon recovery while minimizing capital costs.

Implementation Method 1

accumulating non-condensable gases as a thermal barrier, with a vapour density lower than the solvent vapour, to restrict vertical heat flow and chamber growth

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

controlling the in situ pressure to achieve a condensation temperature for the solvent within the formation which is suitable for reducing a viscosity of the in situ hydrocarbon by warming and solvent effects

Methodology Applied

Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

a condensing solvent process which mobilizes the hydrocarbons for extraction by, for example, gravity drainage

Methodology Applied

Scientific EffectCondensation: Condensation

Data Source

PatentUS9476291B2Method of controlling growth and heat loss of an in situ gravity drainage chamber formed with a condensing solvent process

Publication Date: 2016.10.25 HATCH LTD

AI summary

This invention is a solvent based gravity drainage process whereby the vertical growth rate of the chamber is restricted by placing, monitoring and managing a buoyant gas blanket at the top of the vapor chamber. This invention reduces the heat loss to the overburden as well as providing a means to preserve a barrier layer of bitumen saturated reservoir sand at the top of the pay zone in reservoirs where there is limited or no confining layer present.