Thermally Assisted Gravity Drainage for Heavy Oil Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The recovery of bitumen and heavy oil from underground deposits is challenging due to their high viscosities, and existing thermal recovery methods often require significant energy and can lead to undesirable effects like increased H2S or CO2 production and thermal cracking.
Innovation Solution
A method and system for thermally-assisted gravity drainage (TAGD) that involves conducting heating in a reservoir using heater wells and producer wells to reduce the viscosity of bitumen or heavy oil, allowing it to flow by gravity, while controlling temperature and pressure to maintain efficient production without excessive energy use or thermal damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam is injected to heat the reservoir and reduce bitumen viscosity, then the bitumen can flow downward by gravity, but the energy consumption increases and water usage increases
Solution Approach 1:
The patent changes the heating temperature parameter to a lower range (120-200°C) compared to conventional steam-assisted gravity drainage, and introduces a chemical solvent component to enhance the heating efficiency. This allows achieving the same viscosity reduction with lower energy input and reduced water consumption.
Solution Approach 2:
The patent introduces a chemical solvent as an intermediary substance that facilitates heat transfer and enhances the mobilization of bitumen. The solvent acts as a mediator between the heating mechanism and the bitumen, improving recovery efficiency while reducing direct thermal energy requirements.
2Productivity
If high temperature is applied to reduce bitumen viscosity, then the bitumen flows more easily, but thermal cracking and increased H2S or CO2 production occur
Solution Approach 1:
The patent carefully controls the temperature parameter within a specific range (120-200°C) that is sufficient to reduce bitumen viscosity but remains below the thermal cracking threshold. This parameter optimization enables bitumen mobilization while avoiding thermal damage and harmful byproduct generation.
Solution Approach 2:
The patent maintains continuous heating at controlled temperatures to sustain bitumen flowability throughout the production process. This continuous action at moderate temperatures prevents thermal shock and cracking that would occur with rapid or excessive temperature increases, while ensuring consistent production.
3Productivity
If conventional thermal recovery methods are used, then bitumen can be recovered, but the process is expensive and energy-intensive
Solution Approach 1:
The patent introduces a chemical solvent as an intermediary that enhances the thermal recovery process. The solvent facilitates heat transfer and bitumen mobilization, allowing more efficient recovery with lower energy input compared to conventional purely thermal methods.
Solution Approach 2:
The patent modifies the thermal parameters by operating at lower temperatures (120-200°C) and extended time periods, combined with chemical solvent addition. This parameter change enables more energy-efficient bitumen recovery while maintaining production effectiveness.
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
TAGD achieves efficient and economical recovery of bitumen and heavy oil by maintaining a target temperature between 120°C and 160°C, reducing viscosity, and controlling pressure, thus minimizing energy input and avoiding thermal cracking, with predictable heating and lower water usage compared to steam-based methods.
Implementation Method 1
operating the reservoir heater to conductively heat the reservoir and reduce the viscosity of the bitumen or heavy oil
Implementation Method 2
Thermal energy from the steam reduces the viscosity of the viscous hydrocarbons, thereby enabling them to flow downward through the formation under the force of gravity
Data Source
AI summary
A method for producing bitumen or heavy oil from a reservoir, the method comprising: defining at least one lateral section of the reservoir for placement of patterns of heater wells above a producer well; placing the producer well at a substantially centered location at or adjacent to the bottom of the reservoir within each of the lateral sections; placing a triangular pattern of heater wells above the producer well; placing a regular or non-regular pentagonal pattern of heater wells, or a portion thereof, at or above the triangular pattern of heater wells; heating the reservoir with the triangular and pentagonal patterns of heater wells to conductively heat the reservoir and reduce the viscosity of the bitumen or heavy oil; and producing bitumen or heavy oil with the producer well.