Dynamic Steam-Solvent Injection Timing for Heavy Oil Recovery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for heavy oil and bitumen production, such as Steam-Assisted Gravity Drainage (SAGD) and Vapor Extraction (VAPEX), are energy-intensive and economically challenging due to high steam-to-oil ratios, inefficient energy recovery, and high costs associated with solvent use, particularly in heterogeneous reservoirs, necessitating optimization of steam and solvent injection timing and fluid switching.
Innovation Solution
The method involves benchtop gravity drainage dynamic soak experiments to determine the optimal injection fluids and timing based on cumulative oil production and recovery factor rate of change, allowing for fluid switching when a significant decline is observed, thereby reducing energy intensity and improving solvent recovery, using a phased approach with steam, superheated butane, and methane injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam is continuously injected to maintain production, then oil production is sustained, but energy consumption and steam-to-oil ratio increase
Solution Approach 1:
The patent implements dynamic switching between steam injection and solvent injection based on real-time production rate monitoring. The system transitions from continuous steam injection to a phased approach where solvent injection is introduced when production rates decline, optimizing energy consumption while maintaining productivity through adaptive control
Solution Approach 2:
The patent changes the injection fluid parameter from steam to solvent (propane or methane) based on reservoir conditions and production performance. This parameter change allows the system to reduce energy consumption by utilizing solvent extraction mechanisms that are more efficient than thermal steam heating alone
2Productivity
If steam injection is used to thin heavy oil, then oil mobility is improved, but steam-to-oil ratio becomes high and economics deteriorate
Solution Approach 1:
The patent introduces a solvent intermediary (propane or methane) that facilitates oil thinning and mobilization more efficiently than steam. The solvent acts as a mediator that dissolves heavy oil components, reducing viscosity and improving mobility with a lower substance ratio compared to direct steam heating
Solution Approach 2:
The patent changes the injection fluid from steam to hydrocarbon solvent, fundamentally altering the mechanism of oil thinning from thermal to solvation-based. This parameter change reduces the quantity of injection fluid required per unit of oil produced, improving economic efficiency
3Productivity
If solvent is injected to improve recovery, then oil production increases, but solvent cost and complexity increase
Solution Approach 1:
The patent segments the injection process into distinct phases: initial steam injection phase, transition phase where solvent is introduced, and optimized solvent injection phase. This segmentation allows the system to manage complexity by implementing solvent injection only when production rates indicate need, rather than continuously
Solution Approach 2:
The patent employs feedback control by monitoring production rates and switching between steam and solvent injection based on real-time performance data. When production rates decline during steam injection, the system automatically transitions to solvent injection, optimizing recovery while managing system complexity through data-driven decision making
4Productivity
If steam is injected at high pressure to maintain vapor pressure, then oil thinning is effective, but energy intensity increases
Solution Approach 1:
The patent changes the injection parameter from high-pressure steam vaporization to solvent injection at lower pressures. By switching from thermal vaporization mechanisms to solvation mechanisms, the system reduces the energy intensity required while maintaining effective oil thinning and mobilization
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 oil recovery efficiency by accelerating production, reducing steam usage, and improving solvent recovery, resulting in a more environmentally friendly and cost-effective heavy oil production process.
Implementation Method 1
steam is injected into both wells to conductively heat the petroleum deposit between the wells
Implementation Method 2
the now mobile warmed petroleum can be gravity drained to the production well
Implementation Method 3
the effectiveness of the process relies solely on the mass transfer of solvent into the oil
Implementation Method 4
the solvent is heated before being injected into the reservoir and the faster reduction in viscosity of the oil causes an earlier establishment of the communication between the wells
Data Source
AI summary
A method for producing heavy oil, the method including testing a plurality of samples either from a reservoir play or simulating a reservoir play in a temperature and pressure controlled gravity drainage experiment. Test injection fluids are injected into the samples at a reservoir temperature and pressure and Cumulative Oil Production (COP) or Recovery Factor (RF) or similar feature measured over time. An injection profile is obtained by selecting n injection fluids based on a best COP or RF at a given time Tn, wherein n is a number of fluid injection stages and switching to an n+1 injection fluid when a rate of change (ROC) in the COP or RF drops at least 25%-75%, but preferably 40-60% or 50%. The injection profile is then implemented in the reservoir to produce heavy oil. Optimized injection profiles for certain reservoirs are also provided.