Solvent-Assisted Electric Heating for Oil Recovery
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Solution Overview
Problem
Steam-assisted gravity drainage (SAGD) processes for oil recovery are energy-intensive, generate significant carbon dioxide emissions, suffer from inefficiencies due to heat losses, and have high capital and operating costs, making them economically, environmentally, and socially unsustainable.
Innovation Solution
A method and system for oil recovery using solvent-assisted electric heating, where at least one downhole electric heater vaporizes a liquid solvent conveyed into a subsurface formation, operating within a temperature range above the solvent's vaporization temperature but below the steam saturation temperature, to produce a mixture of oil and solvent that can be separated to recover oil.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If steam is used for heating in SAGD, then oil recovery is achieved, but energy consumption increases
Solution Approach 1:
The patent replaces the mechanical/thermal steam generation system with an electrical heating system. Downhole electric heaters directly heat the formation and bitumen without requiring surface steam generation, eliminating the energy-intensive boiler system and reducing overall energy consumption while maintaining oil recovery effectiveness.
Solution Approach 2:
The patent changes the temperature parameter control from high-temperature steam (typically 150-200°C) to controlled electric heating at lower temperatures (50-150°C). This parameter change reduces the energy input required while still achieving bitumen viscosity reduction and flow through the formation.
2Productivity
If steam is used for heating in SAGD, then oil recovery is achieved, but carbon dioxide emissions increase
Solution Approach 1:
The patent substitutes the fossil fuel-based steam generation system with an electrical heating system. By eliminating the combustion process required for steam production, the system removes the source of CO2 emissions while maintaining the heat transfer function necessary for oil recovery.
Solution Approach 2:
The patent converts the harmful effect of steam condensate (which must be treated and recycled) into a beneficial process by using electric heating that produces no condensate. This eliminates the water treatment burden and associated environmental impacts.
3Productivity
If steam is used for heating in SAGD, then oil recovery is achieved, but heat losses increase
Solution Approach 1:
The patent applies heating directly at the source (downhole) before the bitumen needs to be produced. The electric heaters are positioned in the production wellbore, heating the bitumen in-situ and preventing heat losses that would occur during steam transport through surface lines and wellbores.
Solution Approach 2:
The patent extracts the heating function from the steam generation system and places it directly in the wellbore. This separation allows the heating to occur exactly where needed, eliminating the heat losses associated with steam generation, transport, and condensation that plague the traditional SAGD process.
4Productivity
If SAGD equipment is installed, then oil recovery is achieved, but capital costs increase
Solution Approach 1:
The patent replaces expensive steam generation equipment (boilers, burners, steam distribution systems) with relatively simple downhole electric heaters. This substitution dramatically reduces capital costs while maintaining the oil recovery function, making the process economically viable.
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 reduces energy consumption and carbon emissions, minimizes heat losses, and lowers capital and operating costs, making it a more environmentally friendly and economically viable alternative to traditional SAGD methods.
Implementation Method 1
operating at least one downhole electric heater to vaporize liquid solvent conveyed into a subsurface formation
Implementation Method 2
at least one downhole electric heater operable to vaporize liquid solvent conveyed into a subsurface formation
Data Source
AI summary
Embodiments herein generally relate to a method and system for oil recovery using solvent-assisted electric heating. In at least one example, the method comprises A method for oil production using solvent-assisted electric heating, comprising conveying liquid solvent into a subsurface formation; operating at least one downhole electric heater to vaporize the solvent in-situ, the at least one downhole electric heater being operated in a temperature range that is: (i) above the vaporization temperature of the solvent; and (ii) below the steam saturation temperature of the reservoir; conveying a mixture comprising oil and solvent from the subsurface formation to a separation subsystem; and separating, using the separation subsystem, the oil from the solvent.