In Situ Combustion Hydrocarbon Recovery via Segmented Well Configuration
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Solution Overview
Problem
Viscous hydrocarbons in oil sands deposits are not susceptible to standard oil well production technologies due to their high viscosity, which limits the effectiveness of existing thermal recovery methods like SAGD and ISC, as they require high steam injection rates to create combustion fronts, leading to inefficient hydrocarbon recovery.
Innovation Solution
A process involving the injection of an oxidizing gas through an oxidizing gas injection well to support in situ combustion, utilizing a generally horizontal well pair with a hydrocarbon production well and a combustion gas production well, where the combustion gas production well is vertically above the hydrocarbon production well, allowing for controlled ignition and propagation of the combustion front, reducing the steam-to-oil ratio and enhancing hydrocarbon recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If standard thermal recovery methods like SAGD and ISC are used to recover viscous hydrocarbons, then hydrocarbon mobilization is achieved, but high steam injection rates are required leading to inefficient recovery
Solution Approach 1:
The patent divides the single production well into two separate horizontal wells: one dedicated to producing hydrocarbons and another dedicated to producing combustion gases. This segmentation allows independent optimization of each well's function, enabling efficient hydrocarbon recovery at lower steam injection rates by separating the combustion gas production pathway from the hydrocarbon production pathway.
Solution Approach 2:
The patent introduces an oxidizing gas injection well as an intermediary component that injects oxygen or air into the reservoir to support in-situ combustion. This intermediary enables the combustion process to occur at lower steam injection rates by providing the necessary oxygen supply separately from the steam injection system, thereby improving overall recovery efficiency.
2Reliability
If high steam injection rates are used to create combustion fronts, then in situ combustion is sustained, but operational complexity and costs increase
Solution Approach 1:
The patent segments the combustion support function into a dedicated oxidizing gas injection well, separate from the steam injection and production systems. This allows combustion to be sustained through controlled gas injection at lower rates, reducing the complexity of managing high-rate steam injection while maintaining reliable combustion front propagation.
Solution Approach 2:
The oxidizing gas injection well acts as an intermediary that supplies oxygen to the combustion zone independently of the steam injection system. This intermediary component simplifies the overall system by decoupling the combustion support function from the thermal injection function, enabling more manageable operational parameters.
3Object-affected harmful factors
If combustion gases and hydrocarbons are produced through the same well, then equipment simplicity is maintained, but gas interference and corrosion risks increase
Solution Approach 1:
The patent segments the production function into two separate horizontal wells: one exclusively for hydrocarbon production and another exclusively for combustion gas production. This physical separation eliminates gas interference and corrosion issues in the hydrocarbon production well, as combustion gases are diverted to the dedicated combustion gas production well. The segmentated configuration protects the hydrocarbon production equipment from harmful combustion gases.
Solution Approach 2:
The patent extracts the combustion gas production function from the hydrocarbon production well and places it in a separate dedicated well. This extraction removes the source of gas interference and corrosion from the hydrocarbon production system, protecting the equipment while requiring only the addition of one more well rather than complete system redesign.
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 the overall steam-to-oil ratio required for hydrocarbon recovery, improves the efficiency of hydrocarbon mobilization and production, and separates combustion gases from hydrocarbons, reducing the risk of gas interference and corrosion, thereby enhancing the recovery factor and operational efficiency.
Implementation Method 1
injecting an oxidizing gas into an oil sands reservoir through an oxidizing gas injection well that includes an oxidizing gas injection segment. The oxidizing gas supports in situ combustion in the reservoir.
Implementation Method 2
The mobilized hydrocarbons and aqueous condensate drain, under the effects of gravity, toward the bottom of the steam chamber, where the production well is located.
Implementation Method 3
The heat generated by burning the heavy hydrocarbons in place produces hydrocarbon cracking, vaporization of light hydrocarbons and reservoir water in addition to the deposition of heavier hydrocarbons known as coke.
Implementation Method 4
the light hydrocarbons and the steam move ahead of the burning front, condensing into liquids, facilitating miscible displacement and hot waterflooding
Implementation Method 5
The mobilized hydrocarbons and aqueous condensate drain, under the effects of gravity, toward the bottom of the steam chamber, where the production well is located.
Data Source
AI summary
A process for hydrocarbon recovery performs a steam assisted gravity drainage (SAGD) operation by injecting steam in a steam injection well of a SAGD well pair and continuing to inject steam to establish fluid communication between the steam injection well and an oxidizing gas injection well that includes an oxidizing gas injection well segment that is spaced generally above the steam injection well segment, and producing hydrocarbons from a hydrocarbon production well of the SAGD well pair, the hydrocarbon production well including a generally horizontal production well segment disposed generally parallel to and vertically below a generally horizontal steam injection well segment of the steam injection well such that the steam injection well segment is disposed generally vertically between the production well segment and the oxidizing gas injection well segment. In response to determining that the steam injected in the steam injection well reaches the oxidizing gas injection well or is near a top of the oil sands reservoir, SAGD is discontinued and oxidizing gas is injected through an injection well. The oxidizing gas supports in situ combustion (ISC) in the reservoir. During ISC, combustion gases are produced through the steam injection well of the steam assisted gravity drainage well pair; and the mobilized hydrocarbons are recovered from the reservoir through the hydrocarbon production well of the steam assisted gravity drainage well pair.