Separate Injection Gel Blocking for Permeable Zones
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Solution Overview
Problem
In mineral oil production, highly permeable zones in oil deposits are difficult to block effectively, especially after steam flooding, leading to reduced oil recovery and increased 'watering out' of production, as existing formulations often gel too quickly at high temperatures, preventing them from reaching intended blockage areas.
Innovation Solution
A process involving the separate injection of two aqueous formulations, F1 and F2, into the mineral oil deposit, where F1 contains a water-soluble aluminum(III) salt and F2 includes a water-soluble activator that increases pH upon heating, forming viscous gels only after mixing underground, effectively blocking highly permeable zones and reducing 'watering out' of production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single formulation is injected into the deposit to block highly permeable zones, then the blocking effect is achieved, but the formulation gels too quickly at high temperatures and cannot reach the intended blockage areas
Solution Approach 1:
The single blocking formulation is divided into two separate formulations (first formulation containing aluminum salt, second formulation containing crosslinking agent). These formulations are injected separately and only mix within the deposit, delaying gel formation until the formulations reach the intended permeable zones. This segmentation allows each formulation to travel farther without gelling prematurely.
Solution Approach 2:
The formulations are prepared and injected in a specific sequence (first formulation, then second formulation) before they mix and gel. This preliminary separation and controlled injection timing ensures that the formulations reach the target areas before the gelation process begins, allowing proper placement of the blocking agent in the highly permeable zones.
2Productivity
If water flooding is used to increase deposit pressure and force oil to production boreholes, then yield is substantially increased, but water flows through highly permeable zones and causes watering out of production
Solution Approach 1:
The gel-forming formulation acts as an intermediary substance that is injected into the highly permeable zones to modify their properties. The gel blocks these zones, forcing subsequent water flooding to flow through previously bypassed oil-saturated regions with fine porosity. This intermediary action redistributes the water flow paths to improve oil recovery while preventing direct water-oil mixing at the production borehole.
3Productivity
If steam flooding is used to reduce mineral oil viscosity, then production of heavy or viscous mineral oils is enabled, but steam and condensate strike through highly permeable zones rapidly, reducing efficiency
Solution Approach 1:
The gel formulation is selectively placed in the highly permeable zones rather than uniformly throughout the deposit. This creates local modification of flow properties - the permeable channels are blocked while other regions remain unaffected. This allows steam to be redirected into previously bypassed oil-saturated regions, improving steam utilization efficiency and reducing energy loss through premature steam breakthrough.
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 allows for selective blocking of high-temperature permeable zones, controlling the gel formation distance from the borehole, reducing 'watering out' and enhancing oil recovery by ensuring the formulations reach and block the intended areas, even after steam flooding.
Implementation Method 1
forming viscous gels under the influence of the deposit temperature
Implementation Method 2
the mixture forming highly viscous gels under the influence of the deposit temperature
Implementation Method 3
F2 includes a water-soluble activator that increases pH upon heating
Data Source
AI summary
A process for producing mineral oil from mineral oil deposits, in which the mineral oil yield is increased by blocking highly permeable regions of the mineral oil formation by separate injection of at least one acidic formulation which comprises water-soluble Al(III) salts, and one urea- or urea derivative-comprising formulation into the deposit, said formulations not mixing with one another until within the deposit, and the mixture forming highly viscous gels under the influence of the deposit temperature. The process can be used especially in the final stage of deposit development, when watering out in production increases, and particularly after the steam flooding of the deposits.