Microbial Plug Dynamics for Reservoir Sweep Efficiency
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Solution Overview
Problem
Existing methods for enhancing oil recovery in hydrocarbon reservoirs are limited and lack dynamic control over plug formation and expansion, leading to inefficiencies in oil extraction and increased water production, which reduces profitability.
Innovation Solution
A method involving the selection and introduction of specific microorganisms, such as Clostridium thermocellum, and a nutrient solution that allows for controlled microbial growth and plug formation in hydrocarbon-containing geological formations, enabling dynamic adjustment of plug position and extent in response to reservoir conditions and external stimuli.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If injection liquid is pumped into the reservoir to increase oil recovery, then the degree of recovery is improved, but the injection liquid follows flow channels and leaves too much oil behind, reducing profitability
Solution Approach 1:
The patent introduces a precursor substance (nutrient solution) before the main injection liquid to stimulate microorganisms in advance. These microorganisms grow and form plugs in flow channels before the bulk injection liquid arrives, redirecting the flow to previously unswept oil zones and improving overall recovery while reducing oil left behind.
Solution Approach 2:
The patent utilizes indigenous microorganisms already present in the reservoir by providing them with nutrient solutions. These microorganisms self-organize to form biofilms and plugs that control fluid flow, eliminating the need for external polymer injection and reducing operational complexity while improving sweep efficiency.
2Productivity
If plugs are formed using gel-forming polymers to improve sweep efficiency, then injection liquid is forced into new zones, but the method lacks dynamic control over plug position and extent
Solution Approach 1:
The patent employs living microorganisms that can dynamically respond to nutrient gradients and environmental conditions. By controlling nutrient injection timing and location, the position and extent of microbial plugs can be adjusted in real-time, providing dynamic control that static polymer plugs cannot achieve.
Solution Approach 2:
The patent changes the state of microorganisms from dormant to active through parameter changes in the nutrient solution (composition, concentration, temperature). This allows control over when and where plugs form, enabling precise positioning and extent control while maintaining adaptability to reservoir conditions.
3Productivity
If microorganisms are added to form biofilms and plugs, then flow resistance increases and sweep efficiency improves, but the method lacks precise control over when and where plugs form
Solution Approach 1:
The patent implements feedback mechanisms by monitoring reservoir conditions (pressure, temperature, flow rates) and adjusting nutrient injection accordingly. This closed-loop control system allows precise management of plug formation timing and location, improving operational control while maintaining sweep efficiency benefits.
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 by forming a self-regulating microbial plug that can expand into new oil zones, reducing permeability in water channels and increasing sweep efficiency, thereby improving oil extraction while minimizing water production.
Implementation Method 1
The microorganisms can also form biopolymers in situ, for example xanthan. Individually or in combination, cells, biofilm and polymers can form a plug.
Implementation Method 2
The injection liquid is intended to flow through the reservoir as far as one or more production wells. The injection liquid is intended to form a hydrophilic front which pushes hydrophobic hydrocarbon, especially oil, before it towards the production well.
Implementation Method 3
The plug can be partially permeable, but the flow resistance increases such that the injection liquid is forced to flow around the plug and thus into those parts of the reservoir that now have the least flow resistance.
Data Source
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Figure 3A~3D
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AI summary
The present invention relates to a method of establishing a microbial plug in a hydrocarbon-containing geological formation which has been flooded with water, the method comprising: a) introducing into the formation a microbial inoculum, the microorganisms of which are: (i) spores or otherwise in a dormant state, (ii) capable of sporulation, (iii) cellulolytic or hemicellulolytic, (iv) thermophiles, extreme thermophiles or hyperthermophiles, (v) unable to utilise hydrocarbons as a carbon source, and (vi) not indigenous to the hydrocarbon-containing geological formation; b) simultaneously or sequentially introducing into the formation a growth medium which provides a carbon source which can be utilised by the microorganisms introduced in step (a) but not by indigenous microorganisms; c) exposing the inoculum to conditions which enable the microorganisms to enter an active growth phase within water channels in the geological formation; and d) introducing an injection liquid comprising further growth medium as defined in step b) into the formation via an injection well; as well as to the methods of maintaining such plugs, to methods of controlled alteration of the position and/or extent of an established plug and to the plugs themselves.