Microcapsule Sustained Release System for Reservoir Chemical Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for delivering and releasing oil field chemicals, such as tracers and biocides, in hydrocarbon reservoirs face challenges including handling different physical states, reactivity, inhomogeneous compositions, and rapid release rates, leading to ineffective treatments and increased production costs.
Innovation Solution
A composition comprising microcapsules containing oil field chemicals embedded within a bulk polymer matrix, allowing for controlled and sustained release over extended periods, with microcapsules having various structures such as core-shell or multi-core-shell configurations to manage properties like density and reactivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oil field chemicals are delivered using conventional methods, then the chemicals can be introduced into the reservoir, but the release rate is rapid and uncontrolled leading to ineffective treatment
Solution Approach 1:
The chemical delivery system is segmented into multiple microcapsules embedded in a polymer matrix, each microcapsule containing the oil field chemical. This segmentation allows controlled release as the polymer degrades gradually, transforming the delivery from a single rapid release event to multiple controlled release events over time.
Solution Approach 2:
The polymer matrix is pre-formed with embedded microcapsules before deployment, creating a sustained-release structure in advance. The polymer is designed to degrade at a controlled rate, preliminarily establishing the release profile before the chemical is needed in the reservoir.
2Adaptability or versatility
If multiple oil field chemicals are used in a composition, then comprehensive treatment can be achieved, but handling different physical states and reactivity becomes difficult
Solution Approach 1:
The polymer matrix acts as an intermediary medium that accommodates multiple chemicals in different physical states (solids, liquids, gases). The matrix provides a unified structure that simplifies handling while allowing diverse chemicals to be delivered through the same degradation mechanism.
Solution Approach 2:
The delivery system uses a composite structure combining polymer matrix with embedded microcapsules containing different chemicals. This composite approach allows multiple chemicals with different properties to be integrated into a single manageable formulation that maintains their individual characteristics while enabling coordinated release.
3Loss of information
If chemical tracers are used for reservoir monitoring, then fluid flow can be tracked, but the tracers may react with reservoir components leading to precipitation and loss of signal
Solution Approach 1:
The tracer chemical is extracted from direct contact with the reservoir environment by enclosing it within the polymer matrix. The polymer serves as a protective barrier that prevents premature reactions with reservoir components while allowing the tracer to be released gradually when needed for monitoring.
Solution Approach 2:
The polymer matrix provides preliminary protection against harmful reactions between the tracer and reservoir components. By pre-encapsulating the tracer, the system prevents precipitation and signal loss that would occur if the tracer were introduced directly into the reservoir.
4Speed
If fracturing fluid thickeners are used to carry proppant, then fluid viscosity increases for effective transport, but the thickener must be degraded later to facilitate flow back
Solution Approach 1:
The polymer thickener is designed with periodic functionality: first providing high viscosity to carry proppant during injection, then degrading to low viscosity to facilitate flow back. This time-dependent transformation allows the same material to perform opposing functions at different stages of the fracturing process.
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
The solution enables uniform, long-term release of oil field chemicals, improving treatment efficacy and reducing the need for frequent reintroduction, thereby enhancing reservoir monitoring and production efficiency while maintaining chemical integrity.
Implementation Method 1
Articles comprising microcapsules incorporated into a continuous bulk polymer matrix can provide for the sustained release of the oil field chemical into oil field fluids over periods of time from weeks to years.
Implementation Method 2
If the fracturing fluid contains a viscosifying thickener, it is normal to supply a so-called breaker (which is usually an oxidizing agent, an acid or an enzyme) into the fracture to degrade the thickener
Data Source
Figure 1A~1F
Figure 2
Figure 3~4
AI summary
Compositions containing a mixture of microcapsules (1, 10, 11, 13, 14, 15) and a bulk polymer, where the microcapsules have an oil field chemical contained within the microcapsules are described. The microcapsules can be present in a variety of configurations. The microcapsules contain a core (2, 12) or a micro-matrix (7) containing the oil field chemicals. The core or micro-matrix can be surrounded by one or more polymeric shells (3), where each shell contains at least one polymer that affects the release of the oil field chemical from the composition. The compositions provide for the sustained release of an oil field chemical into fluid in an oil field reservoir over long periods of time. Methods of making the compositions and articles containing the compositions are described. Methods of tracing the movement of fluid in a hydrocarbon reservoir using the compositions, and methods of providing for the sustained release of oil field chemicals are also described.