Non-spherical Ceramic Proppants for High-Stress Fracture Conductivity
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Solution Overview
Problem
Existing well treating particulates, particularly proppants, face challenges in achieving high compressive strength, conductivity, and chemical resistance, especially at high temperatures and pressures, while also preventing sand and fines migration and unwanted deposits in subterranean formations, with spherical particulates being limited in effectiveness and requiring frequent treatment to maintain optimal conditions.
Innovation Solution
Non-spherical particulates with oblong, elliptical, or cylindrical shapes, capable of being porous or non-porous and filled with chemical treatment agents, which form close-packed structures for enhanced stress tolerance and porosity, allowing for improved fracture conductivity and sand control, and sustained release of treatment agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If spherical particulates are used as proppants, then fracture conductivity is maximized, but compressive strength and stress tolerance are insufficient at high reservoir closure stresses
Solution Approach 1:
The patent applies asymmetry by transitioning from spherical proppants to non-spherical shapes (ellipsoidal, cylindrical, or irregular forms). This shape change increases the contact area between particles, distributing stress more effectively and enhancing compressive strength and stress tolerance while maintaining adequate fracture conductivity.
Solution Approach 2:
The patent employs composite materials by combining ceramic cores with resin coatings to create multi-layered proppants. This composite structure provides both the compressive strength of ceramics and the stress distribution benefits of non-spherical geometries, resolving the contradiction between strength requirements and shape limitations.
2Productivity
If ultra lightweight proppants are used to reduce fluid velocity requirements, then fracture area propped increases, but compressive strength is lost at high temperature and pressure conditions
Solution Approach 1:
The patent applies parameter changes by carefully controlling the density and composition of ceramic materials to achieve optimal balance between weight and strength. The resin coating parameters are also adjusted to ensure adequate protection at high temperatures and pressures while maintaining the lightweight advantage for improved fracture conductivity.
Solution Approach 2:
The patent uses composite materials combining lightweight ceramic cores with protective resin coatings. This composite structure maintains the low density needed for high fracture conductivity while the resin layer preserves compressive strength under high temperature and pressure reservoir conditions.
3Strength
If spherical particulates are used for gravel packing, then uniform packing is achieved, but stress distribution and sand control effectiveness are reduced
Solution Approach 1:
The patent applies asymmetry by using non-spherical particulates with varied geometries (ellipsoidal, cylindrical, irregular shapes) in gravel packing applications. This asymmetry increases inter-particle contact area and improves stress distribution throughout the pack, enhancing both stress tolerance and sand control effectiveness compared to uniform spherical particles.
4Productivity
If frequent treatment interventions are performed to maintain optimal well conditions, then productivity is maintained, but operational time and costs increase
Solution Approach 1:
The patent applies preliminary action by incorporating chemical treatment agents within the proppant structure before deployment. These pre-loaded agents are released gradually over time to prevent scale, corrosion, and other formation damages proactively, maintaining productivity without requiring frequent intervention trips.
Solution Approach 2:
The patent implements continuity of useful action through sustained-release chemical treatment agents embedded in the proppants. These agents provide continuous protection against formation damages over extended periods, eliminating the need for frequent discontinuous interventions and maintaining uninterrupted productivity.
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 non-spherical particulates demonstrate increased stress tolerance, porosity, and permeability, effectively maintaining well productivity and preventing sand migration, while allowing for a sustained release of chemical treatment agents, reducing the need for frequent interventions and enhancing the efficiency of hydraulic fracturing and sand control operations.
Implementation Method 1
form close-packed structures for enhanced stress tolerance and porosity
Implementation Method 2
allowing for a sustained release of treatment agents
Data Source
AI summary
Non-spherical particulates are useful in the stimulation of subterranean formations. A proppant pack composed of the non-spherical particulates exhibits greater porosity than a corresponding proppant pack composed of spherical particulates. In addition, the non-spherical particulates exhibit higher conductivity at higher stresses than spherical shaped particulates.