Sintered Rod-Shaped Proppant for Fracturing Wellbore Conductivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional proppants face challenges in maintaining high compressive strength and conductivity under extreme conditions, leading to reduced well productivity and increased production costs due to issues like proppant breakage, flowback, and incompatibility with well treatments like hydrofluoric acid.
Innovation Solution
A high-strength, rod-shaped proppant made from a composition comprising at least 90% alumina and 0.15-3.5% TiO2, sintered to achieve superior hardness, toughness, and resistance to closure pressures, with a unique breaking behavior that maintains permeability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional proppants are used to maintain high compressive strength under extreme conditions, then proppant breakage is reduced, but conductivity and permeability deteriorate due to tight packing
Solution Approach 1:
The patent employs spherical proppant particles with smooth surfaces to optimize packing behavior. The spherical shape allows particles to arrange in configurations that maintain both structural integrity under compression and adequate void space for fluid flow, resolving the contradiction between strength and conductivity.
Solution Approach 2:
The patent modifies physical parameters of the proppant including surface smoothness, particle size distribution, and sphericality to achieve optimal performance. By controlling these parameters, the proppant maintains high compressive strength while preserving fracture conductivity through improved packing characteristics.
2Ease of operation
If proppant particles are made smaller to improve flowability, then ease of injection is improved, but crush resistance deteriorates under high closure pressures
Solution Approach 1:
The patent utilizes a controlled distribution of particle sizes where smaller particles fill voids between larger particles. This segmentation approach allows smaller particles to improve flowability and packing efficiency while the overall gradation maintains adequate crush resistance by distributing stress across multiple size classes.
Solution Approach 2:
The patent optimizes the particle size parameter by establishing specific size ranges and distributions. This parameter control enables the proppant to achieve both good flowability for injection and sufficient crush resistance under closure pressures through the selected size spectrum.
3Productivity
If spherical proppants are used to maximize permeability, then conductivity is improved, but proppant flowback increases due to reduced interlocking
Solution Approach 1:
The patent employs spherical proppant particles that inherently maximize permeability and conductivity. The spherical geometry creates optimal flow paths while the smooth surfaces and uniform shape promote stable packing that reduces particle movement and flowback, counter to the assumption that spheres increase flowback.
Solution Approach 2:
The patent utilizes cementitious materials that can set and bind proppant particles in place. This approach provides a cost-effective method to secure spherical proppants and prevent flowback, treating the binding mechanism as a temporary measure that stabilizes the proppant pack.
4Strength
If high alumina content is used to increase hardness and strength, then crush resistance is improved, but compatibility with hydrofluoric acid treatments deteriorates
Solution Approach 1:
The patent employs composite proppant materials that combine alumina with other minerals such as silica, bauxite, or titania. This composite approach maintains the hardness and strength benefits of high alumina content while the additional mineral phases provide resistance to hydrofluoric acid degradation, resolving the compatibility issue.
Solution Approach 2:
The patent modifies the chemical composition parameters by adjusting the ratios of alumina, silica, and other oxide components. This parameter optimization achieves the desired balance between mechanical strength (hardness) and chemical stability (acid compatibility) for field applications requiring both properties.
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 rod-shaped proppant exhibits enhanced crush resistance, increased void volume for improved oil and gas flow, reduced flowback, and prolonged well life, while minimizing equipment wear and production costs.
Implementation Method 1
A method of making a proppant or anti-flowback additive is provided. The method comprises providing a composition comprising at least about 90% by weight alumina and between about 0.15% and about 3.5% by weight TiO2; milling the composition; forming at least one rod from the milled composition; and sintering the at least one rod.
Data Source
AI summary
A sintered rod-shaped proppant and anti-flowback agent possesses high strength and high conductivity. The sintered rods comprise between about 0.2% by weight and about 4% by weight aluminum titanate. In some embodiments, the sintered rods are made by mixing bauxitic and non-bauxitic sources of alumina that may also contain several so-called impurities (such as TiO2), extruding the mixture, and sintering it. The starting material may optionally be milled to achieve better compacity and crush resistance in the final sintered rod. A fracturing fluid may comprise the sintered rods alone or in combination with a proppant, preferably a proppant of a different shape.