Graphene-Enhanced Elastomeric Stator for Downhole Pump Reliability
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Solution Overview
Problem
Elastomeric stator assemblies in progressive cavity pumps face challenges with high viscosity uncured compounds, premature failure due to vulcanization, and reduced properties from traditional reinforcing agents, leading to reliability and durability issues in high-temperature, abrasive downhole drilling environments.
Innovation Solution
Incorporation of graphene particles, cross-linkable polymers, and coupling agents to enhance structural and thermal properties, along with reduced filler material, allowing for lower viscosity compounds that maintain stability and flowability, and integration of cross-linkable plasticizers to lock in plasticizers and improve modulus and tear resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional reinforcing carbon blacks and plasticizers are used to reduce viscosity during manufacturing, then the uncured compound flows better through the mould cavity, but the cured elastomer becomes softer with reduced modulus and dynamic stability
Solution Approach 1:
The patent changes the chemical composition parameters by replacing traditional carbon black fillers with graphene particles and changing the plasticizer type to cross-linkable varieties. This allows the compound to maintain low viscosity during processing while the cross-linkable plasticizer reacts during vulcanization to form a stable network, preserving modulus and dynamic stability in the cured state.
Solution Approach 2:
The patent creates a composite material system combining graphene particles with cross-linkable plasticizers in the elastomer matrix. The graphene provides reinforcement without significantly increasing viscosity, while the cross-linkable plasticizer forms chemical bonds during curing, creating a composite structure that maintains both processability and final mechanical properties.
2Ease of manufacture
If higher loadings of plasticizer are used to offset high viscosity from nanoparticles, then the compound becomes less viscous and mixes faster, but traditional plasticizers leach out at high temperatures causing shrinkage and de-bonding
Solution Approach 1:
The patent extracts the problematic property of traditional plasticizers (their ability to leach out at high temperatures) by replacing them with cross-linkable plasticizers that form chemical bonds. This removes the harmful effect while retaining the beneficial low-viscosity and mixing properties.
Solution Approach 2:
The patent changes the chemical reactivity parameter of the plasticizer by selecting cross-linkable varieties that can undergo chemical reactions during vulcanization. This transformation from physically bound to chemically bound plasticizer eliminates leaching while maintaining the desired rheological properties during processing.
3Strength
If nano-particles like graphene are incorporated to enhance structural properties, then the cured elastomer gains improved modulus and tear resistance, but the uncured compound viscosity increases exponentially
Solution Approach 1:
The patent changes the chemical composition by combining graphene particles with cross-linkable plasticizers. The plasticizer reduces viscosity during processing, counteracting the viscosity-increasing effect of graphene. During curing, the cross-linking reaction locks in the graphene reinforcement, achieving high strength without compromising processability.
Solution Approach 2:
The cross-linkable plasticizer acts as an intermediary substance that mediates between the graphene particles and the elastomer matrix. It reduces the interaction between graphene and polymer chains during processing (lowering viscosity) while forming chemical bonds during curing to secure the graphene reinforcement for enhanced mechanical properties.
4Productivity
If the uncured compound remains stable for extended mixing and molding time, then complete mould filling is achieved, but the compound begins vulcanization prematurely increasing viscosity exponentially
Solution Approach 1:
The patent changes the chemical stability parameters by selecting a vulcanization system with appropriate reactivity. The peroxide-cured NBR/HNBR formulation provides a controlled cure rate that allows sufficient time for the compound to flow and fill the mould cavity while preventing premature cross-linking that would increase viscosity and cause filling defects.
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 graphene-enhanced elastomeric stator assembly exhibits increased heat tolerance, abrasion resistance, and extended runtime with improved tensile, shear, and compressive modulus, reducing failures and maintenance needs in drilling operations.
Implementation Method 1
graphene particles, which can enhance the structure of the stator and increase heat tolerance by providing additional heat dissipation benefits
Implementation Method 2
If plasticizers can be peroxide cross-linked to a polymer, then the same plasticizer can be cross-linked to a functionalized graphene particle, permanently locking the plasticizer into the polymeric matrix
Implementation Method 3
By reacting a plasticizer into the polymers and graphene particles, higher than traditional loadings of plasticizer can be compounded into a recipe
Data Source
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AI summary
An enhanced elastomeric stator assembly and method of making the same is disclosed. The elastomeric stator may be structurally, thermally, and/or chemically enhanced through the incorporation of graphene particles, cross-linkable polymers, coupling agents that extend cross-links, and by the reduction of filler material. The graphene particles can be incorporated in functionalized or non-functionalized form or in a combination thereof, the functionalized graphene increasing the number of cross-links in the overall structure, thereby enhancing the structural robustness of the elastomeric stator. The compound can be formulated to have a relatively low viscosity and other characteristics that allow the material to flow through a mould cavity.