Synthetic Cement Viscosity and Strength Balance
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Solution Overview
Problem
Traditional cements face challenges in achieving a balance between solution viscosity and compressive strength, compatibility with oil-based muds, and stability under varying temperatures, leading to issues with pumpability, adhesion, and fracturing in well cementing processes.
Innovation Solution
A synthetic cement composition comprising low viscosity monofunctional monomers, difunctional monomers, unsaturated styrenic block copolymers, and a free radical initiator, which allows for controlled setting and high compressive strength, compatible with oil-based muds, and maintains mechanical properties across a wide temperature range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If traditional Portland cement is used to achieve high compressive strength, then the cement has adequate strength, but the solution viscosity is too high for extended pumping and the cement is prone to fracturing under stress
Solution Approach 1:
The patent changes the chemical composition parameters by using vinyl ester monomers (50-90 wt%), difunctional monomers (5-40 wt%), and unsaturated styrenic block copolymers (5-20 wt%) instead of traditional Portland cement. This parameter change achieves compressive strength of 1000-5000 psi while maintaining solution viscosity of 50-1000 cP, enabling both high strength and extended pumpability without fracturing under stress
Solution Approach 2:
The patent creates a composite material system combining multiple monomer types and unsaturated styrenic block copolymers. The vinyl ester monomers provide the base matrix, difunctional monomers create crosslinking for strength, and unsaturated styrenic block copolymers enhance toughness and reduce brittleness. This composite approach achieves both high compressive strength and improved elasticity to prevent fracturing
2Strength
If traditional cement is used to ensure adequate set strength, then the cement provides structural integrity, but it is incompatible with oil-based muds causing poor adhesion and flow channeling
Solution Approach 1:
The patent changes the chemical compatibility parameters by formulating cement composed entirely of vinyl ester monomers, difunctional monomers, and unsaturated styrenic block copolymers. This chemical parameter change makes the cement compatible with oil-based muds, maintaining set strength of 1000-5000 psi even with 20 wt% mud contamination, and enabling reliable adhesion to formation through the chemically compatible polymer-based matrix
Solution Approach 2:
The patent achieves homogeneity in chemical composition by using a fully polymer-based cement system without traditional Portland cement components. The uniform polymer matrix of vinyl ester monomers crosslinked with difunctional monomers and modified by unsaturated styrenic block copolymers creates a homogeneous material that is inherently compatible with oil-based muds, eliminating the phase separation and adhesion problems of traditional cement
3Loss of time
If traditional cement is used to achieve rapid setting, then the cement sets quickly, but the setting time cannot be controlled and the cement may set too fast for deep well pumping
Solution Approach 1:
The patent introduces dynamic controllability of setting time through the use of unsaturated styrenic block copolymers and free radical initiators. The setting time can be dynamically adjusted by varying the initiator concentration and copolymer content, allowing the cement to remain pumpable for extended periods (viscosity 50-1000 cP) while maintaining controllable setting characteristics adaptable to different well depths and pumping rates
Solution Approach 2:
The patent changes the kinetic parameters of the setting reaction by selecting specific free radical initiators and unsaturated styrenic block copolymers. This parameter change enables control over the polymerization rate and crosslinking speed, allowing setting times to be adjusted according to pumping requirements while maintaining final compressive strength of 1000-5000 psi
4Strength
If traditional cement is used to ensure adequate bond strength, then the cement bonds to formation, but it forms flow channels through flocculated drilling mud
Solution Approach 1:
The patent changes the rheological and chemical parameters by using a polymer-based cement composition with vinyl ester monomers, difunctional monomers, and unsaturated styrenic block copolymers. This parameter change prevents flocculation of drilling mud, maintains bond strength of 1000-5000 psi, and eliminates flow channeling by creating a chemically compatible cement-mud system that does not undergo phase separation
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 synthetic cement achieves a balance of solution viscosity and compressive strength comparable to Portland cement, enabling effective well cementing with improved adhesion and reduced fracturing, even in the presence of oil-based mud contamination, and maintains pumpability for extended periods.
Implementation Method 1
The composition of the synthetic cement comprises mono-functional monomers such as vinyl ester, acrylate/methacrylate; difunctional monomers such as dicyclopentadienyl moieties having a free radical reactive species or the mixture thereof with 1,3-butylene glycol dimethacrylate; unsaturated styrenic block copolymer, and a free radical initiator
Data Source
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AI summary
The present invention relates to a synthetic cement that comprises a low viscosity monofunctional monomer, a dicyclopentadienyl moiety having a pendant free radical reactive species, 1,3-butyleneglycol dimethacrylate, unsaturated styrenic block copolymer, and a peroxide curing agent. Additionally it may include weighting agents depending on the circumstances of the well, as is well known to those skilled in the art. Other additional components such as oil based mud, suspending agents, Portland cement, acrylates and methacrylates, retardant curing additives, and clays may optionally be incorporated into the synthetic cement. The synthetic cement is activated by heat, for example, and can be crafted to set within a certain time frame, for example in 4 hours, so that it pumpable for as long as need be, and then be set to seal the well in the manner desired.