Foamed Elastomer Cement Sheath Integrity
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Solution Overview
Problem
Cement compositions used in subterranean applications often fail due to shear, tensile, and compressional stresses, leading to cracking and bond breakdown, particularly in high-pressure and high-temperature conditions, resulting in lost production, environmental pollution, and hazardous operations.
Innovation Solution
Incorporating particulate foamed elastomers into cement compositions, which are permeable and swellable, to enhance mechanical properties and provide self-healing capabilities, preventing segregation and improving bonding between the cement and pipe or formation surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If elastomeric materials are included in cement compositions to modify mechanical properties, then the tensile strength and flexibility of set cement are improved, but the elastomeric materials segregate during placing and setting, leading to undesirable density gradients
Solution Approach 1:
The patent changes the physical state and density parameters of the elastomeric material by foaming it, transforming solid rubber particles into low-density foam particles. This parameter change allows the elastomers to remain suspended in the cement slurry without segregating, while still providing the desired mechanical property modifications including improved tensile strength and flexibility.
Solution Approach 2:
The patent creates a composite material system by combining cement with foamed elastomer particles. This composite approach allows the elastomers to be integrated into the cement matrix in a controlled manner, preventing segregation while maintaining the beneficial mechanical properties of both materials throughout the set cement structure.
2Reliability
If cement is used to form a sheath in high-pressure and high-temperature conditions, then the cement provides structural support and sealing, but the cement fails due to shear, tensile, and compressional stresses, leading to cracking and bond breakdown
Solution Approach 1:
The patent applies composite materials by integrating foamed elastomers into the cement matrix. The elastomeric phase provides flexibility and crack-bridging capabilities, while the cement provides structural strength. This composite structure enables the cement sheath to withstand shear, tensile, and compressional stresses without cracking or bond breakdown, maintaining sealing integrity under high-pressure and high-temperature conditions.
Solution Approach 2:
The patent changes the mechanical parameters of the cement by incorporating foamed elastomers, which modify the stress-strain behavior of the set cement. The elastomeric particles act as stress distributors and crack arrestors, changing how the cement responds to applied stresses and improving its overall reliability under demanding downhole conditions.
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 use of particulate foamed elastomers in cement compositions enhances mechanical properties, prevents segregation, and provides self-healing by swelling to fill cracks, thereby improving the durability and integrity of the cement sheath under stressful conditions.
Implementation Method 1
the elastomers may swell when contacted by gas, hydrocarbons, or water thus providing 'self-healing' properties in the event the cement sheath is damaged or cracked
Implementation Method 2
the use of particulate foamed elastomers, as compared to unfoamed elastomers, is that the particulate foamed elastomers may stay more evenly dispersed throughout the cement slurry, rather than segregating
Data Source
AI summary
Methods of subterranean cementing involving cement compositions comprising particulate foamed elastomers and associated methods are provided. In one embodiment, the methods comprise introducing a cement composition into a subterranean location, wherein the cement composition comprises a hydraulic cement, a particulate foamed elastomer, and an aqueous fluid; and allowing the cement composition to set in the subterranean location.