Extended-Life Cement Using Red Mud Solids for Low-Temperature Strength
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Solution Overview
Problem
Extended-life cement compositions face challenges in developing sufficient compressive strength at lower subterranean temperatures and maintaining acceptable thickening times, with limited geographic availability of key components.
Innovation Solution
Incorporating red mud solids and hydraulic cement in extended-life cement compositions, which can be stored in a pumpable fluid state for extended periods, activated to form a hardened mass with sufficient compressive strength, and using set retarders and dispersants to manage setting and rheology.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If extended-life cement compositions are designed to remain pumpable for extended periods at room temperature, then storage time is improved, but compressive strength development at lower subterranean temperatures deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying the chemical composition parameters of the cement system. Specifically, it uses a calcium sulfate hemihydrate-based system with controlled amounts of gypsum (0-50 wt% of hemihydrate) and calcium aluminate cement (5-50 wt% of hemihydrate) to adjust the setting and strength development characteristics. This compositional parameter adjustment allows the cement to maintain pumpability during extended storage while ensuring adequate compressive strength development at lower temperatures after placement.
Solution Approach 2:
The patent employs composite materials by combining multiple cementitious components: calcium sulfate hemihydrate as the primary binder, gypsum for controlled setting, calcium aluminate cement for early strength and temperature resistance, and various additives. This multi-component composite system addresses the contradiction by leveraging the complementary properties of each material - the hemihydrate provides extended pumpability, while the calcium aluminate cement ensures strength development at lower temperatures.
2Strength
If cement compositions are activated to develop compressive strength, then strength is improved, but thickening time control becomes more difficult
Solution Approach 1:
The patent controls thickening time by adjusting chemical composition parameters, specifically the water-to-cement ratio (0.25-0.75), gypsum content (0-50 wt% of hemihydrate), and calcium aluminate cement content (5-50 wt% of hemihydrate). These parameter adjustments allow independent control of setting time and strength development, enabling the cement to maintain acceptable thickening times even when activated for strength development.
Solution Approach 2:
The patent uses gypsum as an intermediary substance that mediates between the hemihydrate and water, controlling the setting reaction rate. The gypsum provides a controlled source of sulfate ions that regulate the formation of ettringite and other hydration products, thereby controlling thickening time while allowing strength development to proceed. This intermediary mechanism decouples the relationship between activation and thickening time control.
3Strength
If conventional cement compositions are used, then compressive strength is achieved, but extended storage in pumpable state is not possible
Solution Approach 1:
The patent employs calcium sulfate hemihydrate as a short-lived binder that provides temporary workability during storage and then transforms into a strength-providing cementitious matrix. The hemihydrate particles remain dormant and pumpable during extended storage, then undergo hydration when water is added, transitioning from a non-strength material to a strength-developing system. This approach allows extended storage without sacrificing final strength.
Solution Approach 2:
The patent performs preliminary action by pre-mixing the hemihydrate, gypsum, calcium aluminate cement, and additives in dry form, creating a stable, pumpable slurry that can be stored for extended periods. The chemical reactions are delayed until water is added at the time of use, allowing the composition to maintain its pumpable state during storage while being prepared in advance. This preliminary preparation without immediate activation enables extended storage.
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 compositions provide reduced capital expenditures, minimize waste disposal issues, and offer suitable strength for subterranean applications, even in low-temperature environments, with red mud solids being readily available in certain regions.
Implementation Method 1
a cementitious component comprising red mud solids and hydraulic cement
Implementation Method 2
using set retarders and dispersants to manage setting and rheology
Implementation Method 3
using set retarders and dispersants to manage setting and rheology
Data Source
AI summary
Extended-life cement compositions are provided and, more particularly, extended-life cement compositions are provided that comprise a cementitious component comprising red mud solids and hydraulic cement. A method of cementing may comprise providing an extended-life cement composition comprising a cementitious component, water, and a cement set retarder, wherein the cementitious component comprises red mud solids and a hydraulic cement; activating the extended-life cement composition; introducing the extended-life cement composition into a subterranean formation; and allowing the extended-life cement composition to set in the subterranean formation.