Composite Well Cement Slurry With Delayed Swelling Isolation
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Solution Overview
Problem
Existing cement compositions used in wells drilled with water-based drilling fluids face challenges in maintaining zonal isolation and resisting crack formation due to changing stresses, such as pressure testing and temperature increases, leading to potential loss of fluid isolation in zones.
Innovation Solution
A composite cement slurry comprising cement particles, water, and water swellable particulates derived from an elastomeric material doped with superabsorbent moieties, which have a delay swelling mechanism to prevent swelling during mixing and pumping, ensuring effective zonal isolation and crack resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If water swellable particulates are added to cement composition to improve zonal isolation, then crack resistance is improved, but swelling during mixing and pumping may occur causing loss of zonal isolation
Solution Approach 1:
The elastomeric material is pre-modified with superabsorbent moieties and functional groups before being incorporated into the cement composition. This preliminary chemical modification enables the material to delay swelling until the wellbore environment is appropriate, preventing premature swelling during mixing and pumping while maintaining zonal isolation capabilities.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the elastomeric material by incorporating superabsorbent moieties and specific functional groups. These parameter changes alter the swelling kinetics, transforming the material from one that swells immediately upon water contact to one that delays swelling until triggered by specific wellbore conditions, thus preventing premature volume expansion during handling.
2Strength
If superabsorbent moieties are incorporated into elastomeric material to enhance water absorption, then crack resistance is improved, but swelling may occur during mixing and pumping operations
Solution Approach 1:
The elastomeric material is pre-modified with superabsorbent moieties and functional groups before being incorporated into the cement composition. This preliminary chemical modification enables the material to delay swelling until the wellbore environment is appropriate, preventing premature swelling during mixing and pumping while maintaining zonal isolation capabilities.
Solution Approach 2:
The patent introduces an intermediary mechanism in the form of functional groups and superabsorbent moieties that mediate between water contact and swelling. These intermediaries act as triggers that only activate swelling under specific wellbore conditions, preventing direct water-induced swelling during mixing and pumping operations while still enabling crack resistance through controlled water absorption.
3Reliability
If elastomeric material is used to provide delay swelling mechanism, then zonal isolation is maintained, but the material may still swell under changing stresses such as pressure testing and temperature increases
Solution Approach 1:
The patent creates a composite elastomeric material system combining the elastomeric matrix with superabsorbent moieties and specific functional groups. This composite structure provides delay swelling capability to maintain zonal isolation while the cross-linked gel network and functional group modifications prevent swelling under changing stresses such as pressure testing and temperature increases, thereby maintaining zonal isolation reliability.
Solution Approach 2:
The patent modifies the chemical and physical parameters of the elastomeric material by incorporating superabsorbent moieties and specific functional groups. These parameter changes alter the swelling kinetics, transforming the material from one that swells immediately upon water contact to one that delays swelling until triggered by specific wellbore conditions, thus preventing premature volume expansion during handling.
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 composite cement slurry maintains zonal isolation and prevents crack formation, providing long-term physical stability and integrity in wells under varying conditions.
Implementation Method 1
water swellable particulates that are embedded in the cement and derived from an elastomeric material
Implementation Method 2
the elastomeric material of the water swellable particulates may be doped with superabsorbent moieties to confer water absorbing properties to the water swellable particulates
Implementation Method 3
a delay swelling mechanism may be indictive of a negative charge repulsion attached to at least one functional group associated with the elastomeric material
Data Source
AI summary
Composite cement compositions and slurries for treating a well following a water-based wellbore operation are provided and comprise cement comprising at least one of cement particles and cementitious material, water, and water swellable particulates that are embedded in the cement, derived from an elastomeric material, and present at a concentration of at least about 2% by weight of the cement but no more than about 30% by weight of the cement. Methods for treating a well drilled with a water-based drilling mud are provided and comprise pumping the composite cement compositions and slurries into the well and treating the well by allowing the composite cement compositions and slurries to set or cure after being pumped into the well.