Chemically Bonded Phosphate Ceramic Sealant for Deep Wells
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Solution Overview
Problem
Conventional cements used in oil and gas well applications are inadequate for deep and geothermal wells due to limitations in temperature and pressure resistance, setting time, and compatibility with saline environments, and do not effectively utilize drilling wastes for value-added products.
Innovation Solution
Development of chemically bonded phosphate ceramic (CBPC) formulations comprising specific ratios of MgO, KH2PO4, fly ash, boric acid or borax, and water, which can set within 3 to 6 hours at varying temperatures and pressures, and can be adjusted for use in fresh or saltwater environments, including the use of aluminum phosphate for high-temperature applications and calcium phosphate for waste recycling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cements are used in deep and geothermal wells, then the formulation is simple and readily available, but the temperature and pressure resistance is insufficient and setting time is too long
Solution Approach 1:
The patent changes the chemical composition parameters by using chemically bonded phosphate ceramic formulations with specific ratios of MgO (9.9-14.5%), KH2PO4 (29.7-27.2%), class C fly ash (19.8-36.3%), class F fly ash (19.8-0%), boric acid or borax (0.39-1.45%), and water (20.3-21.86%). This chemical parameter change enables the sealant to set within 3-6 hours at temperatures less than 250°F while providing superior temperature and pressure resistance for deep and geothermal well applications.
Solution Approach 2:
The patent employs composite materials by combining multiple components including MgO, KH2PO4, class C fly ash, class F fly ash, boric acid or borax, and water in specific proportions. This composite phosphate ceramic formulation achieves both rapid setting (3-6 hours) and high temperature/pressure resistance, overcoming the limitations of conventional single-material cements in deep and geothermal well environments.
2Reliability
If conventional cements are used for sealing, then the material is easy to obtain, but the bonding characteristics and resistance to carbon dioxide and organic gases are inadequate
Solution Approach 1:
The patent uses composite phosphate ceramic materials combining MgO, KH2PO4, class C fly ash, class F fly ash, and boric acid or borax in specific ratios. This composite formulation provides superior bonding characteristics and resistance to carbon dioxide and organic gases, achieving reliable sealing performance in challenging well environments despite the increased formulation complexity.
Solution Approach 2:
The patent modifies the chemical composition parameters by incorporating specific ratios of reactive components (MgO 9.9-14.5%, KH2PO4 29.7-27.2%, class C fly ash 19.8-36.3%, class F fly ash 19.8-0%, boric acid or borax 0.39-1.45%). These parameter changes enhance the chemical stability and gas resistance of the sealant, providing reliable long-term performance in deep and geothermal wells.
3Loss of substance
If drilling wastes are disposed of conventionally, then the disposal process is simple, but no value-added products are created
Solution Approach 1:
The patent converts drilling wastes (class C and class F fly ash) from harmful disposal materials into beneficial components of the phosphate ceramic sealant formulation. By incorporating these wastes at specific concentrations (class C fly ash 19.8-36.3%, class F fly ash 19.8-0%), the invention transforms waste disposal into a value-added process that creates effective sealing materials while reducing environmental impact.
Solution Approach 2:
The patent recovers and utilizes drilling wastes (class C and class F fly ash) that would otherwise be discarded. By incorporating these recovered materials into the phosphate ceramic sealant formulation in controlled proportions, the invention creates value-added products from waste streams, simultaneously achieving waste management and functional sealant performance.
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 CBPC formulations provide superior strength and bonding characteristics, are self-bonding, resistant to carbon dioxide and organic gases, and can effectively seal deep and geothermal wells, while also enabling the recycling and stabilization of drilling wastes, thus offering a cost-effective solution for niche applications.
Implementation Method 1
Chemically bonded phosphate ceramic (CBPC) formulations comprising specific ratios of MgO, KH2PO4, fly ash, boric acid or borax, and water
Implementation Method 2
KH2PO4 present in the range of from about 29.7 to about 27.2% by weight of the sealant, and water present in the range of from about 20.3 to about 21.86% by weight of the sealant
Data Source
AI summary
A sealant for an oil or geothermal well capable of setting within about 3 to about 6 hours at temperatures less than about 250° F. for shallow wells less than about 10,000 feet and deep wells greater than about 10,000 feet having MgO present in the range of from about 9.9 to about 14.5%, KH2PO4 present in the range of from about 29.7 to about 27.2%, class C fly ash present in the range of from about 19.8 to about 36.3%, class F fly ash present in the range of from about 19.8 to about 0%, boric acid or borax present in the range of from about 0.39 to about 1.45%, and water present in the range of from about 20.3 to about 21.86% by weight of the sealant.A method of sealing wells is disclosed as are compositions for very high temperature wells is disclosed as is a composition for treating oil field wastes.