Liquid CO2 Extraction of Drill Cuttings Contaminants
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Solution Overview
Problem
The disposal of drill cuttings from well drilling operations poses an environmental challenge due to contamination with residual drilling mud and hazardous hydrocarbons, which are difficult to remove efficiently using existing methods.
Innovation Solution
A method and system utilizing an expandable liquid solvent, such as carbon dioxide, to extract contaminants from drill cuttings by forming a mixture, measuring properties of the mixture to determine when the desired level of contaminant removal is achieved, and terminating the process accordingly, ensuring the drill cuttings are cleaned to a residual level below 1% by weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional methods are used to remove contaminants from drill cuttings, then the contaminants can be removed, but the extraction time is excessive (1.5 hours)
Solution Approach 1:
The patent changes the physical-chemical parameters of the extraction system by introducing expandable liquid solvent (such as liquid CO2) and controlling its expansion characteristics. By adjusting pressure and temperature parameters, the solvent selectively extracts contaminants from drill cuttings, achieving rapid decontamination in 45 minutes compared to traditional 1.5-hour methods
Solution Approach 2:
The patent utilizes phase transition of the expandable liquid solvent. The solvent is introduced in liquid form, then expanded to supercritical or gaseous state to enhance extraction efficiency. This phase change mechanism enables rapid contaminant removal by creating favorable mass transfer conditions, reducing extraction time from 1.5 hours to 45 minutes while maintaining effective contaminant removal
2Manufacturing precision
If traditional contaminant removal methods are used, then contaminants can be removed, but the process is costly
Solution Approach 1:
The patent optimizes processing parameters including pressure (50-300 psi), temperature (ambient to elevated), and solvent-to-cuttings ratio to achieve cost-effective extraction. By controlling these parameters, the system reduces energy consumption and operational costs while maintaining effective contaminant removal, saving $20-22 per ton compared to traditional methods
Solution Approach 2:
The patent employs expandable liquid solvent such as liquid CO2, which is relatively inexpensive and can be easily replenished. The solvent system is designed for single-use or limited-cycle operation, where the low cost of the solvent and simple disposal/regeneration process reduces overall processing costs compared to traditional expensive treatment methods
3Loss of time
If expandable liquid solvent is used to extract contaminants, then extraction time is reduced to 45 minutes, but the system complexity increases
Solution Approach 1:
The patent employs an expandable liquid solvent system that performs multiple functions: extraction of various contaminants (hydrocarbons, drilling mud), phase transition for separation, and potential reuse. This multi-functional approach consolidates what would otherwise require multiple separate treatment units, reducing overall system complexity despite the advanced chemistry involved
Solution Approach 2:
The expandable liquid solvent acts as an intermediary substance that facilitates contaminant removal without requiring complex mechanical separation equipment. The solvent mediates the extraction process by dissolving contaminants, then through phase expansion, automatically separates from the cuttings, simplifying the overall system design compared to traditional mechanical or thermal treatment systems
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
This approach reduces the extraction time and costs, allowing for the efficient and environmentally friendly disposal of clean drill cuttings, with a potential savings of $20-22 per ton by ensuring the cuttings are sufficiently cleaned within 45 minutes compared to traditional methods which may take 1.5 hours.
Implementation Method 1
contacting the drill cuttings with an expandable liquid solvent to form a mixture comprising the expandable liquid solvent and a portion of the contaminants
Implementation Method 2
expanding the mixture to separate the expandable liquid solvent from the contaminants to recover an expanded solvent stream and a contaminant stream
Data Source
AI summary
Embodiments disclosed herein relate to a method including passing liquid carbon dioxide over drill cuttings carrying contaminants to form a mixture comprising liquid carbon dioxide and a portion of the contaminants; measuring a property of the mixture; and terminating the passing liquid carbon dioxide over drill cuttings based on the measured property.