Hydrophobically Associating Polymers for Bitumen Encapsulation

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Solution Overview

Problem

Conventional drilling fluids used in bitumen recovery from oil sands face challenges such as bitumen sticking to drilling components, high torque and drag, and difficulties in separating solvents from drilling fluids, due to the anionic charge and hydrophobic nature of bitumen, which existing solutions like cationic polymers and surfactants do not adequately address, especially in complex formations like Athabasca Oil Sands.

Innovation Solution

A drilling fluid composition comprising hydrophobically associating polymers that adsorb strongly on bitumen surfaces, preventing dispersion and sticking, and being compatible with conventional anionic additives, along with a water continuous phase and clay minerals, effectively inhibiting bitumen dispersion and encapsulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional water-base drilling fluids with anionic polymer additives are used, then the anionic surface charge of bitumen particles increases causing bitumen to disperse into the drilling fluids, but the dispersed bitumen particles re-aggregate on metal or plastic surfaces causing bitumen sticking and accretion problems

Engineering Contradiction:

Improvebitumen dispersion stabilityVSAvoidbitumen sticking to drilling components

Core Design Contradiction:

Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a cationic polymer as an intermediary substance that mediates between the anionic bitumen particles and the drilling fluid system. The cationic polymer binds to the negatively charged bitumen surfaces through electrostatic attraction, forming a protective coating that prevents bitumen-sticking interactions with metal and plastic drilling components while maintaining dispersion stability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite system by combining cationic polymers with conventional anionic drilling fluid additives. This composite approach allows the cationic polymer to specifically address bitumen sticking through electrostatic binding while the anionic additives maintain overall drilling fluid performance, achieving both dispersion stability and sticking prevention.

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If solvents are added to the drilling fluid to dissolve bitumen, then bitumen dissolves from cuttings, but solvents also dissolve bitumen from oil sand formations causing hole washing out and require frequent drilling fluid refreshing

Engineering Contradiction:

Improvebitumen dissolution efficiencyVSAvoidbitumen loss from formation

Core Design Contradiction:

Quantity of substanceVSLoss of substance

Solution Approach 1:

The patent extracts the bitumen-dissolving function from the bulk drilling fluid by introducing solid absorbent materials (such as clays or specialized adsorbents) that selectively bind bitumen from the drilling fluid. This localized extraction prevents bitumen from redepositing on formation walls while avoiding the need to refresh the entire drilling fluid system.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent applies different functional properties to different regions of the drilling system: the cationic polymer provides sticking prevention at the bitumen-drilling component interface, while solid absorbents provide localized bitumen removal at the formation-drilling fluid interface, creating spatially differentiated solutions to the bitumen management problem.

Inventive Principle:

Principle #3Local quality

3Object-affected harmful factors

If cationic polymers are added to encapsulate bitumen, then bitumen encapsulation occurs, but compatibility issues arise with conventional anionic drilling fluid additives

Engineering Contradiction:

Improvebitumen sticking preventionVSAvoidcompatibility with anionic additives

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent modifies the parameters of the cationic polymer system by carefully controlling the ratio of cationic to anionic components, the molecular weight and charge density of the polymers, and the concentration levels. These parameter adjustments allow the system to maintain electrostatic binding effectiveness for bitumen sticking prevention while ensuring compatibility with conventional anionic drilling fluid additives through balanced charge interactions.

Inventive Principle:

Principle #35Parameter changes

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 hydrophobically associating polymers inhibit bitumen sticking and dispersion, ensuring effective recovery and encapsulation, reducing operational issues like torque and drag, and maintaining compatibility with conventional drilling fluid additives.

Implementation Method 1

hydrophobically associating polymers that adsorb strongly on bitumen surfaces, preventing dispersion and sticking

Methodology Applied

Scientific EffectHydrophobic interaction: Hydrophobe

Implementation Method 2

hydrophobically associating polymers that adsorb strongly on bitumen surfaces

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS7879768B2Drilling fluid composition comprising hydrophobically associating polymers and methods of use thereof

Publication Date: 2011.02.01 MUD ENG

AI summary

The present disclosure relates to drilling fluids for use in bitumen recovery from oil sands. In particular, the disclosure relates to a drilling fluid composition containing hydrophobically associating polymers which encapsulate the bitumen, and a method and use of the composition.