Acid Precursor Wellbore Fluid for Filter Cake Removal
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Solution Overview
Problem
Existing methods for removing filter cakes from wellbores are inefficient and can damage the formation or wellbore, as they fail to effectively convert oil-wet components to water-wet surfaces for unimpeded natural resource flow.
Innovation Solution
A composition comprising an acid and/or acid precursor, a surfactant, and an aqueous base fluid is placed in contact with oil-wet solids in the wellbore, where the acid or acid precursor hydrolyzes to release acid, converting oil-wet solids to water-wet solids, facilitating the removal of filter cakes while minimizing formation damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional methods are used to remove filter cakes, then some removal effect is achieved, but the formation or wellbore is damaged
Solution Approach 1:
The patent changes the chemical parameters of the treatment composition by using a controlled pH system with acid precursors that slowly release acid. This allows the composition to effectively remove filter cake while maintaining pH levels that prevent formation damage, resolving the contradiction between removal efficiency and formation protection
Solution Approach 2:
The patent introduces acid precursors as intermediary substances that gradually convert to active acid forms. These precursors act as mediators between the need for strong acid action to remove filter cake and the need to limit direct acid exposure that causes formation damage, enabling effective removal with minimized harm
2Productivity
If strong acid is used to remove oil-wet filter cakes, then removal efficiency is improved, but formation damage increases
Solution Approach 1:
The patent applies preliminary action by first converting oil-wet surfaces to water-wet surfaces using the acid composition before significant acid exposure can occur. This preliminary wetting conversion enables subsequent safe removal of the filter cake while preventing the formation damage that would result from direct strong acid exposure
Solution Approach 2:
The patent implements periodic action through the controlled, gradual release of acid from acid precursor substances. Instead of applying strong acid all at once, the acid is released periodically and progressively, maintaining effectiveness for filter cake removal while limiting peak acid concentrations that would cause formation damage
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 method efficiently removes oil-based filter cakes and converts oil-wet surfaces to water-wet, allowing for unimpeded natural resource flow and reducing the risk of formation damage, enabling effective wellbore servicing and completion operations.
Implementation Method 1
the acid or acid precursor hydrolyzes to release acid
Implementation Method 2
converting oil-wet solids to water-wet solids
Implementation Method 3
a composition comprising an acid and/or an acid precursor, a surfactant, and an aqueous base fluid
Data Source
AI summary
A method of servicing a wellbore in a subterranean formation comprising placing a composition comprising an acid and/or an acid precursor, a surfactant, and an aqueous base fluid into contact with oil-wet solids in the wellbore; wherein the acid and/or acid precursor is selected from the group consisting of acetic acid; lactic acid; glycolic acid; oxalic acid; propionic acid; butyric acid; monochloroacetic acid; dichloroacetic acid; trichloroacetic acid; hydrochloric acid; nitric acid; sulphuric acid; sulphonic acid; sulphinic acid; phosphoric acid; phosphorous acid; phosphonic acid; phosphinic acid; sulphamic acid; aliphatic polyesters; glucono-delta-lactone; glucoheptonic lactone; poly(ε-caprolactones); poly(hydroxybutyrates); poly(anhydrides); aliphatic polycarbonates; poly(amino acids); polyphosphazenes; poly(ortho esters); or combinations thereof.