Gellable Drilling Fluids Sealing Lost Circulation Zones
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Solution Overview
Problem
Current drilling fluids face challenges in efficiently sealing lost circulation zones during wellbore drilling, leading to resource-intensive and time-consuming remediation processes, which can result in drilling fluid leaks, drill head damage, and even blowouts.
Innovation Solution
A gellable drilling fluid comprising a base fluid and formaldehyde-based resins, with water-soluble acid catalyst precursors that initiate polymerization to convert the fluid into a gelled state, effectively sealing porous areas, cracks, and fractures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional drilling fluids are used, then the drilling operation can proceed, but lost circulation zones cause drilling fluid leaks and require resource-intensive remediation
Solution Approach 1:
The drilling fluid is pre-formulated with formaldehyde-based resins and water-soluble acid catalyst precursors in a liquid state, allowing rapid in-situ gelation upon contact with formation water. This preliminary preparation eliminates the need for time-consuming on-site mixing and curing operations, enabling quick response to lost circulation zones.
Solution Approach 2:
The drilling fluid undergoes a phase transition from liquid to gel state through acid-catalyzed polymerization of formaldehyde-based resins. This phase change enables the fluid to convert from a pumpable liquid suitable for circulation to a gel state capable of sealing fractures and porous formations, providing both mobility and sealing effectiveness.
2Productivity
If drilling fluid is pumped in liquid state, then circulation is efficient, but sealing capability is insufficient for lost circulation zones
Solution Approach 1:
The drilling fluid exhibits dynamic rheological properties, remaining in a pumpable liquid state during circulation to maintain efficient flow and carry cuttings, then transitioning to a gel state upon contact with formation water to provide sealing capability. This dynamic behavior allows the same fluid to serve both circulation and sealing functions effectively.
Solution Approach 2:
The acid-catalyzed polymerization process induces a phase transition from liquid to gel, enabling the drilling fluid to adapt its physical state based on operational requirements. The liquid phase ensures efficient circulation while the gel phase provides the necessary sealing capability for lost circulation zones.
3Reliability
If formaldehyde-based resins are added to drilling fluid, then gelling capability is improved, but the fluid may gel prematurely before reaching the formation
Solution Approach 1:
Water-soluble acid catalyst precursors serve as intermediaries that remain dormant in the liquid drilling fluid until activated by contact with formation water. These precursors initiate polymerization only when the fluid reaches the formation, preventing premature gelling while ensuring reliable gelation at the target location. The catalyst precursor acts as a controlled-release agent for the gelling process.
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 gellable drilling fluid efficiently transitions from a liquid to a gelled state, providing a rapid and effective sealing solution for lost circulation zones, reducing the risk of leaks and damage, and enabling safer and more efficient wellbore drilling operations.
Implementation Method 1
The introduction of a water-soluble acid catalyst precursor to the drilling fluid may initiate the conversion of the water-soluble acid catalyst precursor into a water-soluble acid catalyst
Implementation Method 2
the water-soluble acid catalyst may polymerize at least a portion of the formaldehyde-based resins present in the drilling fluid, which may cause the drilling fluid to become a gelled state material
Implementation Method 3
The drilling fluid, in gel form, may then be suitable to seal the porous areas, cracks, fractures, or other geological features which cause the lost circulation zone
Data Source
AI summary
In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid and one or more formaldehyde-based resins. The drilling fluid may further comprise one or more water-soluble acid catalyst precursors or the reaction products of such water-soluble acid catalyst precursors. The base fluid may include an aqueous or non-aqueous solution. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.