Gellable Drilling Fluid Sealing Lost Circulation Zones

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Solution Overview

Problem

Current drilling fluids lack efficient solutions for sealing lost circulation zones in 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-insoluble acid catalyst precursors that initiate polymerization to convert the fluid from a liquid to a gelled state, effectively sealing porous areas and fractures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional drilling fluids are used in lost circulation zones, then the drilling operation can continue, but the drilling fluid leaks through fractures and porous areas causing resource loss and operational delays

Engineering Contradiction:
Improvesealing effectivenessVSAvoiddrilling fluid loss
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the physical state parameter of the drilling fluid from liquid to gel through controlled polymerization. The fluid remains liquid during pumping but transforms to a gelled state that can seal fractures and porous areas, preventing further fluid loss while maintaining operational reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The drilling fluid undergoes a phase transition from liquid to gel state through in-situ polymerization initiated by water-insoluble acid catalyst precursors. This phase change enables the fluid to seal lost circulation zones effectively, converting a harmful leakage issue into a beneficial sealing mechanism

Inventive Principle:
Principle #36Phase transitions

2Reliability

If sealing composition is introduced to remediate lost circulation zones, then the leakage can be stopped, but the process is resource-intensive and time-consuming

Engineering Contradiction:
Improvesealing effectivenessVSAvoidremediation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The drilling fluid is pre-formulated with formaldehyde-based resins and water-insoluble acid catalyst precursors during the drilling operation. When lost circulation is detected, the catalyst precursors are activated to initiate polymerization, eliminating the need for separate remediation operations and significantly reducing remediation time

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The drilling fluid contains all necessary components (formaldehyde-based resins and water-insoluble acid catalyst precursors) to perform self-sealing when lost circulation occurs. The system activates its own sealing mechanism in-situ without requiring external sealing compositions or additional remediation equipment, reducing both time and resource investment

Inventive Principle:
Principle #25Self-service

3Reliability

If the drilling fluid is converted to gel state immediately, then sealing effectiveness is improved, but the fluid loses its flowability and cannot be pumped through the wellbore

Engineering Contradiction:
Improvesealing effectivenessVSAvoidfluid pumpability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The polymerization process is controlled to occur periodically or on-demand rather than immediately. Water-insoluble acid catalyst precursors remain dormant during pumping, then activate when lost circulation is detected, allowing the fluid to maintain liquid state during transport and transform to gel state only when needed for sealing

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

Water-insoluble acid catalyst precursors serve as intermediaries that remain inactive during fluid circulation and only activate polymerization when lost circulation occurs. This intermediary mechanism allows the fluid to maintain pumpability during transport while enabling gelation for sealing when required

Inventive Principle:
Principle #24Intermediary (Mediator)

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 seals lost circulation zones, reducing leakage and operational challenges, while allowing controlled gelling for various geological features, thereby enhancing drilling safety and efficiency.

Implementation Method 1

The water-insoluble acid catalyst precursor may form an acid catalyst in the drilling fluid

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 2

The 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

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Data Source

PatentUS11078398B2Drilling fluids that include water-insoluble acid catalyst precursors
Publication Date: 2021.08.03 SAUDI ARABIAN OIL CO

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-insoluble acid catalyst precursors or the reaction products of such water-insoluble acid catalyst precursors. 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.