Wax-Coated Particles for Drilling Fluid Lost Circulation Control

Solution Overview

Problem

Conventional lost circulation materials for drilling operations are ineffective in controlling lost circulation, often requiring large amounts of solid additives that disrupt drilling fluid properties, cause permanent damage to formations, and are costly, with existing solutions being environmentally unfriendly and not suitable for all drilling fluids.

Innovation Solution

The use of drilling fluid additives comprising particles coated or blended with wax or waxy substances, which are insoluble in hydrocarbons at drilling temperatures, to form a hydrophobic barrier that reduces lost circulation and is geothermally removable, thereby minimizing formation damage and environmental impact.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional lost circulation materials (solids like sawdust, wood fibers, calcium carbonate) are added to drilling fluid, then lost circulation is reduced, but the drilling fluid properties are disrupted and large amounts of solid additives are required

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention changes the physical-chemical parameters of the lost circulation material by coating solids with wax, transforming them from conventional hydrophilic solids to hydrophobic particles. This parameter change allows the materials to be effectively used with oil-based drilling fluids, reducing the need for large quantities of additives and minimizing disruption to drilling fluid properties.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention creates composite particles by combining conventional lost circulation solids (calcium carbonate, barite, etc.) with wax coatings. These composite materials retain the sealing capability of the solids while gaining hydrophobicity from the wax, enabling effective lost circulation control with reduced additive quantities and minimal fluid property disruption.

Inventive Principle:

Principle #40Composite materials

2Reliability

If conventional lost circulation materials are used, then lost circulation is controlled, but permanent damage to formations occurs and environmental impact increases

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The wax coating is designed to be temporarily present during drilling operations to provide lost circulation control, then naturally degrades or is removed after drilling. This allows the conventional solids to fulfill their sealing function during the operation and then be discarded naturally, minimizing long-term formation damage and environmental impact compared to permanent solid additives.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The wax coating acts as a temporary, disposable layer that provides the necessary hydrophobic barrier during drilling and then naturally degrades. This short-living coating eliminates the need for permanent solid additives that would cause long-term formation damage, aligning with the principle of using temporary protective measures that can be naturally removed.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If wax-coated particles are used, then lost circulation is reduced and environmental impact is minimized, but the particles must be insoluble in hydrocarbons at drilling temperatures

Engineering Contradiction:

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention selects and modifies wax materials with specific melting points and solubility characteristics that are stable at drilling temperatures. By carefully controlling the physical parameters of the wax coating, the particles remain insoluble in hydrocarbon-based drilling fluids during operation, maintaining their hydrophobic barrier function while adapting to the specific temperature and chemical conditions of the drilling environment.

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 wax-coated particles effectively seal off loss zones, enhance filter cake stability, and reduce the environmental impact of drilling operations, while being more economical and less damaging to formations compared to traditional additives.

Implementation Method 1

The additive has particles comprising one or more solids in association with a wax or waxy substance... to form a hydrophobic barrier that reduces lost circulation

Methodology Applied

Scientific EffectHydrophobic barrier formation: Hydrophobe

Implementation Method 2

which are insoluble in hydrocarbons at drilling temperatures, to form a hydrophobic barrier that reduces lost circulation and is geothermally removable

Methodology Applied

Scientific EffectGeothermal removal: Melting

Data Source

PatentUS8607895B2Drilling fluid additive for reducing lost circulation in a drilling operation

Publication Date: 2013.12.17

AI summary

Generally, the present invention provides drilling fluid additives for reducing or controlling lost circulation in a drilling operation. The additives comprises particles. The particles comprise one or more solids in association a wax or waxy substance. A drilling fluid comprising a drilling fluid additive of the invention is also provided, as well as a method and use of the drilling fluid additive in a drilling operation to reduce or control lost circulation. Methods for manufacturing the drilling fluid additives are also described.