Volcanic Ash Drilling Mud for Salt and Temperature Tolerance

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Solution Overview

Problem

Conventional bentonite muds face limitations in drilling evaporite, anhydrite, and reactive shale formations due to poor tolerance to salts, cement contamination, pH changes, and temperature, leading to borehole problems and increased well costs.

Innovation Solution

The use of a water-based drilling mud composition containing volcanic ash, a viscosifier, and a pH buffer, along with a gas neutralizer, which maintains desirable properties and neutralizes gases released during drilling, enhancing tolerance to salts and temperature while preventing mudcake and rheological changes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional bentonite muds are used for drilling, then hole cleaning and cuttings suspension are achieved, but tolerance to salts, cement contamination, pH changes, and temperature changes above 100°C is poor

Engineering Contradiction:

Improvedrilling performanceVSAvoidtolerance to salts, cement contamination, pH changes, and temperature changes

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent uses a composite material system combining bentonite with volcanic ash (specifically tuff) to create a drilling mud formulation that maintains the hole cleaning and cuttings suspension capabilities of bentonite while adding salt tolerance and thermal stability from the volcanic ash component. This composite approach resolves the contradiction by integrating materials with complementary properties.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters of the drilling mud by incorporating volcanic ash particles with specific size distributions (D10, D50, D90 values) and chemical compositions. This parameter modification enables the mud to tolerate higher salt concentrations and temperatures above 100°C while maintaining its functional properties for hole cleaning and cuttings suspension.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If bentonite mud is used in evaporite, anhydrite, and reactive shale formations, then drilling operations can proceed, but serious borehole problems occur due to high dissolution capacity of fresh water

Engineering Contradiction:

Improvedrilling operationsVSAvoidhole enlargement and loss of circulation

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The volcanic ash acts as an intermediary substance that modifies the interaction between the drilling mud and reactive formations. It reduces the direct harmful interaction between fresh water in the bentonite mud and the evaporite, anhydrite, or reactive shale formations, thereby preventing hole enlargement and loss of circulation while allowing drilling operations to proceed.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the high dissolution capacity of fresh water, which is normally a harmful factor causing hole enlargement, into a beneficial property by combining it with volcanic ash. The volcanic ash modifies the water's interaction with reactive formations, transforming what would be a harmful dissolution effect into a controlled process that maintains borehole stability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If gas is released from subterranean formation during drilling, then drilling continues, but mud properties change and require treatment

Engineering Contradiction:

Improvedrilling continuityVSAvoidmud properties

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent implements a feedback mechanism where gas presence in the drilling mud is detected (through gas sampling probes or surface monitoring systems), and based on this detection, gas neutralizing agents are added to the mud system. This closed-loop control maintains mud property stability despite continuous gas release during drilling operations, allowing drilling to proceed without interruption.

Inventive Principle:

Principle #23Feedback

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 mud composition exhibits high tolerance to salt concentrations, cement, and temperature, reducing drilling costs and associated problems, and is environmentally friendly, suitable for drilling in challenging formations like salt formations.

Implementation Method 1

neutralizing the gas by injecting a quantity of a second drilling mud additive through the subterranean zone, the second drilling mud additive including a gas neutralizer

Methodology Applied

Scientific EffectGas neutralization: Chemical Bonding

Implementation Method 2

a quantity of a first drilling mud additive including a volcanic ash

Methodology Applied

Scientific EffectAdsorption: Adsorption

Data Source

PatentUS10513648B2Techniques to manage mud properties

Publication Date: 2019.12.24 SAUDI ARABIAN OIL CO

AI summary

Methods and systems for maintaining stability of contaminated drilling muds within a desirable range by chemical and/or physical treatment. In one aspect, a method includes injecting a drilling mud in a subterranean zone, the drilling mud including a quantity of a first drilling mud additive including a volcanic ash, determining a presence of a gas associated to a process of the subterranean zone, and neutralizing the gas by injecting a quantity of a second drilling mud additive through the subterranean zone, the second drilling mud additive including a gas neutralizer.