We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Are Drilling Fluids?

By Jeremy Laukkonen
Updated May 21, 2024
Our promise to you
All The Science is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At All The Science, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject-matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

Drilling fluids are liquid or gaseous substances that are often pumped into boreholes during drilling operations. These fluids are typically called drilling mud when liquids are used, though that does not mean they consist of actual mud. Liquid drilling fluids can be either water or oil based, and gaseous fluids often contain air. One main purpose of drilling fluid is to maintain the stability of a borehole, though it can also perform several other tasks. Some other functions include facilitating the removal of drilled material from the borehole, controlling the pressures within a formation, cooling and lubricating the bit, and even transferring hydraulic power to components of the bottom hole assembly.

There are many different kinds of drilling fluids, each of which has qualities that are uniquely suited to particular situations. Most drilling fluids can be broken up into the categories of liquid and gas based. Liquid based fluids are usually called drilling mud, and can be further broken down into water and oil based solutions. Water is sometimes used by itself, though it is more commonly mixed with bentonite clay and various other chemicals. The clay is colloquially referred to as "gel" in the oil and gas industry, and the chemical additives are usually meant to control various characteristics such as viscosity.

Oil-based drilling fluid can be either synthetic or natural, and diesel fuel is one naturally occurring substance that is sometimes used. These fluids are often chosen for applications where greater lubrication qualities are required, or a great deal of heat is likely to be generated in the drilling process. Synthetic oils are usually chosen when the toxic fumes from natural oils could be dangerous, which is often a consideration in the closed working conditions found in offshore oil rigs.

Gaseous drilling fluids sometimes consist of air that is pumped into the drill string, though various other gasses can also be included. Air is sometimes mixed with water as well, which can increase the viscosity of a drilling fluid, provide added dust control, or help clean out the borehole. Polymers are sometimes included in an air/water mixtures when a foaming agent or other additive is required.

The main purpose of a drilling fluid is to maintain the integrity of a borehole, and to prevent the fluids present in rock formations from entering the drill string. Another primary function is to help pass drill cuttings up the borehole to the surface, where they can be disposed of. The fluid is often relied on for cooling and lubrication properties, both to the drill bit and bottom hole assembly machinery such as mud motors. Hydraulic pressure present in the fluid can also be used to power mud motors and other components.

All The Science is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.

All The Science, in your inbox

Our latest articles, guides, and more, delivered daily.