Black Earth Humic: A Great Drilling Additive

Posted by Jody Lockhart

Jun 20, 2013 11:27:00 AM

The Downhole Applications of Humic

Alberta gas drilling rig via Wikimedia resized 600

While Black Earth is known as an agricultural additive, many aren't aware that it can be applied to drilling muds, therefore increasing its efficiency.

As a drilling fluid additive, humic substances are known to help improve mud rheology and help reduce water loss, with the best results being performed under high temperatures and pressure. For the most part, drilling fluid additive compositions are used in conjunction with synthetic, oil based, and/or water based fluids. These additives are especially helpful in reducing lost circulation, seepage loss and numerous other functions. Black Earth delivers a superior performance when compared to other lignite products on the market.

What are Humics?

Humic acids such as leonardite, humalite and humate are similar naturally occurring materials that are enriched in humic and other organic acids. These substances are primarily used as a soil amendment in agriculture and reclamation. Humic substances are known to improve overall water retention and soil texture as well as improving living cell metabolism and growth. They also provide available carbon to microorganisms living in the soil, and, most important, they're environmentally safe.

Leonardite, Humalite and similar Humic acid products are used not only for waste-water and effluent treatment, but also as a conditioner for oilfield drilling fluids. Humic acid actually helps reduce viscosity while also maintaining fluid density.

Drilling Fluid Studies Comparing Black Earth and Lignite

Mined throughout Europe, the United States, India and Australia, lignite is usually known as brown or rosebud coal; considered by some as the lowest form of coal, it has a consistency ranging in between coal and peat. Lignite is primarily used as a fuel source for steam and electric power generation. Lignite has a carbon content of close to 35%, a high inherent moisture content ranging close to 66%, and ash content that ranges from 6% to 19% compared to bituminous coal, which often ranges from 6% to 12%.

Lignite is considered extremely volatile in some cases, as it is easier to convert into gas and liquid petroleum, when compared to other coals.It has a tendency to spontaneously combust, which makes it very delicate to transport, yet procedures that effectively remove the moisture from lignite's structure, have made it easier to manage.

One particular Black Earth study on Drilling Fluid Formation involved comparing Humalite and other coal derivatives, including lignite, as an additive in drilling fluid, with their efforts being on the reduction of viscosity as well as the filtration rate.

This particular formulation design featured based material including Water, Sodium chloride, Polymer, Caustic, Polyglycerol and Barite, with Black Earth Humalite and Lignite as the additives under investigation.

In comparing Black Earth Humalite against Lignite, Black Earth generally ranked better in several instances. While running about even around 4.0 in terms of pH (at a 10% solution), Black Earth surpassed Lignite in terms of Alkali Solubility (80% over 60%) as well as Brine solubility (where Black Earth ranks as good, compared to a poor showing for lignite).

The results of this particular study showed that Sub-bituminous coal derived additives are also effective for filtration control at high chloride environment.

Overall, Black Earth Humalite performed exceptionally well in regard to viscosity and filtrate.

Download the Black Earth drilling case studies:

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Topics: black earth, humalite, drilling, humic acid, leonardite, soil additive