A drilling fluid and method for drilling in a coal containing formation. The method includes: providing a mixed metal-viscosified drilling fluid including at least 1% potassium salt; circulating the drilling fluid through the well; and drilling into a coal seam.

Amine-functionalized saccharide polymers, including oligosaccharides and polysaccharides, may be effective for promoting clay stabilization in subterranean formations. Oxidative synthesis of amine-functionalized saccharide polymers using sodium hypochlorite pentahydrate as an oxidation reagent may afford a different distribution and type of sites of oxidative opening as compared to other types of oxidation reagents. Amine-functionalized saccharide polymers may be prepared by exposing a saccharide polymer comprising a trans-vicinal diol to an oxidation reagent comprising sodium hypochlorite pentahydrate, reacting the trans-vicinal diol to form a site of oxidative opening bearing at least one aldehyde, exposing the at least one aldehyde to an amine to form an imine intermediate at the site of oxidative opening, and reducing the imine intermediate into a secondary or tertiary amine at the site of oxidative opening.

Amine-functionalized saccharide polymers, including oligosaccharides and polysaccharides, may be effective for promoting clay stabilization in subterranean formations. Oxidative synthesis of amine-functionalized saccharide polymers using sodium hypochlorite pentahydrate as an oxidation reagent may afford a different distribution and type of sites of oxidative opening as compared to other types of oxidation reagents. Amine-functionalized saccharide polymers may be prepared by exposing a saccharide polymer comprising a trans-vicinal diol to an oxidation reagent comprising sodium hypochlorite pentahydrate, reacting the trans-vicinal diol to form a site of oxidative opening bearing at least one aldehyde, exposing the at least one aldehyde to an amine to form an imine intermediate at the site of oxidative opening, and reducing the imine intermediate into a secondary or tertiary amine at the site of oxidative opening.

Provided is a method for hydraulic fracturing in a borehole in a geological formation using a process fluid including an environmentally friendly biostabiliser. The biostabiliser is characterised in that it includes at least one organic acid, or a salt, alcohol or aldehyde thereof, such that the at least one organic acid is selected from the hop acids, resin acids, fatty acids and mixtures thereof.

The present application discloses water-based drilling fluid system compositions and methods for making water-based drilling fluids systems. According to one embodiment, a drilling fluid system may include a drilling fluid and a lubricant. The lubricant may be synthesized from plant-based raw material oil.

The present invention relates to a process fluid comprising an environmentally friendly biostabiliser, for industrial scale use in the Earth's crust, preferably for use in oil and natural gas extraction, in particular in hydraulic fracturing. The biostabiliser is characterised in that it comprises at least one organic acid, or a salt, alcohol or aldehyde thereof, wherein the at least one organic acid is selected from the group consisting of hop acids, resin acids, fatty acids and mixtures thereof. The biostabiliser is preferably a mixture of hop extract, rosin and myristic acid. The invention further relates to corresponding application and production methods.

A method includes adding a clay to water to form a suspension of clay in water, the clay including pieces of clay having an average diameter of at least 2 μm; adding a dispersant to the suspension of clay in water to form a drilling fluid; and injecting the drilling fluid into a well. In the drilling fluid, the dispersant interacts with the clay to form nanoscale particles of clay having an average diameter of less than 500 nm.

Method of treating a portion of a subterranean formation comprising the injection of an aqueous fluid containing a modified polysaccharide bearing ethylenically unsaturated double bonds and an initiator of radical polymerization.

Method of treating a portion of a subterranean formation comprising the injection of an aqueous fluid containing a modified polysaccharide bearing ethylenically unsaturated double bonds and an initiator of radical polymerization.

A drilling mud composition including Aloe vera particles with a largest dimension of 75-600 μm, an aqueous base fluid, and a viscosifier, where the Aloe vera particles are present in the drilling mud composition at a concentration of less than 150 ppm, relative to the total weight of the drilling mud composition. A process for fracking a geological formation, whereby the drilling mud composition is injected into the geological formation through a well bore at a pressure of at least 5,000 psi to fracture the geological formation.