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.

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.

A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore in the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide. The method further includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid includes an aqueous solvent, a hydrogen sulfide scavenger including particles of a manganese oxide supported on a porous support. The particles are suspended in the aqueous solvent. The method further includes reacting the hydrogen sulfide scavenger with the hydrogen sulfide present in the formation fluid to form a manganese sulfide.

A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore in the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide. The method further includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid includes an aqueous solvent, a hydrogen sulfide scavenger including particles of a manganese oxide supported on a porous support. The particles are suspended in the aqueous solvent. The method further includes reacting the hydrogen sulfide scavenger with the hydrogen sulfide present in the formation fluid to form a manganese sulfide.

The present disclosure a leak-proof lost-circulation control water-based drilling fluid composition and preparation method and use thereof.

The present disclosure a leak-proof lost-circulation control water-based drilling fluid composition and preparation method and use thereof.

In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid, one or more formaldehyde-based resins, and one or more water-soluble acid catalysts. The base fluid may include an aqueous or non-aqueous solution. The one or more water-soluble acid catalysts may be present in an amount sufficient to reduce the pH of the drilling fluid to less than or equal to 6. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.

In accordance with one or more embodiments of the present disclosure, a drilling fluid may include a base fluid, one or more formaldehyde-based resins, and one or more water-soluble acid catalysts. The base fluid may include an aqueous or non-aqueous solution. The one or more water-soluble acid catalysts may be present in an amount sufficient to reduce the pH of the drilling fluid to less than or equal to 6. The present disclosure also describes sealed subterranean petroleum formations that include such drilling fluids and methods for sealing subterranean wellbores by utilizing such drilling fluids.

Described herein are fluids used to inhibit swelling of clay or shale formations, where the fluids include a drilling fluid and a clay stabilizer that include a potassium salt with a plurality of cations and are injectable into a wellbore.

Described herein are fluids used to inhibit swelling of clay or shale formations, where the fluids include a drilling fluid and a clay stabilizer that include a potassium salt with a plurality of cations and are injectable into a wellbore.