A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore into the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide (H.sub.2S). The method includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid composition includes 0.25 to 2 wt. % of a primary H.sub.2S scavenger which is potassium permanganate. The drilling fluid composition includes an invert emulsion which includes a continuous phase including mineral oil and a dispersive phase including water. The potassium permanganate present in the drilling fluid composition reacts with the H.sub.2S present in the formation fluid to produce a dispersion of manganese-containing particles which are at least one selected from the group consisting of manganese sulfide and manganese sulfate.

A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore into the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide (H.sub.2S). The method includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid composition includes 0.25 to 2 wt. % of a primary H.sub.2S scavenger which is potassium permanganate. The drilling fluid composition includes an invert emulsion which includes a continuous phase including mineral oil and a dispersive phase including water. The potassium permanganate present in the drilling fluid composition reacts with the H.sub.2S present in the formation fluid to produce a dispersion of manganese-containing particles which are at least one selected from the group consisting of manganese sulfide and manganese sulfate.

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. The method includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid includes 1 to 3 wt. % of a weighting agent which includes hydrophobic metallic zinc nanoparticles including a metallic core and organic ligands present on a surface of the metallic core, based on a total weight of the drilling fluid. The drilling fluid includes an invert emulsion including a continuous phase and a dispersive phase including water.

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. The method includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid includes 1 to 3 wt. % of a weighting agent which includes hydrophobic metallic zinc nanoparticles including a metallic core and organic ligands present on a surface of the metallic core, based on a total weight of the drilling fluid. The drilling fluid includes an invert emulsion including a continuous phase and a dispersive phase including water.

A method may include providing a cement composition comprising ground vitrified clay, hydrated lime, and water; and introducing the cement composition into a subterranean formation.

A method may include providing a cement composition comprising ground vitrified clay, hydrated lime, and water; and introducing the cement composition into a subterranean formation.

Some examples of producing water-based drilling fluids including ecofriendly lubricating additives are described. A raw material oil including fatty acids with a short chain alcohol is esterified in the presence of a catalyst to produce alkyl ester products and triglycerides. The alkyl ester products are washed and heated to remove any residual water or the short chain alcohol. A first quantity of the alkyl ester products is mixed with a second quantity of a water-based wellbore drilling fluid.

Some examples of producing water-based drilling fluids including ecofriendly lubricating additives are described. A raw material oil including fatty acids with a short chain alcohol is esterified in the presence of a catalyst to produce alkyl ester products and triglycerides. The alkyl ester products are washed and heated to remove any residual water or the short chain alcohol. A first quantity of the alkyl ester products is mixed with a second quantity of a water-based wellbore drilling fluid.

The invention relates to the field of drilling fluid, in particular to a saturated salt water drilling fluid of salt response type intelligent polymer and preparation method thereof. The drilling fluid contains two or more of the following components stored in admixture or separately: bentonite, NaOH, KCl, calcium carbonate, barite, NaCl, supramolecular fluid loss additive, supramolecular shear-enhancing agent, plugging agent, coating agent and water. The drilling fluid provided by the invention has the characteristics of salt response and self-assembly, can keep rheological properties such as rapid recovery of the sheared structure, low extreme high shear rate viscosity, good shear dilution property and the like in a high-salt environment, has good fluid loss reduction performance, reservoir protection performance and debris dispersion inhibition performance, and has good temperature resistance and pollution resistance performance.

The invention relates to the field of drilling fluid, in particular to a saturated salt water drilling fluid of salt response type intelligent polymer and preparation method thereof. The drilling fluid contains two or more of the following components stored in admixture or separately: bentonite, NaOH, KCl, calcium carbonate, barite, NaCl, supramolecular fluid loss additive, supramolecular shear-enhancing agent, plugging agent, coating agent and water. The drilling fluid provided by the invention has the characteristics of salt response and self-assembly, can keep rheological properties such as rapid recovery of the sheared structure, low extreme high shear rate viscosity, good shear dilution property and the like in a high-salt environment, has good fluid loss reduction performance, reservoir protection performance and debris dispersion inhibition performance, and has good temperature resistance and pollution resistance performance.