Drilling fluid compositions include invert emulsion fluids having an oleaginous phase, an aqueous phase, and an emulsifier composition that includes an ethoxylated alcohol compound and a polyaminated fatty acid compound. The ethoxylated alcohol compound has the formula R.sup.1—(OCH.sub.2CH.sub.2).sub.n—OH, where R.sup.1 is a hydrocarbyl group having from 8 to 22 carbon atoms and n is from 1 to 8. The ethoxylated alcohol compound has a Hydrophilic-Lipophilic Balance (HLB) of less than or equal to 6. The polyaminated fatty acid compound has the formula R.sup.2—CO—NH—CH.sub.2—CH.sub.2—N(COR.sup.2)—CH.sub.2—CH.sub.2—NH—CO—R.sup.3, where R.sup.2 is a hydrocarbyl group having from 1 to 20 carbon atoms and R.sup.3 is a hydrocarbyl group having from 1 to 10 carbon atoms or an alkylene carboxylate group having formula —R.sup.4—COOH, where R.sup.4 is a saturated or unsaturated hydrocarbylene having from 1 to 10 carbon atoms. Methods of drilling wells include operating a drill in a wellbore in the presence of drilling fluid compositions.

Some embodiments of the present disclosure are directed to synthetic functionalized additives, which may comprise a layered magnesium silicate. The present disclosure is also directed to drilling fluids that may comprise an aqueous base fluid and a synthetic functionalized additive. The present disclosure is further directed to methods for producing drilling fluids.

Some embodiments of the present disclosure are directed to synthetic functionalized additives, which may comprise a layered magnesium silicate. The present disclosure is also directed to drilling fluids that may comprise an aqueous base fluid and a synthetic functionalized additive. The present disclosure is further directed to methods for producing drilling fluids.

Described herein are methods of enhancing the rheological properties of a colloidal mineral suspension in a liquid with high-intensity acoustical energy. In some examples, the colloidal mineral suspension may be dehydrated after treatment with high-intensity acoustical energy.

Described herein are methods of enhancing the rheological properties of a colloidal mineral suspension in a liquid with high-intensity acoustical energy. In some examples, the colloidal mineral suspension may be dehydrated after treatment with high-intensity acoustical energy.

The present invention refers to a composition for water-based foamed fluid with high thermal stability for drilling depressed areas in oil and gas wells, comprising: i) a base fluid or drilling water consisting of fresh water; ii) a stabilizing agent; ii) a viscosifying agent; iv) a filtering reducing agent; v) a clay inhibiting agent; vi) an alkalizing agent and acid gas sequestering agent; vii) a thermal stabilizing agent; and viii) a foaming agent. Also, the present invention refers to a system that uses said composition for fluid and water-based foamed fluid with high thermal stability, the method of preparing the composition for fluid, the method of preparing the fluid and application of the composition and fluid in a water-based foamed fluid system with high thermal stability for drilling depressed or low-pressure areas in oil and gas wells.

The present invention refers to a composition for water-based foamed fluid with high thermal stability for drilling depressed areas in oil and gas wells, comprising: i) a base fluid or drilling water consisting of fresh water; ii) a stabilizing agent; ii) a viscosifying agent; iv) a filtering reducing agent; v) a clay inhibiting agent; vi) an alkalizing agent and acid gas sequestering agent; vii) a thermal stabilizing agent; and viii) a foaming agent. Also, the present invention refers to a system that uses said composition for fluid and water-based foamed fluid with high thermal stability, the method of preparing the composition for fluid, the method of preparing the fluid and application of the composition and fluid in a water-based foamed fluid system with high thermal stability for drilling depressed or low-pressure areas in oil and gas wells.

Methods and compositions for modified well fluids. One method including combining an amount of a synthetic functionalized additive with an intermediate well fluid composition to form a synthetic functionalized additive-containing well fluid composition; the synthetic functionalized additive comprising a synthetic layered magnesium silicate that is covalently bonded to a functional group, and the intermediate well fluid composition comprising a water-based continuous phase with solid particles, wherein the synthetic functionalized additive increases suspension stability of the solid particles versus a well fluid composition comprising the solid particles without the synthetic functionalized additive.

Methods and compositions for modified well fluids. One method including combining an amount of a synthetic functionalized additive with an intermediate well fluid composition to form a synthetic functionalized additive-containing well fluid composition; the synthetic functionalized additive comprising a synthetic layered magnesium silicate that is covalently bonded to a functional group, and the intermediate well fluid composition comprising a water-based continuous phase with solid particles, wherein the synthetic functionalized additive increases suspension stability of the solid particles versus a well fluid composition comprising the solid particles without the synthetic functionalized additive.

A method for controlling loss circulation in a subterranean formation and a convertible drilling mud operable to convert into a solid gel lost circulation material. The method includes circulating in a wellbore a nanosilica drilling fluid having a pH in a range of from about 8 to about 11 and a gel pH of less than 8, where the nanosilica drilling fluid includes an aqueous-based drilling mud, an alkaline nanosilica dispersion, and at least one additive. The method also includes introducing into the nanosilica drilling fluid an amount of a chemical activator sufficient to produce a convertible drilling mud where the chemical activator is an acid and the pH of the convertible drilling mud is less than the gel pH. The method also includes allowing the convertible drilling mud to convert into a solid gel lost circulation material.