An apparatus to test a drilling fluid in a laboratory includes a test cell configured to test the fluid to determine a Sag Factor of the fluid. The test cell may be heated with a heating jacket to a predefined temperature. A plurality of densitometers are configured to continuously measure a density of the fluid circulating in the test cell. A computing device processes the density measurements to determine a Sag Factor of the drilling fluid.

An apparatus to test a drilling fluid in a laboratory includes a test cell configured to test the fluid to determine a Sag Factor of the fluid. The test cell may be heated with a heating jacket to a predefined temperature. A plurality of densitometers are configured to continuously measure a density of the fluid circulating in the test cell. A computing device processes the density measurements to determine a Sag Factor of the drilling fluid.

Disclosed are methods of preparing drilling fluid compositions containing treated calcium bentonite. One such method includes mixing calcium bentonite with an aqueous mixture containing soda ash, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition. Another method includes mixing the calcium bentonite with an aqueous mixture containing soda ash and magnesium oxide, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition.

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 0.05 to 1 wt. % of a rhamnolipid surfactant 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 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.

The present application discloses a nanometer self-locking bentonite film-forming agent, a method for preparing the same, and a film-forming drilling fluid.

A fluid pressure transmission pill (FPTP) having an ultra-high viscosity for use in association with hydrocarbon drilling and exploration operations, particularly, managed pressure drilling (MPD) operations, is described. The ultra-high viscosity pill is a weighted pill composition that includes a hydrocarbon fluid, a thixotropic viscosifying agent, one or more activators, an emulsifier/wetting agent, a fluid loss control additive, and a weighting material. In accordance with selected aspects of the described fluid pressure transmission pill, the ratio of the amount of the thixotropic viscosifying agent to the activator is a ratio of about 7:1, and the weighting material is a barium-containing solid-phase material. Also described are methods of use of such FPTP products in subterranean operations, such as well killing operations during managed pressure drilling.

A fluid pressure transmission pill (FPTP) having an ultra-high viscosity for use in association with hydrocarbon drilling and exploration operations, particularly, managed pressure drilling (MPD) operations, is described. The ultra-high viscosity pill is a weighted pill composition that includes a hydrocarbon fluid, a thixotropic viscosifying agent, one or more activators, an emulsifier/wetting agent, a fluid loss control additive, and a weighting material. In accordance with selected aspects of the described fluid pressure transmission pill, the ratio of the amount of the thixotropic viscosifying agent to the activator is a ratio of about 7:1, and the weighting material is a barium-containing solid-phase material. Also described are methods of use of such FPTP products in subterranean operations, such as well killing operations during managed pressure drilling.

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 nanosilica containing fluid system for shale stabilization in a shale formation. The nanosilica containing fluid system comprising a functionalized nanosilica composition operable to react with shale at the surface of the shale formation to form a barrier on the shale formation. The functionalized nanosilica composition comprising a nanosilica particle, the nanosilica particle having a mean diameter, and a functionalization compound, the functionalization compound appended to the surface of the nanosilica particle. And an aqueous-based fluid, the aqueous-based fluid operable to carry the functionalized nanosilica composition into the shale formation. The functionalization compound is an amino silane. The aqueous-based fluid is selected from the group consisting of water, deionized water, sea water, brine, and combinations thereof.