A drilling fluid formulation is provided, which includes an aqueous base fluid, a synthetic modified phyllosilicate as an anti-sagging additive, an inorganic base, and a weighting agent (e.g. barite). The synthetic modified phyllosilicate contains a clay material (e.g. smectite) and a metal selected from ruthenium, rhodium, palladium, osmium, iridium, and platinum. The synthetic modified phyllosilicate is effective in preventing barite sagging as demonstrated by low sag factor when drilling at elevated temperatures. Rheology properties of the drilling fluid including gel strength, yield point, plastic viscosity, and storage modulus are also specified.

A wellbore fluid may include an oleaginous continuous phase; a non-oleaginous discontinuous phase; an emulsifier stabilizing the non-oleaginous phase within the oleaginous phase; a low density material selected and in an amount to result in a specific gravity of the wellbore fluid that is less than 0.83; and at least one rheology modifier selected to suspend the low density material within the wellbore fluid.

A method of hydraulic fracturing may comprise mixing at least one liquid sand mixture with a fluid to produce a fracturing fluid; and conveying the fracturing fluid to two or more wellbores simultaneously, wherein the wellbores penetrate a subterranean formation.

A method of hydraulic fracturing may comprise mixing at least one liquid sand mixture with a fluid to produce a fracturing fluid; and conveying the fracturing fluid to two or more wellbores simultaneously, wherein the wellbores penetrate a subterranean formation.

A hydraulic fracturing method for recovering oil from a low-temperature subterranean oil formation is disclosed. Before, during, or after inducing hydraulic fracturing within the formation, a particulate, degradable polyester diverting agent is introduced into the formation in an amount effective to improve oil production from the formation. The diverting agent is allowed to degrade, and oil is recovered. The diverting agent has a melting point greater than the average temperature of the formation and is selected from: (i) ethylene glycol succinates; (ii) acid-terminated ethylene glycol succinates; (iii) acid-terminated polyglycolic acids; (iv) acid-terminated polylactic acids; (v) mixtures of any of (i) through (iv) with a half acid ester; and (vi) mixtures of polylactic acids or polyglycolic acids with a half acid ester. These easily synthesized classes of particulate polyester diverting agents degrade more effectively than polylactides under the conditions present in low-temperature wells and should help to enhance well productivity.

The present disclosure provides water-based well treatment fluids methods of using such fluids in treating subterranean formations to prevent swelling and/or migration of fines. The water-based well treatment fluid contains an aqueous continuous phase and a clay stabilizing agent comprising less than 20% by weight, based on the total weight of the clay stabilizing agent, of an unhindered primary amine and a second amine selected from an alkanolamine, a polyalkylene polyamine, a compound having a formula R.sub.4—(CH.sub.2).sub.d—NH.sub.2 where R.sub.4 is a piperazino group or a morpholino group and d is an integer from 0 to 10, a compound having the formula where his an integer from about 2 to about 7 and a mixture thereof.

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A method of reducing lost circulation in a wellbore includes introducing a fluid including a fluid loss control additive comprising shape memory polymer, shape memory alloy, or both into the wellbore. The method further includes allowing the fluid loss control additive to lodge within fractures within a subsurface formation in the wellbore. The method further includes allowing the fluid loss control additive to expand within the fractures, thereby forming a barrier between the wellbore and the subsurface formation to reduce lost circulation in the wellbore.

Loss circulation material (LCM) and method for treating loss circulation in a wellbore in a subterranean formation, including placing the LCM having a solid body with permeable portions or pores into the wellbore to dispose the LCM at the loss circulation zone, and collecting solids onto the LCM at the loss circulation zone to form a barrier. The LCM may be applied at a loss circulation zone in a hydrocarbon reservoir section of the subterranean formation, and upon subsequent hydrocarbon production the collected solids may be dislodged by the produced hydrocarbon to allow for hydrocarbon production through the permeable portions or pores of the disposed LCM.

Compositions are provided for preventing or alleviating loss of fluids from natural or artificial reservoirs formed in subterranean geological formations and methods for deployment of said compositions. The compositions can be delivered to the subterranean reservoirs in any number of steps and are comprised of rock surface adhesion promoter(s), particles that may consist of solids, gels and liquids, crosslinking agent(s) and a liquid medium. The method of the invention uses the composition of the invention in preventing or alleviating loss of fluid stored in a reservoir existing in a subterranean formation. In the method, the composition is preferably provided in a series of weighted or unweighted “pills” for introduction into the reservoir. Such a series may include from one to any number of consecutive treatments. Multiple pills or treatments may be used if needed.

An invert emulsion drilling fluids having a combination of fatty acids derived from waste vegetable oil (WVO) and a fatty alcohol as a rheology modifier. An invert emulsion drilling fluid may include a water in oil emulsion, an invert emulsifier, a fatty alcohol having six to thirty carbon atoms, and a fatty acid having six to eighteen carbon atoms. The fatty acid is provided by esterifying a waste vegetable oil to produce a methyl ester of the waste vegetable oil and cleaving an ester group from the methyl ester of the waste vegetable oil. The invert emulsion drilling fluid may be formulated free of organoclay. Methods of drilling a wellbore using an invert emulsion drilling fluid are also provided.