A wellbore fluid includes an aqueous fluid, a viscosifer, a stabilizer agent, and a lubricant. The aqueous fluid is an inhibitive divalent fluid. A method of preparing the divalent wellbore fluid are provided or formulated, includes methods produce the divalent wellbore fluids, and methods inject or circulate the inhibitive divalent wellbore fluids into a wellbore or borehole provided in a formation and/or into a reservoir of the formation.

Water-in-oil emulsions are provided that include an alkyl propylene diamine and an ethoxylated alcohol as the inverting surfactant, which is present in an amount less than 5 percent by weight of the water-in-oil emulsion.

A drilling fluid may include a carrier and a lubricant composition. The lubricant composition includes ethylene bottoms heavy pyrolysis oil. For example, the heavy pyrolysis oil may be bottoms of a fractionated fuel oil product separated from ethylene gas produced by a cracking of a hydrocarbon feedstock in a furnace.

Ether amines, or salts thereof, are proposed for use herein as lubricity additives for drilling fluids. Methods for wellbore operations and for improving lubricity include adding an ether amine to the drilling fluid. The ether amine is represented by the general formula:

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where R1 is represented by the general formula:

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where R5 is a straight chain, branched, or cyclic aliphatic radical with about 3 to 20 carbon atoms; X is 0 to 10; R2 is a straight chain, branched, or cyclic aliphatic radical with about 3 to 20 carbon atoms; and R3 and R4 are each one of H or a straight chain, branched, or cyclic aliphatic radical.

An drilling mud composition is described, which includes an aqueous base fluid, a viscosifier, and a weighting material. The drilling mud composition also includes an anti-sagging agent that comprises a dimethylamino methyl ester, such as methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate. The anti-sagging agent may be used to prevent barite sagging, where barite is used as a weighting material. Small amounts of the anti-sagging agent may be used to maintain a low sag factor while drilling, and without causing unwanted increases in viscosity. The anti-sagging agent is effective for both vertical and inclined wellbores.

A lubricant composition, comprising (i) a vegetable oil; (ii) a surfactant; and (iii) a lime soap dispersing agent, wherein a mixture of the lubricant composition and a brine forms less than about 1 wt. % insoluble particulates based on a total weight of the mixture. A wellbore servicing fluid comprising (i) a lubricant composition comprising (a) a vegetable oil; (b) a surfactant; and (c) a lime soap dispersing agent; and (ii) a drilling mud comprising a base fluid wherein the base fluid comprises a brine. A method of servicing a wellbore comprising placing into a wellbore disposed in a subterranean formation a wellbore servicing fluid comprising a lubricant composition comprising (a) a vegetable oil; (b) a surfactant; and (c) a lime soap dispersing agent; a base fluid; and (iv) a brine.

Terpene-based spotting fluid compositions and processes for freeing differentially stuck pipe are provided. A spotting fluid composition includes a terpene and an acid, such that the acid initiates an exothermic polymerization reaction of the terpene. Another spotting fluid composition includes an invert emulsion having a terpene external phase and a non-miscible organic hygroscopic fluid internal phase. The terpene emulsion spotting fluid composition may be introduced downhole in the vicinity of a portion of a differentially stuck pipe such that the spotting fluid composition contacts a filter cake surrounding the portion of the differentially stuck pipe. An acid may be introduced downhole in the vicinity of a portion of a differentially stuck pipe such that the acid initiates an exothermic polymerization reaction of the terpene of the terpene emulsion spotting fluid composition.

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.

The invention relates to the field of oilfield chemistry, and discloses a self-repairing plugging gel polymer for drilling fluid, a preparation method and application thereof, and the drilling fluid containing the gel polymer, wherein the polymer contains a structural unit A, a structural unit B, a structural unit C and a structural unit D, and the structural unit A is a structural unit with a structure shown in the formula (1); the structural unit B is a structural unit with a structure shown in the formula (2); the structural unit C is a structural unit with a structure shown in the formula (3); the structural unit D is a structural unit having a structure represented by the formula (4). The polymer provided by the invention has excellent mechanical properties and good self-repairing properties, and when the polymer is used as a plugging agent of water-based drilling fluid, the polymer has good plugging properties and high plugging layer repairing efficiency, and simultaneously has good high-temperature resistance.

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