A method for cementing a wellbore, including pumping a volume of an anti-corrosion fluid comprising at least one corrosion inhibitor into a casing and displacing the anti-corrosion fluid into an annular space outside the casing with a volume of cement. A displacement fluid may then be injected into the casing to displace the cement into the annular space, wherein a combined volume of cement and anti-corrosion fluid fills the annular space along a height of the casing. A height of the cemented annular space may be less than the height of the casing, the anti-corrosion fluid being retained in the annular space axially above a cemented annular space, forming an anti-corrosion fluid annular space. Partially cementing in this manner may simultaneously protect the casing from corrosion while allowing easier workover operations proximate the anti-corrosion fluid annular space.

The present invention relates to the use of amphiphilic sequenced copolymers as an agent for controlling the filtrate in a fluid (F) injected under pressure into an underground formation, comprising—at least one chain (C) soluble in the fluid (F); and—at least one block (B) that is insoluble in the fluid (F).

The present invention relates to the use of amphiphilic sequenced copolymers as an agent for controlling the filtrate in a fluid (F) injected under pressure into an underground formation, comprising—at least one chain (C) soluble in the fluid (F); and—at least one block (B) that is insoluble in the fluid (F).

A method of servicing a wellbore in a formation comprising circulating in the wellbore a wellbore servicing fluid wherein an equivalent circulating density of the wellbore servicing fluid is from about 1% to about 15% greater than a fracture pressure of the formation, and introducing to the wellbore a balloon-inhibiting tunable spacer (BITS) fluid wherein at least about 1 wt. % of the BITS fluid is retained by the formation.

In one embodiment, a retarded acid system comprises an aqueous acid and a retarding surfactant. The aqueous acid may comprise from 5 wt. % to 25 wt. % of a strong acid, that is, an acid having a K.sub.a greater than or equal to 0.01. The aqueous acid may further comprise from 75 wt. % to 95 wt. % water. The retarding surfactant may have the general chemical formula R—(OC.sub.2H.sub.4).sub.X—OH where R is a hydrocarbon having from 11 to 15 carbon atoms and x is an integer from 6 to 10. The retarding surfactant may have a hydrophilic-lipophilic balance from 8 to 16.

In one embodiment, a retarded acid system comprises an aqueous acid and a retarding surfactant. The aqueous acid may comprise from 5 wt. % to 25 wt. % of a strong acid, that is, an acid having a K.sub.a greater than or equal to 0.01. The aqueous acid may further comprise from 75 wt. % to 95 wt. % water. The retarding surfactant may have the general chemical formula R—(OC.sub.2H.sub.4).sub.X—OH where R is a hydrocarbon having from 11 to 15 carbon atoms and x is an integer from 6 to 10. The retarding surfactant may have a hydrophilic-lipophilic balance from 8 to 16.

A method of servicing a wellbore in a formation comprising circulating in the wellbore a wellbore servicing fluid wherein an equivalent circulating density of the wellbore servicing fluid is from about 1% to about 15% greater than a fracture pressure of the formation, and introducing to the wellbore a balloon-inhibiting tunable spacer (BITS) fluid wherein at least about 1 wt. % of the BITS fluid is retained by the formation.

A method of servicing a wellbore may comprise providing a treatment fluid comprising a carrier fluid and hollow particles, wherein the hollow particles may comprise an outer wall that encapsulates a gas. The method may further comprise introducing the treatment fluid into a wellbore annulus and trapping at least a portion of the treatment fluid in the wellbore annulus. The carrier fluid may degrade the outer wall of the hollow particles in the wellbore annulus and release the encapsulated gas.

A method of servicing a wellbore may comprise providing a treatment fluid comprising a carrier fluid and hollow particles, wherein the hollow particles may comprise an outer wall that encapsulates a gas. The method may further comprise introducing the treatment fluid into a wellbore annulus and trapping at least a portion of the treatment fluid in the wellbore annulus. The carrier fluid may degrade the outer wall of the hollow particles in the wellbore annulus and release the encapsulated gas.

The present disclosure relates to spacer fluids for use in subterranean operations and, more particularly, in certain embodiments, to spacer fluids that include a spacer additive comprising a biopolymer polysaccharide gum, a modified cellulose, and a solid scouring material while being essentially free of clay and crystalline silica.