The disclosure provides a method of treating a subterranean formation penetrated by a wellbore. The method includes introducing a gas phase gas into fractures of the subterranean formation extending from the wellbore, followed by introducing a carrier fluid into the subterranean formation under sufficient pressure to fracture a portion of the subterranean formation and release hydrocarbons from the subterranean formation. The gas phase gas occupies the fractures at a sufficient pressure to cause the carrier fluid to be diverted to additional fractures of the subterranean formation defined by the portion.

An effective amount of at least one anionic surfactant may be present within a high salinity foamed fluid composition in an effective amount to generate an IFT as low as 10.sup.−3 mN/m. The anionic surfactant may be a sulfonate surfactant and/or a sulfate surfactant. The foamed fluid composition may be used to perform an operation, including but not limited to, a gas lift operation, a drilling operation, a completion operation, a stimulation operation, a fracturing operation, an injection operation, an enhanced oil recovery operation, and combinations thereof.

The fracturing methods described in the present disclosure provide advantage over the current fracturing methods. The disclosed fracturing methods can change the fracture gradient of the downhole subterranean formation. For example, one or more of the fracture gradients of the low and high stress zones of the downhole subterranean formation can be changed. Furthermore, the methods of present disclosure, in relation to current practices, can decrease the extent and/or degree of fracturing within low stress downhole formations and increase the degree of fracturing within high stress formations.

A method of treating a subsurface formation comprises mixing an unfractionated hydrocarbon mixture, water, and natural gas with a foaming agent to form a stimulation fluid comprising foam. The unfractionated hydrocarbon mixture comprises ethane, propane, butane, isobutane, and pentane plus. The method further includes increasing a pressure of the stimulation fluid and injecting the stimulation fluid into the subsurface formation.

A method of treating a subterranean formation from a well, the method which comprises preparing a proppant slurry which comprises (a) proppant particles and (b) a first carrier fluid; preparing a proppant free injection liquid which comprises a second carrier fluid wherein the first and second carrier fluids are immiscible and wherein no proppant is intentionally added to the proppant free injection liquid; and injecting the proppant slurry and the proppant free injection liquid into the formation, is provided.

A novel inorganic fine particle reinforced foam system for an oil-gas field and preparation method thereof. The reinforced foam system comprises a gas phase and a liquid phase; the gas phase is nitrogen, carbon dioxide or the air; the liquid phase is prepared from, by mass: 0.2-0.8 wt % of a foaming agent, 0.5-2.0 wt % of novel inorganic fine particles and balance of water; the novel inorganic fine particles are fine particulate matter with diameters being smaller than or equal to 2.5 microns captured and screened from the atmosphere.

Various embodiments disclosed relate to foam compositions and methods of using the same for treatment of subterranean formations. In various embodiments, the present invention provides a method of treating a subterranean formation including placing a foam composition in the subterranean formation. The foam composition can include a blowing agent and a surfactant. The foam composition can include at least one of a) a foam agent including an alkoxylated alcohol ether sulfate, and b) a polysaccharide foam stabilizer.

The present invention relates to a foam containing water, between 5 and 30 wt % on total weight of the foam of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), a foaming agent, and at least 25 vol % on total volume of the foam of a gas, and having a pH of between 2 and 5, to a viscosified composition containing water, between 5 and 30 wt % on total volume of the composition of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), and at least 0.01 wt % on total weight of the composition of a viscosifying agent, and having a pH of between 2 and 5, and to a process for treating a subterranean formation comprising introducing the above foam or viscosified composition into the formation.

The present application provides a gas-generating aqueous fluid containing a gas-generating compound like an azo compound, and an organic amine like a primary, secondary or tertiary amine, a hydrazine, a hydrazide, or a semicarbazide. The aqueous fluid may also a viscosifier, and a foaming surfactant. The present application also provides a method of using the gas-generating composition to modulate density of a wellbore fluid for use in downhole applications. The method optionally includes adding an oxidizer to the wellbore fluid.

Described herein is a multi-phase aqueous composition containing a surfactant; a first phase comprising water, an acid, and a water-soluble acid retarding agent; and a second phase selected from the group consisting of an immiscible organic phase, a gas, and combinations thereof. Further described are methods of making and using such compositions.