A well cleanup process involves removing an impermeable filter cake from a formation face with thermochemical and chelating agents to allow formation fluids to flow from a reservoir to a wellbore. The method may be used with oil and water-based drilling fluids with varied weighting agents, e.g., bentonite, calcium carbonate, or barite. Such thermochemical agents may involve two salts, e.g., NO.sub.2.sup.− and NH.sub.4.sup.+, which, when mixed together, can generate pressure and heat, in addition to hot H.sub.2O and/or N.sub.2. For example, the thermochemical agents may comprise Na.sup.+, K.sup.+, Li.sup.+, Cs.sup.+, Mg.sup.2+, Ca.sup.2+, and/or Ba.sup.2+ with NO.sub.2.sup.− and NH.sub.4.sup.+ with F.sup.−, Cl.sup.−, Br.sup.−, I.sup.−, CO.sub.3.sup.2−, NO.sub.3.sup.−, ClO.sub.4.sup.−, and/or .sup.−OH. The thermochemical agents in combination with a chelator such as EDTA can removed the filter cake after 6 hours with a removal efficiency of 89 wt % for the barite filter cake in water based drilling fluid, exploiting the generation of a pressure pulse and heat which may disturb the filter cake and/or enhance barite dissolution and polymer degradation.

A method for the preparation of a scale inhibitor and a method of inhibiting the formation of scale uses a water soluble polymeric gelling agent, in particular synthetic polymer, which has been degraded and reduced in its molecular weight.

A method for the preparation of a scale inhibitor and a method of inhibiting the formation of scale uses a water soluble polymeric gelling agent, in particular synthetic polymer, which has been degraded and reduced in its molecular weight.

A composition includes a nonionic fluorinated polymeric surfactant, a nonfluorinated surfactant, and a scale treatment. Additionally, a method for scale treatment is provided. The method includes injecting gas into the aforementioned composition to produce a foam and injecting the foam into a formation. In the formation, the foam may be exposed to a first temperature at which it has a first viscosity. The foam may be maintained inside the formation for a period of time, and then recovered from the formation, at which point it is exposed to a second temperature and has a second viscosity.

A composition includes a nonionic fluorinated polymeric surfactant, a nonfluorinated surfactant, and a scale treatment. Additionally, a method for scale treatment is provided. The method includes injecting gas into the aforementioned composition to produce a foam and injecting the foam into a formation. In the formation, the foam may be exposed to a first temperature at which it has a first viscosity. The foam may be maintained inside the formation for a period of time, and then recovered from the formation, at which point it is exposed to a second temperature and has a second viscosity.

A thermochemical soap stick, system, and method for unloading liquid from a well, the thermochemical soap stick having thermochemical reagents and to be provided into a wellbore in a subterranean formation, the thermochemical soap stick to dissolve in the liquid giving a thermochemical reaction to generate gas to foam the liquid, and displacing the liquid from the wellbore via pressure of the subterranean formation.

A thermochemical soap stick, system, and method for unloading liquid from a well, the thermochemical soap stick having thermochemical reagents and to be provided into a wellbore in a subterranean formation, the thermochemical soap stick to dissolve in the liquid giving a thermochemical reaction to generate gas to foam the liquid, and displacing the liquid from the wellbore via pressure of the subterranean formation.

In a well in a subterranean formation, treatment fluids for time-released iron control are utilized. These treatment fluids contain a time-released form of a complexing agent or reducing agent, wherein the agent forms a soluble product with iron. The time-released form prevents loss of the agent prior to delivery to the desired site and at the desired time(s). Methods for controlling iron in a well in a subterranean formation utilize these treatment fluids containing a time-released form of a complexing agent or reducing agent and these methods create soluble products when the agent interacts with the iron to control the iron from the formation and/or well.

Provided is a method that may include introducing into a wellbore as a single stage treatment a composition that may include a fluid formulation that is a water-in-oil emulsion having an organic phase and an aqueous phase, the aqueous phase dispersed in the organic phase; maintaining the wellbore by shutting-in the well; and hydraulic fracturing the wellbore. The composition may contain a chelating agent and may interact with an oil-based sludge or filter cake, which may contain barite, at a target zone, allowing the composition to remove a portion of the oil-based mud sludge or filter cake.

Provided is a method that may include introducing into a wellbore as a single stage treatment a composition that may include a fluid formulation that is a water-in-oil emulsion having an organic phase and an aqueous phase, the aqueous phase dispersed in the organic phase; maintaining the wellbore by shutting-in the well; and hydraulic fracturing the wellbore. The composition may contain a chelating agent and may interact with an oil-based sludge or filter cake, which may contain barite, at a target zone, allowing the composition to remove a portion of the oil-based mud sludge or filter cake.