A method for in situ solution mining of a mineral from an underground evaporite stratum using a set of wells in fluid communication with at least one mineral cavity with some wells operated in solvent injection mode and other wells operated in brine production mode and optionally with some inactive wells, comprising switching the operation mode of one or more wells. The evaporite mineral preferably comprises trona. The at least one cavity may be formed by directionally drilled uncased boreholes or by lithological displacement of the evaporite stratum at a weak interface with an underlying insoluble stratum by application of a lifting hydraulic pressure to create an interfacial gap. The extracted brine can be processed to make valuable products such as soda ash and/or any derivatives thereof. This method can provide more uniform dissolution of mineral in the cavity, minimize flow channeling, minimize sodium bicarbonate blinding for solution mining of incongruent trona ore, and/or may avoid uneven deposit of insolubles.

A method for the stimulation of a hydrocarbon-bearing formation, said method comprising the steps of: providing a wellbore in need of stimulation; inserting a plug in the wellbore at a location slightly beyond a predetermined location; inserting a perforating tool and a spearhead or breakdown acid into the wellbore; positioning the tool at said predetermined location; perforating the wellbore with the tool thereby creating a perforated area; allowing the spearhead acid to come into contact with the perforated area for a predetermined period of time sufficient to prepare the formation for stimulation; removing the tool form the wellbore; and initiating the stimulation of the perforated area using a stimulation fluid. Also disclosed is a corrosion inhibiting composition for us with the acid composition.

A system and method for hydraulic fracturing including mixing seawater with an additive to precipitate sulfate from the seawater and mixing a flocculating agent with the seawater to agglomerate the sulfate precipitates.

Methods for mining soluble minerals from a subterranean deposit. A fluid is injected into a horizontal injection wellbore passing through the deposit and allowed to enter a mining/fracture plane having at least one fracture, extending from the horizontal injection wellbore, at a pressure sufficient to further fracture the deposit, maintain the mining/fracture plane or open the mining/fracture plane. The injected fluid is allowed to dissolve some of the soluble minerals from the deposit thereby forming a mineral solution which is produced from horizontal production wellbores that intersect the mining/fracture plane.

A method for the fracking or stimulation of a hydrocarbon-bearing formation, said method comprising the steps of: providing a wellbore in need of stimulation; inserting a plug in the wellbore at a predetermined location; inserting a perforating tool and a spearhead or breakdown acid into the wellbore; positioning the tool at said predetermined location; perforating the wellbore with the tool thereby creating a perforated area; allowing the spearhead acid to come into contact with the perforated area for a predetermined period of time sufficient to prepare the formation for fracking or stimulation; removing the tool form the wellbore; and initiating the fracking of the perforated area using a fracking fluid.

Also disclosed is a corrosion inhibiting composition for us with the acid composition.

A method for the stimulation of a hydrocarbon-bearing formation, said method comprising the steps of: providing a wellbore in need of stimulation; inserting a plug in the wellbore at a location slightly beyond a predetermined location; inserting a perforating tool and a spearhead or breakdown acid into the wellbore; positioning the tool at said predetermined location; perforating the wellbore with the tool thereby creating a perforated area; allowing the spearhead acid to come into contact with the perforated area for a predetermined period of time sufficient to prepare the formation for stimulation; removing the tool form the wellbore; and initiating the stimulation of the perforated area using a stimulation fluid.

Also disclosed is a corrosion inhibiting composition for use with the acid composition.

Method of decomposing high molecular weight polymer downhole to prevent chelation of iron by residual high molecular weight polymer thereby producing flowback without iron contamination as chelated iron. A secondary method is also described to treat iron chelated produced water with oxidants at surface conditions, utilizing aluminum electrolytes, specifically low basicity polyaluminum chloride, to either co-precipitate residual polymer and bound iron, or to substitute chelated iron with aluminum in the polymer-metal complex, resulting in liberating of iron to enable neutral pH oxidation and removal by precipitation, coagulation, flocculation and physical separation. The produced water with removed iron can be then stored or re-used for other oilfield applications.

Methods for cavern rubblization for enhanced potash recovery are disclosed. In embodiments, such a method includes pressure cycling. The method can include pressurizing a cavity to maximum flow capacity followed by rapid relief of the cavity pressure. In this embodiment, this cycle of pressurization and rapid relief is repeated several times. Other embodiments of cavern rubblization and methods for enhanced potash recovery, a technique of fluid pulsing is used. According to embodiments, a tool can be used to pulse pressure through clay seams to be wetted. According to both embodiments, these methods increase potash recovery during mining.

A system and method for hydraulic fracturing including mixing seawater with an additive to precipitate sulfate from the seawater and mixing a flocculating agent with the seawater to agglomerate the sulfate precipitates.

The invention includes methods for stimulating a hydrocarbon-bearing formation by perforating a wellbore and introducing an acidic composition in the wellbore. A preferred embodiment includes inserting an isolation plug in the wellbore at a predetermined location followed by inserting a perforating tool and a breakdown acid into the wellbore. The wellbore is perforated by the tool to create a perforated area. The breakdown acid is allowed to come into contact with the perforated area for a predetermined period of time sufficient to prepare the formation for stimulation. The tool is then removed from the wellbore wherein stimulation of the perforated area is thereby initiated. Also disclosed is a corrosion inhibiting composition for use with the acidic composition.