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.

An object of the present invention is to provide a salt water thickener that uniformly (favorably) disperses ultrafine cellulose fibers even in a liquid containing a salt (electrolyte). The salt water thickener comprises ultrafine cellulose fibers and a water-soluble polymer and can thereby uniformly disperse the ultrafine cellulose fibers even in a liquid containing a salt. The salt water thickener of the present invention is uniformly dispersed even in a liquid containing a salt and therefore exerts a high viscosity. The salt water thickener of the present invention can also be used as an additive for a fluid. The salt water thickener of the present invention can be used for purposes, for example, subterranean formation processing.

A system and a method for use of electric motors in fracturing operations are disclosed. The system includes an electric motor, a turbine generator, an encoderless vector control subsystem, and at least one pump. The turbine generator is adapted to generate electric power for the system. The encoderless vector control subsystem is coupled between the turbine generator and the electric motor to control the electric motor using determined parameters that are based in part on vibration induced in a feature associated with the turbine generator. The at least one pump is adapted to receive torque input from the electric motor.

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.

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.

Systems and methods for predicting and optimizing the effects of acidizing treatment of carbonate rock are disclosed. The disclosed methods predict the conflicting effects of increased production (i.e., wormhole creation) and reduced rock compressive strength due to acid rock reactions. The mechanical stability of stimulated wellbores, such as horizontal wellbores, can be determined under different acidizing conditions, such as acid type and volume. The acidizing conditions can be optimized to maximize short and long-term production.

A novel method for the placement of spearhead acid and stimulation of a hydrocarbon-bearing formation, said method comprising the steps of: providing a wellbore in need of multiple stages of stimulation; inserting an isolation plug in the wellbore at a predetermined location; inserting a perforating tool and a spearhead or breakdown acid into the wellbore simultaneously exposing the wireline and tool to the acid; 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.

A system and a method for use of electric motors in fracturing operations are disclosed. The system includes an electric motor, a turbine generator, an encoderless vector control subsystem, and at least one pump. The turbine generator is adapted to generate electric power for the system. The encoderless vector control subsystem is coupled between the turbine generator and the electric motor to control the electric motor using determined parameters that are based in part on vibration induced in a feature associated with the turbine generator. The at least one pump is adapted to receive torque input from the electric motor.

A process for the fracking or stimulation of a hydrocarbon-bearing formation, said process 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 fracking or stimulation; removing the tool form the wellbore; and initiating the fracking of the perforated area using a fracking fluid.

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.