A cemented open hole selective fracing system is shown. In the producing zone, an open hole is drilled therein and a production tubing is cemented in place. At preselected locations along the production tubing, the production tubing will have sliding valves located there along. The sliding valves may be selectively opened by a shifting tool, and the cement around the sliding valve dissolved. Thereafter, the formation may be fraced immediately adjacent the opened sliding valve. By selectively ope...

The present invention provides a method for enhancing the production of hydrocarbons from a subterranean formation. A hydrocarbon bearing formation, surrounding a well bore, is fractured with a fracturing fluid to create one or more fractures in the formation. The formation includes a higher permeability zone and a lower permeability zone with the fractures extending across both the higher and lower permeability zones. The lower permeability zone may contain a substantially higher concentration ...

A preferred novel breaker-crosslinker-polymer complex and a method for using the complex in a fracturing fluid to fracture a subterranean formation that surrounds a well bore by pumping the fluid to a desired location within the well bore under sufficient pressure to fracture the surrounding subterranean formation. The complex may be maintained in a substantially non-reactive state by maintaining specific conditions of pH and temperature, until a time at which the fluid is in place in the well b...

A subterranean region is plugged by flowing into it an aqueous emulsion containing an epoxy-resin-forming polyepoxy polymer, an acrylic-resin-forming polycarboxy polymer, and a material for controlling the rate of the interaction of said polymers, with the proportions of said materials arranged to cause the emulsion to become a resinous plug after being emplaced.

This is a method for increasing the permeability of an underground formation adjacent a well bore. The first step is to plug existing fractures in the formation from the interwell area to a location near the well bore. Next, the bore of the well and the fracture immediately adjacent to the bore are filled with a liquid explosive which is stemmed. Then the explosive is detonated, forming new fractures into the previously unfractured portion of the formation.

An improved method of fracturing an underground fluid bearing formation penetrated by a well bore for the production of fluids therefrom by injecting a composition capable of forming a fluid permeable barrier in said formation at a pressure sufficient to form fissures therein extending from said well bore, and thereafter maintaining pressure on the composition for a predetermined period to permit the composition to set and form a fluid permeable barrier in the formed fissures.

A method of treating an earth formation, especially a calcareous earth formation, containing petroleum and connate brine to stimulate production of the petroleum without substantially increasing the production of brine. A liquid pre-flush composition, including a water solution of polar solvent having dissolved in the solution rosin soap and fatty acid soap is injected into the formation. The preflush composition reacts with the connate brine to produce a precipitate that blocks the brine-bearin...

An improved method of fracturing an underground fluid bearing formation penetrated by a well bore for the production of fluids therefrom by injecting a composition capable of forming a fluid permeable barrier in said formation at a pressure sufficient to form fissures therein extending from said well bore, and thereafter maintaining pressure on the composition for a predetermined period to permit the composition to set and form a fluid permeable barrier in the formed fissures.

A method for fracturing a horizontal well at a plurality of locations along the length of the horizontal portion of the well by plugging previously fractured downstream fracture zones with a mixture of a proppant and a slump-inhibiting material.

A preferred novel breaker-crosslinker-polymer complex and a method for using the complex in a fracturing fluid to fracture a subterranean formation that surrounds a well bore by pumping the fluid to a desired location within the well bore under sufficient pressure to fracture the surrounding subterranean formation. The complex may be maintained in a substantially non-reactive state by maintaining specific conditions of pH and temperature, until a time at which the fluid is in place in the well b...