Abstract: This specification discloses a technique of hydraulically fracturing a subterranean formation wherein there is used a fracturing fluid comprised of an aqueous solution of an interaction product of a polysaccharide and a galactomannan.

Abstract: This specification is directed to a method of producing oil from an oil-containing subterranean formation by a caustic waterflood. Oil containing carboxylic acids is passed through an ion-exchange resin to selectively remove the carboxylic acids therefrom. The removed carboxylic acids are injected into the formation in conjunction with the caustic waterflood to enhance the production of oil from the formation.

Abstract: This specification discloses a method of recovering thermal energy from a coal formation having a preferred vertical fracture orientation. An injection well and a production well are provided to extend into the coal formation and a vertical fracture is formed by hydraulic fracturing techniques and propagated into the coal formation to communicate with both the wells. The vertical fracture is propped in the lower portion only. A combustion-supporting gas is injected into the propped portion of the fracture and the coal is ignited. Injection of the combustion-supporting gas is continued to propagate a combustion zone along the propped portion of the fracture and hot product gases generated at the combustion zone are produced to recover the heat or thermal energy of the coal. Water may also be injected into the fracture to transport the heat resulting from the combustion of the coal to the production well for recovery.

Abstract: This specification discloses a method of recovering the thermal energy of a subterranean coal formation that is penetrated by at least two wells. The subterranean coal formation is fractured by hydraulic fracturing techniquesto form at least two spaced apart fractures which extend through the coal formation and communicate with both of the wells. A combustion-supporting gas is injected into a first fracture and the coal is ignited to form a combustion front. Injection of the combustion-supporting gas is continued to propagate the combustion front through the coal formation along the first fracture. The heat or thermal energy generated by the combustion of the coal is conducted through the formation intermediate the fractures and into a second fracture. Water is injected via one well into the second fracture and flowed therethrough to the other well to absorb the thermal energy released by the combustion of the coal.

Abstract: This specification discloses a system and method for blending a dry chemical and a liquid. The system is comprised of a hopper for receiving and feeding the dry chemical into a pipe where it is transported by gas to a liquid weir and there mixed with the liquid. The hopper is adapted for having a positive pneumatic pressure applied at an upper location thereof and a negative pneumatic pressure applied at a lower location thereof to feed the dry chemical into a pipe. The dry chemical is then transported by gas through the pipe and directed from the downstream end of the pipe into the liquid weir. The liquid weir is adapted for having liquid flowed therethrough to mix and blend the liquid with the dry chemical. A container is provided to contain the blended mixture.

Abstract: This specification discloses a method of controlling an active zone that is penetrated in the drilling of a well. In accordance with the method there is formed a mixture of inert particulate material and an oil-wetting dispersing agent in a light oil and the mixture is circulated to a lower portion of the well and maintained there to allow the inert particulate material to separate from the light oil and form a plug in the well to control the active zone.

Abstract: This specification discloses a method of completing a cased well that penetrates a subterranean formation to control the production of sand from the formation. The well is provided with perforation tunnels that extend through the casing and communicate with the formation. Removable plugs are formed in the perforation tunnels and thereafter a gravel pack is formed and consolidated in the well within the casing adjacent the perforation tunnels. Thereafter the removable plugs are removed from the perforation tunnels to provide unobstructed tunnels for the flow of fluids from the formation into the well. The formation adjacent the perforation tunnels may also be consolidated to mitigate the movement of sand from the formation into the perforation tunnels.

Abstract: This specification discloses a method of producing hydrocarbons from an unconsolidated hydrocarbon-bearing formation that is penetrated by a well that has an irregular wall adjacent the formation. Granular particles that are water-wet are injected down the well to fill the irregularities in the wall and a packer that has lateral passageways therethrough is set against the well wall. Pressure is applied via the packer to the formation in an amount no greater than the overburden pressure on the formation and hydrocarbons are produced from the formation via the lateral passageways of the packer into the well.

Abstract: This specification discloses a method of creating a horizontally disposed fracture in a subterranean formation that is penetrated by a wellbore. Two packers are set in the wellbore against the formation to be fractured to define with the wellbore and intermediate the packers a fracture treatment zone. Hydraulic pressure is applied to the fracture treatment zone in an amount slightly less than that required to create a vertical fracture in the formation. Acoustical energy is applied in the fracture treatment zone to form a resonant condition therein and to provide rigid coupling of acoustic stress pulses between the packer and the formation and form a horizontal fracture in the formation. The horizontal fracture is propagated into the formation by the continued application of the hydraulic pressure to the fracture treatment zone.