In acidizing a well, fluid inclusive of at least one carbonyl compound, an aqueous liquid and at least one material which contains or forms sulfite ions in the aqueous liquid is injected to form at least one alpha-hydroxysulfonic acid in contact with acidifiable material in and around the well.

The invention relates to a blow torch (6) for a cutting process, in particular a steam cutting process, comprising a control device (3), a liquid supply system, in particular a container (5) for a liquid (8), and a power source (2), the blow torch (6) being connected via lines (9, 10) to the power source (2). The blow torch (6) is connected by a supply line (7) to the liquid supply system. At least one duct or flow passage for the liquid (8) having a predeterminable cross section and path is provided in the blow torch (6) and is designed to convert the liquid (8) into a gaseous state, in particular a gas (19).

Viscous oil in a geological formation is recovered by producing hydrogen peroxide near the formation, injecting hydrogen peroxide into the formation to effect its decomposition and reaction of oxygen with resident hydrocarbon, and recovering oil in response to injection of hydrogen peroxide.

A steam injection pipe system within a cased wellbore is processed to reduce the emissivity of an outwardly facing surface. The pipe system is combined with: (1) a cleaning device or process for maintaining the low emissivity surface; and (2) a mixed fluid non-condensable gas supply to exclude steam from an annular space. This achieves a low cost and low thermal loss steam injection system. The pipe is composed of stainless steel and is polished to reduce the emissivity. The pipe is assembled and run into a cased wellbore. The polished surface of the pipe sections is solvent washed and surrounded by a non-condensable gas within the casing/pipe annulus. The non-condensable gas is introduced at the periphery of the injection pipe, mixed with the steam, and separated down-hole to fill the annulus. The cleaned low emissivity surface and mixed feed fluid gas supply achieves a significant reduction in heat loss without costly pipe insulation when compared to bare pipe injection.

There is disclosed an improved process and apparatus for generating a gaseous media for stimulating and/or fracturing a hydrocarbon bearing well formation comprised of a substantially horizontally-disposed gas generator having a first catalyst reaction bed, an expansion chamber, a second catalyst reaction bed, a venturi chamber for forming a gaseous stream to be introduced into the hydrocarbon bearing well formation.