The Invention relates to an underground drilling rig (10) and a method for its erection, wherein the method, in a special embodiment, comprises erecting a mast structure (20) of the drilling rig (10) extending from a horizontal tunnel (production tunnel) into a vertical mast shaft (14) and by means of an erecting structure (50), wherein the mast structure (20) comprises a plurality of mast segments (60) connected to one another or connectable to one another.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

A method of drilling vertical and horizontal pathways to mine for solid natural resources involves a drill bit, at least one reamer, a first plugging material, and a second plugging material; drilling a testing wellbore to a specific vertical depth with the drill bit and identifying at least one desired mining section wherein the desired mining section is associated with a corresponding vertical depth; creating a new bottom end for the testing wellbore by filling the testing wellbore up to an offset distance with the first plugging material; drilling a horizontal access hole from the new bottom end into the desired mining section with the drill bit and enlarging it with a reamer; excavating cuttings from the desired mining section through the horizontal access hole; filling the horizontal access hole with the second plugging material; and repeating the drilling, enlarging, and filling process to create a plurality of lateral holes.

A method of drilling vertical and horizontal pathways to mine for solid natural resources involves a drill bit, at least one reamer, a first plugging material, and a second plugging material; drilling a testing wellbore to a specific vertical depth with the drill bit and identifying at least one desired mining section wherein the desired mining section is associated with a corresponding vertical depth; creating a new bottom end for the testing wellbore by filling the testing wellbore up to an offset distance with the first plugging material; drilling a horizontal access hole from the new bottom end into the desired mining section with the drill bit and enlarging it with a reamer; excavating cuttings from the desired mining section through the horizontal access hole; filling the horizontal access hole with the second plugging material; and repeating the drilling, enlarging, and filling process to create a plurality of lateral holes.

A method for mining using a laser to cause spalling includes the steps of generating and delivering a laser beam to a work surface of a geological strata having a sought after mineral to be removed from the stratum; moving the laser beam about three perpendicular axes so that a focal point of the laser beam moves across the working surface and rapidly increases the surface temperature of the working surface; providing a source of a cooling media, and delivering the cooling media to the working surface so as to rapidly cool the working surface subsequent to the rapid surface temperature increase generated by the laser beam so as to effect a fracturing of the working surface and to generate a plurality of chips from the working surface; and removing the chips spalled from the working surface.

A process for in situ thermal recovery of hydrocarbons from a reservoir is provided. The process includes: providing an oxygen-enriched mixture, fuel, feedwater and an additive including at least one of ammonia, urea and a volatile amine to a Direct-Contact Steam Generator (DCSG); operating the DCSG, including contacting the feedwater and the additive with hot combustion gas to obtain a steam-based mixture including steam, CO.sub.2 and the additive; injecting the steam-based mixture or a stream derived from the steam-based mixture into the reservoir to mobilize the hydrocarbons therein; and producing a produced fluid including the hydrocarbons.

A method for mining using a laser to cause spalling includes the steps of generating and delivering a laser beam to a work surface of a geological strata having a sought after mineral to be removed from the stratum; moving the laser beam about three perpendicular axes so that a focal point of the laser beam moves across the working surface and rapidly increases the surface temperature of the working surface; providing a source of a cooling media, and delivering the cooling media to the working surface so as to rapidly cool the working surface subsequent to the rapid surface temperature increase generated by the laser beam so as to effect a fracturing of the working surface and to generate a plurality of chips from the working surface; and removing the chips spalled from the working surface