Abstract: This invention relates to the solution mining of subterranean trona deposits which comprises treating the ore "in situ" with an aqueous solvent containing sodium hydroxide at a concentration of not less than approximately 1% and no greater than that which will leave the brine thus produced with no less than approximately 1.5 parts of sodium bicarbonate per hundred parts of sodium carbonate when saturated.

Abstract: A technique is described for igniting the oil shale rubble pile in an in situ oil shale retort. A gas-air burner is lowered through a hole to a plenum over the oil shale to be ignited. An excess of air is passed through the hole and around the burner so that it is kept cool as the flame from it impinges on the rubble pile. The air also transfers heat downwardly into the rubble pile and provides oxygen for combustion of carbonaceous material in the shale. Preferably the burner is in a cylindrical housing having a flame exit at its lower end so that a hot flame is ejected downwardly.

Abstract: An in situ retorting method and system for recovering hydrocarbons from an oil shale deposit. A retorting zone is formed in the deposit and is comprised of at least two galleries which are separated by a barrier of oil shale thick enough to prevent leakage of gas between galleries. A plurality of rooms are formed within each gallery and are defined by walls of oil shale having substantially less thickness than said barriers. As a gallery is completed, it is sealed and rubblized oil shale within the rooms of said gallery is retorted and the products recovered. Since the barriers between galleries protect workers against gas from a retorting gallery, work can continue on adjoining galleries while said gallery is being retorted.

Abstract: A method of liquefying a coal formation in situ wherein the coal formation has been preheated as by a coal gasification project, includes the steps of establishing injection and removal passages connecting the coal formation to the surface, injecting water having a temperature below the formation temperature into the formation to gradually lower the temperature of the formation while forming synthesis gas, injecting a solvent material, having the capability of dissolving the coal, into the formation after it has been reduced to the desired temperature, injecting synthesis gas into the formation to hydrogenate the coal, allowing the formation to subside as the coal is dissolved therein so that more surface area of coal is exposed to the solvent, and removing the admixture of coal and solvent material from the formation as a synthetic crude oil.

Abstract: The fluid productivity of a relatively unconsolidated oil producing subterranean siliceous reservoir is improved by a limited flow rate sequential injection of oil solvent, relatively dilute hydrogen fluoride-free acid, and relatively dilute hydrogen fluoride containing-acid, and a gradual returning of the well to production.

Abstract: A method for operating an in situ combustion process in a petroleum containing reservoir wherein a plurality of air injection wells are spaced so that the approximate distance between the wells will be twice the distance at which the flux of air to the burning front from a single injection well becomes negligible.

Abstract: One embodiment includes an oil recovery process, more particularly a secondary or tertiary type crude oil recovery process utilizing a drive fluid to move a displacing fluid through a subterranean formation wherein the displacing fluid displaces crude oil therefrom and is driven through the formation by means of the drive fluid. The crude oil recovery process is improved by utilizing as the drive fluid a thickened, transparent, aqueous solution of a water-soluble sulfated, polyethoxylated C.sub.10 -C.sub.18 primary alcohol or alkylated phenol. The displacing fluid is generally an aqueous surfactant solution, a miscible displacing medium or most preferably a microemulsion. In a further embodiment, the water-soluble, polyethoxylated C.sub.10 -C.sub.18 primary alcohol or alkylated phenol is employed as a mobility control agent in a waterflood thereby increasing the sweep efficiency thereof.

Abstract: A method for consolidating an oil-bearing formation by the use of a consolidating material together with a combustion promoter whereby oxidation occurs upon the injection of an oxygen-containing gas, thereby affecting consolidation of the formation.

Abstract: A pressure operated safety valve adapted to be mounted in a well tubing, which may be moved to open or closed positions independently of pressure in the tubing and locked in and unlocked from the open position using control fluid pressure.

Abstract: A three surfactant system usable in high temperature petroleum formations containing water having from about 200 to about 14,000 parts per million polyvalent ions such as calcium and/or magnesium dissolved therein and a pH of from 5 to 9, and a method of using said surfactant system for recovering petroleum from high temperature subterranean petroleum-containing formations. The three component surfactant system comprises (1) water-soluble salt of an alkyl or alkylaryl sulfonate wherein the alkyl chain may have from 5 to 25 carbon atoms, (2) a phosphate ester surfactant with an average molecular weight not to exceed 1000, and (3) a surfactant having the following betaine-related structure: ##EQU1## wherein R is an alkyl group having from 12 to 24 carbon atoms, and n is an integer from one to five. The surfactant combination is stable up to at least 225.degree.F and resistant to bacterial attack and inhibits scale formation.

Abstract: Micellar systems which are neither oil-external nor water-external can be formed from petroleum sulfonates, e.g., crude oil sulfonates formulated with water and, optionally, cosurfactants, e.g., hexanol. Because such micellar systems resist uptake of both oil and water, they are suitable for long distance displacement in which injection wells are spaced at least about 300 feet from production wells.

Abstract: Methods are provided for acidization of wells which are particularly useful in deep high-temperature oil and gas wells. The methods include injection of an acid halide which upon reaction with water in situ in the subterranean formation surrounding the well forms two acids, one of which is a halogen acid.

Abstract: Apparatus and method for cementing a liner in a well bore in which the apparatus may comprise: a setting tool having a tubular mandrel connected in a pipe string for extension through the liner; a liner wiper releasably disposed within the liner near one end of the mandrel; a plug member for effecting a movable seal behind cement as it is pumped through the pipe string into the liner; a seal assembly sealingly engaging the exterior of the mandrel and the interior of the liner above the liner wiper; and a latch assembly releasably connecting the seal assembly to the liner so as to permit limited axial movement of the mandrel without disturbing the axial position of the seal assembly. In the method of cementing a liner using the apparatus, the force due to pressure applied to the seal assembly, during pumping of cement, is transferred to the liner without transfer to the mandrel.

Abstract: An improved anionic waterflood additive is prepared by alkylating an aromatic hydrocarbon such as benzene with a branched-chain alkene having about 10 to about 35 carbon atoms such as a propylene tetramer dimerization reaction product in the presence of an alkylation catalyst such as AlCl.sub.3 ; sulfonating the thus formed alkylate product or a fraction thereof to form a sulfonic acid; converting the sulfonic acid to a sulfonate by reacting with a base component such as an alkali metal hydroxide, ammonium hydroxide, or an alkali metal carbonate; and overbasing the sulfonate by admixing with an excess of base component such that the ratio; "weight of excess base component/weight of sulfonate" is about 0.03 to about 3.0. The anionic waterflood additive is injected into a petroliferous formation, the formation is waterflooded, and oil is recovered.

Abstract: 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.

Abstract: In order to increase the productivity of oil and gas wells, hydrochloric acid and phosphoric acid are pumped into the well. Thereafter, aqueous ammonia is forced into the bottom of the well by nitrogen under pressure. This produces a violent exothermic reaction in the formation around the bottom of the well which emulsifies the paraffin and disintegrates the limestone, so as to open the formation by forming large passages and cavities over large areas and distances, permitting the oil or gas to flow freely through the formation to the well bore.