Abstract: An apparatus and method are disclosed for determining the steam quality of a steam-water mixture prior to passage of the mixture from a steam injection well into steam-floodable formations located adjacent the well. The apparatus which may be lowered down into a steam injection well comprises a radiation emitting source located a selected distance away from a radiation detecting source. The steam-water mixture passes between the emitter and the detector. In operation an increase in the water content of the mixture causes attenuation of the radiation received by the detector. The decrease in the radiation received by the detector decreases the output signal of the detector. Corresponding signal changes as the steam quality of the mixture varies may be studied to determine the existing downhole steam quality at a particular location in the well.

Abstract: Relative permeabilities to flowing steam water and/or oil phases within cores of earth formations are determined by flowing such fluids at reservoir conditions, sealing them within the cores, X-ray scanning the sealed cores and determining the saturations from densities and/or tagged oil volumes and determining the permeabilities from measured pressures and temperatures.

Abstract: Oil is produced by drilling parallel horizontal wells within a deep subterranean reservoir, extending parallel vertical fractures between the wells, heating the reservoir by flowing hot fluid through all fractures and producing oil by displacing fluid between the fractures.

Abstract: Viscous asphaltenic crude oils are converted to pumpable liquid oil products in field locations by precipitating and separating asphaltenes, then mildly thermally converting the asphaltenes to mobile asphaltene-conversion products that can be mixed with at least the maltene components of the crude oils to form the pumpable liquid oil products.

Abstract: A substantially solids-free sample of an oil having substantially the same hydrocarbon distribution as a heavy oil contained in a subterranean reservoir is prepared by vacuum-topping a field sample of the oil or oil-containing material while cold-trapping volatiles, diluting the topped oil with a volatile oil solvent, mechanically separating the solution from entrained solids, vacuum-distilling the solvent from the dissolved oil and recombining the oil and the cold-trapped volatiles.

Abstract: In producing shale oil from a relatively permeable leached zone within a subterranean oil shale deposit, hot aqueous fluid is flowed between wells along paths which are vertically varied. An initial flow between near-bottom injection and production locations within the leached zone is varied by steps inclusive of producing fluid from a near-top location and injecting fluid into the initial production location.

Abstract: In producing shale oil by circulating hot fluid into and out of void spaces within a subterranean oil shale, a plurality of cavities are formed around a central well, the cavities and the well are interconnected by leaching an areally extensive void space within a layer of water-soluble mineral, and hot fluid is circulated in through the cavities and out through the central well.

Abstract: The forming of a rubble-containing cavity within a subterranean oil shale is improved by: leaching water-soluble minerals to form an areally extensive void in or above an upper portion and an areally extensive permeable zone or void within or contiguous with a lower portion of the oil shale; displacing an explosive fluid into the lower permeable zone; and detonating the explosive.

Abstract: In producing shale oil by circulating hot fluid into and out of a rubble-containing cavern within a subterranean oil shale, plugging is avoided by permeating a portion of oil shale, consolidating a permeated portion, inflowing fluid outside the consolidated portion, and outflowing fluid from within the consolidated portion so the fluid is filtered through the consolidated portion.