Abstract: A method of making a load bearing surface comprising mixing flyash with phosphogypsum in predetermined amounts to form a subbase disposed on a subgrade, sequentially spraying water onto the subbase and compacting for a plurality of cycles until the materials therein are intimately mixed, densified, and the subbase layer is saturated with water. A base layer comprising a mixture of flyash and phosphogypsum in predetermined amounts is disposed on the subbase layer and sequentially sprayed with water and compacted for a plurality of cycles until the materials therein are intimately mixed, densified, and the base layer is saturated with water. The load bearing surface produced has CBR values ranging from 50 to 90 at 0.1 inch penetration.

Abstract: The sweep efficiency of a steam drive process is improved and steam override reduced significantly if steam is injected into a formation until channeling has begun, after which steam injection is terminated and a slug of a thermally stable diverting fluid comprising a high molecular weight hydrocarbon within the temperature range of 500.degree. to 1000.degree. F. is injected into the steam-swept zone and allowed to cool until the diverting fluid has increased in viscosity to a value greater than the in place oil thereby creating a highly immobile slug in the steam-swept zone. Thereafter, injection of steam is continued and oil recovered. Multiple cycles of steam injection and rejection of slugs of diverting fluid may be repeated to improve sweep efficiency depending upon the vertical thickness of the formation.

Abstract: A method for determining the foaming characteristics of a crude oil stream at the wellhead comprising introducing the production crude oil stream from the wellhead into an elongated, horizontal separator under reduced pressure at a controlled flow rate, withdrawing evolved gas from the upper portion of the separator and measuring the flow rate thereof, withdrawing oil from the lower portion of the separator and measuring the flow rate thereof, controlling the pressure on the separator at a lower pressure than the wellhead pressure, controlling the liquid level of the oil in the separator, measuring the volume of oil in the separator, and measuring the volume of foam in the separator.

Abstract: A well completion for an injection well includes continuous tubing disposed within a tubing string. Oxygen is supplied to a fire flood process through the continuous tubing and water is supplied through the tubing string. The tubing string and continuous tubing are valved and seated in a manner which provides for safe injection of high purity oxygen into the subsurface formation.

Abstract: This invention concerns a process for extracting chromium (III) from an aqueous solution containing chromium (III) with an extractant comprising a mixture of mono-2-ethylhexyl phosphoric acid and di-2-ethylhexyl phosphoric acid. An organic solvent such as a low aromatic kerosene is employed in this invention for dilution and dissolution of the extractant. Aqueous acid waste streams containing chromium (III) can be reduced to a chromium (III) concentration of 80 ppm thereby enabling the stream to be reclaimed.

Abstract: The vertical conformance of a steam drive process is improved by conducting the steam flood process in two stages. In the first stage, steam is injected into the lower portion of the formation via an injection well and oil is recovered from the upper portion of the formation via a spaced apart production well. Once there is a breakthrough of steam at the production well, injection of steam and production are terminated. In the second stage, the roles of the injection well and production well are reversed. A thermal recovery fluid comprising steam or hot water is injected into the lower portion of the formation via the production well and oil is recovered from the lower portion of the formation via the injection well until the oil recovered contains an unfavorable amount of steam or water.

Abstract: Oil is recovered from an oil-bearing reservoir in a process employing an in-situ combustion process utilizing a combustion-supporting gas containing at least 75% by volume pure oxygen, and preferably substantially pure oxygen, and a sequence in which the production well or wells are cyclically throttled. In place of using an in-situ combustion process, mixtures of steam and carbon dioxide or mixtures of steam and low molecular weight C.sub.3 -C.sub.8 hydrocarbons are injected into the reservoir and the production well is cyclically throttled. The production well flow rate is restricted until the bottom-hole pressure of the well has increased to an amount of about 30% to about 90% of the fluid injection pressure at the injection well. Thereafter, the production well is opened and oil is recovered therefrom as the bottom-hole pressure declines. The throttled production cycle may be repeated at appropriate intervals during the process.

Abstract: Oil is recovered from an oil-bearing reservoir in a process employing an in-situ combustion process utilizing a combustion-supporting gas containing at least 75% by volume pure oxygen, and preferably substantially pure oxygen, and a sequence in which the production well or wells are cyclically throttled. In place of using an in-situ combustion process, mixtures of steam and carbon dioxide or mixtures of steam and low molecular weight C.sub.3 -C.sub.8 hydrocarbons are injected into the reservoir and the production well is cyclically throttled. The production well flow rate is restricted until the bottom-hole pressure of the well has increased to an amount of about 30% to about 90% of the fluid injection pressure at the injection well. Thereafter, the production well is opened and oil is recovered therefrom as the bottom-hole pressure declines. The throttled production cycle may be repeated at appropriate intervals during the process.

Abstract: Oil is recovered from an oil-bearing reservoir in a process employing an in-situ combustion process utilizing a combustion-supporting gas containing at least 75% by volume pure oxygen, and preferably substantially pure oxygen, and a sequence in which the production well or wells are cyclically throttled. In place of using an in-situ combustion process, mixtures of steam and carbon dioxide or mixtures of steam and low molecular weight C.sub.3 -C.sub.8 hydrocarbons are injected into the reservoir and the production well is cyclically throttled. The production well flow rate is restricted until the bottom-hole pressure of the well has increased to an amount of about 30% to about 90% of the fluid injection pressure at the injection well. Thereafter, the production well is opened and oil is recovered therefrom as the bottom-hole pressure declines. The throttled production cycle may be repeated at appropriate intervals during the process.

Abstract: Measuring the foaming characteristics of crude oil comprises saturating the crude oil with a gas inert to the crude oil under high pressure and passing the gas-saturated oil into a flash separator. The amount of foam formed is measured with respect to the amount of gas withdrawn from the flash separator and the amount of oil contained therein.

Abstract: The present invention relates to an improved process for the recovery of bitumen from tar sands comprising first heating the raw tar sands with steam at a temperature sufficient to visbreak a portion of the bitumen without significant thermal cracking thereby producing a vaporous distillate product mixed with steam and lowering the viscosity and specific gravity of the residual bitumen on the heat treated tar sands. The distillate product and steam are cooled and condensed and mixed with the heat treated tar sands containing residual beneficiated bitumen to form a slurry. Bitumen is then recovered from the slurry by a hot-water separation process.

Abstract: Viscous crude oil is mixed with an oil diluent having a relatively low viscosity and the resulting mixture having a predetermined viscosity and flow rate is pumped in a pipeline to a point of use. The flow rates of the viscous crude oil and the diluent are controlled with the aid of a digital computer in response to signals representative of the viscosity and specific gravity of each component, the desired viscosity of the mixture and the flow rate of the mixture. The viscosity of the mixture is maintained substantially at the design viscosity of the pipeline at the operating temperature of the pipeline and the flow rate of the mixture is substantially equal to the design capacity of the pipeline.

Abstract: A method for the recovery of oil from a subterranean, viscous oil-containing formation by injecting steam into the lower portion of the formation, simultaneously injecting water into the formation to build up the pressure of the formation to about 300 psia, maintaining the formation pressure at about 300 psia during the steam drive, and producing oil from the upper portion of the formation.

Abstract: A method for recovering viscous oil from a subterranean, viscous oil-containing formation by initiating an in-situ combustion operation in the formation using a mixture of oxygen and an inert gas having a low oxygen concentration, preferably about 21 vol. %. After a predetermined period of time, the oxygen concentration is increased to a predetermined higher level, preferably within the range of 95 to 99.5 vol. %. Once the oxygen concentration has reached the desired value, water may be simultaneously injected continuously or intermittently. After a predetermined period of time, produced combustion gas enriched in carbon dioxide separated from the produced oil is compressed and recycled as a diluent for the injected oxygen in place of the inert gas.

Abstract: Viscous oil is recovered from a subterranean, viscous oil-containing formation by injecting a slug of CO.sub.2 carbonated water containing a CO.sub.2 solubility promoter, a slug of a CO.sub.2 solubility demoter, and a water drive to displace the mobilized oil to a production well for recovery.

Abstract: This invention discloses a method and system for continuously measuring the amount of solid cuttings picked up by a drilling mud being circulated in a well being drilled into subterranean formations and the amount of drilling mud carried over with the cuttings when the cuttings are separated from the drilling mud by a shale shaker. The cuttings and carryover mud discharged from the shale shaker are introduced into a vessel wherein the weight and volume of the solid cuttings and carryover mud are continuously measured and the volume fraction of solid cuttings .phi..sub.c is determined in accordance with the following equation: ##EQU1## wherein W is the weight of a fixed volume of solid cuttings and carryover mud discharged from the shale shaker, V is the volume of solid cuttings and carryover mud discharged from the shale shaker, P.sub.m is the density of the drilling mud, and P.sub.c is the density of the solid cuttings. The volume fraction of the carryover mud .phi..sub.

Abstract: Recovery of oil in a subterranean oil-bearing formation comprising injecting a slug of an aqueous solution containing a water-soluble salt comprising sodium oxalate or sodium fluoride, injecting a slug of CO.sub.2 and injecting a driving fluid to displace the oil toward a production well for recovery. The water-soluble salt forms an insoluble precipitate with calcium ions in the formation and preserves more of the injected CO.sub.2 for oil displacement including preventing undesirable changes in formation permeability.

Abstract: An in-situ combustion method for recovering viscous oil from a subterranean, viscous oil-containing formation comprising injecting a mixture of essentially pure oxygen and carbon dioxide into the formation to initiate an in-situ combustion operation followed by injecting essentially pure oxygen.

Abstract: This invention is a comminution process for treating coal with a drying gas to form fractures which weaken the structure of the coal and make it easier to disintegrate mechanically, chemically or by fluid force. Another aspect of this invention is a process for treating an underground formation of coal with a dry gas for a time sufficient to form cracks and fractures in a portion of the formation in order to increase the permeability of the coal formation to the flow of fluids therethrough. Processes for in-situ combustion of the coal formation are therefore more efficient since the coal formation is more permeable to the flow of gas therethrough.

Abstract: In-situ combustion of heavy subterranean oil formations, e.g., tar sands, is improved by introducing into the oil formation a stream of a combustible gas. The stream of gas may contain a small proportion of hydrocarbons condensable at temperature and pressure conditions of the formation. The improvement is applicable to both forward and reverse in-situ combustion processes.