Abstract: The invention encompasses a process and equipment for an aggressive approach to remediation of specific hydrocarbon contaminated soil and groundwater using horizontal sparging pipes in or below the contamination with a matrix of vertical pipes that act to conduct sparger gas with associated hydrocarbons to the surface for hydrocarbon removal before recycle and also to collect and strip hydrocarbons washed horizontally into the collector pipes by injection of a washing fluid through a matrix of vertical wash pipes spaced between the collector pipes.

Abstract: Disclosed is a process for the recovery of oil from a subterranean oil reservoir by miscible displacement using a predominantly nitrogen-containing gaseous displacing fluid which may contain lesser quantities of carbon dioxide. The miscibility of the first portion of the gaseous displacing phase injected into the formation is greater than the miscibility of the subsequent portion, as a consequence of increased concentrations of carbon dioxide and/or normally liquid hydrocarbons for the purpose of decreasing the time and distance which the gaseous nitrogen-containing displacing fluid must travel into the reservoir before attaining a conditionally miscible transition zone at reservoir conditions of temperature and pressure. The concentration of carbon dioxide and/or normally liquid hydrocarbons may be decreased in a reverse taper function, after which essentially pure nitrogen or nitrogen containing only minimal amounts of more soluble components may be injected into the formation.

Abstract: Oil is produced from a steeply dipping subterranean reservoir containing high viscosity petroleum by injecting a fluid comprising steam into the lower portion of the reservoir and withdrawing the oil from production wells in an intermediate portion of the reservoir while injecting a fluid such as cold water into the updip portion of the reservoir to prevent loss of steam vapor therethrough.

Abstract: Disclosed is a Process for the recovery of oil from a subterranean oil reservoir by miscible displacement. An initial light hydrocarbon slug is injected into the reservoir at a rate which results in fingering of the hydrocarbon through the reservoir oil to produce a light hydrocarbon-reservoir oil mixture. Thereafter, a predominantly nitrogen containing gas is injected into the reservoir at a rate resulting in a flow velocity which is less than the velocity of the previously injected light hydrocarbon. Injection of the nitrogen containing gas strips the previously injected light hydrocarbon from the oil to form a transition zone of conditional miscibility. The miscible zone is then displaced through the reservoir by injection of a suitable driving agent. By injecting the light hydrocarbon slug, the path length through the reservoir needed to establish the conditionally miscible transition zone at the reservoir conditions of temperature and pressure can be materially decreased.

Abstract: Recovery of oil from a dipping subterranean oil-bearing reservoir is effected by the injection of a first slug of a light hydrocarbon at a high rate to insure mixing with the reservoir oil adjacent the injection well followed by the injection of a second slug of carbon dioxide at a low rate to form a conditionally miscible transition zone with the altered reservoir oil and thereafter by the injection of a drive agent.