Abstract: Process for hydraulically guiding a layer of gellable grout solution (containing water-soluble Al or Fe salts, alkali metal silicates, or silica sols) to form a sealed confining layer beneath or around a contaminated zone beneath the water table which prevents both lateral and down-ward movement of contaminants or contaminated water.

Abstract: A mixture of an epoxy material and two hardeners is placed in a subsurface zone in which it is desired to form an impermeable zone, and the epoxy is thereafter allowed to harden. The epoxy material and hardeners are characterized inthat: (1) each hardener has a different activation temperature; (2) the amount of each hardener in the mixture is less than that required to totally react the epoxy material; (3) the epoxy material has a low viscosity at subsurface conditions of temperature and pressure; (4) the epoxy material is substantially immiscible with any fluids which are present in the subsurface area; and (5) the hardening time of the epoxy material is of short duration at subsurface conditions of temperature and pressure.

Abstract: A process for sealing casing leaks comprises cleaning out the annulus between the tubing and the casing, situating a gelable mixture in the annulus at the loci of the leak in the casing, pressuring the mixture through the leak into the formation and effecting gelation of the mixture. Optionally, the remaining gelable mixture may be circulated out of the annulus. Gelable mixtures can be comprised of various organic and inorganic gel polymers.

Abstract: The addition of vaporized solvent to injected steam in a fracture-assisted steamflood process provides surprisingly significant enhancement of the process as compared to both the basic fracture-assisted steamflood process of the Britton et al. U.S. Pat. No. 4,265,310 patent and to a conventional matrix drive type steamflood process utilizing solvent. Much lower solvent losses to the formation are observed than are generally provided by conventinal matrix drive type steamflood processes utilizing solvent. Dramatically different effects of the addition of heat-scavenging water follow-up after the steam injection phase are observed as compared to a conventional process utilizing solvent. Directly opposite effects are observed from changes in solvent composition as compared to conventional matrix drive type steamflood processes utilizing steam; for the present invention SOR is decreased by going to lighter solvents, whereas with a conventional process, lighter solvents increase the SOR.