Abstract: Improved methods and apparatus are provided for recovering high viscosity oils from a sub-surface earth formation utilizing horizontal well apparatus. A plurality of horizontal drill holes extend from a large diameter vertical shaft hole into the formation of interest. Steam may be injected into the formation through selectively placed conventional vertical wells terminating within the oil-bearing formation, while oil is recovered from the lateral drill holes. A noncondensible gas or cold water may be injected into the formation subsequent to steam injection to enhance the overall recovery of oil.

Abstract: Improved methods and apparatus are provided for recovering high viscosity oils from sub-surface earth formations. In particular, a large diameter shaft hole is employed and a plurality of substantially horizontal drill holes extend radially from the shaft hole into the formation. It is a feature of this invention to provide vertically spaced drill holes oriented to improve the recovery of the oil. Methods are provided for further enhancing oil recovery by coordinating the injected fluid with the location of injection within the formation.

Abstract: This invention relates to methods and systems for recovering high viscosity oils, petroleum substances and other minerals from subsurface earth formations. In particular, one or more large diameter shaft holes are provided which preferably terminate in an enlarged subterranean chamber. A plurality of drill holes are provided, with perforated piping which extend radially from the chamber into the formation, and from which oil and the like may be recovered. It is a particular feature of this invention to provide means and methods for injecting a mixture of steam and a noncondensable gas into the drill holes, whereby the driving mechanism of the formation may be selectively maintained or enhanced at the same time the viscosity of the oil in the formation is reduced.