초록 ▼

Shale oil is produced from a subterranean interval of oil shale, where the interval is initially substantially impermeable and contains a specified grade and thickness of oil shale. Said interval is conductively heated from borehole interiors which are kept hotter than about 600°C. and are heated at

Shale oil is produced from a subterranean interval of oil shale, where the interval is initially substantially impermeable and contains a specified grade and thickness of oil shale. Said interval is conductively heated from borehole interiors which are kept hotter than about 600°C. and are heated at a rate such that kerogen pyrolysis products formed within the oil shale create and flow through horizontal fractures which subsequently extend into fluid-producing wells that are positioned in specified locations.

대표청구항 ▼

In a process in which oil is produced from a subterranean oil shale deposit by extending at least one each of heat-injecting and fluid-producing wells into the deposit, establishing a heat-conductive fluid-impermeable barrier between the interior of each heat-injecting well and the adjacent deposit,

In a process in which oil is produced from a subterranean oil shale deposit by extending at least one each of heat-injecting and fluid-producing wells into the deposit, establishing a heat-conductive fluid-impermeable barrier between the interior of each heat-injecting well and the adjacent deposit, and then heating the interior of each heat-injecting well at a temperature sufficient to conductively heat oil shale kerogen and cause pyrolysis products to form fractures within the oil shale deposit through which the pyrolysis products are displaced into at least one production well, an improvement for enhancing the uniformity of the heat fronts moving through the oil shale deposit, which comprises: determining variations with depth in the composition and properties of the oil shale deposit; completing said heat-injecting and fluid-producing wells selectively into a treatment interval of oil shale in which the oil shale deposit (a) is at least about 100 feet thick, (b) is substantially impermeable and free of mobile water, (c) has a composition and thickness such that the product of the average Fischer Assay grade times the thickness of the treatment interval is at least about 3,000 and (d) thereby contains components capable of interacting in a manner enhancing the uniformity of a front of conductively transmitted heat, with said wells being arranged so that, at least substantially throughout said treatment interval, the well boreholes are substantially parallel and are separated by substantially equal distances of about 30 to 100 feet; and within the interior of each heat-injecting well maintaining an average temperature which, selectively along said treatment interval, is at least about 600°C., but is not high enough to thermally damage equipment within the well, while heat is being transmitted away from the well at a rate not significantly faster than that permitted by the thermal conductivities of the earth formations adjacent to the heated interval within the well. A process for exploiting a target oil shale interval, by progressively expanding a heated treatment zone band from about a geometric center of the target oil shale interval outward, such that the formation or extension of vertical fractures from the heated treatment zone band to the periphery of the target oil shale interval is minimized.