A technical and economic study of candidate underground mining systems for deep, thick oil shale deposits : Hoskins, WN Wright, FD Tobie, RL Phase I report. 67F. US Bur. Mines, PB 249 884/AS, Jul. 1975, 331P

Abstract

Results of a study on the technical and economic feasibility of mining the deep, thick, oil shale deposits of Colorado's Piceance Creek Basin are reported. The study was divided into two phases: first, a technical feasibility study of applicable mining methods, and second, an economic feasibility study, based on the designs developed in the first phase. The first phase, completed in July, 1975, recommended four mining methods for the phase II study. The four methods are: chamber and pillar mining, sublevel stoping with spent shale backfill, sublevel stoping with full subsidence, and block caving using load haul dump (LHD). All mine designs were developed for 85,000 tons per day minimum production or enough feedstock for 50,000 barrel per day surface processing plant. Initial capital investment for the mining methods ranged from $77,200,000 for chamber and pillar, to $122,872,000 for block caving, using LHD's. Mining costs, including all direct, indirect and fixed costs, except royalty and lease payments, ranged from $1.04 per ton for chamber and pillar to $1.35 per ton for block caving, using LHD's. As a result of the study, it was determined that underground mining of deep oil shale deposits is technically feasible and low in cost permore » ton.« less