Geochemical Analysis and Studies of the Effects of Retorting Conditions on Oil Yield from Oil Shale from the Nekheil Area

Abstract

Egypt is facing an excruciating energy crisis that is expected to aggravate in the near future. This research presents a solution to such a crisis by developing the tremendous oil shale resources that exist in the Quseir - Safaga district in the Eastern Desert which is expected to contain around 12 Bbbl of oil and 24 Tcf of gas. This oil is larger than the country's conventional oil reserve (4.4 billion barrels). This study attempts to assess the hydrocarbon potential and geochemically characterize the Duwi oil shale from the Nekheil mining area in Quseir – Safaga District in the Eastern Desert of Egypt which has been proved to be the most prolific. Visual and microscopic description, Rock-Eval pyrolysis, LECO C 230, LECO SC 632 furnace and XRF tests are used. The study is also concerned with determining the influence of retorting conditions (maximum temperature, particle size and residence time) on oil yield, gas plus loss and oil API gravity. Experiments revealed that the oil shale has excellent petroleum potential (total organic carbon (TOC) = 15.90%; S2=102.31 mg HC/gm. rock; generative potential = 106.07 mg HC/gm. rock). It is immature (Tmax = 416o C; production index = 0.3545) and is of type I kerogen (HI = 643.5 mg HC/gm. TOC; S2/S3 = 19.98 mg HC/mg CO₂). It has total sulfur (TS) of 4.70% and total carbon (TC) of 20.20%. XRF data revealed the concentration of 39 elements. Retorting process indicated that the best pyrolysis conditions for maximum oil yield are particle size of 25.4 mm and maximum retorting temperature of 450o C. The API gravity of the generated oil is 18.6o API and its yield is 121 liter/ton of rock. A residence time of 20 minutes which would produce 95.76% of this yield seems reasonable.

AAPG Datapages/Search and Discovery Article #90194 © 2014 International Conference & Exhibition, Istanbul, Turkey, September 14-17, 2014