Show r Geologist Tells T v Of Favorable I Oil Indications BY HAY BATE RAYE E COLTON COLTOR I b j r Petroleum Pe oleum Geologist Geologic conditions under which oil and gas las may map form torm and tod accumulate appear at at this writ writ ing to be best bes exemplified in rocks of at the Uintah Basin Balin which are sedimentary in origin Of the sedimentary rocks the petroleum geologist finds findl that those which were deposited un un- un under der marine sea sea conditions are ani the most most- favorable for tor the oc- oc of petroleum Marine sea bodies bodIe of water such as h ascog long cog vanished lakes uinta and and which covered what is today northeastern Utah and n northwestern Colorado together with a portion of southwestern Wyoming during past periods of the go record teemed I with organic life Ute which which after alter death provided an abundance of organic matter Under pro pro- proper proper per conditions of burial and de de- decay cay bacteria no doubt acted upon u p 0 n this organic orante matter and formed various hydrocarbons bons which ultimately yielded the complex mixture which we today know as petroleum or ot crude oil oU Sedimentary seldom rested during geologic time without being subjected to great stress Compression and tension resulting from from- forces such as al the Wasatch up lilt frac frac- fractured frac- frac fractured and bent the rocks of the earths earth's crust Even the most impervious rocks such such as a dense became fractured and petroleum originating from the marine animal and marine plant life of the ancient lakes Jake no jio doubt worked worked its it's It way through the fine maze of cracks into more porous and pervious layers of strata Water was often im im- imprisoned In hi the rocks at the time of deposition and as the petrol petrol- petroleum eum trickled into a permeable sand it did not mix with the water but being lighter rose to the upper part pott of the fluid level in the sand und and then probably migrated horizontally through the sand san until trapped as fol tal lows lowI 1 By an structure 2 By change in porosity 3 By pinching OU of the sand and 4 By any feature which prevented pre pre- prevented vented further migration of the fluids fl The term anticline indicates from the geologic viewpoint an upward arch of at the beds of ot the earths earth's surface and if U oU oil and gas are found in a structure of this type they will be recover recover- recovered recovered ed from the tops of the folds of the structure If the oil and gas be recover recover- recovered ed from a sand body they will be recovered from the small pores pore of interstices of the sand body proper Other probable oil and gas traps here in the Uintah Basin are as al follows l-Domal l structure I 2 Terrace i Ii IJ 3 J 4 Overturned fold 5 Small volcanic dikes and necks As stated sedimentary rocks offer good chances of petroleum recovery In view of the fact that large amounts of organisms usually are associated with such types of rocks and these offer good source beds for the con con- concentration of petroleum NOTE The Green River Ba Ba- Ba Basin Basin sin is a twin of the Uintah Ba Ba- Ba Basin sin This will be discussed in another article of this series ap ap- appearing I as an exclusive feature in this newspaper Ray E Colton |