﻿164 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  In 
  all 
  of 
  these 
  fields 
  [Pennsylvania, 
  New 
  York, 
  and 
  eastern 
  Ohio], 
  without 
  im- 
  

   portant 
  exception 
  standstones 
  buried 
  in 
  shales 
  have 
  proved 
  to 
  be 
  the 
  reservoirs 
  

   of 
  oil 
  and 
  gas 
  when 
  the 
  latter 
  are 
  found 
  in 
  large 
  quantity. 
  The 
  overlying 
  shale 
  

   is 
  the 
  cover 
  or 
  roof 
  of 
  the 
  reservoir 
  ; 
  the 
  underlying 
  shale 
  appears 
  to 
  be 
  the 
  source 
  

   from 
  which 
  the 
  bituminous 
  products 
  are 
  derived. 
  

  

  As 
  to 
  limestone 
  reservoirs, 
  Orton 
  was 
  more 
  fully 
  informed 
  than 
  any 
  

   geologist 
  of 
  his 
  time, 
  in 
  view 
  of 
  his 
  studies 
  of 
  the 
  Trenton. 
  The 
  fol- 
  

   lowing 
  is 
  quoted 
  from 
  the 
  same 
  report 
  (p. 
  86) 
  : 
  

  

  The 
  limestone 
  has 
  been 
  penetrated 
  for 
  about 
  550 
  feet 
  without 
  being 
  exhausted. 
  

   Through 
  most, 
  if 
  not 
  all 
  of 
  its 
  extent, 
  it 
  is 
  petroliferous, 
  as 
  is 
  shown 
  by 
  the 
  

   drillings, 
  but 
  the 
  accumulated 
  stocks 
  of 
  both 
  oil 
  and 
  gas 
  are 
  always 
  found 
  in 
  the 
  

   uppermost 
  beds 
  of 
  the 
  stratum, 
  and 
  generally 
  not 
  more 
  than 
  15 
  feet 
  below 
  its 
  

   upper 
  surface. 
  * 
  * 
  * 
  The 
  oil 
  rock 
  carries, 
  at 
  a 
  lower 
  level 
  than 
  that 
  in 
  which 
  

   the 
  oil 
  is 
  found, 
  but 
  sometimes 
  dangerously 
  near, 
  a 
  brine 
  of 
  unusual 
  character. 
  

   It 
  has, 
  in 
  fact, 
  the 
  composition 
  of 
  a 
  bittern, 
  or 
  a 
  water 
  left 
  over 
  from 
  the 
  con- 
  

   centration 
  of 
  ordinary 
  brine. 
  * 
  * 
  * 
  The 
  facts 
  as 
  to 
  the 
  occurrence 
  of 
  oil 
  and 
  

   gas 
  in 
  this 
  stratum 
  seem 
  reconcilable 
  with 
  the 
  theory 
  that 
  they 
  have 
  risen 
  through 
  

   the 
  limestone 
  rock 
  until 
  they 
  find 
  themselves 
  arrested 
  in 
  their 
  ascent 
  by 
  the 
  

   overlying 
  shales, 
  and 
  their 
  accumulation 
  therefore 
  takes 
  place 
  at 
  this 
  point. 
  

  

  PERMEABILITY 
  

  

  Orton 
  had 
  noted 
  the 
  difference 
  in 
  permeability 
  of 
  these 
  main 
  classes 
  

   of 
  oil 
  reservoirs 
  and 
  also 
  the 
  variations 
  which 
  occurred 
  in 
  each. 
  It 
  had 
  

   been 
  early 
  established 
  in 
  Pennsylvania 
  that 
  different 
  portions 
  of 
  the 
  

   oil 
  sands 
  communicated 
  with 
  some 
  degree 
  of 
  freedom, 
  for 
  adjacent 
  wells 
  

   were 
  found 
  to 
  affect 
  each 
  other's 
  yields. 
  As 
  an 
  example, 
  he 
  cites 
  the 
  

   Bradford 
  sand 
  and 
  its 
  division 
  into 
  gas, 
  oil, 
  and 
  salt-water 
  zones, 
  the 
  

   gas 
  holding 
  the 
  highest 
  and 
  the 
  salt 
  water 
  the 
  lowest 
  levels, 
  and 
  found 
  

   "the 
  conclusion 
  well-nigh 
  irresistible 
  that 
  the 
  entire 
  rock 
  is 
  permeable 
  

   and 
  that, 
  in 
  the 
  course 
  of 
  ages, 
  the 
  various 
  contents 
  have 
  been 
  differenti- 
  

   ated 
  as 
  we 
  now 
  find 
  them, 
  under 
  the 
  influence 
  of 
  gravitation." 
  In 
  con- 
  

   trast, 
  he 
  found 
  that 
  in 
  other 
  areas 
  "there 
  was 
  no 
  necessary 
  and 
  absolute 
  

   connection 
  between 
  different 
  portions 
  of 
  an 
  oil 
  sand"; 
  the 
  stratum 
  

   might 
  be 
  divided 
  into 
  lenticular 
  masses 
  which 
  might 
  be 
  nearly 
  or 
  en- 
  

   tirely 
  disconnected. 
  "The 
  rapid 
  changes 
  in 
  thickness 
  of 
  the 
  oil-sand 
  

   in 
  adjacent 
  wells 
  furnishes 
  conclusive 
  proof 
  upon 
  this 
  point. 
  We 
  can 
  

   follow 
  the 
  stratum 
  down 
  to 
  a 
  feather 
  edge 
  by 
  these 
  records." 
  In 
  the 
  

   Berea 
  sand 
  of 
  eastern 
  Ohio 
  he 
  observed 
  that 
  such 
  interruptions 
  occurred 
  

   frequently. 
  "Communication 
  through 
  a 
  few 
  square 
  miles 
  of 
  the 
  rock 
  

   can 
  be 
  occasionally 
  inferred, 
  but 
  beyond 
  this 
  we 
  have, 
  thus 
  far, 
  found 
  

   no 
  warrant 
  for 
  going." 
  It 
  was 
  Orton's 
  observation 
  that 
  in 
  the 
  lime- 
  

   stone 
  reservoirs 
  the 
  same 
  freedom 
  of 
  communication 
  did 
  not 
  exist 
  as 
  

   in 
  the 
  sandstones. 
  He 
  noted, 
  however, 
  that 
  the 
  gas 
  wells 
  at 
  Findlay 
  

   affected 
  each 
  other 
  noticeably. 
  He 
  recognized 
  that 
  there 
  could 
  not 
  

   be 
  as 
  free 
  communication 
  through 
  massive 
  limestones 
  as 
  through 
  sand- 
  

   stones. 
  In 
  the 
  case 
  of 
  sandstones, 
  however, 
  he 
  did 
  not 
  apparently 
  

  

  