﻿178 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  denser 
  strata 
  and 
  caused 
  fluid 
  movements 
  in 
  the 
  capillary 
  spaces, 
  but 
  

   there 
  is 
  little 
  in 
  the 
  way 
  of 
  direct 
  evidence 
  to 
  support 
  this 
  thesis. 
  Dias- 
  

   trophic 
  movements, 
  by 
  producing 
  fractures 
  and 
  faults, 
  have 
  opened 
  

   new 
  channels 
  for 
  the 
  vertical 
  movement 
  of 
  fluids 
  from 
  one 
  porous 
  bed 
  

   to 
  another 
  or 
  have 
  brought 
  into 
  contact 
  reservoir 
  beds 
  not 
  previously 
  

   communicating. 
  

  

  MIGRATION 
  THROUGH 
  THE 
  CARRIER 
  BED 
  

  

  The 
  term 
  "carrier 
  bed" 
  was 
  introduced 
  by 
  Rich 
  (1931) 
  to 
  designate 
  

   porous 
  beds, 
  such 
  as 
  coarse 
  sands 
  or 
  cavernous 
  limestones, 
  which 
  were 
  

   favorable 
  in 
  texture 
  to 
  the 
  movement 
  of 
  oil. 
  While 
  the 
  term 
  was 
  in- 
  

   tended 
  especially 
  to 
  describe 
  beds 
  that 
  would 
  facilitate 
  long-distance 
  

   migration, 
  it 
  is 
  a 
  convenient 
  designation 
  for 
  any 
  porous 
  stratum 
  

   through 
  which 
  petroleum 
  may 
  have 
  moved, 
  and 
  it 
  is 
  used 
  here 
  in 
  that 
  

   broader 
  sense. 
  

  

  It 
  has 
  been 
  postulated 
  that, 
  during 
  the 
  compaction 
  of 
  a 
  series 
  of 
  

   sedimentary 
  rocks, 
  water 
  carrying 
  globules 
  of 
  petroleum 
  has 
  moved 
  

   from 
  the 
  source 
  bed 
  into 
  the 
  more 
  porous 
  adjoining 
  carrier 
  beds. 
  

   Firstly, 
  if 
  a 
  bed 
  were 
  sufficiently 
  extensive 
  to 
  have 
  a 
  surface 
  outcrop 
  

   along 
  the 
  margin 
  of 
  the 
  basin, 
  the 
  excess 
  water 
  would 
  have 
  an 
  oppor- 
  

   tunity 
  to 
  follow 
  it 
  toward 
  the 
  outcrop 
  and, 
  perhaps, 
  there 
  to 
  make 
  its 
  

   escape. 
  But 
  the 
  same 
  outcrop 
  would 
  also 
  permit 
  the 
  entry 
  into 
  the 
  

   carrier 
  bed 
  of 
  meteoric 
  waters 
  and, 
  depending 
  upon 
  the 
  altitude 
  of 
  

   the 
  outcrop 
  and 
  other 
  conditions, 
  the 
  meteoric 
  waters 
  might 
  be 
  able 
  

   to 
  resist 
  the 
  outward 
  movement 
  of 
  the 
  connate 
  waters 
  to 
  such 
  an 
  extent 
  

   that 
  their 
  escape 
  through 
  the 
  carrier 
  bed 
  might 
  be 
  prevented. 
  In 
  that 
  

   case, 
  the 
  line 
  of 
  least 
  resistance 
  to 
  the 
  movement 
  of 
  the 
  excess 
  water 
  

   might 
  be 
  across 
  the 
  bedding, 
  through 
  the 
  less 
  pervious 
  rocks 
  forming 
  

   its 
  cover. 
  Secondly, 
  if 
  the 
  carrier 
  bed 
  does 
  not 
  have 
  a 
  surface 
  out- 
  

   crop, 
  the 
  excess 
  waters 
  deposited 
  with 
  the 
  sediments 
  will 
  ordinarily 
  

   have 
  only 
  one 
  avenue 
  of 
  ultimate 
  escape 
  — 
  across 
  the 
  bedding 
  planes. 
  

   It 
  seems 
  probable 
  that 
  most 
  of 
  the 
  excess 
  interstitial 
  water 
  must 
  have 
  

   passed 
  upward 
  through 
  the 
  section, 
  for, 
  at 
  the 
  time 
  when 
  the 
  basin 
  

   was 
  in 
  formation 
  and 
  compaction 
  was 
  in 
  process, 
  the 
  basin 
  would 
  

   usually 
  not 
  have 
  been 
  sufficiently 
  deformed 
  and 
  eroded 
  to 
  provide 
  the 
  

   carrier 
  beds 
  with 
  surface 
  outcrops. 
  

  

  Once 
  having 
  entered 
  the 
  carrier 
  bed, 
  the 
  particles 
  of 
  petroleum 
  

   which 
  had 
  passed 
  through 
  the 
  capillary 
  pores 
  of 
  the 
  source 
  rock 
  would 
  

   tend 
  to 
  coalesce 
  into 
  larger 
  globules 
  in 
  the 
  wider 
  interstitial 
  spaces 
  of 
  

   the 
  carrier 
  bed. 
  These 
  larger 
  globules 
  would 
  be 
  capable 
  of 
  lateral 
  

   movement 
  through 
  the 
  carrier 
  bed 
  but 
  would 
  not 
  be 
  able 
  to 
  enter 
  the 
  

   smaller 
  capillary 
  spaces 
  of 
  an 
  overlying 
  clay 
  or 
  shale. 
  If 
  the 
  water 
  

   in 
  the 
  carrier 
  bed 
  were 
  forced 
  upward 
  as 
  a 
  result 
  of 
  compaction, 
  the 
  

   globules 
  of 
  oil 
  would 
  be 
  left 
  behind 
  and 
  would 
  be 
  held 
  at 
  the 
  interface. 
  

  

  