﻿DETAILS 
  OF 
  THE 
  DEVELOPED 
  TERRITORY. 
  95 
  

  

  one 
  log 
  reports 
  ''no 
  shell" 
  until 
  the 
  first 
  oil 
  zone 
  is 
  reached. 
  Wher- 
  

   ever 
  "shell" 
  is 
  penetrated 
  accumulations 
  of 
  gas 
  or 
  oil 
  or 
  both 
  are 
  

   generally 
  encountered. 
  The 
  shale 
  seems 
  -to 
  be 
  somewhat 
  more 
  sandy 
  

   in 
  this 
  area 
  than' 
  farther 
  west 
  or 
  in 
  the 
  Graciosa- 
  Western 
  Union 
  

   region. 
  

  

  Three 
  oil 
  zones 
  are 
  recognizable 
  in 
  the 
  area 
  under 
  discussion, 
  

   although 
  practically 
  all 
  the 
  strata 
  from 
  the 
  top 
  of 
  the 
  uppermost 
  

   zone 
  to 
  the 
  bottom 
  of 
  the 
  lowest 
  are 
  more 
  or 
  less 
  petroliferous 
  at 
  

   one 
  point 
  or 
  another. 
  

  

  The 
  first 
  productive 
  zone 
  (A) 
  is 
  penetrated 
  at 
  a 
  depth 
  of 
  1,600 
  

   to 
  2,100 
  feet, 
  varying 
  according 
  to 
  the 
  position 
  of 
  the 
  well 
  geograph- 
  

   ically 
  and 
  relatively 
  to 
  the 
  axis 
  of 
  the 
  anticline. 
  Its 
  top 
  is 
  from 
  550 
  

   to 
  700 
  feet 
  above 
  the 
  top 
  of 
  zone 
  B 
  in 
  this 
  area. 
  Zone 
  A 
  is 
  produc- 
  

   tive 
  for 
  a 
  distance 
  in 
  the 
  wells 
  of 
  20 
  to 
  more 
  than 
  500 
  feet. 
  Of 
  course 
  

   this 
  does 
  not 
  mean 
  that 
  the 
  beds 
  are 
  productive 
  in 
  any 
  one 
  well 
  for 
  

   the 
  whole 
  distance 
  of 
  500 
  feet, 
  but 
  that 
  throughout 
  the 
  zone 
  alternat- 
  

   ing 
  barren 
  and 
  productive 
  beds 
  occur 
  at 
  such 
  close 
  and 
  as 
  a 
  rule 
  

   irregular 
  intervals 
  as 
  to 
  preclude 
  their 
  practical 
  differentiation. 
  The 
  

   productive 
  measures 
  in 
  this 
  first 
  zone 
  consist 
  both 
  of 
  hard 
  frac- 
  

   tured 
  shale 
  or 
  "shell" 
  and 
  more 
  or 
  less 
  porous 
  sandy 
  layers. 
  In 
  at 
  

   least 
  one 
  of 
  the 
  wells 
  the 
  oil 
  accumulates 
  only 
  under 
  the 
  hard 
  "shell" 
  

   layers. 
  Zone 
  A 
  is 
  the 
  only 
  one 
  penetrated 
  by 
  some 
  of 
  the 
  wells 
  

   farthest 
  away 
  from 
  the 
  anticlinical 
  axis. 
  In 
  these 
  wells 
  it 
  appears 
  

   to 
  be 
  much 
  more 
  petroliferous 
  than 
  in 
  wells 
  higher 
  up 
  on 
  the 
  fold. 
  

  

  The 
  second 
  oil 
  zone 
  (B) 
  is 
  from 
  550 
  to 
  700 
  feet 
  below 
  the 
  top 
  of 
  

   zone 
  A, 
  and 
  its 
  upper 
  limit 
  is 
  about 
  300 
  or 
  400 
  feet 
  above 
  the 
  top 
  of 
  

   zone 
  C, 
  although 
  it 
  can 
  hardly 
  be 
  said 
  to 
  be 
  distinct 
  from 
  C 
  in 
  all 
  

   the 
  wells, 
  so 
  rich 
  in 
  oil 
  are 
  some 
  of 
  the 
  intervening 
  strata 
  between 
  

   them. 
  True 
  sands 
  of 
  medium 
  grain, 
  in 
  addition 
  to 
  the 
  productive 
  

   hard 
  shale, 
  yield 
  the 
  oil 
  in 
  this 
  zone. 
  

  

  The 
  third 
  oil 
  zone 
  (C) 
  is 
  encountered 
  in 
  some 
  of 
  the 
  deeper 
  wells 
  

   nearest 
  the 
  axis 
  of 
  the 
  main 
  anticline. 
  This 
  zone 
  has 
  been 
  pene- 
  

   trated 
  for 
  as 
  much 
  as 
  150 
  feet, 
  the 
  whole 
  distance 
  being 
  very 
  rich 
  

   in 
  petroleum. 
  It 
  is 
  overlain 
  by 
  a 
  considerable 
  thickness 
  of 
  black 
  

   shale, 
  also 
  more 
  or 
  less 
  petroliferous, 
  between 
  which 
  and 
  the 
  rich 
  

   zone 
  is 
  a 
  thin, 
  hard 
  "shell" 
  layer. 
  The 
  oil-yielding 
  rock 
  is 
  a 
  true 
  

   sand, 
  coarse 
  in 
  places 
  and 
  even 
  becoming 
  pebbly 
  toward 
  its 
  base 
  in 
  

   certain 
  portions 
  of 
  the 
  area. 
  To 
  the 
  coarseness 
  of 
  the 
  material 
  is 
  

   doubtless 
  due 
  the 
  great 
  productiveness 
  of 
  the 
  zone. 
  

  

  PRODUCT. 
  

  

  The 
  oil 
  in 
  the 
  Hall-Hobbs-Rice 
  ranch 
  area 
  runs 
  from 
  26° 
  to 
  29° 
  

   Baume 
  and 
  is 
  dark 
  brown 
  in 
  color. 
  Gas 
  accompanies 
  the 
  oil 
  and 
  also 
  

   occurs 
  isolated 
  under 
  some 
  of 
  the 
  more 
  impervious 
  "shell" 
  layers 
  

   in 
  the 
  shale. 
  No 
  water 
  is 
  reported 
  in 
  any 
  of 
  the 
  wells. 
  

  

  