Chapter 3 Petroleum Prospecting (????)

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Chapter 3 Petroleum Prospecting(????)

• ????(Surface observation)
• -by observation on earth surface
• ???? (Geological exploration)
• -downward projection of geologic information
• ??????(Geochemical exploration)
• --tracing hydrocarbons in soil and water
• ????? (Geophysical exploration)
• -physical measurements of gravity, magnetic
• and seismic of subsurface

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????(Surface Observation)

• ??(???)???
• -???????
• seeps (plate 13-1, 13-2, and fig.
  13-1)

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????--Seeps

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???? -- Seeps

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(No Transcript)
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?????
-??????????????? -??????????? -?????????????(???
?????????) -??
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????

• ???? ?????
• ?????????????????????????????????????(plate
  13-3)?
• ????????????????(fig. 13-2)?
• ?????????????????????????(fig 13-3 13-4 13-5
  13-6 13-7)?

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???????????????????????????????????(plate 13-3)?
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???????????????????, ??????(fig. 13-2)?
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???? --???????????????Marker bed (fig 13-3)?
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???? ????????(Well logs)??Marker
bed????????????????(fig 13-6)?
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???? --?Well logs????Marker bed????????????????(fi
g 13-5)?
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???? -- ?????????(Microfossils)????????????????(fi
g 13-4)?
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???? -- ?????????????????????????(fig 13-7)?
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?????? Geochemical exploration

• Geochemistry is the application of chemistry to
  the study of the earth.
• Geochemistry can be used to trace hydrocarbons in
  soil and water indicating of the proximity of a
  petroleum trap.
• Geochemistry can also be used to identify the
  source rock for a specific crude oil. The crude
  oils in traps can then be correlated with source
  rocks to determine the migration path for the
  petroleum.

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?????? to trace hydrocarbons

• Traces of hydrocarbons in soil and water are
  often good indications of the proximity of a
  petroleum trap (fig. 13-8).
• -- microseeps
• -- hydrocarbon halo(??)
• -- sniffers(???)
• -- Vitrenite reflectance

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Vitrenite reflectance
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?????? to trace hydrocarbons
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Plays and Trends -1

• A play is a combination of trap, reservoir rock,
  and seal that has been shown by previous
  discovered fields to contain commercial petroleum
  deposits in an area.

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Plays and Trends -2

• A trend or fairway is the area along which the
  play has been proven, and more field could be
  found. (fig 13-9).

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Plays and Trends -3

• A prospect is the exact location where the
  geological and economic conditions are favorable
  for drilling an exploratory well.

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Plays and Trends - 4

• There are four major geological factors in the
  success of a particular prospect.
• (1) There must have been a source rock that
  generated petroleum.
• (2) There must have been a reservoir rock to
  hold the petroleum.
• (3) There must be a trap. This includes a
  reservoir rock configuration that has four-sided
  closure, a seal on the reservoir rock, and no
  breach of the trap.
• (4) The timing must be right. The trap had to
  be in position before the petroleum migrated the
  area.

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Plays and Trends - 5

• An economic analysis of the prospect should
  include reserves and risk calculations.

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?????

• ?????????????????????????
• ??????????
• (a)?????????,???????
• ???????????
• (b)????????????,???
• ?????

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?????

• ???????????????????????????????
• ????
• ??-??????????
• ??-?????
• ????-??????
• ????-???????????

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???????
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????(????)(Gravity Method)

• ??????????????

????
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??????

• (1)The gravity pendulum(????)
• -????(????)
• (2)The gravimeter(???)
• -Hocks law, ??
• (3)The Hoyt gravimeter
• (4)The astatized gravimeter

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(3)The Hoyt gravimeter (4)The
astatized gravimeter

??????????????????
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??????-?????????????????? (???????????)

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??????-?????????????????? (???????????)

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????????(magnetic method)

?? -???? -?????????????? ???????? (a)???-???? (
b)???-???? (c)???-permeability??????
(???????) ?????
BµH Fluxpermfield strength
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????
-?????????????????????????? (1)the permeability
(???) (2)the magnetization(??) -???????????(magn
etite)??(????)????????? ???,???????????(
susceptibility),k,??,????k??
????????? -?????????,??

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????(Dome or anticline)

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??????-??????????????????

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??/?????? (Fault)

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???? (Seismic Exploration)

• ???? (Seismic Exploration)
• -- ???(Seismic reflection method)
• -- ???(Seismic refraction method)

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???(Seismic reflection method)

• Data Acquisition
• Data Processing
• Data Interpretation

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??????

• ??????(Data acquisition)
• ???,
• ????
• ??????????
• ?
• ???????
• ?
• ???????
• ?
• ??????????????
• ?
• ???????????(????)
• ?
• ??????(Data processing)
• ??????
• ?

??
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• Data Acquisition

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??????
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?????????
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????????
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Vibrator Truck
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??????Geophone??
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????????
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??????????????Air gun ?streammer
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?????????
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• Data Processing

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???
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?? ???
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?? ???
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?? ???(Bright spot)
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• Data Interpretation

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?? ???
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Seismic Profile (correlating with drilling data)
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?? ??? (Salt dome)
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?? ????
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?? ????????? (Isochron map)
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?? ????????? (Structure map)
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???????

???, ???? ?????? ? ???? ? ???????
??
? ???????????? ??????(????) ?
???????????? ? ????(??)???(????
?????????????)
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????(????)-Well Logging
????
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???
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???(Stratigraphy)

• ????(Rock Strata)?
• --- ??(Origin)
• --- ??(Composition)
• --- ??(Distribution)?
• --- ???(Succession)

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????(Stratigraphic test, or strata test)

• ??????????????

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????(Stratigraphic correlation)

• ?????,???????
• -- ??(Strata)
• -- ??(fossils)
• --- ????(Rock hardness or softness)
• --- ????(Electric data)
• It is much easier to correlate wells because the
  data that are collected by
• drillers logs,
• sample logs,
• electrical logs
• enable the geologists to predict more precisely
  where similar rock
• formations will occur in each case

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Subsurface correlation

• It is based primarily on
• -stratigraphic continuity, or
• -the fact that formations maintain the same
• thickness from one well to another.
• Any change in thickness can be a geologic
  indicator of
• -a change in the conditions that formed the
• strata, or
• -may be a signal of an event that could
  cause
• petroleum to accumulate.

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Structure Map
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Oil and gas discoveries
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???wiggle trace ? ???