Geologic Interpretation

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  • AES15I TUDelft

    Interpretation Course 2010/11

    tentamen 5/04/11

    Name ^ ^ ^ ^ ^ r .

    number

    Please print your name and student number on MX^apers

    Question #1: Give the SEG polarity convention for recording seismic dats on tape. Describe the way of displaying seismic data on paper and on a trace interpretation system (3 points)

    Question #2: Name types of sources surveys (1 point)

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    and receivers used in marine seismic

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    Question #3; Give the five main stages of seismic processing

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    i #4: Give the formula of the zero-incidence reflection coefficient (1 and indicate why at larger angels of incidence, this formula does not

    hold any mors (1 point).

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  • ABSJ5I0 TUDelft

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    Question #& Give the main characteristics of a zero-phase and a^ininium wavelet Which wavelet is physicaiiv realizable and why? (3 po.nts)

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    Question #6: Which welMogs are needed for the generation 0f a s y n ^ t e i f . SS ram and why? (2 points). And which ones are useful to have also available? (1 point) l^v c ^ ^ H c ^ c

    Question #7: Describe briefly the steps in which a synthetic seismogram is calculated (3 points). ,

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  • TUDelft AES1510

    Question 8 : Indicate the sequence boundaries In the t i p re below and indicate the iand-ward direction (1 point) Identify and indicate thme typical sedimentary features in the diagram (2 points) ,

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    Question #9: See the section in the East Texas Salt Basin. List the secondary features that point to the presence of salt, (4 pomts)

    Question #10: See the interpretation in depth displayed below. The feuit S^fern indicates wrench tectonics. Give the precise name o the s S a i ^ There is one other indication that indicates mmmm as the main mechanism. What is that? (3 points)

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  • AFS15W TDB

    Question #11: Sse the acGurate name of the regime. (2 points)

    ic style. Give the

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    Sedimeh?Gry OVrburdan

    Hormal GbUque-slip faults

  • ABS 1510

    Question # 12: Given a muiti-iithology environment, what boundary conditions should be met for the sucGessful application of a layer cake depth conversion? (2 points)

    Question #13: Give the clennition of drift (1 point) and list three causes of drift (2 points)

    Question #14 : Describe the advantages and shortGomings of seismic inversion methods in roci< property terms (3 points)

    Question #15: On a separate page a VSP is displayed. Identify a) the f i M arrivals, b) the dov^ngoing primaries and c) the downgoing multiple events (2 points)

  • AES15J

    Question #16: Which lithologies do often exhibit fairiy constant interval velocities?(1 point)

    Question #17: Describe the effects on acoustic impedance of exchanging brine as pore-fill with hydrocarbons. iVIake a distinGtioh between oil and gas (3 poi nts)

    Question Give the typical features for the seismic expression of a gas-water contact (1 point)

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  • AESISIO

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    Question #20-. Wiiattype of information can be obtaified from AVO (AVA) analysis (1 point)

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  • AES1510 TUDelji

    ^rpretation Course 2010/11

    mmmen 27/01/11

    Name

    Student number

    Please printvour name and student number on ALL papers

    Question #1: C3ive the vSEG poiarity convention for recording seismic data on tape. Describe the European variant of displaying seismic data on paper (2 points)

    Question #2; Name t; surveys (1 point)

    f sources and receivers used in land seismic

    Question #3; Give the three main themes.- key points - of seismic processing (1 point) and give an example of a proce'^s with each*theme {ope bonus point),

  • AESISIO

    Question #4: Give tiie formula of tlie zero-incidence reflection coefficient (1 point).

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    Question #5: C5ive tiie main cliaractenstics of a zero-ptiase and a minimum phase wavelet. Which wavelet is preferred in seismic interpretation and why?

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    (3 points)

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    Question #6: Which well-iogs are needed for the generation of a synthetic seismogram and why? (2 points). And which ones are useful to have also available? (1 point)

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    Question #7; Describe bnefly the two main purposes of a ynthetic seismogram (2 points). . ^>'''

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  • AESJ5I0 TlJDelfi

    Question 8: Indicate the sequence boundaries in the figure below and indicate theland-ward direction (1 point) identify and indicate three typical sedimentary features in the am (2 points)

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    Question #9; See ttie section in tlie Offsliore Aquitaine Basin, Three structures are annotated with the number "8", Determine which one(s) have salt in their core and rank them according to age of activity. Reason your

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    ] answers. (4 points

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    Question #10: identify the unit in which well F6.1 has been dnlled in lithoiogy terms see the separate sheet. Determine its lithoiogy. i he section has been displayed using the tiuropean variant of the SEGY convention (2 points)

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  • AES15I0 TU Delfi

    Question #11; See the map beiovv & identify the tectonic style. Give the accurate name of the regime. (2 points) :

    Norm? Fhrust: or Reverse

    Question # 12: What is the iimitation in the use of a horizontal velocity distribution for time-to-depth conversion (2 points)

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    :)uestion #13: Give the definition of drift (1 ppint) and list three causes of drift (2 paints) / ' > ' ~-

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  • AES 1510 TUDelft

    Question #14 : Describe the funciamentai shortcoming of seismic inversion methods in rock property terms (2 points)

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    Question #15; On a separate page a VSP is displayed. Identify a) the first arnva s b) the upgoing primaries and c) the upgoing muitipie events (3 points)

    Question #16: Which lithologies do often exhibit a horizontal velocity distribution ?(1 point)

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    Question #17: Describe the effects on acoustic impedance of exchanging brine as pore-fil! v^ith hydrocarbons. Make a distinclion between oil and gas (3 Doints)

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  • AESI5J0 TUDelft

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    Question #18: Give three types of hydrocarbon traps (1 point)

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    Question #19: Give the typical features for the seismic expression or a gas-water contact (1 point) .

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    Question #20; What type of information can be obtained from AVO (AVA) analysis (1 point)

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