aplikasi basin analysis

eddy purnomo 4 unpad bdg

APLIKASI BASIN ANALYSIS APLIKASI BASIN ANALYSIS DALAM EKSPLORASI MIGASDALAM EKSPLORASI MIGAS

eddy purnomo / 620438jatinangor Desember 2009


MATERI KULIAH

PENDAHULUANPRINSIP2 DASAR CEKUNGAN SEDIMEN• Cekungan sedimen vs Plate tectonic• Mekanika lithosfer

MEKANISME PEMBENTUKAN CEKUNGAN SEDIMEN• Lithosperic stretching• Flexure• Strike slip deformation

THE SEDIMENTARY BASIN FILL• Faktor pengontrol• Depositional style

EVOLUSI CEKUNGAN SEDIMEN• Subsidence history• Thermal history

APLIKASI DALAM INDUSTRI E & P MIGAS


BASIN ANALYSIS

• Geological Model

• Evolusi stratigrafi dan struktural

• Assessment petroleum play

• Exploration Play concept : producible reservoir, petroleum charge

system, regional top seal, trapping mechanism, timing

• Chronostratigrafi-tectonostratigrafi model vs lithostratigrafi model

• Kwalitatif dan kwantitatif measurement


CEKUNGAN SEDIMEN

• Lithospheric stretching : rift basin, passive margin, post rift basin / sag

• Lithospheric flexure : oceanic trench, foreland basin

• Transform – Wrench related basin : pull apart basin

• Back arc basin, fore arc basin, intra arc basin


FAKTOR PENGONTROL CEKUNGAN

• Tektonik

• Perubahan muka air laut / iklim


Source Rock

• Biological derived organic matter buried in sedimentary rock

(shale & carbonate)

• anoxic environment

• Lake, lacustrine, delta, shelf, enclosed marine

• Next process tergantung dari jenis kerogen, temperatur dan

waktu


Reservoir

• Limestone, sandstone dan others

• Porositas, permeabilitas & distribusi lateral – vertical heterogen

• Diagenetic processes : dissolution, dolomitization, fracturing,

rekristalisasi, sementasi & Qz growth

• Lst reservoir : environmental control + post sedimentation proc.

Sst reservoir : provenance type & distance


Cap rock

• Aspek penting namun sering diabaikan

• Fine grain sediment & evaporite – salt

• Sealing capacity – mathematical analysis

• Gas leaks (diffusi) lebih mudah drpd oil leaks

• Litologi, ductility, tebal, distribusi lateral, kedalaman


Trapping Mechanism

• Struktural, stratigrafis, kombinasi & hydrodinamic

• Faulted anticline vs against fault

• Khronostratigrafis – tektonostratigrafis model


CEKUNGAN SEDIMEN

• Lithospheric stretching : rift basin, passive margin, post rift basin / sag

• Lithospheric flexure : oceanic trench, foreland basin

• Transform – Wrench related basin : pull apart basin

• Back arc basin, fore arc basin, intra arc basin


RIFT BASIN

• Source rock : lake, lacustrine sediment : fresh water algae, bacteria

land plant material, Botryococcane biomarker : oil prone (waxy, low

sulphur content, GOR <<)

• Predominantly clastic reservoir

• Stratigraphic trap

• Intraformational shale – post rift shale sequence

• Early Tertiary @ KBI & Mesozoic @ KTI


PASSIVE MARGIN

• Deltaic source rock : fresh water algae, bacteria, land plant material

(abundant) gas prone w/ small amount of light crude


• Stratigraphic – structural trap, rollover listric normal fault

• Intraformational shale, prodelta shale

• Early – Late Tertiary


POST RIFT – SAG BASIN

• Shelf – open marine

• Carbonate – calcareous shale source rock : salt water algae,

bacteria, land plant material >> oil prone w/ small amount of gas

• Predominantly fine grain clastic – carbonate reservoir

• Stratigraphic – structural trap, carbonate build up

• Marine shale, MFS shale

• Mid – Late Tertiary


OCEANIC TRENCH

• Source rock : deep marine shale w/ small amount of TOC

• Poor - no reservoir

• Struktur komplek

• Shale sequence sangat dominan

• Potensi migas kecil


FORELAND BASIN

• Source rock : land plant material, Pre Collision sediment -

limestone oil & gas prone


• Structural trap, rollover imbricated thrust fault

• Intraformational shale

• Early – Late Tertiary (Zagros folded belt)

eddy purnomo 4 unpad bdgGeological Cross Section

NW

?

?

Fm. Biak

Fm. Pooh

Ofiolit

?

Tiaka FieldDonggi Field

SE


STRIKE SLIP RELATED BASIN (PULL APART BASIN)

• Source rock (lake – lacustrine) : fresh water algae, bacteria,

land plant material (abundant) oil & gas prone


• Stratigraphic – structural trap, wrench related trap

• Intraformational shale, prodelta shale

• Early – Late Tertiary (Ombilin basin)


BACK ARC BASIN

• Failed rift basin (Aulacogen)

• Source rock (lake – lacustrine) : fresh water algae, bacteria,

land plant material oil & gas prone

• Carbonate - clastic reservoir

• Stratigraphic – structural trap

• Intraformational shale, regional top seal

• Early Tertiary – Quarternary (KBI basin)


Samuel & Gultom, 1984

eddy purnomo 4 unpad bdgSamuel and Gultom (1984)


Samuel and Gultom (1984)


FORE ARC BASIN

• Shelf – stable platform basin

• Source rock (shelf – shallow marine) : salt water algae, bacteria,

oil prone

• Heat flow <<<, biogenic gas

• Carbonate - clastic reservoir

• Stratigraphic – structural trap

• Intraformational shale, regional top seal

• Mid Tertiary – Quarternary

• Meulaboh block ~ non commercial gas discovery


STRIKE SLIP RELATED BASIN (PULL APART BASIN)

~ INTRA ARC BASIN


TERIMA KASIH

aplikasi basin analysis

Documents

small amount

fresh water

land plant

intra arc

fore arc basin

stratigraphic

rift basin

oceanic trench