> Selamat untuk IATMI yang telah melakukan langkah besar dengan
mengadakan seminar geologi yang sangat penting untuk bisa lebih mendalami
karakter reservoir untuk dipalikasikan dalam operasi perminyakan.
Seminar antar ilmu seperti ini jelas sangat berguna bagi peningkatan
saling mengerti antara ahli kebumian dan insinyur insinyur perminyakan.
Sekali lagi selamat !!!!
Si Abah
______________________________________________________________________
IATMI sedang mengadakan worshop
“carbonate complexity : characterization,
> modeling and
simulation” di Yogyakarta dari 22-25 April 2008. Workshop
>
dihadiri sekitar 80 orang dari berbagai institusi pemerintah, oil
> companies, service companies, dan perguruan tinggi.
>
> Workshop didahului oleh kursus satu hari tentang aspek geologi
dan
> reservoir engineering karbonat dibawakan oleh Alit Ascaria
(Premier Oil)
> dan Doddy Abdassah (ITB).
>
>
Workshop dibuka pada 23 April 2008 oleh Ketua IATMI Kuswo Wahyono,
> dilanjutkan dengan pidato sambutan oleh John Sinulingga mewakili
> Pertamina Eksploitasi (panitia workshop adalah IATMI Komda
Cirebon
> –Pertamina), dan pidato/presentasi kunci dari
Handoyo Eko Wahono
> (BPMIGAS) tentang lapangan-lapangan karbonat
yang dikembangkan dalam
> lima tahun terakhir, Bob Yulian
(BPMIGAS) tentang kemajuan eksplorasi
> target karbonat di
Indonesia, dan Gatot Kariyoso Wiroyudo (Shell)
> tentang investasi
teknologi Shell dalam mengerjakan karbonat.
>
> Makalah
teknis yang dipresentasikan sebanyak 16 makalah. Workshop
>
diselingi dengan fieldtrip ke Gunung Kidul mengunjungi singkapan
>
karbonat Wonosari.
>
> Pembicara mendapatkan kesempatan
berbicara cukup tenang karena waktu
> yang diberikan antara 20-30
menit, pertanyaan 5-10 menit. Workshop ini
> jelas bermanfaat
menambah wawasan aspek GGRE karbonat. Karbonat
> merupakan
objektif sangat penting karena menyusun sekitar 50 % reservoir
>
lapangan2 produksi di Indonesia. Bahkan dalam lima tahun terakhir, 54 %
> recoverable reserve lapangan-lapangan baru berasal dari
reservoir
> karbonat, maka karbonat tak kalah penting dari
reservoir silisiklastik,
> bahkan bisa lebih.
>
>
Saya diundang IATMI berkontribusi makalah tentang geologi regional
> karbonat di Indonesia. Di bawah ini adalah abstraknya, semoga
berguna.
>
> Mahasiswa tidak banyak yang hadir. Karena
merasa ada yang kurang kalau
> saya hanya mempresentasikan makalah
saya kepada para profesional di
> workshop, maka pada hari yang
sama saya ke UGM dan mempresentasikan
> materi yang sama di
hadapan para mahasiswa tetapi dalam format
> penyampaian kepada
mahasiswa. Setelah itu, masih di UGM, saya
> melanjutkan
mempresentasikan makalah ”Sandhyakala ning Jenggala dan
>
Majapahit : Hipotesis Kebencanaan Geologi” – kali ini jauh
lebih tenang
> tak seperti saat mempresentasikan makalah ini di
PIT IAGI 2007 Bali yang
> mesti berpacu dengan waktu yang
terbatas. Waktu yang terbatas atau
> terburu2 akan menyulitkan
pendengar mencerna materi yang disampaikan.
> Sebagai informasi,
hipotesis ini telah ”ditangkap” National Geographic
>
Channel untuk menjadi tayangan (pengambilan gambar sudah dilalukan) di
> dalam film dokumenter ”LUSI”.
>
>
Demikian, laporan singkat.
> awang – Grand Mercure –
24/4/2008, 02.15
>
> LAMPIRAN
>
>
Geologic Controls on Carbonate Reservoirs in Indonesia :
>
Regional Overview
>
> Awang Harun Satyana
>
> (BPMIGAS)
>
> Carbonate reservoirs are
characterized by extreme heterogeneity of
> porosity and
permeability. This is related to the complexities of the
>
original depositional environment and the diagenetic influences that
can
> modify the original textures. Wide variety of environmental
facies and
> diagenetic changes express controls of geologic
factors. Therefore, in
> characterizing carbonate reservoirs, it
is important to evaluate
> geologic controls which influence
carbonate sedimentation and
> diagenesis.
>
>
Being located at warm humid tropical shallow water, in Indonesia
>
carbonates are geographically and temporally widespread. They occur in
a
> range of ages and depositional settings which were often
affected by
> coeval tectonism, siliciclastic input or volcanism.
The carbonates
> developed in various tectonic settings of
back-arc, intra-arc, fore-arc,
> and foreland basins; island arc;
micro-continents; and continental
> passive margins. They
developed as patch reefs of land-attached platform
> such as
Baturaja buildups in South Sumatra and West Java, fringing reefs
>
such as Kais buildups on Arar High, the Bird’s Head of Papua,
barrier
> reefs such as Ujung Pangkah reefs in East Java, and
pinnacle reefs
> overlying offshore isolated platforms such as
reefs of the Cepu High,
> East Java and Arun reefs in North
Sumatra. In each a variety of
> carbonate depositional systems,
the reefs often developed on structural
> highs. Subsidence,
uplift, active faulting, tilting or associated
>
silici/volcaniclastic input strongly affected facies variability,
> stratal/platform geometries, sequence development and carbonate
> termination. These geologic factors influence distribution and
continuity
> of the carbonate reservoirs.
>
>
Ages of carbonates influence the basic ingredients of carbonates.
> Diversity, abundance, dominant mineralogy, and relative importance
of
> sediment-producing marine invertebrates are various through
the geologic
> periods. This will influence the response of
carbonates when they are
> changed by diagenesis. Producing
carbonate reservoirs in Indonesia range
> in ages from the
Jurassic Manusela fractured oolitic carbonates in Seram
> Island,
Eastern Indonesia to Pliocene globigerinid limestones of the
>
Madura Strait. Paleogene carbonates in Indonesia are commonly dominated
> by larger foraminifera. These carbonates typically form
large-scale
> platforms or isolated shoals. Good poroperms can be
preserved in shoal
> or redeposited carbonates lacking micrite.
Secondary porosities
> developed due to fracturing, chemical
dissolution during burial, or as
> karstic cavities. However, the
opportunities for leaching were limited.
> Neogene carbonates
often contain abundant aragonitic bioclasts, such as
> corals.
They typically develop as reefal buildups, shelfal deposits or as
> isolated platforms. Compared with Paleogene carbonates, poroperms
are
> generally higher in Neogene carbonates, various porosities
all occur. The
> most important, common and economic carbonate
reservoirs in Indonesia are
> the Miocene buildups such as Arun in
North Sumatra, Baturaja in South
> Sumatra and West Java, Kujung I
or Prupuh in East Java, and Kais in
> Salawati, Papua.
>
> Petrographic studies of carbonate reservoirs in Indonesia
have shown
> that they have been subjected to a number of
diagenetic processes
> including compaction (stylolization),
dissolution, cementation,
> neomorphism, silicification,
dolomitization and fracturing. Most of
> these processes are
common to all depositional facies types (reefal,
> near reef,
shallow shelf and outer shelf open marine). Original particle
>
types of the sediments inherited from the deposition play an important
> role in this respect. Interconnected corallites commonly suffer
> dissolution resulting in porosities. Neomorphism is especially
common in
> micritic carbonates reducing their porosities.
Dolomitization has a
> varied distribution and in many cases is
associated with clay minerals.
> It may affect reservoir poroperms
and be a factor in generation of
> undesirable non-hydrocarbon
gases. Stylolization and silicification are
> localized features.
Study of sequence of diagenetic events is important
> for knowing
the
> preservation or occlusion of porosities.
>
> An understanding of the geologic controls on carbonate
depositional
> environments, spatial and temporal facies
distributions and controls on
> deposition and diagenesis is
essential in order to characterize
> carbonate reservoirs and to
evaluate their considerable economic
> potential.***
>
>
> ---------------------------------
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--
_______________________________________________
Nganyerikeun hate
batur hirupna mo bisa campur, ngangeunahkeun hate jalma hirupna pada
ngupama , Elmu tungtut dunya siar Ibadah kudu lakonan.
