daftar isi.pdf

PT. PERTAMINA EP ASEET 2 (REGION SUMATERA)

Jl. Jenderal sudirman No. 3, Prabumulih, Sumatera Selatan, 31122 Telepon: (0713)382201 Fax: (0713)320115/320116

http://www.pertamina-ep.com

Muhammad Guntur | Laporan Kerja Praktek Interpretasi Data Log dalam Menetukan Nilai

Saturasi Air (SW) Pada Sumur UH-23. iii

DAFTAR ISI

LEMBAR PENGESAHAN

KATA PENGANTAR ......................................................................................... i

DAFTAR ISI ....................................................................................................... iii

DAFTAR GAMBAR ............................................................................................ iv

DAFTAR TABEL ................................................................................................ v

BAB I PENDAHULUAN .................................................................................... . 1

I.1. Latar Belakang ..................................................................................... . 1

I.2. Maksud dan Tujuan ............................................................................... 2

I.3. Pembatasan Masalah ............................................................................. 2

I.4. Metode Penulisan .................................................................................. 2

BAB II REGIONAL GEOLOGI .......................................................................... 3

II.1. Sejarah singkat PT Pertamina EP Asset Field Prabumulih .................... 3

II.2. Lokasi dan Wilayah Kerja .................................................................... 4

II.3. Geologi Regional ................................................................................. 6

II.3.1. Basemant Rock ........................................................................... 9

II.3.2. Formasi Lahat ........................................................................... . 9

II.3.3. Formasi Talang Akar ................................................................... 9

II.3.4. Foemasi Batu raja ........................................................................ 9

II.3.5. Formasi Gumai .......................................................................... 10

II.3.6. Formasi Air Benakat ................................................................. 10






II.3.7. Formasi Muara Enim ................................................................. 10

II.3.8. Formasi Kasai ........................................................................... 10

II.4. Geologi Lapangan Prabumulih ........................................................... 11

BAB III TINJAUAN PUSTAKA ....................................................................... 13

III.1. Pengertian Log dan Well Logging..................................................... 13

III.2. Macam-macam metode yang digunakan untuk memperoleh data log 14

III.2.1. Wireline Logging ..................................................................... 14

III.2.2. Logging While Drilling ............................................................ 17

III.3. Tipe- Tipe Log.................................................................................. 20

III.3.1. Log Listrik ......................................................................... 20

III.3.1.a. Log Spontaneous Potensial (SP) ........................... 20

III.3.1.b. Log Resistivitas ................................................... 21

III.3.2. Log Radioaktif ................................................................... 27

III.3.2.a. Log Gamma Ray .................................................. 27

III.3.2.b. Log Porositas ....................................................... 30

III.3.3.Log Akustik (Log Sonik) ..................................................... 35

III.3.4. Log Capiler ........................................................................ 36

III.4. Interpretasi kualitatif ......................................................................... 38

III.4.1. Zona Batuan Reservoar ...................................................... 38

III.4.2. Jenis Litologi ...................................................................... 39

III.4.3. Jenis Fluida Pengisi Formasi .............................................. 40

III.5. Interpretasi kuantitatif ....................................................................... 40

III.5.1. Porositas............................................................................. 41

III.5.2. Faktor Formasi ................................................................... 44

III.5.3. Resistivitas Air (Rw) .......................................................... 45

III.5.4. Kandungan Serpih .............................................................. 47

III.5.5. Saturasi Air (Sw) ................................................................ 49

III.5.6. Volume Bulk Air ................................................................ 50






III.5.7. Saturasi Hidrokarbon (Sh) .................................................. 51

BAB. IV. METODOLOGI PENELITIAN ......................................................... 52

IV.1. Tahap Pendahuluan dan Pengumpulan data ...................................... 52

IV.2. Tahap Analisa data dan Interpretasi .................................................. 52

IV.2.1. Analisa Data .................................................................................. 52

IV.2.2. Interpretasi Kualitatif ..................................................................... 54

IV.2.3. Interpretasi secara Kuantitatif ........................................................ 55

BAB.V. HASIL DAN PEMBAHASAN .............................................................. 59

V.1. Perhitungan petrofisika......................................................................... 60

BAB. VI. PENUTUP ........................................................................................... 70

VI.1. Kesimpulan ...................................................................................... 70

VI.2. Saran ................................................................................................ 71

DAFTAR PUSTAKA

LAMPIRAN






DAFTAR GAMBAR

II.1. Peta Lokasi PT Pertamina EP Region Sumatera ......................................................... 5

II.2. Struktur Regional Cekungan Sumatera Selatan ................................................ 7

II.3. Stratigrafi Cekungan Sumatera Selatan ............................................................ 8

III.1. Alat-alat yang digunakan dalam wireline logging ......................................... 14

III.2. Berbagai jenis alat logging. .......................................................................... 16

III.3. Alat LWD .................................................................................................... 19

III.4. Contoh shale baseline dan didefinisikan SSP dalam log SP. Shale

baseline menunjukkan defleksi positif maksimum (dalam sampel ini) dan

terjadi berlawanan dengan serpih. SSP (Static SP) adalah defleksi negatif

maksimum dan terjadi berlawanan bersih, porous dan batupasir

permeabel yang berkomposisi air. ......................................................... … 21

III.5. Prinsip Kerja Alat Laterolog ......................................................................... 23

III.6. Prinsip Kerja Alat Induksi ............................................................................ 24

III.7. Kontras karakteristik resolusi lapisan dari alat resistivitas dan aplikasi

geologinya. .................................................................................................. 25

III.8. Format khas log resistivitas. (1) kombinasi Dual Laterolog; (2) induction,

kombinasi spherically focused log. Keduanya dari Schlumberger................. 26

III.9. Profil sumur bor terinvasi lumpur ................................................................. 27

III.10. Log sinar gamma dan spektral log sinar gamma, beberapa respon yang

khas. Log sinar gamma menunjukkan radioaktivitas alami. Spektral log

gamma ray memberikan kelimpahan unsur- unsur radioaktif alami dari

Thorium- Th, Uranium- U, dalam bagian per juta (ppm) dan Potassium-

K dalam%. F = feldspar, M = mika, * = glauconite. ..................................... 29

III.11. Proses hamburan dan penyerapan sinar gamma. ......................................... 30






III.12. Log densitas; beberapa respon yang khas. Log densitas menunjukkan

densitas bulk. *Densitas dan porositas dengan densitas formasi air (fresh)

1.0g/cm3. (skala sama dengan gambar 3.11 log neutron). ............................. 31

III.13. Log neutron; beberapa respon yang khas. Log neutron menunjukkan

indeks hidrogen yang diubah menjadi unit porositas neutron. *Porositas

dengan air segar dan alat CNL Schlumberger (skala sama dengan gambar

III.10 log porositas)...................................................................................... 34

III.14. Sistem BHC ............................................................................................... 35

III.15. Tipikal Respon caliper untuk berbagai litologi. ........................................... 37






DAFTAR TABEL

III.1. Resolusi lapisan minimum dari alat resistivitas ............................................. 25

III.2. Faktor- faktor penyebab respon kaliper. ........................................................ 36

III.3. Densitas matriks dari berbagai litologi ......................................................... 41

III.4. Densitas matriks untuk beberapa mineral pembentuk batuan (dalam Glover) 42

III.5. Koefisien dan eksponen berbeda yang digunakan untuk menghitung

faktor formasi (F) ......................................................................................... 44

III.6. . Bulk Volume Water sebagai Fungsi dari Ukuran Butir dan Litologi. A

comparative chart. ....................................................................................... 50

V.1. Data Literatur ................................................................................................ 60

V.2. Hasil Analisa Hidrokarbon dengan Interactive Petrophysics ......................... 62

daftar isi.pdf

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