Karakteristik Reservoir Batupasir Berdasarkan Routine Core Analysis Pada Sumur Tsl Lapangan Cstsld, Cekungan Sumatera Tengah.
DAFTAR ISI
Halaman
SARI
......................................................................................................... i
KATA PENGANTAR ...................................................................................... iii
DAFTAR ISI..................................................................................................... vi
DAFTAR TABEL............................................................................................. ix
DAFTAR GAMBAR ........................................................................................ x
BAB I PENDAHULUAN................................................................................ 1
1.1 Latar Belakang..................................................................................... 1
1.2 Batasan Masalah .................................................................................. 2
1.3 Maksud dan Tujuan ............................................................................. 3
1.4 Lokasi Penelitian.................................................................................. 3
1.5 Waktu Penelitian.................................................................................. 4
1.6 Kegunaan Penelitian ............................................................................ 4
BAB II TINJAUAN PUSTAKA ..................................................................... 6
2.1. Geologi Regional Cekungan Sumatra Tengah.................................... 6
2.1.1 Struktur Geologi dan Tektonik Cekungan Sumatera Tengah .... 7
2.1.2 Stratigrafi Cekungan Sumatera Tengah ..................................... 9
2.2 Geologi Lokal Daerah Studi ............................................................... 17
2.3 Batuan Inti (Core) ........................................................................... 19
2.3.1 Routine Core Analysis................................................................ 21
2.4 Fasies
........................................................................... 21
vi
2.5 Lingkungan Pengendapan.................................................................. 23
2.5.1 Estuary
........................................................................... 23
2.6 Log Spektral Sinar Gamma................................................................ 27
2.7 Mineral Lempung ........................................................................... 30
2.8 Saturasi
........................................................................... 32
2.9 Porositas
........................................................................... 33
2.10 Permeabilitas
........................................................................... 35
BAB III METODE PENELITIAN .................................................................. 39
3.1 Objek Penelitian
.......................................................................... 39
3.2 Langkaah-langkah Penelitian ............................................................. 39
3.2.1 Tahap Persiapan dan Pengumpulan Data.................................... 39
3.2.2 Tahap Penelitian dan Pengolahan Data ...................................... 40
3.2.3 Tahap Pembahasan dan Penyusunan Laporan ........................... 41
3.3 Bagan Alir Penelitian ......................................................................... 41
3.4 Deskripsi core
........................................................................... 42
3.5 Fasies
........................................................................... 42
3.6 Wireline Log
........................................................................... 43
3.7 Metode Analisa Core Rutin ............................................................... 44
BAB IV HASIL DAN PEMBAHASAN ......................................................... 54
4.1. Koreksi Kedalaman ........................................................................... 55
4.2. Penentuan Litofasies dan Asosiasi Fasies........................................... 57
4.3. Keterdapatan Mineral Lempung ......................................................... 75
4.4. Nilai Saturasi Air dan Minyak, Porositas, Permeabilitas.................... 79
vii
4.5. Kualitas Reservoir
........................................................................... 81
BAB V KESIMPULAN
........................................................................... 87
DAFTAR PUSTAKA
........................................................................... 89
LAMPIRAN
viii
DAFTAR TABEL
Tabel 2.1 Contoh deskripsi core pada batuan reservoar (Sudomo, 1996)........ 20
Tabel 4.1 Saturasi, porositas dan permeabilitas fasies A ................................ 81
Tabel 4.2 Saturasi, porositas dan permeabilitas fasies B ................................ 82
Tabel 4.3 Saturasi, porositas dan permeabilitas fasies C ................................ 83
Tabel 4.4 Saturasi, porositas dan permeabilitas fasies D ................................ 84
Tabel 4.5 Saturasi, porositas dan permeabilitas fasies E ................................. 85
Tabel 4.6 Saturasi, porositas dan permeabilitas fasies F ................................. 86
ix
DAFTAR GAMBAR
Gambar 1.1 Lokasi Penelitian ..................................................................... 4
Gambar 2.1 Lokasi Cekungan Sumatera Tengah dan Batas-batasnya
(Heindrick dan Aulia, 1993)...................................................... 7
Gambar 2.2 Pola Struktur Geologi Regional yang berkembang pada
Cekungan Sumatera Tengah (Heidrick dan Aulia, 1993). ........ 9
Gambar 2.3 Perkembangan
Tektonik
Cekungan
Sumatra
Tengah
(Heidrick dan Aulia, 1993)....................................................... 16
Gambar 2.4 Kolom Stratigrafi Cekungan Sumatera Tengah (Eubank dan
Makki, 1981; Heidrick dan Aulia, 1993) ................................17
Gambar 2.5 Penampang yang mendefinisikan lingkungan Estuary
(Dalrymple, 1992 dalam Walker , 2006)................................... 24
Gambar 2.6 A. Tipe energi, B. Morfologi Estuary Wave Dominated, C.
Sedimen Fasies Estuary Wave Dominated (Dalrymple dan
Zailin, 1990 dalam Walker, 2006) ............................................ 25
Gambar 2.7 Distribusi A. Tipe Energi B. Elemen Morfologi yang terdapat
pada Tide Dominated Estuary yang ideal (Darlymple, 2006)... 27
Gambar 2.8 Thorium/Potassium rasio-plot. .................................................... 29
Gambar 2.9 Thorium/Potassium crossplot. ..................................................... 30
Gambar 2.10 Klasifikasi authogenic clay menurut Neashem (1977)............. 32
Gambar 2.11 Model porositas efektif (dimodifikasi oleh Schlumberger,
2003)..........................................................................................34
x
Gambar 2.12 Pengaruh pertambahan ukuran butir terhadap porositas dan
permeabilitas ............................................................................. 36
Gambar 2.13 Pengaruh sortasi terhadap porositas dan permeabilitas ............. 37
Gambar 2.14 Besar porositas pada bentuk susunan geometri yang berbeda
butiran dalam batuan ................................................................. 38
Gambar 3.1 Bagan Alir Penelitian .................................................................. 41
Gambar 3.2 Alat Dean Stark ........................................................................... 45
Gambar 3.3 Hasil pengukuran Dean Stark...................................................... 46
Gambar 3.4 Grain volume porosimeter........................................................... 49
Gambar 3.5 Direct pore volume porosimeter.................................................. 50
Gambar 3.6 Permeameter ................................................................................ 51
Gambar 3.7 EGL 255 (Coretest system, Inc. EGL - 255 operator s manual) . 53
Gambar 4.1 Sinar gamma core 2..................................................................... 55
Gambar 4.2 Sinar gamma core 3..................................................................... 56
Gambar 4.3 Core interval 2344
2352 kaki (Sumber: TS. Lab duri) .......... 59
Gambar 4.4 Core interval 2352 - 2360 kaki (Sumber: TS. Lab duri) ............. 59
Gambar 4.5 Core interval 2360
2366 kaki (Sumber: TS. Lab duri) ............ 61
Gambar 4.6 Core interval 2366
2371,6 kaki (Sumber: TS. Lab duri) ......... 61
Gambar 4.7 Core interval 2373 - 2379 kaki (Sumber: TS. Lab duri) ............. 62
Gambar 4.8 Core interval 2388 - 2400 kaki (Sumber: TS. Lab duri) ............. 64
Gambar 4.9 Core interval 2400 - 2404 kaki (Sumber: TS. Lab duri) ............. 64
Gambar 4.10 Core interval 2763 - 2766 kaki (Sumber: TS. Lab duri) ........... 65
Gambar 4.11 Core interval 2777 - 2781 kaki (Sumber: TS. Lab duri) ........... 66
xi
Gambar 4.12 Core interval 2781 - 2787 kaki (Sumber: TS. Lab duri) .......... 67
Gambar 4.13 Core interval 2787 - 2793 kaki (Sumber: TS. Lab duri) .......... 68
Gambar 4.14 Core interval 2794 - 2806 kaki (Sumber: TS. Lab duri) .......... 68
Gambar 4.15 Core interval 2811 - 2823 kaki (Sumber: TS. Lab duri) .......... 69
Gambar 4.16 Core interval 2826,7
2828 kaki (Sumber: TS. Lab duri) ...... 70
Gambar 4.17 Core interval 2829 - 2837 kaki (Sumber: TS. Lab duri) .......... 70
Gambar 4.18 Core interval 2838 - 2850 kaki (Sumber: TS. Lab duri) .......... 71
Gambar 4.19 Posisi Fasies Pada Daerah Penelitian (1) Tidal Sand Bar, (2)
Estuarine Sand Flat, (3) Tidal Channel, (4) Estuarine
Channel (Dalrymple, 1992)....................................................... 72
xii
Halaman
SARI
......................................................................................................... i
KATA PENGANTAR ...................................................................................... iii
DAFTAR ISI..................................................................................................... vi
DAFTAR TABEL............................................................................................. ix
DAFTAR GAMBAR ........................................................................................ x
BAB I PENDAHULUAN................................................................................ 1
1.1 Latar Belakang..................................................................................... 1
1.2 Batasan Masalah .................................................................................. 2
1.3 Maksud dan Tujuan ............................................................................. 3
1.4 Lokasi Penelitian.................................................................................. 3
1.5 Waktu Penelitian.................................................................................. 4
1.6 Kegunaan Penelitian ............................................................................ 4
BAB II TINJAUAN PUSTAKA ..................................................................... 6
2.1. Geologi Regional Cekungan Sumatra Tengah.................................... 6
2.1.1 Struktur Geologi dan Tektonik Cekungan Sumatera Tengah .... 7
2.1.2 Stratigrafi Cekungan Sumatera Tengah ..................................... 9
2.2 Geologi Lokal Daerah Studi ............................................................... 17
2.3 Batuan Inti (Core) ........................................................................... 19
2.3.1 Routine Core Analysis................................................................ 21
2.4 Fasies
........................................................................... 21
vi
2.5 Lingkungan Pengendapan.................................................................. 23
2.5.1 Estuary
........................................................................... 23
2.6 Log Spektral Sinar Gamma................................................................ 27
2.7 Mineral Lempung ........................................................................... 30
2.8 Saturasi
........................................................................... 32
2.9 Porositas
........................................................................... 33
2.10 Permeabilitas
........................................................................... 35
BAB III METODE PENELITIAN .................................................................. 39
3.1 Objek Penelitian
.......................................................................... 39
3.2 Langkaah-langkah Penelitian ............................................................. 39
3.2.1 Tahap Persiapan dan Pengumpulan Data.................................... 39
3.2.2 Tahap Penelitian dan Pengolahan Data ...................................... 40
3.2.3 Tahap Pembahasan dan Penyusunan Laporan ........................... 41
3.3 Bagan Alir Penelitian ......................................................................... 41
3.4 Deskripsi core
........................................................................... 42
3.5 Fasies
........................................................................... 42
3.6 Wireline Log
........................................................................... 43
3.7 Metode Analisa Core Rutin ............................................................... 44
BAB IV HASIL DAN PEMBAHASAN ......................................................... 54
4.1. Koreksi Kedalaman ........................................................................... 55
4.2. Penentuan Litofasies dan Asosiasi Fasies........................................... 57
4.3. Keterdapatan Mineral Lempung ......................................................... 75
4.4. Nilai Saturasi Air dan Minyak, Porositas, Permeabilitas.................... 79
vii
4.5. Kualitas Reservoir
........................................................................... 81
BAB V KESIMPULAN
........................................................................... 87
DAFTAR PUSTAKA
........................................................................... 89
LAMPIRAN
viii
DAFTAR TABEL
Tabel 2.1 Contoh deskripsi core pada batuan reservoar (Sudomo, 1996)........ 20
Tabel 4.1 Saturasi, porositas dan permeabilitas fasies A ................................ 81
Tabel 4.2 Saturasi, porositas dan permeabilitas fasies B ................................ 82
Tabel 4.3 Saturasi, porositas dan permeabilitas fasies C ................................ 83
Tabel 4.4 Saturasi, porositas dan permeabilitas fasies D ................................ 84
Tabel 4.5 Saturasi, porositas dan permeabilitas fasies E ................................. 85
Tabel 4.6 Saturasi, porositas dan permeabilitas fasies F ................................. 86
ix
DAFTAR GAMBAR
Gambar 1.1 Lokasi Penelitian ..................................................................... 4
Gambar 2.1 Lokasi Cekungan Sumatera Tengah dan Batas-batasnya
(Heindrick dan Aulia, 1993)...................................................... 7
Gambar 2.2 Pola Struktur Geologi Regional yang berkembang pada
Cekungan Sumatera Tengah (Heidrick dan Aulia, 1993). ........ 9
Gambar 2.3 Perkembangan
Tektonik
Cekungan
Sumatra
Tengah
(Heidrick dan Aulia, 1993)....................................................... 16
Gambar 2.4 Kolom Stratigrafi Cekungan Sumatera Tengah (Eubank dan
Makki, 1981; Heidrick dan Aulia, 1993) ................................17
Gambar 2.5 Penampang yang mendefinisikan lingkungan Estuary
(Dalrymple, 1992 dalam Walker , 2006)................................... 24
Gambar 2.6 A. Tipe energi, B. Morfologi Estuary Wave Dominated, C.
Sedimen Fasies Estuary Wave Dominated (Dalrymple dan
Zailin, 1990 dalam Walker, 2006) ............................................ 25
Gambar 2.7 Distribusi A. Tipe Energi B. Elemen Morfologi yang terdapat
pada Tide Dominated Estuary yang ideal (Darlymple, 2006)... 27
Gambar 2.8 Thorium/Potassium rasio-plot. .................................................... 29
Gambar 2.9 Thorium/Potassium crossplot. ..................................................... 30
Gambar 2.10 Klasifikasi authogenic clay menurut Neashem (1977)............. 32
Gambar 2.11 Model porositas efektif (dimodifikasi oleh Schlumberger,
2003)..........................................................................................34
x
Gambar 2.12 Pengaruh pertambahan ukuran butir terhadap porositas dan
permeabilitas ............................................................................. 36
Gambar 2.13 Pengaruh sortasi terhadap porositas dan permeabilitas ............. 37
Gambar 2.14 Besar porositas pada bentuk susunan geometri yang berbeda
butiran dalam batuan ................................................................. 38
Gambar 3.1 Bagan Alir Penelitian .................................................................. 41
Gambar 3.2 Alat Dean Stark ........................................................................... 45
Gambar 3.3 Hasil pengukuran Dean Stark...................................................... 46
Gambar 3.4 Grain volume porosimeter........................................................... 49
Gambar 3.5 Direct pore volume porosimeter.................................................. 50
Gambar 3.6 Permeameter ................................................................................ 51
Gambar 3.7 EGL 255 (Coretest system, Inc. EGL - 255 operator s manual) . 53
Gambar 4.1 Sinar gamma core 2..................................................................... 55
Gambar 4.2 Sinar gamma core 3..................................................................... 56
Gambar 4.3 Core interval 2344
2352 kaki (Sumber: TS. Lab duri) .......... 59
Gambar 4.4 Core interval 2352 - 2360 kaki (Sumber: TS. Lab duri) ............. 59
Gambar 4.5 Core interval 2360
2366 kaki (Sumber: TS. Lab duri) ............ 61
Gambar 4.6 Core interval 2366
2371,6 kaki (Sumber: TS. Lab duri) ......... 61
Gambar 4.7 Core interval 2373 - 2379 kaki (Sumber: TS. Lab duri) ............. 62
Gambar 4.8 Core interval 2388 - 2400 kaki (Sumber: TS. Lab duri) ............. 64
Gambar 4.9 Core interval 2400 - 2404 kaki (Sumber: TS. Lab duri) ............. 64
Gambar 4.10 Core interval 2763 - 2766 kaki (Sumber: TS. Lab duri) ........... 65
Gambar 4.11 Core interval 2777 - 2781 kaki (Sumber: TS. Lab duri) ........... 66
xi
Gambar 4.12 Core interval 2781 - 2787 kaki (Sumber: TS. Lab duri) .......... 67
Gambar 4.13 Core interval 2787 - 2793 kaki (Sumber: TS. Lab duri) .......... 68
Gambar 4.14 Core interval 2794 - 2806 kaki (Sumber: TS. Lab duri) .......... 68
Gambar 4.15 Core interval 2811 - 2823 kaki (Sumber: TS. Lab duri) .......... 69
Gambar 4.16 Core interval 2826,7
2828 kaki (Sumber: TS. Lab duri) ...... 70
Gambar 4.17 Core interval 2829 - 2837 kaki (Sumber: TS. Lab duri) .......... 70
Gambar 4.18 Core interval 2838 - 2850 kaki (Sumber: TS. Lab duri) .......... 71
Gambar 4.19 Posisi Fasies Pada Daerah Penelitian (1) Tidal Sand Bar, (2)
Estuarine Sand Flat, (3) Tidal Channel, (4) Estuarine
Channel (Dalrymple, 1992)....................................................... 72
xii