cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
Mika Rizki Puspaningrum
Contact Email
mika.puspaningrum@itb.ac.id
Phone
+6281246804772
Journal Mail Official
mika.puspaningrum@itb.ac.id
Editorial Address
Jl. Ganesha No. 10 Bandung 40132
Location
Kota bandung,
Jawa barat
INDONESIA
Bulletin of Geology
Published by Institut Teknologi Bandung
ISSN : 25800752     EISSN : 25800752     DOI : 10.5614/bull.geol.
Core Subject : Science, Engineering,
Earth & Planetary Sciences Energy Engineering
Bulletin of Geology is a research-based periodical scientific open access journal published by Faculty of Earth Sciences and Technology, Institut Teknologi Bandung (ITB). The published article in Bulletin of Geology covers all geoscience and technology fields including Geology, Geophysics, Geodesy, Meteorology, Oceanography, Petroleum, Mining, and Geography. The submitted abstract must be written in English and Bahasa Indonesia, but the article content is English or Bahasa Indonesia.
Arjuna Subject : Ilmu Bumi dan Planet (semua kategori) - Geologi
Articles 5 Documents
 1 
Search results for , issue "Vol 6 No 1 (2022): Bulletin of Geology" : 5 Documents clear
STUDI GEOMEKANIKA 3D DENGAN ANALISIS BIDANG LEMAH LAPISAN (PLANE OF WEAKNES) DI LAPANGAN ALPHA, MADURA UTARA Restio Adhyaksa Brata
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Alpha field which located at offshore North Madura, East Java Indonesia, is known for the economic hydrocarbon reserve based on the previous drilling campaign results. The success of the production results had strengthened the decision to further develop this field by targeting several upcoming wells. But drilling process in this field was not easy and encounter many drilling problems such as breakouts, stuck pipes, well collapse and even wells need to be sidetracked. From the drilling perspective, the carbonate dominant formation is challenging and shows high uncertainty for the drilling parameter. 1D geomechanics analysis was applied in the previous drilling campaign to provide the analysis of rock properties and recommended drilling parameters. The wellbore instability problem has been reduced after the 1D geomechanics analysis application, although the main drilling problem still occurred such as breakout and well collapse. Blocky caving then observed in some of the wells in the interbedded carbonate and shale in Kujung Formation, and this type of caving is potentially indicating the plane of weakness issue. Based on those drilling experiences, the advanced geomechanics study is mandatory for the safety and successful well drilling. Anisotropy in the rock properties over the study field may lead to the invalid 1D geomechanics model in the prediction of rock properties for the upcoming well trajectory. Besides that, the pressure and rock stresses are also varying in every location where it is affected by tectonics and fault plane. Based on that, the disadvantages of the 1D geomechanics model need to be escalated to the 3D model with support from the seismic attributes and 3D static reservoir model. 1D logs of rock properties in every offset well were upscaled and propagated over the field as a 3D cube. 3D cube of rock properties with pore pressure and vertical stress then will be the inputs to calculate 3D horizontal stresses over the field by using Blanton & Olson Formula. The presence of the blocky caving in several wells in the Kujung Formation indicates another factor that can cause well collapse. However, this factor was not analyzed in the previous drilling campaign. This blocky caving potentially represents the bedding plane failure due to the low attacking angle of the well trajectory and formation bedding. To avoid bedding failure, the stresses applied to the bedding plane due to pressure from drilling activities must be calculated by using Kirsch Formula. The stress applied to the bedding plane can be maintained by using correct mud weight and reduce the well inclination. 3D geomechanics model helps in the rock properties prediction in the trajectory of the upcoming well. Added to that, the plane of weakness analysis helps to predict the stress applied in the bedding plane due to drilling activities. The integration of the 3D geomechanics model with the plane of weakness analysis provides the accurate drilling parameter and the mud weight recommendation for safe and successful well drilling and increased the cost efficiencies.
POTENSI PENGAYAAN TIMAH DAN UNSUR TANAH JARANG PADA ENDAPAN PLASER DI DAERAH AIR BELO, KABUPATEN BANGKA BARAT Firdaus El Afghani
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Daerah penelitian terletak di Air Belo, Kabupaten Bangka Barat. Penelitian bertujuan untuk menentukan daerah potensi timah dan unsur tanah jarang serta menentukan arah eksplorasi lanjut di daerah penelitian. Studi ini berfokus pada endapan aluvial yang tergolong sebagai endapan plaser. Endapan plaser di daerah penelitian terdiri atas dua jenis yaitu endapan aluvial purba dan endapan sungai aktif. Metode penelitian yang dilakukan antara lain pemetaan geologi, analisis geokimia, dan Grain Counting Analysis (GCA). Analisis geokimia dengan metode X-ray Fluorescence (XRF) Portable dilakukan terhadap sampel endapan aluvial dan granit untuk mengetahui kandungan timah dan unsur tanah jarang. Mineral berat yang terkandung dalam endapan aluvial diidentifikasi menggunakan GCA. Berdasarkan analisis geokimia, daerah pengayaan timah terletak di area tenggara daerah penelitian sedangkan daerah pengayaan unsur tanah jarang terbagi menjadi tiga area yaitu area baratlaut, baratdaya, dan utara daerah penelitian. Oleh karena itu, arah eksplorasi lanjut untuk timah yaitu pada arah tenggara daerah penelitian sedangkan arah eksplorasi lanjut untuk unsur tanah jarang yaitu arah baratlaut, baratdaya, dan utara daerah penelitian. Disisi lain, GCA menunjukkan bahwa mineral berat yang diduga membawa timah dan unsur tanah jarang adalah kasiterit, zirkon, dan turmalin. Densitas mineral menjadi faktor pengontrol penyebaran timah dan unsur tanah jarang di daerah penelitian. Sebagai contoh, unsur tanah jarang lebih tersebar dibandingkan timah dikarenakan mineral pembawa unsur tanah jarang seperti turmalin (ρ=2,9-3,1 g/cm3) dan zirkon (ρ=4,6-5,8 g/cm3) memiliki densitas yang lebih rendah sehingga lebih mudah tertransport dibandingkan kasiterit (ρ=6,98-7,01 g/cm3).
1D GEOMECHANICAL MODELING AND CRITICALLY-STRESSED FRACTURES ANALYSIS IN NATURALLY FRACTURED RESERVOIR, MUARA LABOH GEOTHERMAL FIELD, WEST SUMATRA, INDONESIA Taufik Al Amin; Marino Christiano Baroek; Sonny Santana; Benyamin Sapiie; Indra Gunawan
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The effectiveness of geological structures to promote fluid flow is influenced by both geometric factors of the structural context and the local stress field. Multiple investigations have demonstrated that critically stressed fractures/faults promote dilatation and slip at flow-friendly zones. One-dimensional (1D) geomechanics and critically-stressed fractures analyses are carried out in one of the development well, ML-2, in Muara Laboh geothermal field, West Sumatra, Indonesia. The main purpose of this study is to establish the permeability pattern on fractures/faults and its relationship to the present-day in-situ stress. The analyses utilize wellbore data consisting of borehole images, gamma-ray (GR), shear and compressional sonic logs, pressure and temperature survey, and drilling data. Geomechanical modeling applies empirical stress estimation to log data and pressure test results, which is calibrated by stress polygon and the occurrence of wellbore failures. Linearized Mohr-Coulomb failure envelopes and failure criteria are used to determine the critically-stressed fractures. The 1D geomechanics model result shows that the in-situ stress regime in ML-2 well predominantly is strike-slip and the maximum horizontal stress direction is about N60°E, following far-field field stress direction. Critically-stressed fractures are more likely to happen in the NNE-SSW direction and its reciprocal. The high intensity of critically-stressed fractures tends to be associated with productive interval/feed zones.
Komposisi Fauna Vertebrata Holosen Awal di Situs Gua Panglima, Gunung Parung, Kalimantan Timur Benyamin Perwira Shidqi; Mohammad Ruly Fauzi; Mika Rizki Puspaningrum; Yan Rizal; Truman Simanjuntak
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Sari Gua panglima merupakan salah satu gua karst yang terletak di Gunung Parung, Kalimantan Timur, Indonesia. Penelitian arkeologi dilakukan dalam endapan lantai Gua Panglima yang dibagi menjadi 5 zona stratigrafi utama. Penelitian berfokus di kotak galian TP1 dan TP2 yang menghasilkan temuan sisa fauna vertebrata melimpah yang terdiri atas gigi, rahang, tulang utama, dan fragmen tulang lainnya. Analisis temuan vertebrata berupa identifikasi takson dan kuantifikasi temuan teridentifikasi (NISP) bertujuan untuk mengetahui himpunan fauna dan kondisi lingkungan di sekitar Gua Panglima. Sisa temuan vertebrata di Gua Panglima terdiri atas 8 kelompok besar takson yaitu Primata, Artiodactyla, Perrisodactyla, Carnivora, Rodentia, Reptilia, Pholidota, Chiroptera, dan Actinopterygii. Keseluruhan temuan diidentifikasi menjadi 38 takson yang terdiri atas tingkat famili hingga spesies. Temuan sisa fauna vertebrata berjumlah 8672 spesimen dengan total temuan teridentifikasi (NISP) berjumlah 2227 dan temuan tidak teridentikasi berjumlah 6445. Temuan terdiri atas elemen gigi berupa incisor, canine, premolar, dan molar (16,3% NISP, n = 360), elemen rahang berupa mandibula dan maxilla (5,5% NISP, n = 124), dan elemen tulang utama berupa antler, astragalus, calcaneus, carapace, carpal, caudal, costae, femur, humerus, metacarpal, metatarsal, oscoxa, pelvis, phalanges, plastron, radius, scapula, supraorbital, tibia, ulna, dan vertebrae (78,2% NISP, n = 1743). Temuan hasil penggalian Gua Panglima diperkirakan memiliki rentang umur kurang Holosen Awal – Tengah. Komposisi fauna pada Gua Panglima memiliki signifikansi secara kronologi dengan beberapa situs pada periode dan lokasi berdekatan seperti Gua Niah dan Pulau Palawan. Kemiripan komposisi fauna pada ketiga situs tersebut memberikan gambaran bagaimana perkembangan ekologi pada hutan hujan tropis Kalimantan yang relatif tidak terlalu berubah pada periode tersebut. Meskipun begitu, komposisi fauna pada temuan Gua Panglima tidak dapat dipisahkan dengan konteks hunian manusia prasejarah dengan ditemukannya artefak arkeologi lainnya. Abstract Panglima Cave is one of the karstic caves located in Parung Mountain, East Kalimantan, Indonesia. Archaeological research was conducted on the Panglima Cave sediment deposit that is divided into 5 main stratigraphic zones. This research focuses on unconsolidated sediment deposit from TP1 and TP2 box excavation that yields an abundant amount of vertebrate fossil remains including teeth, jaw, and other bones fragment. The analysis of fossil specimens for taxonomy identification and specimen quantification (NISP) is defined to comprehend fauna assemblage and its paleoenvironment. The collection reveals 8 main fauna groups which are composed of Primates, Artiodactyl, Perissodactyl, Carnivore, Rodent, Reptile, Pholidota, Chiroptera, and Actinopterygii. The whole identified fossil is comprised of 38 taxa that varied from family to species. Panglima Cave fossil remains had a total amount of 8672 specimens with 2227 of them being identified specimens (NISP) and the rest 6445 are unidentified specimens. Fossil element variations are consisting of teeth elements from incisor, canine, premolar, and molar (16,3% NISP, n = 360), jaw elements from mandible and maxilla (5,5% NISP, n = 124), and primary bone elements from antler, astragalus, calcaneus, carapace, carpal, caudal, costae, femur, humerus, metacarpal, metatarsal, oscoxa, pelvis, phalanges, plastron, radius, scapula, supraorbital, tibia, ulna, and vertebrae (78,2% NISP, n = 1743). Panglima cave deposits are estimated to have formed from to Early – Middle Holocene. The fauna composition has a chronological context from several archaeological and paleontological sites around Borneo Island, such as Niah Cave and Palawan Island. The similarity of fauna distribution from those three sites reflects the relatively constant ecological condition of Borneo tropical forest since the Late Pleistocene. However, the Panglima Cave fauna assemblage is indivisible with prehistory human occupancy as demonstrated by other archaeological findings on this site.
GEOMORFOLOGI SESAR AKTIF DI PULAU RUMBERPON, PAPUA Astyka Pamumpuni; Benyamin Sapiie; Ipranta Ipranta; Imam Achmad Sadisun
Bulletin of Geology Vol 6 No 1 (2022): Bulletin of Geology
Publisher : Fakultas Ilmu dan Teknologi Kebumian (FITB), Institut Teknologi Bandung (ITB)

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Morfologi di bagian Leher Burung, Papua didominasi oleh bentuk morfologi sesar naik dan lipatan. Morfologi yang menunjukkan lipatan ideal yang masih muda, bentukan antiform merepresentasikan antiklin. Namun demikian, data kegempaan di daerah Leher Burung, Papua menunjukkan banyaknya gempa dengan mekanisme sesar normal dan sesar mendatar. Observasi geomorfologi di lokasi Leher Burung, di Pulau Rumberpon dilakukan pada studi ini dengan menggunakan data DEM dengan resolusi 8m dari DEMNAS. Analisis geomorfologi ditekankan pada identifikasi sesar aktif. Data kegempaan yang berupa lokasi gempa (epicenter dan hipocenter), magnitudo, dan waktu kejadian didapatkan dari katalog kegempaan yang telah direlokasi. Mekanisme fokal gempa didapatkan dari katalog CMT. Data kegempaan digunakan untuk melihat hubungan data kegempaan dan hasil analisis geomorfologi. Hasil analisis geomorfologi menunjukkan adanya sesar normal yang aktif berkorelasi dengan arah jurus dari mekanisme fokal yang ada di area ini. Observasi menunjukkan adanya bukti-bukti sesar normal dengan arah jurus utara-selatan (N-S) dan timur laut-barat daya (NE-SW). Fitur-fitur geomorfologi yang terpetakan antara lain adalah laguna yang memanjang, lembah paralel, penampang topografi yang menunjukkan seri rangkaian sesar normal, gawir sesar, dan relay-ramp. Fitur geomorfologi yang ada menunjukkan adanya seri sesar normal aktif memiliki kemiringan ke barat dengan jurus ke utara-selatan sesuai dengan arah jurus dari mekanisme fokal kegempaan yang ada. Kesesuaian antara mekanisme fokal gempa dan bukti morfologi menunjukkan adanya sesar normal aktif di area Leher Burung, terutama di Pulau Rumberpon. Mekanisme pembentukan sesar di Pulau Rumberpon ini terkait erat dengan Sesar Yapen-Sorong dan adanya pembelokan ke kanan zona sesar tersebut.

Page 1 of 1 | Total Record : 5

 1 

Filter by Year

2022 2022


Reset
Filter By Issues
All Issue Vol 8 No 1 (2024): Bulletin of Geology Vol. 8 no. 1 Vol 7 No 4 (2023): Bulletin of Geology Vol 7 No 3 (2023): Bulletin of Geology Vol 7 No 2 (2023): Bulletin of Geology Vol 7 No 1 (2023): Bulletin of Geology Vol 6 No 3 (2023): Bulletin of Geology Vol 6 No 2 (2022): Bulletin of Geology Special Issue: International Seminar on Earth Sciences and Te Vol 6 No 1 (2022): Bulletin of Geology Vol 5 No 4 (2021): Bulletin of Geology Vol 5 No 3 (2021): Bulletin of Geology Vol 5 No 2 (2021): Bulletin of Geology Vol 4 No 1 (2020): Bulletin of Geology Vol 3 No 3 (2019): Bulletin of Geology Vol 3 No 2 (2019): Bulletin of Geology Vol 3 No 1 (2019): Bulletin of Geology Vol 2 No 2 (2018): Bulletin of Geology Vol 2 No 1 (2018): Bulletin of Geology Vol 1 No 2 (2017): Bulletin of Geology Vol 1 No 1 (2017): Bulletin of Geology More Issue