cover
Contact Name
Sandri Erfani, S.Si, M.Eng.
Contact Email
sandri.erfani@eng.unila.ac.id
Phone
+6282350155362
Journal Mail Official
jge.tgu@eng.unila.ac.id
Editorial Address
Geophysical Engineering Department Engineering Faculty Universitas Lampung, Prof. Dr. Sumantri Brojonegoro Street No 1, Rajabasa District, Bandar Lampung, Indonesia 35145
Location
Kota bandar lampung,
Lampung
INDONESIA
JGE (Jurnal Geofisika Eksplorasi)
Published by Universitas Lampung
ISSN : 23561599     EISSN : 26856182     DOI : https://doi.org/10.23960/jge
Core Subject : Science,
Jurnal Geofisika Eksplorasi adalah jurnal yang diterbitkan oleh Jurusan Teknik Geofisika Fakultas Teknik Universitas Lampung. Jurnal ini diperuntukkan sebagai sarana untuk publikasi hasil penelitian, artikel review dari peneliti-peneliti di bidang Geofisika secara luas mulai dari topik-topik teoritik dan fundamental sampai dengan topik-topik terapandi berbagai bidang. Jurnal ini terbit tiga kali dalam setahun (Maret, Juli dan November), Volume pertama terbit pada tahun 2013 dengan nama Jurnal Geofisika Eksplorasi (JGE).
Articles 216 Documents
JGE Cover July 2021 Editor JGE
Jurnal Geofisika Eksplorasi Vol 7, No 2 (2021)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v7i2.150

Abstract

JGE Cover July 2021
PRE STACK DEPTH MIGRATION UNTUK KOREKSI EFEK PULL UP DENGAN MENGGUNAKAN METODE HORIZON BASED DEPTH TOMOGRAPHY PADA LAPANGAN ‘A1 DAN A2’ Attikah Azzahra; Bagus Sapto Mulyatno; Bambang Mujihardi
Jurnal Geofisika Eksplorasi Vol 4, No 1 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i1.6

Abstract

In the case of seismic data processing with sandstone lithology such as shale and carbonate often get the result of data processing which have pull up effect especially on the time domain migration result. Pre stack depth migration is a processing based on focusing the amplitude according to the actual depth by using the input interval velocity. Migration is performed using kirchhoff pre stack depth migration algorithm. Pre stack depth migration is done with modeling of horizontal based depth tomography method. This method uses residual moveout correction applied along the horizon-picking line. This research uses two field data that is A1 and A2 Field. A1field has characteristics of carbonate rock that produce pull up shaped similar to carbonate layer. A2 field has a pull-up effect that is not very clear but has build up because of the layer above it. Stages performed starting from the processing of pre stack time migration in the form of velocity picking, generate rms velocity and migration time domain. The pre stack depth migration process begins with a velocity transformation with the dix transformation equation to generate interval velocity, migrate Pre stack depth migration, perform horizon interpretations and perform velocity modeling using the horizon based depth tomography method. The iteration is done 4 times and resulted in the final section of pre stack depth migration which has been corrected by pull up effect.
Introduction and Table of Content JGE Vol 4 No 2 July 2018 Editor JGE
Jurnal Geofisika Eksplorasi Vol 4, No 2 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i2.47

Abstract

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ROCK FORMATION AND SITE CLASS IN BANDAR LAMPUNG Rustadi Rustadi; Eko Rananda
Jurnal Geofisika Eksplorasi Vol 6, No 3 (2020)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v6i3.101

Abstract

Soil characteristics are important impact for the scale of damage caused by earthquake vibrations. The impact caused by an earthquake in a location depends on the shear wave velocity (Vs). The study examined the effect of sedimentary rock formations on shear wave velocity and site class based on SPT tests in two rock formations in Bandar Lampung. The value of Vs, Vs30 and site class is determined based on the N-SPT value. Older rock formations of Quaternary age, have produced compaction at a shallow depth of 2 m from the surface, with Vs30 360 m/s and site class C. While the formation is younger, compactions are formed at a depth of 20 m, Vs 30 200 m/s and site class D.
ANALISIS TINGKAT RESIKO DAMPAK GEMPABUMI DI KABUPATEN CILACAP MENGGUNAKAN METODE DSHA DAN DATA MIKROTREMOR Kukuh Dialosa; Rustadi Rustadi; Bagus Sapto Mulyatno; Cecep Sulaeman
Jurnal Geofisika Eksplorasi Vol 4, No 3 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i3.42

Abstract

Soil mechanical research has been done in Cilacap Regency using DSHA method and microtremor data. This study aims to analyze the local land response to earthquakes based on the dominant frequency parameters (f0), amplification factor (A0), wave velocity VS30 and seismic hazard analysis through deterministic approach. This research uses 193 microtremor measurement points using a short period TDS-303 type (3 component) seismometer. Microtremor data were analyzed using the Horizontal to Vertical Spectral Ratio (HVSR) method in geopsy software. DSHA analysis refers to the source of the Lembang Fault earthquake and Java Subduction zone for deterministic calculations. Based on the analysis of HVSR method, Cilacap Regency is located on land type 1 (frequency 0-1.33 Hz) and soil type 2 (frequency 1,33-5 Hz) according to Kanai Classification (1983), dominated amplification value 1,104 to 8,171 times, then Dominated by soil class E (VS30 value 183 m / s) and soil class D (183 m / s VS30 366 m / s) according to NEHRP Classification (2000). This indicates that Cilacap Regency has high vulnerability to earthquake disaster. Based on the estimated value of PGA calculation method of DSHA, from the calculation of earthquake source Subduction obtained Java PGA bedrock 0,045 g - 0,0671 g and PGA surface rock 0,1926 g - 0,4855 g and calculation of Lembang Fault obtained PGA bedrock 0, 09 g - 0.025 g and PGA surface rocks 0.017 g - 0.089 g. Based on risk map analysis (combination of dominant frequency analysis, amplification, susceptibility factor and ability factor), the highest risk areas are Kec. Adipala, Kasugihan, Binangun, Nusawungun, Cil. Middle, Cil. South, Cil. North, allegedly the soil layer constituent area is a layer of thick and soft sediments. While the low risk of Kec. Majenang and Dayeuh Luhur.
ALTERNATIF PEMODELAN NUMERIK KOPEL THERMO-HYDRO -MECHANIC INJEKSI CO2 PADA FORMASI GEOLOGI BAWAH PERMUKAAN Cahli Suhendi; Mohammad Rachmat Sule
Jurnal Geofisika Eksplorasi Vol 6, No 1 (2020)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v6i1.62

Abstract

CO2 injection into subsurface formations is a potential method to reduce CO2 gas emissions in the atmosphere. Geological and geophysical studies are carried out as an effort to analyze the storage capacity and potential risks. The results are then used to analyze the response of reservoir rock to the injected CO2 fluid. The effect of fluid injection on reservoir rocks is complex and involves a coupled system of fluid flow-geomechanics. CO2 fluid injection can increase fluid pressure that affects the local stress conditions of reservoir and surrounding rock. Meanwhile, changes in temperature due to the presence of CO2 fluid also affect reservoir rock stress, although not significantly. The complexity of the subsurface reservoir system includes thermomechanical and hydromechanical analysis involving multi-phase and multi-component fluids. To study these complex interactions, a program which can simulate the coupling between multi-phase and multi-component fluid-flows-geomechanics is needed. To accommodate these needs, Rutqvist et al (2002) have proposed a numerical modeling approach by linking TOUGH2-ECO2N and FLAC3D. In this study we developed an external program that linking TOUGH2 with different fluid modul (ECO2M), and FLAC3D using these approaches to run the coupled THM simulation automatically and seamlessly until the end of simulation.
ANALISIS RESERVOAR MIGAS (SANDSTONE) MENGGUNAKAN MULTIATRIBUT SEISMIK PADA LAPANGAN TG12, CEKUNGAN BARITO, KALIMANTAN SELATAN Edo Pratama; Bagus Sapto Mulyatno; Ahmad Zaenudin
Jurnal Geofisika Eksplorasi Vol 5, No 1 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i1.19

Abstract

The study using multi attribute seismic has been done on TG12 field which situated at Lower Foreland Formation, Barito Basin dominated by sandstone on layer area of the target X. The objective of the study is to map the sandstone reservoir by predict distribution value of gamma ray log, neutron porosity, and density which goes through wells such as FM1, FM2, FM3, and FM4 on seismic data. Total attribute that is being used by step wise regression method by considering validation error. Multiattribute process only applied on FM2, FM3, and FM4 wells, whereas FM1 is used as a test well to determine the correlation value between seismic data and log data that is being used. In addition, from well test correlation showing great correlation result of neutron porosity log and density log both obtain the correlation around 0.6322 and 0.6557 while the gamma ray log obtain low correlation that is 0.1647 towards multi attribute result. The processing result of multi attribute obtained distribution of sandstone with gamma ray estimation range value of 65-75.8API, neutron porosity estimation range value 0.15-0.2262, while density estimation range value 2.4308-2.77gr/cc.
INVERSI 2D DATA MAGNETOTELURIK UNTUK MENGETAHUI KEBERADAAN HIDROKARBON DAERAH BULA, MALUKU Elen Novia Limswipin; Syamsurijal Rasimeng; Karyanto Karyanto; Noor Muhammad Indragiri
Jurnal Geofisika Eksplorasi Vol 4, No 3 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i3.38

Abstract

There had been done a regional research which tittle is “2D inversion magnetotelluric data for understanding the hidrocarbon presence in Bula, Maluku”. This study aims to determine the resistivity distribution area of research based on data Magnetotelluric, identifying the presence of hydrocarbons based on the value of the resistivity of the results of 2D inversion of data Magnetotelluric. Methods of data processing done are (i) transform raw data from the time domain into the frequency domain, (ii) reduce noise by robust processing, (iii) process combine, (iv) Selection cross power, (v) inversion 1D and 2D. 2D inversion results is sectional subsurface resistivity distribution, layer having resistivity values 7-16 Ωm along MT1 and MT7 point at a depth of 1000 meters is a clay stone which is indicated as cap rock. Layer with resistivity values 34-120 Ωm, which is between the point MT6 and MT7 at a depth of 1500 meters is indicated as the sandstone reservoir. Based on geologic information and sectional 2D inversion seen their fault based on the resistivity contrast is between the point MT2 and MT3, MT3 and MT4 and MT6 and MT7.
STRUKTUR GEOLOGI DAN VULKANOSTRATIGRAFI; PENDEKATAN MODEL ELEVASI DIGITAL DAN CITRA LANDSAT 8 Hari Wiki Utama
Jurnal Geofisika Eksplorasi Vol 6, No 2 (2020)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v6i2.80

Abstract

Morphological change and deformation have been happen on natural landscape on volcanic complex. Their would been seen topography formation the give contour line expression, drainage pattern as especially character for understanding geological guideline such as structural geology and lithology. In the geological and geophysics on volcanic complex can use early methode with Digital Elevation Model (DEM) of research scale map and Landsat Image 8 for understanding structural geology and volcanostratigraphy. Research study on Arjuno Welirang Volcanic Complex, East Java, a part of active volcano in Indonesia. This study used scale map 1:25.000 wich analyzed of topography contour and drainage pattern for determination of geological feature as structural geology and volcanostratigraphy unit. Coherence of dense contour line is an igneous rock lava indicated, whereas distantly space contour line is an indicated of pyroclastic. DEM is a product extraction processes of contour topography. MED dan Citra Landsat 8 could help deliniaton of structural geology and volcanostratigraphy unit, which analyzed of morphology, drainage pattern, source of eruption, morphogenesis, and lithology remark. Based on both of image model on KGAW have dextral fault with oriented of northwestern-southeastern, sinistral fault with oriented of southwestern-northeastern, and then structural volcanic as caldera, crater, and debris avalanche. In the KGAW have five source of main eruption and the the other eruption surrounding of KGAW and their become is composed of volcanostratigraphy unit. Approach to using of DEM and Lendsat Image 8 are a part of early stage on for understanding structural geology and volcanostratigraphy on volcanic complex.
IDENTIFIKASI DAN ESTIMASI SUMBER DAYA BATUBARA MENGGUNAKAN METODE POLIGON BERDASARKAN INTEPRETASI DATA LOGGING PADA LAPANGAN ”ADA”, SUMATERA SELATAN Deddi Adrian; Bagus Sapto Mulyatno
Jurnal Geofisika Eksplorasi Vol 4, No 1 (2018)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v4i1.8

Abstract

As petroleum reserves depleted, certainly encourage the government to search for new energy sources. Eksploration of coal is the right choice because  its potential is so great in Indonesian especially in South Sumatera Province is known have content 37,80% from total resources in Indonesian. Well loggging method is one of geophysics method used to find and estimate coal resources. Advantages of well logging method is able to describe subsurface laterally. The purpose of this study is displaying an overview of subsurface rock layers, determine the direction of distribution by correlating coal seam between wells based on data logging, and to estimate coal resources in the research area. The total area of the author's research is 442.056 m2 has 10 wells. Log data used in this study is gamma ray log dan density log, where coal seams are characterized by gamma ray log response and low log density responses. On the field ”ADA” found four coal seam, that is seam A1 with thickness 8,28 m, seam A2 with thickness 13,62 m, seam B with thickness 18,50, and seam C with thickness 8,84. Direction of coal distribution from South to North with slope angle 5-30º and direction of sincerity from East to West. The author calculates the estimated coal resource using polygon method because this calculates method can be done with a short time and the results are right. Total coal by polygon method of 18.322.653 m3 in tons of 21.987.184–27.483.980 ton while calculations with software rock works 15 amount 18.786.254 m3 in tons of 22.543.505–28.179.381 ton.

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