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
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 88 Documents
ANALISIS TINGKAT RESIKO DAMPAK GEMPABUMI DI KABUPATEN CILACAP MENGGUNAKAN METODE DSHA DAN DATA MIKROTREMOR Dialosa, Kukuh; Rustadi, Rustadi; Mulyatno, Bagus Sapto; Sulaeman, Cecep
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 Suhendi, Cahli; Sule, Mohammad Rachmat
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.
Introduction and Table of Content JGE Vol 4 No 2 July 2018 JGE, Editor
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

xxx
ROCK FORMATION AND SITE CLASS IN BANDAR LAMPUNG Rustadi, Rustadi; Rananda, Eko
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, Vs30 200 m/s and site class D.
OPTIMALISASI PENCITRAAN STRUKTUR BAWAH PERMUKAAN MENGGUNAKAN METODE KIRCHHOFF PRE-STACK TIME MIGRATION PADA DATA SEISMIK LAUT WETAR Rasimeng, Syamsurijal; Ekarena, Amelia Isti; Mulyanto, Bagus Sapto; Subarsyah, Subarsyah; Djaja, Andrian Wilyan
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.v6i2.67

Abstract

Migration is one of the stages in seismic data processing aimed at returning the diffraction effect to the actual reflector point. The processing of a seismic data is adjusted to the existing problems in the data itself, so the accuracy in using the migration technique and determination of data processing parameters greatly affects the resulting seismic cross-section. Kirchhoff Pre-Stack Time Migration is one of the most used migration methods in seismic data processing because it shows better results than conventional stacking methods. The parameters that need to be noticed in the Kirchhoff migration are the migration aperture values. Based on this, variations of migration aperture values used are 75 m, 200 m and 512.5 m. The 512.5-m aperture migration value shows the best seismic cross-section results. This is evidenced by the capability in eliminating bowtie effects around CDP 600 up to CDP 800, eliminating diffraction effects around CDP 3900 to CDP 4050, and showing a seismic cross-section with better lateral resolution compared to the migration value of the aperture of 75 m and 200 m. Based on the seismic cross-section of migration results, the geological structure that can be identified is a fault that found in some CDP.
PRE STACK DEPTH MIGRATION UNTUK KOREKSI EFEK PULL UP DENGAN MENGGUNAKAN METODE HORIZON BASED DEPTH TOMOGRAPHY PADA LAPANGAN ‘A1 DAN A2’ Azzahra, Attikah; Mulyatno, Bagus Sapto; Mujihardi, Bambang
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.
Front Cover JGE Vol 5 No 2 2019 JGE, Editor
Jurnal Geofisika Eksplorasi Vol 5, No 2 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i2.53

Abstract

xxx
SUBSURFACE STRUCTURE OF BATURAGUNG ESCARPMENT REVEALED THROUGH THREE-DIMENSIONAL GRAVITY INVERSION Irawati, Selvi Misnia; Luthfian, Alutsyah; Laesanpura, Agus
Jurnal Geofisika Eksplorasi Vol 7, No 1 (2021)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v7i1.125

Abstract

Baturagung Escarpment is an essential tectonic element of Java Island because it represents a transition from the Southern Mountain Block to the Kendeng Basin. This study has succeeded in producing a three-dimensional model of the Baturagung Escarpment subsurface using gravity anomaly data. The data are distributed along a regional scale transect, whose resolving capability has been tested using a checkerboard test. Our proposed geophysical model can fit the observed data very well, with a 0.77% RMS error. This model exhibits a structural depression bounded by high basement blocks below the Baturagung Escarpment, one of the basement block outcrops at Jiwo Hills. The maximum width of the depression is 10 km, with a depth exceeding 3 km in some places. The depression might be formed because of an extensional tectonic regime that prevailed during the Palaeogene, followed by volcanic arc loads' emplacement up to the early Miocene.
ESTIMASI SEBARAN HIDROKARBON DENGAN MENGGUNAKAN INDIKATOR P-WAVE DIFFERENCE DISPERSION FACTOR PADA LAPANGAN BONAPARTE Erlangga, Mokhammad Puput; Handoyo, Handoyo; Wijaksono, Egie
Jurnal Geofisika Eksplorasi Vol 5, No 3 (2019)
Publisher : Engineering Faculty Universitas Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jge.v5i3.35

Abstract

In the hydrocarbon  exploration, we need the method that result the direct hydrocarbon indicator to estimate the reservoir location and dimension accurately. It is a difficult and long standing problem. The method that used before was inverting the linearized of Zoepprit’s equation. But this method would not result the physical property depend on frequency. We know that the seismic wave propagate in the porous and fluid saturated media will attenuate and wave dispersion. This phenomenon is caused by the dissipation of seismic energy that depend on frequency. So by this idea, we will use the frequency-dependent of physical property to improve the accuracy of direct hydrocarbon indicator. The physical property will be used here is the P-Wave velocity. The method is call the P-Wave Difference Dispersion Factor (PPDF).
KARAKTERISASI RESERVOAR MELALUI ANALISIS PETROFISIKA BERDASARKAN DATA LOG SUMUR “TRD” FORMASI AIR BENAKAT Chasandra, Beny; Dewanto, Ordas; Juniari, Ni Putu
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.v4i1.7

Abstract

The research area was located in South Sumatra Basin on Air Benakat Formation at South-East Jambi Province. The research conducted to know productive the interest zone by petrophysics analysis (volume shale water saturation, and porosity) and its characteristics by well-log. The lithology of TRD Well is sandstone with a few foraminifera. The interpretation based on the petrophysical analysis porosity of the 7th zone on TRD-10 is average 12,4%, saturation water 19,4% and volume shale 6,2%; the 7th zone on TRD-11 well is average porosity 16,2%, saturation water 41,3%, and volume shale 22%; the 11th zone on TRD-14 well is average porosity 33,2%, saturation water 21,2% and volume shale 1,2%; The 6th zone TRD-15 well, porosity 7,02%, saturation water 32,3% and volume shale 5,6%; On the TRD-17 well of the 7th zone is average the porosity 9,04%, saturation water 25,6% and volume shale 4,6%; and 4th zone of TRD-19 well, porosity 23,2% Saturation water 13,5% and volume shale 7,1%. The characteristics of hydrocarbon reservoir on TRD Wells have low water saturation is less than 50%, porosity more than 5% and volume shale less than 25%. From the result of petrophysics parameter value used as the indicator of the productive zone and interpreted that sand reservoir on well TRD has potentially for the reservoir zone with gas prospect.