Jurnal Meteorologi dan Geofisika最新文献

{"title":"Rock Physics Modelling for Estimating the Quality of Reservoir Tight Sand in Bintuni Basin, West Papua, Indonesia","authors":"D. Ambarsari, S. Winardhi","doi":"10.36435/JGF.V16I3.386","DOIUrl":"https://doi.org/10.36435/JGF.V16I3.386","url":null,"abstract":"Permeability is a key to determine the quality of reservoir. Reservoir quality can be dened as the ratio between permeability and porosity of a rock. Besides, permeability is not in uenced by porosity solely, there are otherfactors which aect the value of the permeability of a rock. One of them is aected by the pore structure, which includes turtuosity, surface area, and grain size. To determine how much these factors aect the permeability of a rock, it takes an elastic parameters that can be an indicator of the quality reservoir e.g pore space stiness and critical porosity.Primary data such as petrophysics, XRD data, and permeability are used as input data to determine the quality of reservoir. By using Zimmerman's equation and Nur's model, we will get the value of pore space stiness and critical porosity at each point. The combination of rock quality equation derived from Kozeny Carman's with elastic parameters as indicators produces qualitative rock quality identification. Results of this study is able to show that the pore space stiffness and critical porosity can represent turtuosity, surface area, and grain size of a rock which lead to the determination of rock quality. The method proposed in the present study demonstrated an excellence reservoir quality prediction based on the relation between petrophysical parameters with elastic parameters.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79075475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-D Inversion of Gravity Data Using Iterative Calculation for Subsurface Modeling of Mt. Pandan, East Java, Indonesia","authors":"W. Aji, E. Wahyudi, D. Santoso, W. Kadir","doi":"10.36435/JGF.V16I3.388","DOIUrl":"https://doi.org/10.36435/JGF.V16I3.388","url":null,"abstract":"Mount Pandan is one of the volcanoes located in East Java.There was an earthquake with magnitude 4.2 onThursday, June 25, 2015, at 10.35 pm located in the area of Mount Pandan. The earthquake indicates the active tectonic of Mount Pandan. In addition, Mount Pandan is one of eleven geothermal prospects in East Java. Thus, it is interesting to do a study related to the geological condition of Mount Pandan. So far, most studies have discussed the related surface geology of Mount Pandan. This study aims to provide information related to the subsurface condition of Mount Pandan based on gravity data. In this research, gravity data inversion modeling technique is used to image the subsurface condition of Mount Pandan. The inversion technique used is non linear inversion with iterative calculation method. In this modeling scheme, the model to be determinedis a layer boundary depth model of two layers of rock based on gravity anomaly data. In each layer the rock is assumed to be composed of a set of rectangular prisms with a certain dimension. A collection of prisms representing the rock layers is then computed by the model response and evaluated by comparing it to the observed data. From this evaluation, a modication of the length of the prism is made so thatthe boundary layer model will change. The process of evalu ation and modication of the model is done iteratively until it reaches the number of predened iterations. The result obtained from this gravity inversion modeling is a model of the subsurface boundary of Mount Pandan. The subsurface model obtained is the existence of a formation resembling a rock intrusion, in this case interpreted as an andesitic rockthat intrudes overlying rock layers. This intrusive formation lies at the peak of Mount Pandan and is continuously to the north, with the undisturbed intrusion located around the summit of Mount Pandan.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83111420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PEMODELAN INUNDASI TSUNAMI DI SEPANJANG PESISIR MANADO AKIBAT GEMPABUMI M8,5 DI ZONA SUBDUKSI SULAWESI UTARA","authors":"R. Wahyu, Rignolda Djamaluddin, Gybert E. Mamuaya, Tatok Yatimantoro, P. Priyobudi","doi":"10.31172/JMG.V19I1.448","DOIUrl":"https://doi.org/10.31172/JMG.V19I1.448","url":null,"abstract":"Zona subduksi Sulawesi Utara merupakan kawasan tektonik yang sangat aktif. Seismisitas yang tinggi di wilayah ini disebabkan oleh zona subduksi Sulawesi utara, zona subduksi lempeng laut Maluku dan juga sesar-sesar lokal. Kota Manado terletak di sebuah teluk di pesisir utara Sulawesi. Kondisi ini membuat Kota Manado sangat rentan terhadap bahaya tsunami. Pemodelan inundasi tsunami dilakukan untuk memperkirakan potensi bencana tsunami. Gempabumi dengan magnitude Mw 8.5 digunakan untuk memperkirakan dampak tsunami terburuk. Pemodelan numerik tsunami dilakukan dengan menggunakan TUNAMI-N3 dengan grid bersarang (nested grid). Data batimetri dari GEBCO 1 arcsec dan data topografi dari SRTM 1 arcsec digunakan dalam perhitungan model. Resolusi grid ditingkatkan secara bertahap melalui 6 grid bersarang. Virtual tide gauge dibuat untuk melihat karakter gelombang tsunami di 7 titik sepanjang pantai Manado. Tsunami menggenangi wilayah pantai Manado antara 0,5 hingga 1,2 km ke darat. Ketinggian tsunami maksimum akibat skenario gempa ini adalah 18 meter. Waktu tiba tsunami di pantai sekitar 17 menit setelah gempabumi terjadi. North Sulawesi subduction zone is a very active seismic region. Manado directly faces the subduction zone and therefore made the city prone to tsunami hazards. To the best of our knowledge, there has been no research on how big a threat is a tsunami in Manado. A tsunami inundation modeling was performed to estimate the potential threat of a tsunami in the city. An earthquake with a magnitude of M8.5 represented the worst-case scenario of the tsunami. The numerical model for the tsunami modeling used in this study was TUNAMI-N3 with nested grids. For tsunami calculation, 1 arc-minute GEBCO bathymetric data and 1 arc-second SRTM topographic data were used. Several virtual tide gauge locations were set to detect wave characteristics of the tsunami along the coast of Manado. The results showed that the inundation distance varied from 500 to 1200 meters inland, the tsunami wave height varied from 8 to 18 meters, and tsunami arrived at a coastal area within 17 minutes after the earthquake. According to this inundation model, the tsunami-prone area in Manado might extend up to 500-1200 meters inland near the coastal areas. Local government should have tsunami inundation maps generated using detailed topographic data that will be useful for evacuation plans in case of a tsunami.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83178930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermomagnetic Analysis of the Lake Matano Sediments and the Surrounding Lateritic Soils, South Sulawesi, Indonesia","authors":"S. J. Fajar, G. Tamuntuan, S. Bijaksana, J. Russell","doi":"10.36435/jgf.v16i2.384","DOIUrl":"https://doi.org/10.36435/jgf.v16i2.384","url":null,"abstract":"Thermomagnetic is one of the most commonly used measurements for determining the dominant type of magnetic mineral of samples. The measurement is separated into two distinct processes, heating and cooling. The sample susceptibility is measured for each temperature change, i.e., from room temperature to 700oC and vice-versa. Based on the thermomagnetic measurement results, magnetite is found to be the predominant magnetic minerals in Lake Matano sediments. The present study applied a correlation analysis technique on the results of thermomagnetic measurement of Lake Matano sediments and compared the result to that of lateritic soils to indicate whether a diagenetic process has occurred on the lake sediments.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"83 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80629862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of Converted-Wave Modeling: AVO Application for Shallow Gas Models","authors":"N. C. Viony, Wahyu Triyoso","doi":"10.36435/jgf.v16i2.362","DOIUrl":"https://doi.org/10.36435/jgf.v16i2.362","url":null,"abstract":"The application of converted-wave seismic method in hydrocarbon exploration has increased significantly. Since the conventional seismic ceases to provide an adequate result in complex geology area and it provides an ambiguous brightspot response. The main principle is that an incident P-wave produces reflected and converted P and SV wave when the downgoing P-wave impinges on an interface. Converted-wave seismic uses the multicomponent receiver that records both of vertical component and horizontal component. The vertical component is assumed to correspond to the compressional PP wave and the horizontal correspond to the PS converted-wave. In this research, a synthetic model with the shallow gas and the salt dome below are constructed. The purpose of this study is to analyze the brightspot due to the presence of shallow gas and its effect to the quality of PP and PS wave reflection below the gas zone. To achieve the goal, both vertical and horizontal seismic data processing are performed. In horizontal data processing, the best gamma function (Vp/Vs) value is estimated to produce the better and reliable image. The result shows that the brightspot response in conventional data doesn’t exist in converted-wave data and the imaging below the gas zone in converted-wave data is better than the conventional due to the attenuation and diffraction effect that caused by gas column. Processing is followed by AVO analysis to compare the AVO response of PP and PS data in characterizing gas reservoir. Both PP and PS AVO curve shows the consistency with synthetic AVO from well data. Gas reservoir is a class 1 AVO anomaly with positive intercept and negative gradient on PP data. However, PS AVO curve does not refer any anomaly. It is because S-wave is not sensitive to the existence of rock saturant.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"79 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83931743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Velocity Variation with Angle (VVA) Method on an Anisotropic Model with Thomsen Delta Anisotropy Parameters","authors":"W. Pranowo, S. Winardhi","doi":"10.36435/jgf.v16i2.371","DOIUrl":"https://doi.org/10.36435/jgf.v16i2.371","url":null,"abstract":"Anisotropic properties will influence seismic propagation, for example it will affect wave velocity. One of well-known anisotropi equation for Transversaly Isotropic media is weak anisotropy with Thomsen's notation. Supriyono [2011] tried to estimate all of these variables by using velocity variation with angle (VVA) attribute. This research uses synthetic data, which is CMP Gather to know limitations of VVA attribute, to identify the error values, and to determine the best indicator of anisotropic eect. This research also uses another analysis method, which is grid search inversion to estimate VP0. From this research, Both VVA and grid search invesion still produce signcant error. The effects which will appear because of anisotropic property's presence are hockey-stick and over NMO-stretching.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76800436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implementation of Two-point Quadrature Gauss-Legendre Method on 2D Gravity Anomaly Modeling in Basins with Density Distribution Varied Polynomially as a Function of Depth","authors":"W. Srigutomo, Sesri Santurima, C. A. Hapsoro, Hairil Anwar, I. Djaja","doi":"10.36435/JGF.V16I2.51","DOIUrl":"https://doi.org/10.36435/JGF.V16I2.51","url":null,"abstract":"Study of basin geometry basin is important in geosciences and geophysical exploration. Gravity method can be used to address this issue by measuring gravity anomalies on the surface caused by density contrast between the bedrock and the sediment that fills the basin, geometry of the basin and surface topography. Numerically, gravity anomaly modeling can be conducted using two-point rule Gauss-Legendre Quadrature method, for a case where density contrast varies with depth exponentially. Within the scope of this study, gravity anomalies on the surface are significantly affected by the geometry of the curvature of the bedrock as well as the topographic elevation of the surface and the selected density contrast, and are not significantly affected by the undulation of the bedrock curvature. \u0000 ","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90357190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study of Spectral Induced Polarization Response Based on Laboratory Measurement","authors":"D. A. Zaky, Suparwoto Suparwoto","doi":"10.36435/jgf.v16i2.374","DOIUrl":"https://doi.org/10.36435/jgf.v16i2.374","url":null,"abstract":"The spectral induced polarization (SIP) method can provide apparent complex resistivity based on measurements of multi frequency. SIP method also can provide more detail information about physical properties of rocks and minerals because SIP can give spectral parameters or Cole-Cole parameters such as, changeability (m), time constant (τ) and frequency dependence (c). An Experimental study in laboratory has been conducted to knowing the SIP response of some test sample. The measurement system is built with digital oscilloscope Pico ADC-100 as device for sampling the input and output voltage. Amplifier is used to doubled up the signal and input differential. The range frequency of measurement is 10−2 Hz - 103 Hz. Porouspot Cu − CuSO4 is used to minimize the polarization at potential electrode. A Matlab listings is used to calculate the response of impedance and phase. The result from calibration that used the parallel circuit RC indicate that the measurement system was good. SIP response of porous model indicate that the response form an asymptotic resistivity, and the peak of phase is in the range frequency where the dispersion happen. The result also indicate that resistivity of small grain size model is larger than the big grain size model. Result from sample of mineralized rocks did not indicate a perfect SIP response, it is influenced by the contact between mineral and water was minimum.","PeriodicalId":32347,"journal":{"name":"Jurnal Meteorologi dan Geofisika","volume":"185 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78235699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}