Seismic Data Interpretation

Batugamping berumur Oligo-Miosen merupakan salah satu reservoir migas yang penting di bagian utara Jawa Barat (Setiawan, 2012). Di permukaan, batugamping ini ditemukan terutama di bagian selatan Jawa Barat, meliputi daerah Bayah hingga bagian barat kota Sukabumi (Pasir Bongkok, Gunung Walat dan Gunung Guruh) serta di daerah Padalarang (Koolhoven, 1933; Koesoemadinata dan Siregar, 1984; Sujatmiko dan Santosa, 1992). Di daerah Bayah, batugamping berumur OligoMiosen (Formasi Cijengkol dan Citarate) tersingkap dengan pola radialmengelilingi
Kubah Bayah yang berintikan batupasir Formasi Bayah berumur Eosen. Sedangkan di daerah Sukabumi, batugamping berumur Oligo-Miosen termasuk dalam Formasi Rajamandala, tersebar barat-timur dari daerah Pasir Bongkok, Gunung Walat hingga Gunung Guruh, batugamping ini terletak di atas Formasi Batuasih dan Formasi Bayah (Martodjojo, 1984). Keberadaan batugamping Oligo-Miosen di bawah permukaan di Jawa Barat bagian barat dan tengah belum dapat terdeteksi sepenuhnya disebabkan oleh buruknya resolusi seismik karena pengaruh batuan
gunung api di permukaan.

Penelitian ini meliputi singkapan batugamping berumur Oligo-Miosen yang terletak di daerah Bayah hingga sekitar Gunung Walat, Sukabumi. Selain itu dipelajari juga data bawah permukaan daerah Rangkas melalui data seismik dan data gayaberat.

Mengingat potensi batugamping berumur Oligo-Miosen ini sebagai reservoir migas dan adanya keterbatasan informasi geologi antara batugamping Oligo-Miosen yang menjadi reservoir migas di paparan utara Jawa Barat dengan yang tersingkap di selatan Jawa Barat, maka perlu dilakukan penelitian lebih lanjut tentang pola perkembangan batugamping ini.

The structure of the south Taiwan fold-and-thrust belt (FTB) comprises a roughly N-S striking, west-verging imbricate thrust system that has been developing since the Late Miocene. Here, we present the results of new surface geological mapping, serial balanced cross sections, long sections, and a map of the basal thrust that are combined with published borehole data and a 3D P-wave tomography model to constrain the structure at depth. The stratigraphy of the area comprises Eocene syn-rift sediments that are unconformably overlain by Oligocene through Middle Miocene shallow water post-rift sediments. These are unconformably overlain by Late Miocene through Holocene-age syn-orogenic sediments. We define the basement to these as the Mesozoic pre-rift rocks of the Eurasian margin, and assign it a P-wave velocity of > 5.2 km/s in the velocity model. The syn-orogenic sediments thicken and get progressively involved in the thrust sheets toward the south. The south Taiwan FTB can be divided into several thrust sheets. In the northern part of the map area, the structural grain is roughly N-S striking, changing southward to become NE-SW oriented. The westernmost thrust sheets form broad, open synclines cored by Pliocene to Holocene sediments, and tight hanging wall anticlines formed by Miocene rocks. Along its eastern flank, a narrow, complexly folded anticlinorium is developed in Miocene rocks. Restoration of the cross-sections indicates about 15 to 17 km of shortening. The basal thrust deepens from the surface towards the E and SE in a staircase trajectory, with narrow ramps and wide flats, reaching up to 8 km depth in the east before ramping down into the basement. The basal thrust has two pronounced, NE-striking oblique ramps that coincide with sigmoidal changes in shape of structures in the hanging wall. These correlate with a SW-NE trending increase in the P-wave velocity that is interpreted to image a basement high. We interpret this basement high to be an inherited extensional structure of the margin, and that faults associated with it are being reactivated, causing the changes in strike of the basal thrust, as well as in the surface trace of thrust and fold axes.

Hydrocarbon production from complex siliciclastic systems like those of the Niger Delta Basin often pose a high-risk venture for explorationists due to geological uncertainties created by the presence of faults, and variabilities in the lateral and vertical distribution of reservoir-seal pairs, as well as hydrocarbon charge. In this study, seismic stratigraphy and rock physics concepts were applied in a focused integrated interpretation of 3D seismic and well log data to investigate the hydrocarbon potentials of the "XY" Field, onshore Niger Delta Basin. The study revealed two sand-prone zones belonging to the lowstand systems tract (LST), overlain by the thick shale units of the transgressive systems tract (TST), forming potential seals for the reservoir intervals. Rock physics crossplots linking the estimated reservoir properties to the elastic properties of the rocks revealed that the reservoir intervals are high quality sands, characterized by good porosities. The study underscores the importance of seismic stratigraphy and rock physics approach in the identification of economically viable prospect opportunities in already explored areas.

Marine sedimentary basins are any modern basin that is currently below sea level and influenced by marine sedimentary processes and sedimentation. Many ancient marine sedimentary basins are now deformed and uplifted into modern, mountain chains as part of ongoing or ancient orogenic – or mountain-building – processes.  The modern marine sedimentary basins of the world’s ocean basins can be subdivided into continental shelves, slopes, rises, abyssal plains, and oceanic trenches in passive margin settings (Fig. 1). As these topics have been defined and discussed by other authors of the encyclopedia, I will focus on the origin of the main tectonic classes of marine sedimentary basins in active margin settings that include those produced in rift, collisional, subduction, and strike-slip environments, along with bolide impacts into marine environments

Geographic Information Systems (GIS) have emerged as a cornerstone technology in spatial data management, enabling the capture, storage, analysis, and visualization of geospatial information. Over the last five years, GIS has undergone rapid transformation, propelled by advances in cloud computing, real-time analytics, artificial intelligence (AI), and participatory mapping approaches. This paper critically examines recent developments in GIS between 2020 and 2025, with a focus on the integration of heterogeneous data sources, interoperability challenges, machine learning (ML) applications, and citizen science contributions through Web GIS. Drawing on a synthesis of peer-reviewed literature and case studies, the paper highlights how GIS has evolved into a multidisciplinary decision-making tool across domains such as urban planning, disaster risk management, environmental monitoring, and public health. It further explores the persistent barriers of data quality, privacy, and equitable access, offering insights into emerging trends that can shape the future of GIS. The discussion underscores the importance of interdisciplinary collaboration and ethical considerations in maximizing GIS potential for sustainable development.

Fault Zone Guided Waves (FZGWs) have been observed for the first time within New Zealand's transpressional continental plate boundary, the Alpine Fault, which is late in its typical seismic cycle. Ongoing study of these phases provides the opportunity to monitor interseismic conditions in the fault zone. Distinctive dispersive seismic codas (~7–35 Hz) have been recorded on shallow borehole seismometers installed within 20 m of the principal slip zone. Near the central Alpine Fault, known for low background seismicity, FZGW‐generating microseismic events are located beyond the catchment‐scale partitioning of the fault indicating lateral connectivity of the low‐velocity zone immediately below the near‐surface segmentation. Initial modeling of the low‐velocity zone indicates a waveguide width of 60–200 m with a 10–40% reduction in S wave velocity, similar to that inferred for the fault core of other mature plate boundary faults such as the San Andreas and North Anatolian Faults.

Traditional geotechnical and geophysical investigations were conducted to determine the characteristics of a study site proposed for the construction of an electrical power plant in Al-Shamiyah city, Al-Qadisiya Governorate. These assessments are crucial for ensuring the durability of subsurface layers to support the foundations of engineering structures. The geophysical data consisted of twenty-three Ground Penetrating Radar profiles arranged perpendicularly to each other and nine points of Electrical Resistivity Sounding. These data were integrated with three types of samples-Disturbed, Standard Penetration Test, and Undisturbed-which were collected from nineteen geotechnical engineering boreholes. The samples were analyzed for soil classification, strength, consolidation, and chemical properties of both soil and water. The Ground Penetrating Radar profiles revealed several weak zones, while the resistivity survey points showed random values ranging 2-16 Ωm at depths up to 20 m, indicating loose and incohesive soil. The findings from the geophysical data aligned with the geotechnical analysis, which classified the soil profile into seven distinct layers. Soil activity was assessed through the plasticity index and liquid limit, with an average elasticity index to clay content ratio of-0.53, suggesting poor clay activity. The in-situ allowable bearing capacity of the soil at depths ranging from 1.5 to 22 m was found to be between 4.0 and >17.0 T/m² across all boreholes. Sulfate (SO₃) content ranged from 0.112% to 0.527%. Groundwater levels were measured at 1.7 to 1.45 m, exhibiting high alkalinity content and moderate to high salinity.

High-resolution 2D acoustic profiles, combined with time slices from a 3D data volume, were used to investigate the paleoincised valleys offshore of the present-day Pahang River, South China Sea. Paleovalleys were formed during the regressive phase of the last glacial cycle. They were submerged and possibly filled during valley formation and postglacial marine transgression. Interpretation of acoustic profiles illustrates that the valleys were incised and infilled during the regression and low stand followed by subsequent deglacial sea-level rise. They were overlain by a transgressive ravinement surface suggesting transitional deposits between fluvial-dominated filling and shallow-marine deposition. This ravinement surface is overlain by Holocene shallow marine deposits. A low-sinuosity low-stand valley system changed to a high-sinuosity meander belt and eventually evolved into a deltaic distributary channel system before the complete submergence of the area. The average Late Pleistocene surface lies between 53 and 64 m below present-day mean sea level in the study area with approximately 16-50 m of valley incision. The Holocene shallow marine cover thickness varies from 5 to 10 m.

Extensive seismic reflection interpretation of the Cabo Frio High allowed better understanding of its proximal and distal structure. Seismic lines helped map the salt base and recognize the primary geological interfaces, unconformities, faults, and volcanic intrusions. The proximal Cabo Frio High is a continental basement uplift extending mainly into the Campos Basin. The Cabo Frio Outer High, which is of volcanic origin, lies between Santos and Campos Basins. This volcanism is concentrated at the crossing of two significant structures: Cruzeiro do Sul Lineament and Rio de Janeiro Fracture Zone. The Cabo Frio High fits an NW-SE fold axis, which is well correlated with distension along NW-SE direction generating a regional E-W sinistral plate movement, mainly related to the ENE-WNW sinistral Rio de Janeiro transfer zones. The accumulated uplift is approximately 4 km, achieved by at least four uplifting pulses. The uplifting starts in the Albian-Santonian, characterized by the elevation of the northeast portion of Cabo Frio High, followed by erosion. The sill and dikes intruded in the Upper Cretaceous, and the uplift of the southwest portion of the Cabo Frio High characterizes the second uplift pulse. Subaerial Eocene volcanos characterize the third uplifting pulse. The uplifting of the Blue Marker horizon (Oligocene) characterizes the last pulse.

With respect to the high uncertainties associated with methods of determining lithology and pore fluid using well logs, quantitative rock physics analyses was used to determine the lithology and pore fluid of a reservoir in the Niger Delta. Inaccurate prediction of lithology and pore fluid results in the inaccurate determination of other petrophysical properties and parameters such as porosity, permeability, net pay, etc. The primary objective of this research is to predict lithology and pore fluid using rock physics analysis. However, reservoir zones were also predicted. Density, compressional wave velocity and shear wave velocity logs were used as input to calculate elastic parameters such as velocity ratio, Poisson’s ratio and Bulk Modulus. The calculated velocity ratio log was used to differentiate between sand and shale. Poisson’s ratio and velocity ratio using the Goodway interpretation template was carried out and used to delineate pore fluid content; gas sand, oil sand and s...

Ce document propose un guide détaillé des méthodologies statistiques de base pour l’analyse des questionnaires dans les projets de fin d’études (PFE) en économie, gestion, marketing, finance et logistique. Face au constat que de nombreux étudiants banalisent la conception et le traitement des questionnaires, ce qui compromet la rigueur et la validité de leurs analyses, ce guide vise à fournir des outils pratiques pour améliorer leurs compétences. Il couvre les étapes clés collecte, organisation et analyse des données (descriptive, comparative, prédictive) avec des définitions claires, des exemples concrets appliqués à chaque spécialité et des recommandations éthiques. L’objectif est de permettre aux étudiants de produire des recherches robustes, pertinentes et alignées sur les standards académiques et professionnels.

In this paper, we examined the risk character of the NSEASI index across 10 years (January 1, 2013 -August 31, 2023), consisting of around 2,590 valid trading days following intensive cleaning and outliers adjustment of the data. A daily log return was calculated and shown as a high-risk, low-reward market, with average log returns of 0.0018 and an 11.73% daily volatility. It had extremely high kurtosis (328.199) and almost zero skewness (0.009), implying that the distribution of returns was very skewed to extremes and was not skewed. The characteristic function-based Value at Risk (VaR) model was applied in a stochastic volatility system to rectify the flaw of traditional risk models in the face of this heavy-tailed behaviour. Realistic stochastic dynamics of volatility of returns were obtained using parameter estimation using the method of moments. Comparative analysis using Delta, Delta-Gamma, and Monte-Carlo simulation techniques revealed that the fat-tailed behaviour of the return distribution was better captured when using the CF-based and Monte-Carlo-based approaches. The estimates of VaR at the 5% and 1% confidence levels based on CF (2.80 and 5.10) were significantly higher than those of the Delta and the Delta-Gamma method, which underestimated tail risk. It provides formal backtesting via the Kupiec and Christoffersen tests. It performs a sensitivity analysis and discusses policy implications in the context of financial regulation and corresponding portfolio risk management. We would conclude that CF-based VaR is a more practical and theoretically-grounded alternative to more common methods, in non-Gaussian settings that characterize emerging markets; nevertheless, our findings demonstrate the shortcomings of standard Gaussian-based models in turbulent emerging markets like Kenya. This article recommends the use of advanced stochastic methods in the field of financial risk management and regulation. Future research opportunities include introducing the dynamics of jump-diffusion processes, modeling interdependencies at the constituent level, and improving the dynamic portfolio risk estimation.

Rock physics modelling has been employed in studying the elastic behaviors of reservoir SAND_K2 in the 'KUTI' Field, Niger Delta under a plausible production scenario of increasing water saturation. The study aimed to investigate how variation in reservoir fluid saturation will influence seismic attributes and determine the characteristics of expected time-lapsed (4-D) seismic signals that may be generated due to the effects of production. Multivariate cross-plot analyses of petro-elastic parameters were carried out to establish the seismic characteristics of the target reservoir with different pore fluids in its natural state before production. Fluid replacement modelling was applied to calculate measurable changes in the reservoir's seismic characters by steadily increasing the water saturation from its initial value to 100%. Synthetic logs of petro-elastic parameters were created for different values of water saturation and combined into property cross-plots to predict the dynamic seismic response of the reservoir as brine gradually replaced hydrocarbon. Results showed that fluid changes from hydrocarbon to brine produced significant and quantifiable seismic signatures for timelapse monitoring investigation. At some future points in the production history of the field under increasing water saturation conditions, the density, P-wave velocity and acoustic impedance of SAND_K2 increase and produce a negative seismic difference data of P-wave amplitude. Based on the responses of reservoir SAND_K2 under modelled production conditions, the study concluded that rock physics analysis can help to optimize and enhance the success of time-lapse monitoring of the KUTI Field.

THESIS: Subsurface analysis of Sundaland basins: source rocks, structural trends and the distribution of oil fields STUDENT: Swardhuni Pethe DEGREE: Master of Science COLLEGE: Sciences and Humanities DATE: December, 2013 According to the Ade observation (Ade, W., pers. Comm.) "95% of all commercial oil fields in the Sumatra region occur within 17 km of seismically mappable structural grabens in the producing basins". The Ade observation proposes a link between the subsidence of the source rocks (the Talang Akar Formation) in the grabens and the maturity of the organic material. To test the validity of the Ade observation, subsurface mapping of the region was carried out using geophysical logs. Using the well log information, the basement and the formation tops have been mapped with a special emphasis on Talang Akar and Air Benakat Formations. The isopach maps of these formations show that most of the producing wells on the Sunda shelf are in fact located in and around the major structural basins. Trends in the occurrence of the oil fields have also been observed which are analogous to the orientation of the grabens. Structural mapping of the basins have identified several wrench faults. These are of particular interest as wrench faults provide good structural traps for oil in the Los Angeles and the North Sumatra Basins and may prove to be very important for future exploration in southern Sumatra and northwest Java. In South Sumatra Basin, 77.78% of the potential oil fields are located in the 17 km margin from the grabens. For Sunda/Asri Basins and the Ardjuna Basin, it is 100 and 92 respectively. Identifying the source rocks in this 17 km window will enhance the success rate of oil exploration in the Sundaland Basins.

An attempt was made to describe the quality of the stacked seismic data semi-quantitatively with respect to the spacing of shot and receiver lines. The methods used included: signal-to-noise ratio calculation, seismic-to-well tie accuracy, wavelet extraction effectiveness and reliability of semi-automated interpretation of seismic attributes. This study was focused on the Ordovician-Silurian interval of the Lublin Basin, Poland, as it was considered as a main target for the exploration of unconventional hydrocarbon deposits. Our results reconfirm the obvious dependency between the density of the acquisition parameters and data quality. However, we also discovered that the seismic data quality is less affected by the shot line spacing than by comparable receiver line spacing. We attributed this issue to the fact of the higher irregularity of the shot points than receiver points, imposed by the terrain accessibility. We have also proven that the regularity of receiver and shot point d...

Image segmentation (Shi and Malik, 2000; Hale and Emanuel, 2 003, 2002) for tracking salt boundaries (Lomask and Biondi, 2003; Lomask et al., 2004) is extremely memory intensive. Memory saving measures must be implemented in order to consi der applying this technique to 3D seismic cubes. If coarse bounds can be picked, either ma nually or using another automatic algorithm, this image segmentation algorithm can t hen be used to partition between the bounds. Unfortunately, the quality of the segmentation result is strongly affected by the shape of the image. For example, elongated images are more li kely to be partitioned along their shortest dimension.

Image segmentation can be used to track salt boundaries when the salt boundary amplitude is greater than any other local reflections. We apply a modified version of the normalized cut image segmentation method to partition seismic images along salt boundaries. In principle our method should work even when the boundaries are not continuous, and conventional horizon tracking algorithms may fail. Our implementation of this method calculates a weight connecting each pixel in the image to each pixel in a local neighborhood. The weight is made weak where the negative amplitude of the complex trace along the shortest path between the two pixels has a minimum and is less than a threshold value. This method is demonstrated to be effective on synthetic 2D seismic sections and can easily be modified to be applied to 3D data. To overcome the formidable computational expense and storage requirements, three cost saving approaches are proposed. Firstly, pixels are sampled from windows centered at powers of 2, this greatly increases the sparseness of the weight matrix. Secondly, initial solutions are provided to subsequent segmentations for multiple segmentation passes in iterative velocity analysis. Thirdly, an iterative multiscale approach should allow the tracking of the bright salt events in large 3D cubes.

We present a method for efficiently flattening 3D seismic data volumes. First local dips are calculated over the entire seismic volume. The dips are then resolved into time shifts using a Gauss-Newton iterative approach that exploits the Fourier domain to maximize efficiency. To handle faults (discontinuous reflections), we apply a weight inversion scheme. This approach successfully flattens a synthetic faulted model, a field salt peircement dataset, a field dataset with an angular unconformity, and a faulted field dataset.

Elastic Impedance (EI) merupakan salah satu metode yang digunakan untuk mengidentifikasi litologi reservoir batupasir di Lapangan "D", Formasi Talang Akar, Cekungan Jawa Barat Utara. Zona target yang berada pada Formasi Talang Akar ini, merupakan lapisan TAF-3-1yang berada pada kedalaman 2780 m -2805 m dengan litologi perselingan antara batupasir dan batulempung. Prinsip dasar log Gamma Ray (GR) adalah perekaman intensitas zat radioaktifyang secara alami dan kontinu dipancarkan oleh batuan yang mengandung zat radioaktif (Thorium-Th, Uranium-U, dan Potassium-K). Oleh karena itu, fungsi utama log GR dalam aplikasi stratigrafi dan geologi minyak bumi yaitu untuk membedakan antara lapisan permeabel dan lapisan impermeabel. Analisis yang dilakukan pada data sumur adalah analisis sensitivitas yang digunakan untuk memisahkan antara litologi batupasir dan batulempung yang dilakukan dengan cara melakukan crossplot antara log turunan EI pada sudut 0º-30º dengan log GR dilakukan di sekitar zona target TAF-3-1 dengan kedalaman 2192 m -2202 m. Hasil analisis sensitivitas menunjukkan bahwa sudut EI yang paling sensitif dalam memisahkan antara litologi batupasir dan batulempung adalah sudut 30º.

por la altura profesional e inmensa apertura brindada como persona, profesor y director de este proyecto. Al Ing. Alex Robayo, profesor de la FIGMA y codirector de tesis, por su amable colaboración en este y en otros proyectos de mi carrera.

The characterization of salt tectonics and its gravity-driven deformation processes are the key to a better understanding of the structural evolution of salt-bearing rifted margins. Unlike most salt basins that have experienced long-lasting deformation, the Messinian evaporites in the Levant Basin have been moderately deformed, offering the opportunity to study the early stage of salt tectonic deformation. Despite the availability of seismic reflection, borehole and bathymetrical data, some uncertainties still exist about the mechanisms responsible for the deformation and structural features observed in the deep-water Levant Basin. Our study includes physical experiments based on published seismic and structural interpretations conducted in the Levant Basin. Our physical experiments take into consideration the main driving parameters that controlled the development of the deep-water Levant Basin, testing the interplay and impact of gravity gliding and spreading from the Levant Margin, gravity spreading from the Nile Deep Sea Fan, and the influence of the passive buttress of the Eratosthenes Seamount. Deformation was imposed by depositing successive sand lobes and/or by tilting the experimental table. The physical models included a thick viscous silicone layer, analogue of the Messinian evaporitic sequence, overlain by a granular overburden, simulating the brittle clastic post-Messinian succession. Results show that the prominent gravity-driven force affecting the deformation pattern of the deep-water Levant Basin is the gravity spreading from the Nile Deep Sea Fan, whereas gravity spreading and gliding from the Levant Margin affect only the proximal to the margin areas. Additionally, the buttressing effect of the Eratosthenes Seamount and the location of the salt basin pinch-out played an important role in the final deformation pattern of this region of the Eastern Mediterranean.

This study bridges fiber-optic physics and seismic interpretation by demonstrating how thin hydrocarbon layers act as natural band-stop filters. We adapt the transfer matrix method (TMM) from optical waveguides (refractive index profile: 1.49/1.50/1.49/1.4949) to model seismic wave propagation in stratified media. Results show that layers below tuning thickness produce measurable frequency shadows, enabling detection of pinch-outs and stratigraphic traps. Field data validation confirms diagnostic spectral notches at predicted cutoff frequencies.

A previous study from the "NEMA" field by Adizua and Uzu (2024) evaluated petrophysical properties such as porosity, permeability, net to gross (NTG), and water and hydrocarbon saturation from five wells in the field. In this complementary study, we seek to establish the degree of correlations between permeability-porosity derived from both log and core results in Well 09, where both data are available. The study aims to establish that if a high correlation exists between log and core-derived porosities and permeabilities, we can validate log-derived petrophysical parameters in other well locations (Wells 01, 04, 07 and 12) where core data are unavailable. Petrel routines were used to generate the cross plots. The results showed a correlation coefficient (R) of 0.732845 for the core permeability versus core porosity cross plot. A correlation coefficient (R) of 0.79945 for core porosity versus log porosity cross plot and a correlation coefficient (R) of 0.833588 for core permeability versus log permeability cross plot. The plots revealed that core-derived permeabilities correlated very well with log-derived permeability for NEMA 09. Therefore, we can conclude from our findings that in wells where core data were not available, log-derived permeabilities and porosities were true approximations of the actual subsurface petrophysical parameters in those wells. This would ultimately guide in field development planning and exploitation objectives in the field.

Eksplorasi dan eksploitasi di Indonesia saat ini masih terfokus pada energi konvensional hidrokarbon dibandingkan energi nonkonvensional hidrokarbon seperti gas serpih. Gas serpih adalah salah satu energi nonkonvensional yang kaya material organic dan mencapai kematangan, pada kondisi dan tipe tertentu mampu berfungsi sebagai reservoir minyak dan gas. Formasi Tanjung adalah batuan induk dari Cekungan Barito, terletak diKalimantan Selatan, berpotensi sebagai Shale Hydrocarbon. Pada penelitian ini dilakukan integrasi dari tiga metode diantaranya menggunakan analisis geokimia organik, petrofisika dan interpretasi seismik yang menjadi dasar untuk melihat hubungan kekayaan material organik dan kematangan material organik pada potensi gas serpih di wilayah tersebut. Tahap pertama adalah analisis geokimia organik pada Formasi Tanjung didapat tingkat kekayaan materi organik berkisar 1.26-5.98 wt% (Baik-sangat baik), jendela awal kematangan pada kedalaman 2170 m dan kategori tipe kerogen II/III menghasilkan minyak dan gas. Tahap kedua adalah analisis petrofisika yang meliputi perhitungan TOC secara kontinyu, hasil dari analisis petrofisika ini divalidasi dengan nilai analisis laboratorium, didapat nilai regresi 0.923. Tahap selanjutnya adalah melakukan interpretasi seismik dengan metode inversi impedansi akustik untuk melihat persebaran batuan serpih dengan nilai 17718-28222 ft/s*g/cc, arah penyebaran batuan serpih sebagai potensi shale hydrocarbon berada di timur dan tenggara daerah penelitian.

In seismic physical modeling, piezoelectric transducers are commonly used as generators and detectors of acoustic waves. Physically, these transducers are thin discs with diameters on the order of 1 to 13 mm. In a typical scale model experiment where the acoustic medium is water, dominant frequencies are on the order of 500 kHz, and wavelengths are on the order of 3 mm. Even the smallest transducers have diameters which are significant fractions of a wavelength. Because of this, the radiation and reception patterns of such transducers have pronounced directivities due to wave interference effects. Amplitude information acquired by physical modeling must be corrected to account for the directivities before doing any AVO/AVAZ analysis. This report presents a numerical procedure for determining the directivities of disc-shaped transducers in an acoustic medium such as water. As well, a compact analytical formula for the directivity is derived. We applied these directivity corrections t...

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

The Carlsberg Fault zone is located in the N-S striking Hollviken Graben and traverses the city of Copenhagen. The fault zone is a NNW-SSE striking structure in direct vicinity to the transition zone of the Danish Basin and the Baltic Shield. Recent small earthquakes indicate activity in the area, although none of the mapped earthquakes appear to have occurred on the Carlsberg Fault. We examined the fault evolution by a combination of very high resolution onshore shear-wave seismic data, one conventional onshore seismic profile and marine reflection seismic profiles. The chalk stratigraphy and the localization of the fault zone at depth was inferred from previous studies by other authors. We extrapolated the Jurassic and Triassic stratigraphy from the Pomeranian Bay to the area of investigation. The fault zone shows a flower structure in the Triassic as well as in Cretaceous sediments. The faulting geometry indicates strong influence of Triassic processes when subsidence and rifting...

-prone facies within the Upper Oligocene and Lower Miocene strata on the flanks of the complexly faulted Vinton Dome Field in the northwest Gulf of Mexico show fine-scale, sub-seismic polygonal fracture patterns, averaging 200 ft (approximately 60 m) in diameter. These facies may relate to gravitational slumping away from the salt dome or to dewatering during compaction. Similar dewatered polygons have been identified in mudstones in 3D seismic surveys from the Miocene aged strata in the North Sea and from Cretaceous strata in Alberta but have never been described from the Gulf of Mexico. Well control and modern seismic attribute analyses reveal the relationship between the depositional environment, structural patterns, and salt tectonics. The dome is characterized by a counter-regional fault and three peripheral fault sets, each having a different outline and basis for its formation. The structural setting of the Miocene shelf is the result of the hereditary Upper Oligocene structural design and substantial evolution of sediment dispersal. Salt movement set the stage for thinning and thickening of the Chattian (28.5 to 23.8 Ma) strata creating unconformities and onlap against the salt plug, whereas the overlying Aquitanian (23.8 to 20.52 Ma) strata is generally characterized by major syn-depositional faults. Different lithologies are characterized by nonrigid polygons, suggesting rheological control on fracture density. Homogeneous polygonal features and fracture intensity support a strong link between the major faults and smaller-scale polygonal faults. Fracture systems could be open, healed, or partly open, but significant structural complexity of the shales might affect seal integrity.

-prone facies within the Upper Oligocene and Lower Miocene strata on the flanks of the complexly faulted Vinton Dome Field in the northwest Gulf of Mexico show fine-scale, sub-seismic polygonal fracture patterns, averaging 200 ft (approximately 60 m) in diameter. These facies may relate to gravitational slumping away from the salt dome or to dewatering during compaction. Similar dewatered polygons have been identified in mudstones in 3D seismic surveys from the Miocene aged strata in the North Sea and from Cretaceous strata in Alberta but have never been described from the Gulf of Mexico. Well control and modern seismic attribute analyses reveal the relationship between the depositional environment, structural patterns, and salt tectonics. The dome is characterized by a counter-regional fault and three peripheral fault sets, each having a different outline and basis for its formation. The structural setting of the Miocene shelf is the result of the hereditary Upper Oligocene structural design and substantial evolution of sediment dispersal. Salt movement set the stage for thinning and thickening of the Chattian (28.5 to 23.8 Ma) strata creating unconformities and onlap against the salt plug, whereas the overlying Aquitanian (23.8 to 20.52 Ma) strata is generally characterized by major syn-depositional faults. Different lithologies are characterized by nonrigid polygons, suggesting rheological control on fracture density. Homogeneous polygonal features and fracture intensity support a strong link between the major faults and smaller-scale polygonal faults. Fracture systems could be open, healed, or partly open, but significant structural complexity of the shales might affect seal integrity.

After the sedimentological study of the Sant Llorenc del Munt, Montserrat and Roda deltaic systems, a stratigraphic subdivision based on three different scale transgressiveregressive sequences has been developed. This subdivision has been established on the coastal facies belts from the deduced shoreline (and associated facies belts) migration. These transgressive-regressive sequences are formed by a lower transgressive part with a deepening-upwards trend and a retrogradational staclung pattern and an upper regressive part, with shallowing-upwards trend and a progradational stacking pattern. The lowest scale sequences (metrical) have been named "fundamental sequences". A series of "composite sequences", intermediate scale (decametric to hectometric), have been defined afier the study of the staclung pattem of the fundamental sequences. After the study of the stacking pattem of composite sequences there have been defined a series of large-scale (decametric to kilometric) "composite megasequences".

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

To address one of the central questions of plate tectonics-How do large transform systems work and what are their typical features?-seismic investigations across the Dead Sea Transform (DST), the boundary between the African and Arabian plates in the Middle East, were conducted for the first time. A major component of these investigations was a combined reflection/refraction survey across the territories of Palestine, Israel and Jordan. The main results of this study are: (1) The seismic basement is offset by 3-5 km under the DST, (2) The DST cuts through the entire crust, broadening in the lower crust, (3) Strong lower crustal reflectors are imaged only on one side of the DST, (4) The seismic velocity sections show a steady increase in the depth of the crust-mantle transition (Moho) from ∼26 km at the Mediterranean to ∼39 km under the Jordan highlands, with only a small but visible, asymmetric topography of the Moho under the DST. These observations can be linked to the left-lateral movement of 105 km of the two plates in the last 17 Myr, accompanied by strong deformation within a narrow zone cutting through the entire crust. Comparing the DST and the San Andreas Fault (SAF) system, a strong asymmetry in subhorizontal lower crustal reflectors and a deep reaching deformation zone both occur around the DST and the SAF. The fact that such lower crustal reflectors and deep deformation zones are observed in such different transform systems suggests that these structures are possibly fundamental features of large transform plate boundaries.

Seismik interferometri memanfaatkan ambient noise sebagai sumber informasi sub-surface dalam pengolahan data. Oleh karena itu seismik interferometri termasuk kedalam kategori seismik pasif karena tanpa menggunakan sumber buatan dalam akusisi data. Tahapan pemodelan dilakukan sebagai media pengujian atau validasi sintetik pengolahan seismik interferometri. Model yang digunakan berbeda antara pengolahan data seismik refleksi dengan seismik tomografi. Metoda cross-correlation digunakan untuk mendapatkan Green’s function yang dikenal sebagai virtual source. Alat yang digunakan akusisi data lapangan adalah 24-Recheiver geophone dengan spasi 4 meter antar recheiver. Lama perekaman data lapangan adalah 99.99 detik dengan sampling time 4 milidetik. Pengambilan data seismik interferometri lapangan dengan kondisi traffic noise yang berbeda. Hal tersebut bertujuan untuk melihat perbedaan karakteristik dari dua virtual-source dengan kondisi traffic noise yang berbeda pada hasil dari pengolahann...

An extended marine, active seismic survey has been performed on September, 2001 in the gulfs of Naples and Pozzuoli by recording about 5000 shots at a network of 62 sea bottom and 72 on shore seismographs. 3‐D images of the shallow caldera structure are obtained from the tomographic inversion of about 77000 first P arrival times using the Benz et al. [1996] tomographic technique. The buried rim of the Campi Flegrei caldera is clearly detected at about 800–2000 m depth, as an anular high P‐velocity and high density body. It has a diameter of about 8–12 km and a height of 1–2 km. According to stratigraphic and sonic log data from deep boreholes and tomographic P velocities, the rim is likely formed by solidified lavas and/or tuffs with interbedded lava. This study confirms the existence for a depressed limestone basement beneath the caldera at less than 4 km depth, while no evidence are found for shallower magmatic bodies.

Field tests, as static cone penetration tests (CPT), are widely used in granular soil characterization because they draw continuous profiles of tip resistance qc and sleeve friction fs. Such measurement profiles are affected by two main sources of uncertainties: (1) measurement errors and (2) natural variability of soils. Thus, in order to interpret the inherent variability from CPT measures measurement errors shall be quantified and isolated. Studies and experiences learned from literature can help to have an idea of the extent of measurement errors whereas exploratory spatial data analysis techniques are needed to practically reduce this sources of uncertainty before undertaking variability analyses on soils. The case studied concerns CPTs performed on sandy deposit along Ionian coast in the southern part of Italy in Basilicata Region at Scanzano Jonico site. There the outcropping granular deposit is about 20m depth and it is made up of graded sands from the top to the bottom. Lit...

aproximadamente 5000 km 2 , empleando datos de gradiente de gravedad aéreo adquiridos en 2010, a fin de correlacionar la respuesta gravimétrica con los altos estructurales y los cuerpos de sal interpretados con sísmica 3D. El gradiente de gravedad mide la variación espacial del campo de gravedad en tres direcciones perpendiculares, obteniendo como resultado un tensor, de cinco componentes independientes. La interpretación cualitativa conjunta del tensor permitió delinear cuerpos de sal y además establecer una correlación con el mapa estructural en profundidad del Cretácico Superior (KS). La evaluación de los mapas y atributos residuales de gravedad con el mapa del KS, reveló que el límite norte del Alto de Jalpa y los bloques elevados del sistema de fallas laterales E-W muestran anomalías positivas de gravedad. El análisis indicó una elevada correlación entre altos de gravedad y altos estructurales que corresponden con campos productores, y fue posible diferenciar entre bajos de gravedad generados por bajos estructurales y anticlinales nucleados por sal. Se detectaron tendencias de anomalías positivas con dirección NW-SE, en cuyos extremos se ubican campos productores, mientras que la anomalía central se encontraba en una zona sin sísmica 3D. La integración con sísmica de reciente adquisición en la porción central corroboran la interpretación de un alto estructural. La correlación establecida es una evidencia de las ventajas del gradiente de gravedad para la detección de estructuras nucleadas por sal en áreas conocidas y para la evaluación del potencial en áreas poco exploradas.

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Late Cretaceous-to-present-day mixed carbonate-clastic deposition along the Nicaraguan platform, western Caribbean Sea, has evolved from a tectonically controlled, rifted upper Eocene shallow-to-deep-marine carbonate-siliciclastic shelf to an upper Miocene-to-present-day tectonically stable shallow-marine carbonate platform and passive margin. By integrating subsurface data of 287 two-dimensional seismic lines and 27 wells, we interpret the Cenozoic stratigraphic sequence as 3 cycles of transgression and regression beginning with an upper Eocene rhodolitic-algal carbonate shelf that interfingered with marginal siliciclastic sediments derived from exposed areas of Central America bordering the margin to the west. During the middle Eocene, a carbonate platform was established with both rimmed reefs and isolated patch reefs. A late Eocene forced regression produced widespread erosion and subaerial exposure across much of the platform and was recorded by a regional unconformity. The Oligocene-upper Miocene sedimentary record includes a southeastward prograding delta of the proto-Coco river, which drained the emergent area of what is now northern Nicaragua. The late Miocene-to-present-day period marks a period of strong subsidence with the development of small pinnacle reefs. We describe favorable petroleum system elements of the Nicaraguan platform that include (1) Eocene fossiliferous limestone source rocks documented as thermally mature in

Seismic interpretation involves deciphering subsurface structures, stratigraphy, and reservoir characteristics from seismic data. It is a critical step in understanding subsurface geology, particularly for oil and gas exploration. However, due to inherent challenges involved it faces several challenges that can compromise accuracy which in turn can also lead to incorrect conclusions.
Addressing the challenges typically requires a combination of advanced geophysical techniques, expert knowledge, iterative refinement of interpretation models, integration of multiple data sources, and collaboration among geoscientists.

La profundidad de la base de la fuente magnética fue obtenida usando un método exponencial aplicado a los datos magnéticos del Golfo de México, principalmente sobre la corteza oceánica. El área de estudio fue subdividida por mallas de tres tamaños, una para ventanas de análisis de 100×100 km, otra para ventanas de análisis de 150×1150 km y otra para ventanas de análisis de 200×1200 km. Las mínimas profundidades obtenidas con las tres ventanas de análisis varían entre 14.0 y 17.0 km, y las máximas profundidades entre 35.0 y 37.5 km. En los tres casos en la parte central del golfo se observa una zona de profundidades someras. Las diferencias observadas entre las tres ventanas de análisis son las geometrías y tendencias de las profundidades. Los resultados de la ventana de 100×1100 km tienen mayor correspondencia con el modelo tectónico de corteza del Golfo de México. Las menores profundidades se observan sobre el límite de corteza oceánica-continental transicional, donde la profundidad del Moho sísmico es mayor. Las profundidades de la base de la fuente magnética obtenidas son mayores a las profundidades del Moho sísmico. Palabras clave: corteza oceánica; método exponencial; Golfo de México.

This work presents novel pattern recognition techniques applied on bathymetric data from two large areas in Eastern Mediterranean. Our objectives are as follows: (a) to demonstrate the efficiency of this methodology, (b) to highlight the quick and accurate detection of both hydrocarbon related tectonic lineaments and salt structures affecting seafloor morphology, and (c) to reveal new structural data in areas poised for hydrocarbon exploration. In our work, we first apply a multiple filtering and sequential skeletonization scheme inspired by the hysterisis thresholding technique. In a second stage, we categorize each linear and curvilinear segment on the seafloor skeleton (medial axis) based on the strength of detection as well as the length, direction, and spatial distribution. Finally, we compare the seafloor skeleton with ground truth data. As shown in this paper, the automatic extraction of the bathymetric skeleton allows the interpretation of the most prominent seafloor morphological features. We focus on the competent tracing of tectonic lineaments, as well as the effective distinction between seafloor features associated with shallow evaporite movements and those related to intense tectonic activity. The proposed scheme has low computational demand and decreases the cost of the marine research because it facilitates the selection of targets prior to data acquisition.

Esta tese é o culminar de uma etapa que se iniciou quando em Agosto de 2006 embarquei rumo a Aracajú, a capital do Estado de Sergipe na Bacia de Sergipe-Alagoas. Nessa altura não poderia imaginar o quão importante aquele momento seria para os anos seguintes-talvez porque nunca antes tivesse ouvido falar de Aracajú ou da Bacia de Sergipe-Alagoas. No entanto esse momento foi decisivo e o Brasil, em particular a Bacia de Sergipe-Alagoas, fizeram parte da minha vida diária nos anos que se seguiram. Durante este tempo várias pessoas contribuíram directa ou indirectamente para esta conquista. Tentando não esquecer ninguém, os meus agradecimentos: Ao meu orientador, Duncan Lockhart sem o qual esta tese concerteza não seria a mesma. Não há palavras que descrevam a minha gratidão por me ter ensinado, corrigido e guiado ao longo deste tempo. Melhor era impossível. Muito obrigado! Ao meu orientador, Prof. Luís Menezes Pinheiro por todas as ideias que apresentou para o enriquecimento deste trabalho, pela disponibilidade, e pela enorme paciência em ler e reler todo o trabalho. A sua ajuda foi crucial para levar este projecto a bom porto. Ao Exploration Manager da GALP Exploração, Roland Muggli, por ter depositado em mim a sua confiança e me ter apoiado em todos os momentos.

Following the 12 January 2010 Haiti earthquake, teams of students and faculty members from the United States and Haiti surveyed 170 reinforced concrete (RC) buildings in Port-au-Prince and Léogâne. This paper summarizes the survey results and compares them with results from a similar survey done after the 1999 earthquakes near Düzce, Turkey. The survey results demonstrate that the frequency of damage in RC buildings was higher in Haiti than in Turkey. This increased level of damage is consistent with practical screening criteria based on cross-sectional areas of building columns and walls. Based on these criteria, 90% of the structures surveyed in Haiti would have been classified as seismically vulnerable before the earthquake. Damage was more frequent in structures with captive columns. A two-tiered screening process is suggested to rapidly assess the vulnerability of scores of poorly built low-rise RC buildings in future earthquakes.