Interpretation Of Seismic Data Research Articles

The structure and evolution of the tectonic structure of the southeastern part of the East European Platform and the Caspian oil and gas residual oceanic basin in the Late Precambrian – Cenozoic

Research subject. The southeastern part of the East European Platform and the Caspian oil and gas basin.Aim. The analysis of the structural and evolutional changes of the tectonic structure of the southeastern part of the East European Platform from the Late Precambrian to the Cenozoic and revealing the cause of the occurrence of a large oil and gas basin in the Cis-Caspian depression.Materials and Methods. Geological interpretation of seismic profiling data, shown in geophysical fields and reflecting horizons. Areal distribution of rock complexes of different ages according to drilling data.Results. The history of the southeastern part of the East European Platform is divided into a number of stages. At the end of the Middle Riphean – the first half of the Late Riphean, the Epigrenville supercontinent Rodinia arose (about 1000 million years). The Baltic continent became part of the Rodinia supercontinent. At the end of the Late Riphean – Early Vendian, the Central Russian and Moscow aulacogens emerged, fixing the beginning of the collapse of the Rodinia supercontinent, Cadomian orogeny, and the attachment of Scythia. The Cis-Caspian area turned into a trough, which received a large amount of detrital material from the Cadomian orogen.Conclusion. The analysis of the tectonic structural changes during the Late Precambrian up to the Cenozoic demonstrated drastic evolution of its structure from a deepsea basin with thin crust to a shallow salt basin. These changes did not occur gradually, but over the course of 9 stages of major structural changes. The ninth stage created the conditions for the emergence of a large oil and gas province in the Caspian region.

Architecture and Genesis of Submarine Migrating Channel–Levee Systems in the Pearl River Mouth Basin, Northern South China Sea

Seismic data reveal that the shelf edge of the Pearl River Mouth Basin in the northern South China Sea is characterized by slope channels that have consistently migrated in a north-easterly direction over millions of years. Previous research suggests that the channel migration is driven by the interplay between along-slope bottom currents and downslope turbidity currents. Here, we propose an alternative interpretation, suggesting the migrating channels are actually a series of channel–levee systems and the migration is driven by their own evolution of erosion–deposition under the influence of the Coriolis force. A detailed interpretation of high-resolution seismic data reveals seven types of architectural elements, characteristic of channel–levee systems, which are erosional bases, outer levees, inner levees, channel-axis fills, marginal slumps, drapes, and lobes. An analysis of the sequence stratigraphy and stacking pattern of channels suggests that channel migration from the middle Miocene to the present is discontinuous with at least three regional discontinuities within the channel migration sequence marked by regional drapes. Down-dipping reflections along the margin of channels, previously interpreted as bottom-currents deposits, are here reinterpreted as mass-transport processes along steep channel walls. The migration is most prominent in the middle reach, where erosion and deposition coexist and dominate alternately in two different phases. During the long-term canyon-filling turbidity currents prevailing phase, deposition dominates, leading to the development of a prominent asymmetric right-hand (west) inner levee due to the Coriolis force. In contrast, during the canyon-flushing turbidity currents prevailing phase, erosion dominates and the preferred right-hand (west) inner levee enforces the flow to erode eastward, then drives the channel migrating eastward. The alternating effects of erosion and deposition ultimately result in unidirectional channel migration.

Dynamic sedimentary environments controlled by tectonic processes and sediment supply: Insights from the Yangjiang Sag in the northern South China Sea

The evolution of paleo-environments within sedimentary basins is closely related to a joint effect of tectonic processes and sediment supply, which have rarely been explored in source-to-sink contexts in quantitative studies. In this study, we took the Yangjiang Sag in the northern South China Sea as a case study; its evolution is related to the uplift of the eastern Tibetan Plateau and the initial rifting of the South China Sea, and the 3-D seismic interpretation data covering the entire basin also provided the data support for our research. Based on these data, we identified the basement layer of the basin and reconstructed the evolution processes of the basin’s basement using 3-D tectonic restoration. Then, for the first time, we used a landscape evolution model driven by this calculated basement evolution history to simulate the entire evolutionary process of the sedimentary environment from initial rifting to rapid subsidence in the Yangjiang Sag. The modeling results are in good agreement with actual geological data on the sedimentary environments and seismic profiles. This method, the coupling of tectonic reconstruction and a landscape evolution model, is effective in the quantitative study of evolutionary processes of the sedimentary environment at the basin scale. Meanwhile, the results precisely illustrate that the subsidence of the basin driven by syn-sedimentary faulting has caused obvious geomorphic inversion, leading to a transition of the sedimentary environment from shallow to deep lacustrine facies. The landscape evolution significantly influenced the channel migration and sediment distribution, thereby controlling the shift of the depocenter. In addition, variations in the sediment supply control the sedimentation rate. Rapid uplift in the source area can cause the sediment supply to become the dominant factor influencing the sedimentary environment. This would cause the basin to transform into a progradational system tract, accompanied by continuous delta progradation.

New experimental constraints on seismic velocities and densities across the – quartz transition at deep crustal conditions

At the pressure and temperature conditions of the lower crust, quartz undergoes a displacive phase transition from a trigonal () to a hexagonal phase (). At room pressure, the – quartz transition occurs at 574.1 °C and it is associated with large changes in the thermodynamic and elastic properties. For that reason, it is interpreted as the cause of significant seismic velocity contrasts in the crust seen by seismic tomography. Existing thermodynamic models and Equations of State (EoS) of quartz are mostly constrained by data collected at room pressure (or at high pressure and room temperature). In this work we characterized the – quartz transition experimentally at simultaneous HP–HT conditions using synchrotron X-ray diffraction and acoustic measurements, and derived values of , , the adiabatic bulk modulus () and the shear modulus (G). The data collected in the field agree with the models from the literature, so entrapment pressures of -quartz inclusions calculated via elastic barometry with these EoS should be reliable. However, our measured , , and are significantly lower than those predicted for -quartz. Whatever the cause of this discrepancy, interpretations of seismic data in terms of the properties of -quartz in the lower crust and calculations of entrapment conditions of quartz inclusions in the stability field of -quartz should be treated with caution.

Temperature effects on the joint elastic-electrical properties of Berea sandstones

Joint interpretation of seismic and electrical survey data can help to better characterize the subsurface. However, the key to the successful joint interpretation is to understand the correlations between the elastic and electrical properties (i.e., the joint elastic-electrical properties) of the underground rocks. This work aims to investigate the effects of temperature on the joint elastic-electrical properties of porous rocks by simultaneously measuring the P-wave velocity, electrical conductivity and porosity of five brine saturated Berea sandstones as a function of varying temperature from 25 °C to 140 °C. We find that velocity first increases and then decreases with increasing electrical conductivity with implicitly increasing temperature. We further find that the variation of the temperature dependent joint elastic-electrical properties is determined by the dependence of velocity on temperature with a local maximum, because electrical conductivity shows strong linear increase with increasing temperature. Analyses of the experimental results illustrate that the observed variation of velocity with temperature is the combined and competitive result of the temperature-induced variations in the pore aspect ratio that quantitatively characterizes the pore structure, the properties of brine that fully saturates the samples, and the porosity of the samples, with their importance in descending order. The results reveal how the elastic velocity in Berea sandstones is affected by temperature, which in-turn provides insights into the effects of temperature on the joint elastic-electrical properties of Berea sandstones that will help to improve the joint interpretation of seismic and electrical survey data to better characterize the petroleum and geothermal reservoirs.

Results of 3D seismic surveying for hydrocarbons in the Gulf of Guinea

Seismic methods are among the most important tools in prospecting, exploration, evaluation and operation of oil and gas fields. The work includes three main stages: seismic data collection, their processing and interpretation. Seismic exploration can be carried out in 2D, 3D or 4D modifications. This study focuses on a 3D offshore seismic survey conducted in the deep shelf of the northern Gulf of Guinea in the Côte d’Ivoire Tano sedimentary basin. The purpose of the work is to assess the commercial prospects for discovering hydrocarbon deposits in the RUS-CIV block, identify the capabilities of seismic exploration, demonstrate effectiveness and sustainability of seismic analysis, which has been developed and improved over the years, achieving improved subsurface visualization results. The data providing reliable information on the seismogeological structure of the area under investigation have been obtained as a result of successive marine seismic operations in 2003–2009. A detailed study allowed to form objective ideas about the internal structure of the block, in particular about the layers of Cretaceous deposits. Also, data were obtained on the presence of a fault network in sedimentary rocks, possible hydrocarbon traps, the nature of pore pressures and the type of fluids. However, the conclusions made remain preliminary, have a qualitative nature and should be confirmed by additional analyses due to the fact that there are no drilled wells in the studied block. Based on the study results, the most promising areas have been identified for detailed interpretation based on the analysis of the dynamic characteristics of seismic waves, seismic exploration data and the choice of the exploration well location.

Features of modern interpretation of seismic data on the example of a site in the Middle Caspian waters

The oil and gas industry is a key economic driver of Kazakhstan’s development. The current reality is that the country's GDP growth rates, the level of digitalization in science and its technological advancement, a significant portion of national revenues are still directly dependent on the discovery of new hydrocarbon fields. In this context, the most promising regions for oil and gas exploration are the Pre-Caspian Basin, South Mangyshlak, and the Caspian Sea offshore areas. Particular attention from both domestic and foreign oil companies is focused on the North and Middle Caspian offshore zones. It is worth noting that between 2000 and 2008, 13 fields were discovered in the study area, 6 of which are located in the North Caspian (Kashagan, Kairan, Aktoty, Kalamkas-Sea, Auezov, Khazar). In the Middle Caspian, the following fields have been discovered: Khvalynskoye, Sarmatskoye, Shirotnoye (named after Korchagin), Rakushechnoye, named after Filanovsky, and Rakushechnoye West. The hydrocarbon potential of the region is substantiated not only by the significant thickness of sediments but also by the presence of extensive subsidence zones within the sedimentary cover, characterized by the widespread development of reservoir rocks, cap rocks, and oil-source rock formations. It should be noted that, along with discoveries, there have also been unsuccessful drilling results in several explored structures in the region, including Tub-Karagan-1 (2005), Kurmangazy-1 (2006), Atash-1 (2008), Laganskaya-1 (2008), Kurmangazy-2 (2009), Petrovskaya-1 (2009), and Zhenis (2023). On the other hand, more than 30 local structures, predominantly of Mesozoic age, remain unexplored within the studied area. All these factors are observed against the backdrop of relatively low geological and geophysical study coverage. This leads to the conclusion that there is a critical need to significantly improve the efficiency of geological exploration, which could substantially enhance the research foundation and facilitate the development of a modern geological model of the region. This study demonstrates various technological approaches to seismic data interpretation. To date, a range of technical and software solutions for seismic data processing and interpretation have been developed to address the challenges of hydrocarbon reservoir prediction. Moreover, the analysis has reached a stage where unstacked seismic data are increasingly used as input. The study analyzes the effectiveness of seismic attributes and performs dynamic interpretation of seismic data in one of the areas of the Middle Caspian hydrocarbon basin. This approach has refined the geological structure of the study area, enabled the mapping of clay content zones and reservoirs, and assessed the advantages of the applied interpretation methods in the exploration and prediction of hydrocarbon-bearing targets, where the lithological factor significantly influences the formation of hydrocarbon accumulations. As a result, volumetric models of reservoir distribution, clay content, and hydrocarbon saturation have been constructed.

Correlation between cementation exponent and pore geometry with varying pore pressure for the joint elastic-electrical modelling of porous sandstones

Summary Seismic and electrical surveys are the most employed geophysical exploration applications for understanding the subsurface earth. Differential effective medium (DEM) models are the models to interpret the seismic and electrical survey data with the greatest success. However, cementation exponent and pore aspect ratio as the indispensable geometric parameters in the electrical and elastic DEM models are independent, making the models not suitable for the joint elastic-electrical modelling, a key requirement for the joint interpretation of seismic and electrical exploration data to better understand the increasingly complex hydrocarbon reservoirs. We show how cementation exponent and pore aspect ratio are correlated in three Berea sandstone samples with changing porosity resulting from varying pore pressure. We find that cementation exponent inverted from the electrical DEM model shows a strong positive linear correlation with pore aspect ratio obtained from the elastic DEM model as an implicit function of porosity induced by increasing pore pressure. We also find that the established linear correlation can enable the DEM models to calculate one physical property (e.g., elastic or electrical) from the geometric parameter describing the other property (e.g., electrical or elastic). The results reveal how the elastic and electrical geometric parameters are linked, and provide a consistent microstructure that enables the existing elastic and electrical DEM models to be suitable for the joint elastic-electrical modelling of rocks undergoing varying pore pressure.

The propagation of seismic waves, misinformation, and disinformation from the 2024-10-05 M 4.5 Iran earthquake

The 2024-10-05 Iran M 4.5 earthquake took place at a time of heightened tensions in the Middle East. We perform a discrimination and moment tensor analysis and identify a shallow-dipping, reverse fault source commensurate with the compressional setting of the Iranian interior. Nonetheless, the event's aftermath saw widespread dissemination of misinformation, and potentially active disinformation, concluding that it was in fact a test of an Iranian nuclear weapon. The `evidence' for many of these claims was based on inaccurate interpretation of seismic data. In this paper, we analyse how geophysical `fake news' propagated through social media (mainly Twitter/X) following this event, eventually gaining traction in mainstream, earned media. This event is an illustrative warning of how seismic data can be misinterpreted and/or manipulated in public discourse.

Seismic Post-Stack Attribute and AVO Seismic-Based Analysis in Delineating New Prospect with Filling-Ratio Approach in Estimating Fluid-Contact for Proposed Well

Abstract Delineating new prospects in a mature field requires a more advanced technique of seismic data interpretation in order to reduce the uncertainty level of success. The most conventional practice was to identify the reservoir using post-stack seismic data. In contrast, pre-stack seismic data are sometimes absent in the analysis due to the lack of data itself or the assumption that post-stack seismic data is deemed to be sufficient. Nowadays, it has been proved that the amplitude characteristics of seismic reflections vary with increasing offset. This finding led to Amplitude Versus Offset (AVO) analysis, which assessed the dependencies of reflectivity with increasing offset. This technique is useful in delineating the Direct Hydrocarbon Indicator or the fluid trend. Fluid-contact values are also essential to determine the vertical boundaries of hydrocarbon-saturated reservoirs. The filling-ratio method can answer the challenge of determining these vertical boundary values in a proposed well, which requires at least one proven and/or producing well to provide a sound basis comparison of fluid contacts from their top structure depth to their deepest fluid contact depth. This filling-ratio approach can then be applied with simple mathematical calculations between the proven and/or producing well and the proposed well in reservoir targets. In this case of work, Cisubuh formation is chosen as the layer of interest. It is known to have a bell-shaped sand reservoir from the log response of a nearby well. Both seismic post-stack and pre-stack are utilized in delineating new prospects in the target layer. The post-stack seismic is analysed to predict the sand distribution, while the pre-stack seismic is analysed to predict the fluid indicator across the area of interest. The delineation prospect from these seismic data sets also shows coherency with the interpreted anticlinal structural trap. Fluid contacts from the proven well, in this case, show convincing test results of hydrocarbon with one other prospected well in the same field that contains such hydrocarbon. The method can be justified with the mentioned proven well test and conservatively bounded the hydrocarbon reserves calculations. Hence, the result of the calculated comparison of fluid-contact depth between the proven well and the proposed wells does not over excessively contain such hydrocarbons.

Anisotropy of coal pore connectivity: experiments based on low-field nuclear magnetic resonance and low-temperature nitrogen adsorption

Coal, as an unconventional reservoir, is characterized by the development of micro/nano-meter pores and significant pore differences in different bedding directions. Pore heterogeneity and anisotropy are key factors contributing to the difference in reservoir properties. This not only affects the recovery of resources but also affects the interpretation of seismic data. Currently, research on coal anisotropy mainly focuses on the heterogeneity of pore distribution. Nonetheless, there are few studies and a lack of comprehensive knowledge regarding pore connectivity differences within the same macrolithotype of coal in different bedding directions. We present a novel method to study the anisotropy of pore connectivity in coal. This method used epoxy resin to seal different surfaces of cubic coal samples, combined with refined pore characterization techniques, to achieve anisotropy studies at different pore scales. These included differences in pore connectivity in different bedding directions and anisotropic characteristics of micron/nanoscale pores. The results indicated that the pores in various bedding directions differed considerably in type and distribution mode. There was a wide range of pore types in the bedding-parallel direction, and the pores showed regular variations. In contrast, the pore type was single in the bedding-normal direction, the pore distribution lacked an obvious pattern, and the pore complexity was higher. Moreover, the anisotropy of seepage pores was stronger than that of adsorption pores, which is the main reason for the anisotropy of reservoir properties. Based on the anisotropic study of coal pore connectivity, we can target the design of resource recovery processes to improve resource recovery. For example, in directions with low permeability, measures such as water injection can be taken to enhance permeability. Furthermore, one can also consider the pore size and connectivity in different bedding directions, introducing anisotropic parameters to optimize the permeability anisotropy model and provide better guidance for resource recovery.

Innovative method integrates play fairway analysis supported with GIS and seismic modeling for geothermal potential evaluation in a basement reservoir

The growing demand for clean and sustainable energy sources has prompted the investigation of numerous renewable and ecologically friendly options. Among these, geothermal energy is particularly noteworthy because of its widespread availability, compact size, and consistent, weather-independent power production. A geothermal play fairway analysis (GPFA) model was created for the study area, which is located in Békés county, southeastern Hungary. The GPFA model approach in the current study is the first model developed in Hungary to achieve three main goals. firstly, to quantitatively assess the geothermal potential, secondly, to identify the most favorable areas for geothermal exploration and development, and thirdly, to evaluate the corresponding risk levels in the study area. The study focuses on identifying and assessing three main risk components associated with exploitable geothermal systems in the study area. The risk parameters consist of the heat source, reservoir fracture permeability, and seal. Advanced 3D seismic interpretation, geographic information system (GIS), and 3DHIP (heat in place) calculator techniques are used to evaluate subsurface structural and thermal models. Two phases of seismic interpretation are used; conventional interpretation phase focused on conventional seismic data interpretation and advanced attribute generation phase where various seismic attribute cube volumes are generated. Common Risk Segment Maps (CRS) for each risk parameter are created by combining data from all the elements contributing to that risk using GIS toolbox. The resulted CRS maps of the study area three risk parameters are summed to produce a Composite Common Risk Segment Map (CCRS) map. Based on the constructed CCRS map and the developed GPFA model, the study area holds valuable untapped geothermal potential, poses varying risk levels associated with geothermal exploration and development. The amount of risk resulting from the three risk components is not equal, and the reservoir fracture permeability is the main risk factor. The GPFA model is successfully narrowed down an expansive exploration area of around 350 km2 to just 4 highly promising targets with high geothermal favorability and low risk as future drilling targets. The constructed 3D thermal capacity model indicates that the average heat content in the study area is estimated to be 65,450 Petajoules per square kilometer (PJ/km2), with a recoverable heat energy of 6090 megawatt thermal per square kilometer (MWth/km2). The recoverable heat for the four selected targets is estimated under different production scenarios: a 30-year plan, a 20-year plan, and a 10-year plan and it ranges from 7.5 to 32 MWth/km2, 11 to 48 MWth/km2, 22.2 to 96.8 MWth/km2 respectively. The findings of this study have made important contributions to the field of geothermal exploration approaches and offer valuable insights for making well-informed decisions about sustainable energy development in the study area.

Step characteristics and formation mechanism of strike slip faults in Wuerhe asphalt vein, Junggar Basin

In order to define the geometric characteristics, formation mechanism and fault wall movement direction of steps about mini-extensional shear strike-slip fault zone in Wuerhe asphalt vein. Field outcrop observation, 3D seismic data interpretation, fracture formation time and stress mechanism analysis were carried out. There is no friction in the vein section and the initial fracture shape is maintained. Not only negative steps but also steps is developed, and even steps and negative steps coexist in a cross section. The step is the microtension rupture surface associated with the strike-slip fault plane, which does not have the pointing significance of the fault wall relative movement. The outcrop features are typical, which overturns the consensus of domestic and foreign scholars based on the structural physics simulation experiments that the small steepness generated at the early stage of normal fault, reverse fault and strike-slip fault sections are all negative steps.

Joint Interpretation of Seismic and Electromagnetic Data for CO2 Monitoring Using 3D FWI and 2D CSEM Inversion Techniques: Sleipner CCS Site in Norway

Joint Interpretation of Seismic and Electromagnetic Data for CO2 Monitoring Using 3D FWI and 2D CSEM Inversion Techniques: Sleipner CCS Site in Norway

Seismic Imaging of Halokinetic Sequences and Structures With High‐Resolution, Dual‐Element Acquisition, and Processing: Applications to the Gassum Structure in Eastern Jutland, Denmark

AbstractUnderstanding the structural intricacies of subsurface halokinetic formations is crucial for various geological applications, including geological capture and storage (geological carbon storage (GCS)). This study focuses on the seismic imaging of the Gassum structure in eastern Jutland, Denmark, employing high‐resolution, dual‐element acquisition, and processing techniques. The investigation aims to unravel details in the evolution of the salt dome and its implications for GCS potential. High‐resolution seismic data processing and interpretation reveals a skewed dome structure with steeper flanks on the western and northern sides, characterized by faults and stratigraphic thinning. The asymmetric growth of the dome suggests uneven salt loading during its genesis, influencing local stress fields and structural development, with evidence of syn‐tectonic subsidence that produced salt welds. This is supported by the presence of stratigraphic wedges and an increased depth of imaged horizons within steeper flanks of the dome. A mild piercement of the salt into overlying sediments, onlapping features, and the presence of normal faults that originate from the dome apex and extend radially, all indicate a reactive piercement process in the salt pillow's development stage. This produced an extensional regime in overlying strata, inducing sequence thinning and graben structures. Analysis of reservoir and seal properties unveils adequate conditions for GCS, with a continuous reservoir and thick primary and secondary seals. However, the presence of faults intersecting these formations raises concerns regarding long‐term storage stability. Further investigations into reservoir porosity, migration paths, and volumetric analysis are warranted for conclusive GCS assessments.

GEOSEISMIC CHARACTERISTICS, HYDROCARBON POTENTIAL AND RESOURCES OF THE NORTH KARA SEDIMENTARY BASIN

GEOSEISMIC CHARACTERISTICS, HYDROCARBON POTENTIAL AND RESOURCES OF THE NORTH KARA SEDIMENTARY BASIN

FEATURES OF GEOLOGICAL STRUCTURE AND PROSPECTS OF OIL-AND-GAS BEARING CAPACITY OF THE RIPHEAN AND VENDIAN DEPOSITS IN THE SOUTHEASTERN PART OF THE KAMO ARCH OF THE BAYKIT ANTICLISE

The paper presents the results of the integrated study of the features of geological structure of the southeastern Kamo arch of the Baikit anticlise. Use has been made of both already published and unpublished geological-geophysical data obtained through seismic survey using the common depth point (CDP 2D) and the side view seismic location (SVSL) methods. The conducted research made it possible to improve understanding of the geological structure and formation conditions of the terrigenous-carbonate rocks of the Lower Riphean (Madrа, Yurubchen and Dolgokit formations) and Vendian (Vanavara and Oskoba formations) Kamo Group in the southern Kamo arch of the Baykit anticlese in terms of the prospects for the discovery of hydrocarbon (HC) deposits therein. The interpretation of seismic data (CDP and SVSL) provided the possibility to specify the thickness of the Lower Riphean terrigenous-carbonate rocks, most promising for hydrocarbons, to generate the predictive geology map of the pre-Vendian erosion surface, and to map the HC-promising Early Riphean and Vendian deposit thickness. Along with the previously explored large HC deposits in the central Kamo arch of the Baykit anticlise, the new data presented here testify in favor of the structural-and tectonic conditions for the development of the Lower Riphean and Vendian rocks on the southeastern slope of the Kamo arch of the Baykit anticlise and imply their high potential.

High-resolution GPU-based simulations of quasi-static poroelasticity: seismic attenuation and modulus dispersion in three-dimensional stochastic fracture networks

SUMMARY Fractures significantly impact the elastic and hydraulic properties of geological structures, influencing fields like geothermal energy, hydrocarbon exploration, nuclear waste disposal and $\mathrm{ \mathrm{CO}}_2$ storage. Characterizing these formations is challenging due to the scale disparity between seismic wavelengths and fracture sizes. This study leverages decades of analytical and numerical advancements to evaluate the effective mechanical properties of fractured solids at the mesoscopic scale. A novel numerical method for modelling quasi-static Biot’s poroelastic equations using graphics processing units (GPUs) is introduced for simulating hydromechanically coupled systems. Capable of handling up to 133 million voxel elements on a single GPU, this method offers unprecedented spatial resolution to model complex fracture networks. The GPU-accelerated solver, FastBiot_QS, delivers exceptional performance, achieving a computational speedup of approximately 520 times compared to central processing unit-based methods. The solver’s accuracy is rigorously validated in 1-D and 3-D setups. Simulations reveal that fracture clustering and spatial distribution significantly affect seismic attenuation and modulus dispersion. Clusters of interconnected fractures lead to higher attenuation at higher frequencies, while sparsely distributed fractures result in higher attenuation at lower frequencies. Simulations with log-normal and uniform distributions present intermediate behaviours between densely clustered and sparsely distributed fractures. The study can improve interpretations of seismic data and hydraulic properties in fractured media.

A Comparative Study on Acoustic Characteristics of Methane and Tetrahydrofuran Hydrate-Bearing Sediments

Laboratory acoustic measurements of hydrate-bearing sediments serve as an important reference for the geological interpretation of seismic exploration data. Tetrahydrofuran (THF) hydrates are relatively easy to form with precise control of hydrate saturation, and they overcome the long time it takes for methane in sediments to form hydrate. However, when THF hydrates are used as a substitute for methane hydrate, their acoustic properties yield different results. This study reports the results of a series of laboratory experiments on the formation of methane and THF hydrate in quartz sand and the evaluation of their acoustic properties. It compares the experimental results with the results of calculations from micro-distribution models of the four hydrates using effective medium theory (EMT). Methane hydrate formed by the excess gas method has higher acoustic velocities than THF hydrate at 0–80% saturation, but at 80–100% saturation, the situation reverses, with THF hydrate having a higher wave velocity. The methane hydrate synthesis process follows a mixed micro-distribution, with grain coating predominating at low saturations, the pore-filling mixing mode dominating at medium saturations, and grain coating dominating at high saturations. In addition, THF hydrate has a slow-velocity growth at low saturation and is dominated by a pore-filling model and a load-bearing model at high saturation. We compared our experimental data with a compilation of similar published results to confirm their reliability and support our conclusions. Both hydrate types exhibit distinct micro-distributions across different saturations. Therefore, when testing the elastic characteristics of hydrate sediments, the distinct hydrate synthesis methods and micro-distribution should be considered, especially when using THF hydrate as an alternative to methane hydrate.

Application of Seismic Data Interpretation and Well Log Analysis for Evaluation of Matulla Formation South Abu Zenima Oil Field Gulf of Suez Egypt.

Application of Seismic Data Interpretation and Well Log Analysis for Evaluation of Matulla Formation South Abu Zenima Oil Field Gulf of Suez Egypt.