Arabian Journal of Geosciences最新文献

To estimate acoustic impedance and porosity in inter-well regions, a seismic inversion based on Hooke and Jeeves’ methods has been developed. The Hooke and Jeeves algorithm is a local optimization method that can reach a local or global optimum solution depending on the starting model. To prevent convergence to a local optimum, in the present study, the solution is constrained by well-log data. To optimize parameters, the algorithms are first assessed on synthetic data followed by the coal coking and wedge model. The algorithm’s performance is very satisfactory, according to the error analysis between the inverted and anticipated outcomes. Further, a real data application from the Blackfoot field, Canada, has been performed in two steps: First, a composite seismic trace close to the well location is retrieved, inverted into an impedance, and compared with the well-log impedance. The analysis shows how well the well-log impedance corresponds to the inverted impedance. Finally, in the second step, the entire seismic reflection data is subjected to the Hooke and Jeeves–based inversion, and the volume of acoustic impedance and porosity in the inter-well region is predicted. The paper demonstrates that when local optimization is utilized and is constrained by well-log data, the algorithms yield higher-resolution subsurface information. A low impedance anomaly (ranging from 7000 to 9500 m/s g/cc) was detected between 1040 and 1060 ms of two-way travel time, according to the study of inverted impedance. Additionally, the same zone contains an estimated high porosity anomaly (> 12%) that is thought to be a sand channel/reservoir. According to the results of this study, it is possible to swiftly and affordably assess subsurface parameters like acoustic impedance and porosity using seismic inversion based on the Hooke and Jeeves technique.

Lost circulation has the potential to cause formation damage, wellbore instability and a blowout. Many methods have been introduced, but there is no industry-wide solution available to predict lost circulation due to some constraints in the field. It is essential to predict the onset of loss of circulation to mitigate its effects, reduce operational costs and prevent the risk to people and the environment. A wide range of methods, techniques and treatments, including environmentally friendly materials, are reviewed to mitigate the loss of circulation. Conventional and intelligent methods are presented for detecting and predicting lost circulation events. Using oil field data such as fluid parameters, drilling parameters and geological parameters, artificial intelligence can predict fluid losses using supervised machine learning (ML). Several ML models for predicting fluid loss are reviewed in this paper, and other possible applications are discussed. The sample size, field location, input and output features, performance and ML algorithms are extracted. The paper provides an inclusive presentation of the ML workflow for fluid loss prediction and is anticipated to help and support both drilling engineering practitioners and researchers in the resolution of drilling challenges, with recommendations for future development.

Eco-industrial parks (EIPs) are considered effective means to enhance economic growth, improve competitiveness, maintain environmental quality, and improve social quality. They have many direct and indirect benefits, which makes the majority or most countries seek to implement these projects. Given its importance, international organizations such as United Nations Industrial Development Organization (UNIDO), World Bank Group (WBG), and Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) have developed an international framework for EIP projects which consists of several tools. Among the tools of the framework is EIP selection tool that evaluates the current performance of industrial parks, whether already existing or newly made ones in the following areas: management, environmental, social, economic, replicability, and visibility. The tool highlights the score per category of criteria of the selected park and therefore the scope of intervention on the park. In this study, the EIP selection tool will be used to study the performance of the industrial parks located in the Province of Algiers to consider their potential to be transformed into EIP. Upon applying the tool to assess 3 industrial zones (Rouiba – Reghaia, Oued Semar & Elharrache) and 2 zones of activities (Kaidi & Dar Elbaida) in the province of Algiers, we found that all of the 3 industrial zones have the capabilities of transferring into EIP but the most appropriate zone is Rouiba – Reghaia zone.

Shark teeth from representatives of four families, including Lamnidae, Hemigaleidae, Carcharhinidae and Sphyrnidae belonging to five genera, namely Isurus, Lamna, Hemipristis, Carcharhinus and Sphyrna, were recorded and documented for the first time from the South Garo Hills District of Meghalaya from the Baghmara and Chengapara formations of the Garo Group of rocks of Oligo-Miocene age. They show close affinity and similarities to the Miocene shark tooth assemblages recorded from the Baripada beds of Orissa and the Surma basin of Mizoram. These selachian assemblages from South Garo Hills point to a shallow marine, nearshore coastal environment well connected to the open sea. Thus, the present study provides new insights on the palaeodiversity and palaeoenvironmental setup of the Miocene sediments of South Garo Hills of Meghalaya and also enhances the existing knowledge of chondrichthyan diversity in India during the Miocene time.

This study integrates and optimizes the use of geomorphology, hydrogeology, hydro-geophysics, and remote sensing to get a better understanding of aquifer storage and retrieval mechanisms in the weathered aquifer system of the Usri watershed in Giridih, India. Integrated spatial analysis at the watershed scale has enhanced knowledge of weathered layer geometry, basement topography, broad fractures, and sub-surface flow barriers that affect groundwater availability in different areas of the watershed. The technique used for resource estimation not only estimates dynamic resources, as it has in the past, but also estimates static groundwater resources in weathered aquifers. It has been found that static resources are more than three times more abundant than dynamic resources that go unutilized. The digital basement topographic model of the watershed indicated multiple localized basement depressions. These depressions contain considerable drainable static groundwater resources that can be exploited for sustained extraction by implementing area-specific Aquifer Storage and Retrieval or Artificial Recharge and Retrieval system. The study found that the reliability of inferred lineaments as real fracture is limited in heavily weathered region such as the Usri watershed. The spatial hydro-geophysical characterization of satellite-derived inferred lineaments revealed that the majority of them do not correlate to real fractures.

Using the landslide of Yushu Airport Road 2# as an instance, a large shaking table was utilized to examine the propagation of seismic wave properties of the substrate-overlying slope with low structural planes. XZ acceleration data were obtained for different excitation intensities. The spatial impact of the seismic wave component propagation with elevation was discovered by the examination of the time-history of accelerating. The suggested law of variation damping ratios for the propagation of seismic wave components used processing half-power bandwidth as well as the Fast Fourier Transform (FFT). Its main frequency for propagation of seismic waves was quantified using the spectral ratio of the horizontal component spectrum (H_c) to the vertical component spectrum (V_c), and the predominant frequency of propagation was obtained quantitatively. Furthermore, piecewise spectral curves were refined, and the frequency and specific period spectral differences of the speed increase components at different vibration stages were characterized. The findings demonstrated that when relative height rose, the peak acceleration ratio of the horizontal and vertical components also increased. When the weak structural plane is present, the horizontal acceleration component can propagate directly through the weak structural surface. Vertical acceleration occurs at this point of seismic wave reflection and propagation. The weak structural face has a significant blocking effect on the acceleration amplification of the overlying slope. The slide bed and landslide mass’s horizontal component featured a rich low-frequency component. The primary frequency component spanned from 1.5 to 14.1 Hz. The vertical component had sufficient high-frequency components. The dominant frequency component ranged from 2.3 to 24.8 Hz, while the maximum frequency measured was 11.8 Hz. The vertical component was not amplified much in the horizontal component’s main frequency amplification range. In the frequency range of 8.1 Hz above the horizontal component’s transcendent, the impact was insignificant. The rear part of the slope was sensitive to the vertical seismic component.

In this paper, a specific earth dam in Iran as a case study was selected to introduce a new approach to numerical modeling and safety analysis. First, the dam body and its foundation were accurately modeled in PLAXIS 3D. The datum was collected from official reports. A specific section of the dam and foundation in which some instruments were placed was selected and a comparison of settlements in different parts was made between instrument data and finite element method (FEM) analysis. Since there was no favorable fitting, back analysis seemed to be crucial. Response surface methodology (RSM) was adopted to make some equations that can replace the hardening soil model and be easy to be optimized for desired settlements. Since the runs in the FEM software, PLAXIS 3D would take considerable time and energy, a new approach to use RSM was introduced which is called two-step RSM. It could be seen that if sensitivity analysis is performed on a linear RSM model at first, the second-order model of soil behavior can accurately be predicted with much less effort. Some statistical tests such as ({sigma }^{2}) and ({R}_{adj}^{2}) were considered to prove the adaptability of the new method. Two second-order RSM equations, for both core and shell, were optimized with the help of a genetic algorithm. The results suggested an acceptable fit when compared to instrumental data. Four water level scenarios were selected to run a Safety analysis on the most significant section of the dam which yielded the factors in the favorable ranges.

Graphical Abstract

A major uncertainty exists as regards reservoir continuity across Otam EF8 and Nuke JF7 reservoirs and whether pressure depletion in one reservoir would result in reserve loss in the other if these reservoirs were exploited independently. Reservoir characterization was used to resolve this challenge utilizing a dataset of 3D seismic data, well-log data, biostratigraphic data, fluid composition data, pressure data, and production data via an integrated study. Seismic interpretation was used to characterize the structural and stratigraphic framework of the Niger Delta reservoirs of interest. Fault seal analysis, grain size analysis, fluid composition, and dynamic data analysis were supportive in making inferences on reservoir continuity and pressure communication. Otam EF8 reservoir was identified as a thick, clean sand zone as opposed to the Nuke JF7 reservoir with shaly sand intercalations, which revealed that the EF8 reservoir does not extend to the JF7 reservoir. The permeability and pressure analysis highly suggest communication with its juxtaposing reservoir. The thickness–throw ratio and manual computation of the shale gouge ratio also indicate the potential for fluid communication across the fault. It was established from coupled material balance analysis that these two reservoirs may be in pressure communication, as a relatively good history match was obtained. The study has shown that reservoir continuity and pressure communication across two proximal reservoirs may be mutually exclusive.

Dolerite dikes in the Cambro-Ordovician Amdeh Formation of Oman were never studied in detail and their affiliation to a particular magmatic interval was debatable. We studied the composition, structure, tectonic setting, and age of five dolerite dikes and compared their composition and orientation to those of rocks of other magmatic episodes to assign the dikes to one of them. We provide novel information on these dikes, derived from transmitted and reflective light microscopy, X-ray diffraction, and fluorescence and structural analyses. The dolerites are low-alkali tholeiitic basalts, displaying a monotonous, fine, uniform texture. They mainly contain diopside and albitized anorthite, as well as some clinochlore, epidote, actinolite, quartz, muscovite, goethite, rutile, and pyrite. The dolerites are rich in silicon (Si), aluminum (Al), and iron (Fe) and low in titanium (Ti) and potassium (K). The sodium (Na) content is considerably higher than that of potassium. The five dikes strike either ∼NNW or ∼SW, paralleling the north-northwestern and southwestern rift arms of the regional Permian rift-rift-rift triple junction related to the breakup of Pangea. Geochemical plots of our rock samples and literature information demonstrate compositional similarities with Permian, rift-related mafic rocks of the region. Field relations of an unmapped sixth dolerite dike indicate an intra-Permian intrusion age as well. We conclude that the dikes represent Permian dikes of the Pangean rift system. Our samples plot in fields of oceanic volcanic arcs and continental back-arcs, attributed to melts generated from a subducted pre-Permian slab of corresponding composition. The source material remelted through decompression during Pangean rifting.