Geosciences and Engineering

JOINT INVERSION OF LABORATORY-MEASURED ACOUSTIC PHASE VELOCITY AND QUALITY FACTOR DATA

2023-09-26T08:54:21+02:00

The paper presents a new rock-physical model to describe the pressure dependences of the phase velocity and quality factor (Q). Acoustic laboratory data for P-wave velocity and Q factor were measured on the sandstone sample at 40 different pressures. The spectral ratio method was used to measure the Q factor data utilizing an aluminum sample (with the size and geometry of the rock sample) as a reference. The measured velocity and Q factor data were processed in an inversion procedure. The results showed that both the velocity-pressure and the Q factor pressure dependence can be well-described utilizing the newly developed rock-physical model in forward modeling. From the estimated inversion parameters, v_p and Q can be calculated for the full pressure range.

INVESTIGATION OF HEAVY METALS DESORPTION ENHANCEMENT PROCEDURES IN LOW-PERMEABILITY CONTAMINATED SOILS

2023-12-01T10:34:27+01:00

A significant amount of hydrocarbon contaminants (therefore heavy metal components) has remained in the soil due to careless industrial activities. Effective remediation is difficult, especially in low-permeability soils because it is extremely difficult to get desorption. A lot of research has been conducted on extreme soil acidification, batching of oxidants, air-fluid injection and electrokinetic treatment, there were successful but due to the risk from extreme loads, these methods can only be used solely in controlled ex-situ environments. This paper investigates an eco-friendly in situ treatment with carbamide peroxide in low-permeability silty clay. After several repetitions, the result of tests proved Cu component was fully adsorbed on clayey-silt among applied concentration and circumstances which applied, while two other components were partially adsorbed. Moreover, the experiments carried out to enhancement of desorption proved to be successful for Cu, Zn and Mn with carbamide peroxide.

INVESTIGATION OF GROUNDWATER POTENTIAL UTILIZING GEOSPATIAL TECHNIQUES IN OWERRI, NIGERIA

2024-03-27T09:52:33+01:00

This study used geospatial approaches to examine the potential of groundwater within the study area. Analytic Hierarchy Process (AHP) method was used combining various parameters including Rainfall (39.5%), Geology (23.5%), Slope (12.5%), Drainage Density (8.0%), LULC (6.1%), Lineament Density (5.4%), and Soil Type (5.0%) for an integrated geospatial analysis to assess the potential for groundwater in the study area. Pairwise comparisons were used to assess the relative importance of each parameter. AHP determined these weights after the pairwise matrices were completed. These weights show the relative importance of the themes when assessing the study area's potential for applications such as land-use planning or natural resource management. The AHP technique allows for the systematic evaluation and ranking of alternatives based on a variety of criteria. A groundwater potential index (GPI) map was created by combining all of these thematic maps and classifying the research area into three zones: poor (0.001 %), fair (41.092 %) good (58.686 %), and excellent (0.261 %) groundwater potential areas. The findings showed significant groundwater potential in regions with higher lineament density, low to average slope, and suitable land use and land cover. The weighted overlay strategy was reliable, according to the consistency ratio (CR) analysis of 0.043884. This work shows the importance of an integrated RS and GIS analysis for determining groundwater potential. The results help identify locations with higher groundwater potential and enable sustainable use of groundwater resources.

EXPLORING FOURIER TRANSFORMATIONS: BENEFITS, LIMITATIONS, AND APPLICATIONS IN ANALYZING TWO-DIMENSIONAL RIGHT RECTANGULAR PRISM’S MAGNETIC FIELD

2024-01-15T14:32:08+01:00

Fourier Transformations are crucial in signal processing, offering a unique approach for complex data analysis. This paper explores their advantages and limitations, explaining key concepts like Fourier Transformation, Fourier series, Discrete Fourier Transform, and Continuous Fourier Transform, focusing on practical applications. The strengths, such as signal decomposition into frequency components, are exemplified through a case study on the total magnetic field of two-dimensional right rectangular prisms. However, limitations arise with non-stationary signals due to the assumption of stationarity. Alternative methods like the Wavelet Transformation and Short-Time Fourier Transformation are briefly discussed. Serving as a practical guide, this paper aids researchers in utilizing Fourier Transformations while recognizing scenarios where alternative techniques may be more suitable.

EXPLORING UNCERTAINTY IN FLOW UNIT IDENTIFICATION AND PERMEABILITY PREDICTION

2024-03-27T09:53:15+01:00

The study proposes a comparative uncertainty analysis of the main methods for permeability prediction or estimation, including the Cluster analysis (K-means), the Kozeny-Carman (KyC) equation for flow unit identification, and the K-nearest neighbor Density Estimate (KNN) algorithm, Kozeny-Carman equation, and One Flow Unit (OFU) for permeability prediction or estimation. The proposed analysis is applied to 13 wells in the Sacha field located in the Amazon region of Ecuador, targeting the Hollin and Napo formations, which mainly consist of sandstone, limestone, and shale. The selected wells have a sufficient number of laboratory measurements of permeability and electrical logs of porosity, permeability, natural gamma ray, medium, and deep resistivity. Initially, the K-means clustering and KyC methods are applied to identify the flow units, followed by a regression process to calculate the permeability using the KNN, KyC, and OFU methods. During the clustering process, the KyC method yielded better results, with the experimental data exhibiting uncertainties of less than ±35 mD, except in the outlier flow unit with an average porosity of 16.86% ±3.87% (Flow Unit D) whose average permeability is 407.52 mD and uncertainty of ±504.10 mD. For software simulation purposes, it is recommended to utilize the KyC method, as it employs basic concepts and equations in accordance with hydraulic principles.

COMPARISON OF DIFFERENT ROCK PHYSICS MODELS FOR ACOUSTIC VELOCITY

2024-04-05T10:27:00+02:00

Unlocking the secrets of rocks is an important task to explore, we require a deep understanding of rock physics. By describing the influence of rock physics on seismic velocities, we attempt to provide a comprehensive understanding of rock physics models and their application to predicting velocities. Throughout the discussion of the most used rock physics models. Moreover, we summarize the results of models using synthetic data to represent relationships between rock physics and elastic moduli. Knowing rock physics models for acoustic waves enhances the interpretation of seismic data, improves reservoir characteristics, aids in fluid identification, and supports uncertainty analysis. However, the choice of model depends on the specific properties of the rock and the application.

RECYCLING TECHNIQUES FOR CRYSTALLINE SILICON AND THIN FILM PV PANELS: AN OVERVIEW

2024-03-12T08:09:14+01:00

Over the last few years there has been a growing trend towards using solar electricity as an alternative source of energy. In order to meet the world's projected energy needs, PV panel technology is a major alternative to fossil fuels. Due to the increase in production, PV panels with a lifetime of between 25 and 30 years are potential for photo-voltaic waste over the next few years. The environmental damage caused by PV panels is significantly reduced when they are recycled. The recycling also contributes to the recovery of materials, some of which are rare in nature. The structure of the components that make up this paper. From 2050 onwards, the estimated PV waste projections for the world have been analyzed.