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The process of casing the wellbore in oil and gas drilling consumes a significant amount of time and economic resources. High-energy laser rock fracturing, as an efficient and cost-effective new approach, holds the potential to create a glass-like casing by irradiating the rocks as an alternative to traditional casing. The mechanism behind the vitrification of rocks using laser irradiation, a key factor in achieving glassified casings, remains to be studied. This paper, based on experiments involving scanning sandstone with a line laser, investigates the mechanism of rock vitrification using numerical simulations and X-ray diffractometers. The results demonstrate that the sandstone surface is transformed into glass after laser scanning, with multiple scans and the application of high-speed airflow helping to reduce the formation of bubbles and other phenomena. Furthermore, the speed of laser scanning showed a negative correlation with the laser ablation depth, glass thickness, temperature diffusion rate, and temperature gradient. Based on these findings, a groundbreaking method is proposed for creating high-quality glass by moving the laser to scan the rocks multiple times, offering insights for research into laser-manufactured wellbore casings. Furthermore, this approach holds promising prospects for enhancing and embellishing the exterior of structures and for in situ environmental modifications on planetary surfaces and beyond. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Surface waves are widely used in the study of underground structures at various scales because of their dispersion characteristics in layered media. Whether in natural seismology or engineering seismology, surface wave analysis methods have matured and developed for their respective fields. However, in oil and gas exploration, many data processors still tend to consider surface waves as noise that needs to be removed. To make more people pay attention to the application of surface waves and widely utilize surface waves carrying the near surface information in oil and gas exploration, this paper takes the data processing of LH site in Qinghai, China as an example to apply surface wave analysis methods to oil and gas exploration. We first preprocess and perform dispersion imaging method on the seismic record in the LH site to obtain frequency-phase velocity spectrum with good resolution and signal-to- noise ratio. Then, utilizing clustering algorithms, it automatically identifies and picks dispersion curves. Finally, through a simultaneous inversion algorithm of velocity and thickness, it inverts the dispersion curves and obtain S-wave velocity profiles in the depth range of 0-200 m. The near surface is divided into four zones based on velocity ranges and depth ranges. Additionally, we apply the surface waves inversion results as constraints to first-arrival tomography and obtain objectively accurate P-wave velocity profiles and Poisson's ratio profiles. The results indicate that by applying surface wave analysis methods, the near surface velocity information carried by surface waves can be extracted, providing near surface velocity models for static correction and migration. At the same time, compared with the surface wave application in engineering seismology, the scale of oil and gas exploration is larger, so that the data processing of surface waves is particularly important, otherwise it will affect the picking of the dispersion curve and inversion. [ABSTRACT FROM AUTHOR]

In recent years, the Permian Maokou Formation of the Sichuan Basin shifted focus. Previously, targeting high points and exploring along the long axis were common. Now, the strategy emphasizes finding shoal grainstone reservoirs with pores, leading to significant breakthroughs and making the Maokou Formation a hotspot for exploration. This change requires strong support from sedimentary evolution studies. The eastern and northern Sichuan regions are notable for distinct tectonic and sedimentary features within the Maokou Formation, suggesting promising exploration potential. Analysis of the logging data from 386 wells was conducted and sedimentary facies analysis was carried out using field profiles and drilling cores. Combining the logging curves with sedimentary facies, the sedimentary evolution of the Maokou Formation in the study area was analyzed. Findings reveal a gentle carbonate slope from the first member to the lower submember of the second member. The stratigraphic thickness and sedimentary facies are generally influenced by the ancient Central Sichuan Palaeouplift, with low-energy shoals developing locally. A transition to a rimmed carbonate platform occurs from the upper submember of the second member to the third member, with stratigraphic thickness and sedimentary facies showing a northwest to southeast orientation. The platform develops sequentially from platform facies to platform margin, slope, and shelf facies from west to east, with high-energy shoals developing in the platform margin. Sedimentation history indicates two distinct rise to fall processes of the relative sea level during the Maokou Formation sedimentary period, corresponding to the first member to the lower submember of the second member, and the upper submember of the second member to the third member. The formation of shoal grainstone reservoirs with karst and dolomitization in the gentle slope during the first period was controlled by regional sea level changes, tectonic activities, and the type of carbonate platform. Potential hydrocarbon source rocks developed in submarine troughs during the second period. The region holds promise for unconventional oil and gas exploration, particularly on the west side of the trough with high-energy shoals on platform margins.

Surface waves are widely used in the study of underground structures at various scales because of their dispersion characteristics in layered media. Whether in natural seismology or engineering seismology, surface wave analysis methods have matured and developed for their respective fields. However, in oil and gas exploration, many data processors still tend to consider surface waves as noise that needs to be removed. To make more people pay attention to the application of surface waves and widely utilize surface waves carrying the near surface information in oil and gas exploration, this paper takes the data processing of LH site in Qinghai, China as an example to apply surface wave analysis methods to oil and gas exploration. We first preprocess and perform dispersion imaging method on the seismic record in the LH site to obtain frequency-phase velocity spectrum with good resolution and signal-to-noise ratio. Then, utilizing clustering algorithms, it automatically identifies and picks dispersion curves. Finally, through a simultaneous inversion algorithm of velocity and thickness, it inverts the dispersion curves and obtain S-wave velocity profiles in the depth range of 0–200 m. The near surface is divided into four zones based on velocity ranges and depth ranges. Additionally, we apply the surface waves inversion results as constraints to first-arrival tomography and obtain objectively accurate P-wave velocity profiles and Poisson’s ratio profiles. The results indicate that by applying surface wave analysis methods, the near surface velocity information carried by surface waves can be extracted, providing near surface velocity models for static correction and migration. At the same time, compared with the surface wave application in engineering seismology, the scale of oil and gas exploration is larger, so that the data processing of surface waves is particularly important, otherwise it will affect the picking of the dispersion curve and inversion.

In recent years, the Ordos Basin has undergone a reevaluation, transitioning from a perception of a single block to a focus on understanding the influence of multiple stages and fault systems on hydrocarbon accumulation. This study utilizes the latest 3D seismic and drilling data alongside a theoretical model of strike-slip fault to analyze fault geometry and kinematics in the Xunyi-Yijun area of the basin's southern region. The mechanisms of fault formation are predicted and the related impacts on the formation and accumulation of deep carbonate rocks are also discussed. The results indicate the presence of three fault systems in the Xunyi-Yijun area, with decoupling between deep and shallow layers. The Lower Paleozoic strike-slip faults exhibit distinct characteristics, including high vertical structure, dip swing, and a "flower-shaped" structure in the section. The faults display "compression shear in the northwest, tension shear in the center, and segmental deformation on trunk fractures" on their planes.Moreover, the Lower Paleozoic strike-slip faults experienced two stages of tectonic activities with greater intensity observed from the Late Ordovician to the Silurian, marking the primary period of fault development. The activity intensity during the Middle to Late Permian was relatively weaker, with faults exhibiting inherited strike-slip characteristics. These faults formed two groups, one with a NE strike and the other with a NW strike. Additionally, during the second stage of the Caledonian period, ocean subduction and closure lead to stress being transferred to the basin interior. It is believed that the NE and NW strike basement weak zones existed in the southern Ordos Basin. As a result, the Lower Paleozoic strike-slip fault system likely formed due to the activation of oblique compression. This fault system has the potential to enhance the physical properties of deep carbonate reservoirs and create high-quality karst or tectonic fracture reservoirs in the Xunyi-Yijun area. Moreover, The formation of the "upper source and lower reservoir-lateral source and lateral reservoir" combination along the strike-slip fault belt is an area of interest for deep oil and gas exploration in the Xunyi-Yijun region.

A comprehensive assessment of machine learning applications is conducted to identify the developing trends for Artificial Intelligence (AI) applications in the oil and gas sector, specifically focusing on geological and geophysical exploration and reservoir characterization. Critical areas, such as seismic data processing, facies and lithofacies classification, and the prediction of essential petrophysical properties (e.g., porosity, permeability, and water saturation), are explored. Despite the vital role of these properties in resource assessment, accurate prediction remains challenging. This paper offers a detailed overview of machine learning’s involvement in seismic data processing, facies classification, and reservoir property prediction. It highlights its potential to address various oil and gas exploration challenges, including predictive modelling, classification, and clustering tasks. Furthermore, the review identifies unique barriers hindering the widespread application of machine learning in the exploration, including uncertainties in subsurface parameters, scale discrepancies, and handling temporal and spatial data complexity. It proposes potential solutions, identifies practices contributing to achieving optimal accuracy, and outlines future research directions, providing a nuanced understanding of the field’s dynamics. Adopting machine learning and robust data management methods is crucial for enhancing operational efficiency in an era marked by extensive data generation. While acknowledging the inherent limitations of these approaches, they surpass the constraints of traditional empirical and analytical methods, establishing themselves as versatile tools for addressing industrial challenges. This comprehensive review serves as an invaluable resource for researchers venturing into less-charted territories in this evolving field, offering valuable insights and guidance for future research.

In oil and gas exploration, elucidating the complex interdependencies among geological variables is paramount. Our study introduces the application of sophisticated regression analysis method at the forefront, aiming not just at predicting geophysical logging curve values but also innovatively mitigate hydrocarbon depletion observed in geochemical logging. Through a rigorous assessment, we explore the efficacy of eight regression models, bifurcated into linear and nonlinear groups, to accommodate the multifaceted nature of geological datasets. Our linear model suite encompasses the Standard Equation, Ridge Regression, Least Absolute Shrinkage and Selection Operator, and Elastic Net, each presenting distinct advantages. The Standard Equation serves as a foundational benchmark, whereas Ridge Regression implements penalty terms to counteract overfitting, thus bolstering model robustness in the presence of multicollinearity. The Least Absolute Shrinkage and Selection Operator for variable selection functions to streamline models, enhancing their interpretability, while Elastic Net amalgamates the merits of Ridge Regression and Least Absolute Shrinkage and Selection Operator, offering a harmonized solution to model complexity and comprehensibility. On the nonlinear front, Gradient Descent, Kernel Ridge Regression, Support Vector Regression, and Piecewise Function-Fitting methods introduce innovative approaches. Gradient Descent assures computational efficiency in optimizing solutions, Kernel Ridge Regression leverages the kernel trick to navigate nonlinear patterns, and Support Vector Regression is proficient in forecasting extremities, pivotal for exploration risk assessment. The Piecewise Function-Fitting approach, tailored for geological data, facilitates adaptable modeling of variable interrelations, accommodating abrupt data trend shifts. Our analysis identifies Ridge Regression, particularly when augmented by Piecewise Function-Fitting, as superior in recouping hydrocarbon losses, and underscoring its utility in resource quantification refinement. Meanwhile, Kernel Ridge Regression emerges as a noteworthy strategy in ameliorating porosity-logging curve prediction for well A, evidencing its aptness for intricate geological structures. This research attests to the scientific ascendancy and broad-spectrum relevance of these regression techniques over conventional methods while heralding new horizons for their deployment in the oil and gas sector. The insights garnered from these advanced modeling strategies are set to transform geological and engineering practices in hydrocarbon prediction, evaluation, and recovery.

Rakhi Nala (Gorge) section of Eastern Sulaiman Range, Pakistan hosts world-class geological sections from the Cretaceous to the Recent. Here, Late Eocene Kirthar Formation is having a conformable lower contact with the greenish grey massive shale of the Baska Member of the Ghazij Formation. The rusty beds of the Oligocene Chitarwatta Formation are overlying the Kirthar Formation. To understand the detailed microfacies and depositional setting, detailed fieldwork was carried out in the Kirthar Formation in the outer Sulaiman Foldbelt. The late Eocene Kirthar Formation includes Habib Rahi Limestone, Domanda Shale, Pirkoh Limestone, and Drazinda Shale. Domanda Shale Member was deposited in transgression before Habib Rahi Limestone Member was deposited. It was followed up by the deposition of the second member Pirkoh Limestone and Marl Member. Habib Rahi Limestone, Pirkoh Limestone, and Marl Member have catch-up-to-keep-up deposition with rise and fall of sea level. Some facies of Drazinda and Domanda Shales represent a restricted setting supported by the presence of gypsum, while deep sea facies were also identified. This study will provide a guide for evaluating sedimentological concepts and understanding complex facies in highly oil and gas-prone stratigraphic sequences especially in the Eastern Tethys Region. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Earth Science (1001-8166) is the property of Advances in Earth Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the world's main oil and gas resource, the deep carbonate reservoir has great exploration-development potential. However, it is difficult to make development and exploration due to its complex diagenesis processes. During the formation of carbonate reservoirs, the effect of meteoric water forms karst holes for oil and gas reservoirs, but the complex internal mechanism severely restricts the exploration and development of carbonate reservoirs. This paper takes the deep carbonate reservoirs in the Tarim Basin as the research object, studies the diagenesis processes in deep carbonate reservoirs through geological survey, analyzes the effect of meteoric water on porosity and mineral changes in carbonate reservoirs at different diagenetic stages by using laboratory test, theoretical analysis, and numerical simulation research methods. The numerical simulation method is used to simulate the porosity changes and mineral evolution of reservoirs in different diagenetic stages, and the conclusion is drawn that meteoric water has an impact on reservoir minerals and porosity. The results show that the carbonate reservoirs in the Tarim Basin have high porosity and good permeability, and the reservoirs have experienced deposition, compaction, dissolution, and hydrothermal stages, and have experienced meteoric water effects for a long time, resulting in rock dissolution, regenerative precipitation and chemical reaction; Quartz and feldspar minerals are the most in the sample through laboratory tests, the content of quartz decreased first, then increased and decreased, and the content of chlorite and mica changed little during the whole diagenesis processes. With the injection of organic acid, the porosity of the reservoir increases, with the continuous increase of temperature and pressure, the porosity decreases. After the second injection of organic acid, the porosity increases continuously, and finally, the porosity decreases. TOUGHREACT is used to simulate the static reaction of water and rock, simulating six diagenetic stages. With the injection of organic acid, the porosity increases continuously and then reaches equilibrium. The sudden increase in temperature and pressure leads to an increase in porosity, and the porosity of the reservoir changes little during the second injection of organic acid, and the porosity decreases in the final stage. The research results provide theoretical data support for guiding oil and gas exploration in deep carbonate reservoirs. [ABSTRACT FROM AUTHOR]

The process of casing the wellbore in oil and gas drilling consumes a significant amount of time and economic resources. High-energy laser rock fracturing, as an efficient and cost-effective new approach, holds the potential to create a glass-like casing by irradiating the rocks as an alternative to traditional casing. The mechanism behind the vitrification of rocks using laser irradiation, a key factor in achieving glassified casings, remains to be studied. This paper, based on experiments involving scanning sandstone with a line laser, investigates the mechanism of rock vitrification using numerical simulations and X-ray diffractometers. The results demonstrate that the sandstone surface is transformed into glass after laser scanning, with multiple scans and the application of high-speed airflow helping to reduce the formation of bubbles and other phenomena. Furthermore, the speed of laser scanning showed a negative correlation with the laser ablation depth, glass thickness, temperature diffusion rate, and temperature gradient. Based on these findings, a groundbreaking method is proposed for creating high-quality glass by moving the laser to scan the rocks multiple times, offering insights for research into laser-manufactured wellbore casings. Furthermore, this approach holds promising prospects for enhancing and embellishing the exterior of structures and for in situ environmental modifications on planetary surfaces and beyond.