Arabian Journal of Geosciences最新文献

{"title":"The combined effect of drilling fluid, in-situ stresses and inclination on wellbore stability","authors":"Hasan Karakul","doi":"10.1007/s12517-024-12138-5","DOIUrl":"10.1007/s12517-024-12138-5","url":null,"abstract":"<div><p>A great number of variables (such as rock properties, in-situ stresses, drilling fluid, inclination etc.) are effective on wellbore stability and the combined effect of those variables determines the stability condition of wellbore. The main aim of this study is to analyse the combined effect of drilling fluid, stress state and inclination angle considering that there is no comprehensive study conducted on the topic. In this study, three stress conditions (normal faulting stress condition, reverse faulting stress condition and strike slip faulting stress condition), three drilling fluids (bentonite based, KCl based and polymer based), three inclination angles (0, 45 and 90°) and two depths (2800 and 5000 ft) were considered to evaluate the effect of those parameters on wellbore stability. The results of analyses showed that the number of instabilitity zones around the wellbore increases as the inclination angle increases under normal fault stress state However, number of instability zones are higher for low inclination angle values under reverse and strike slip fault stress states. While the best stability condition was obtained with polymer drilling fluids due to limited decrement on strength properties, the worst stability condition was satisfied with bentonite drilling fluids due to considerable decrement on strength properties as a result of interaction with drilling fluid.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on the permeability evolution mechanism of fractured coal-rock combination under ground stress and gas pressure","authors":"Yulin Li,&nbsp;YiXin Zhao","doi":"10.1007/s12517-024-12128-7","DOIUrl":"10.1007/s12517-024-12128-7","url":null,"abstract":"<div><p>In view of the gas flow problem in the hydraulic fracturing engineering of L-type horizontal well and in the process of gas production in coalbed methane development, the permeability stress test of single fracture coal-rock combination was carried out. The permeability evolution law of fractured coal-rock combination under axial compression, confining compression, and gas pressure is analyzed. The axial compression has little effect on the permeability of coal-rock combination with fractures, and the permeability has no obvious change. Taking 0.25 MPa gas pressure as an example, the permeability of N1 fluctuates between 0.004 and 0.005 mD, and the permeability of N2 and N3 samples fluctuates between 0.002 and 0.0035 mD. With the increase of confining compression, the permeability decreases with the increase of confining compression. Taking the N4 sample as an example, when the gas pressure is 0.50 MPa, the permeability of N4 rapidly decreases from 0.351 to 0.0025 mD. The permeability has decreased by 99.3%. With the increase of gas pressure, the permeability and stress sensitivity of fractured coal-rock combination decrease gradually. In the process of gas pressure loading, the permeability decreases greatly due to the existence of gas slippage effect in the low-pressure stage. When the gas pressure exceeds 1 MPa, the joint action of slip effect and velocity-sensitive effect makes the permeability almost unchanged. Taking the N4 sample as an example, when the axial and confining pressures are 6 MPa, the permeability decays from 1.298 to 0.382 mD, with a decay ratio of 70.6%. Finally, the permeability calculation model of single fracture coal-rock combination under in situ stress and gas pressure can well match the experimental data and clarify the influence of each permeability on the overall permeability. The permeability model shows that the overall permeability depends on the part of the smaller permeability, and the higher permeability only makes the overall permeability increase slightly.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142714184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prognosticators for precipitation variability adopting principal component regression analysis","authors":"Erum Aamir,&nbsp;Abdul Razzaq Ghumman","doi":"10.1007/s12517-024-12111-2","DOIUrl":"10.1007/s12517-024-12111-2","url":null,"abstract":"&lt;div&gt;&lt;p&gt;Precipitation is an intricate phenomenon influenced by several variables. It is extremely important to maintain life on Earth and balance the hydrological cycle. It is such a critical process that its scarcity leads to droughts and abundance leads to flooding, both extremities bring destruction. Nevertheless, predicting it properly through modeling can help attend to the unpredictability of this very important natural phenomenon. This novel research is dedicated to developing an accurate, mathematical model for establishing potential predictors of precipitation using data from the Pakistan Metrological Department (PMD). The study area is selected on its specific topography which is rugged terrain making it susceptible to flash flooding. On the contrary, Baluchistan province has encountered numerous reoccurring droughts and floods in the past few decades, which has destroyed the economy of the province mainly based on agriculture and livestock. Therefore, using precipitation data as a predictor with significant trends, a principal component regression analysis (PCRA) model has been developed for the significant months which are found to be the month of January and June. The Mann–Kendall technique was implemented to find the trend in the monthly precipitation data of 13 stations selected in Baluchistan which shows positive/negative trends in January and June. Principal components of large-scale oceanic and circulation indices, sea water surface temperature (SWST), geopotential height (GPH), sea-level pressure (SLP), relative humidity (RH), outgoing longwave radiation (OLR), and zonal wind (ZW), were the predictors. PCR is more robust than other modeling techniques; it can handle multicollinearity and reduces redundant variables. The current study identified the potential of precipitation variations with the help of two novel climate indices, EQWIN and ENSO-MODOKI, which have not been studied for the study area. The PCR model developed accounts for 73.33% and 95.05% of precipitation variability for January and June. The model successfully passed all pre- and post-estimation tests. The root mean square errors (RMSE) are 10.13 and 3.63 for January and June respectively. The results also show that the (EQWIN) and (EMI-Modoki) have a substantial effect on the precipitation pattern of a large province (Baluchistan), the province that hosts a significant portion of the routes of the Western and Central China-Pakistan Economic Corridor (CPEC) and International Gwadar port. The study addresses 2 SDGs namely SDG # 11.5 (natural disasters) and SDG#13 (climate action). It is also beneficial to the National Disaster Management Authorization (NDMA) and the Pakistan Metrological/Climate Department (PMD) by initiating timely flood alarms, water management indications, and drought threats. PCR modeling will not only reduce the devastation and catastrophe of flash floods due to unprecedented, torrential rain in the rugged terrain. It will save precious human","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on “Origin of cherts in Al Jabal al Akhdar, northeast Libya: petrographical and paleontological evidences” by Bakar et al. (2021)","authors":"Mohsen Henchiri","doi":"10.1007/s12517-024-12134-9","DOIUrl":"10.1007/s12517-024-12134-9","url":null,"abstract":"<div><p>Bakar (Arab J Geosci 14:763, 2021) presented a comprehensive study to answer some questions regarding the origin of cherts and selective silicification of Eocene and Messinian host rocks. Silicification is one of the most significant diagenetic processes influencing the evolution of sedimentary rocks, especially carbonates and evaporites, which makes this study interesting. A large number of sedimentologists, stratigraphers, petroleum geologists, and other related fields are interested in studying silicification owing to the potential information that study of silicification might provide on paleogeography, paleoceanography, stratigraphic correlations, the diagenetic history of carbonate rocks, and other topics. However, I have some comments on some points stated in the paper of Bakar (Arab J Geosci 14:763, 2021).</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geophysical modeling and reservoir performance of Aouinet Wanin F3B sandstone in well A37 NC 169A, Wafa Field, Ghadamis Basin, Libya","authors":"Ahmad M. K. Basal,&nbsp;Mohammad A. Sarhan,&nbsp;Mostafa Gumaa Alfarog,&nbsp;Ahmed Elbahrawy","doi":"10.1007/s12517-024-12131-y","DOIUrl":"10.1007/s12517-024-12131-y","url":null,"abstract":"<div><p>This study focuses on evaluating the quality of the Aouinet Wanin F3B sandstone as a potential hydrocarbon reservoir in Well A37, NC 169A, Wafa Field, Ghadamis Basin, northwest Libya. Capillary pressure data, a key indicator of pore throat size distribution and fluid percolation capability, is crucial for reservoir characterization. However, due to the high costs, time constraints, and environmental concerns associated with mercury injection capillary pressure testing, this study introduces an alternative approach. We utilize routine core analysis data specifically porosity and permeability to model synthetic drainage capillary pressure curves based on Pittman’s modified equations. Our results reveal three distinct rock types represent the reservoir intervals, categorized into mega-, macro-, and micro-pores. The uppermost zone of mega- and macro-pores demonstrates excellent to good reservoir qualities. The log–log plot of pore throat radius versus permeability using Pittman’s R50 equation yielded a 1 mD permeability cutoff, aligning with common reservoir benchmarks, while the Winland R35 equation produced a cutoff of 0.4 mD, slightly outside the acceptable range which is between 0.5 and 1 mD. These findings offer a cost-effective and reliable alternative for reservoir quality assessment.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation of the performance of nano-particles on hybrid gel in lost circulation control","authors":"Hamid Zafari Dehkohneh,&nbsp;Khalil Shahbazi,&nbsp;Benyamin Zaheri Abdehvand,&nbsp;Rasoul Nazemi","doi":"10.1007/s12517-024-12141-w","DOIUrl":"10.1007/s12517-024-12141-w","url":null,"abstract":"<div><p>Gels that initially exhibit low viscosity and later form a stable three-dimensional structure can be successfully employed in controlling fluid loss during drilling operations. Hybrid gels, composed of a cross-linked polymer gel as the continuous phase and an oil-based fluid as the internal phase, offer a more cost-effective and easily controllable solution than conventional polymer gels. This study investigates the performance of hybrid gels enhanced with nanoparticles (NPs) for controlling fluid loss during drilling operations. To evaluate the impact of environmentally friendly NPs (nano-silica (NS) and nano-bentonite (NB)) on gel behavior, several parameters, including initial and final gelation times (IGT and FGT), crosslinking rate (CR), and final viscosity (FV), were assessed under varying conditions of pH, temperature, and salinity. Additionally, gel stability over time, dynamic stability, and maximum sealing pressure were measured. To assess potential reservoir damage, gel degradation was evaluated in hydrochloric acid solutions with concentrations of 15 wt. % and 28 wt. %. Results demonstrate that NPs significantly enhance the performance of hybrid gels, improving sealing pressure by approximately 20% in fractured and highly permeable porous media. The gels exhibited enhanced stability, resistance to high pressures, and minimal reservoir damage. These findings highlight the potential of hybrid gels with NPs as a promising solution for combating fluid loss and improving drilling efficiency and safety.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142694850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on optimization of parameters for microbial improvement of expansive soils based on response surface methodology","authors":"Zhenyu Li,&nbsp;Kun Lin,&nbsp;Shijie Shan,&nbsp;Mengke Wang","doi":"10.1007/s12517-024-12137-6","DOIUrl":"10.1007/s12517-024-12137-6","url":null,"abstract":"<div><p>Expansive soils, known for their susceptibility to early damage due to their swelling and shrinkage properties, pose a significant technical challenge in geotechnical engineering. This study explores the optimization of microbial-induced improvement of these soils, emphasizing the pivotal role of temperature, pH, and time on both microbial growth dynamics and the soil’s swell-shrink behavior. A series of microbial growth and expansive soil swell-shrink tests were conducted, employing response surface methodology (RSM) to develop regression models that delineate the optimal conditions for microbial solution concentration and the free swelling ratio. The findings indicate that temperature and curing time exert a more pronounced influence on these parameters than pH. Notably, microbial solution concentration exhibits a peak with increasing temperature, while the free swelling ratio inversely declines. The curing time’s effect is characterized by an initial peak in microbial solution concentration followed by a gradual decrease, with the free swelling ratio of the soil consistently diminishing. The optimization analysis pinpoints the optimal conditions at 32 °C, pH 6.5, and a curing duration of 48 h, where the reduction in both microbial solution concentration and free swelling ratio is maximized. Under these conditions, microorganisms are used for improvement, the microbial solution’s OD₆₀₀ value peaks at 1.996, significantly reducing the expansive soil’s free swelling ratio from 169 to 64.3%.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142679492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating and comparing seismic hazard parameters for Northeast India: a comprehensive study","authors":"C. Lallawmawma,&nbsp;Josodhir Das,&nbsp;Mukat Lal Sharma","doi":"10.1007/s12517-024-12129-6","DOIUrl":"10.1007/s12517-024-12129-6","url":null,"abstract":"<div><p>This comprehensive study focuses on the evaluation and comparison of seismic hazard parameters in the Northeast Indian region, covering longitude 87°–98°E and latitude 20°–30°N, which is characterized by high seismicity and complex tectonic structures. The study aims to estimate seismicity parameters such as the magnitude-frequency distribution and Gutenberg-Richter <i>a</i> and <i>b</i>-values using maximum likelihood method (MLM) through the Zmap and the statistical approach proposed by Kijko. The study area is divided into six seismogenic source zones, and zone-wise seismicity parameters are estimated using the declustered catalog considering whole earthquake data and data within the completeness period. The study estimated seismicity parameters using completed catalogs. The results showed that the <i>a</i> value ranged from 2.85 to 5.06, and the <i>b</i> value ranged from 0.76 to 0.92 when using Zmap. Meanwhile, when using the Kijko approach, the estimated <i>a</i> value ranged from 2.70 to 4.65, and the <i>b</i> value ranged from 0.64 to 0.85. The estimated seismicity parameters are used to estimate the return periods and probabilities of earthquakes with different magnitudes for each zones. From the probability curve, it is observed that the probability of earthquake occurrences decreases exponentially with magnitude. For all zones, a high probability of occurrence is observed for earthquake magnitude 6 both in 50 and 100 years. The return periods for different magnitudes estimated from the Zmap and Kijko methods are consistent with some variations among the six source zones. Zmap estimates were lower for smaller magnitudes and higher for larger magnitudes than the Kijko method. The difference factor varied depending on the source zone and magnitude. In general, Zmap estimates were lower by a factor of 1.0 to 1.34 for lower magnitudes and higher by a factor of 1.01 to 1.35 for higher magnitudes.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithofacies and microfacies and depositional environment model of the Cenozoic carbonate platform: an example from the Upper Jafnayn Formation of Jafnayn area in north-east Oman","authors":"Abdullah Al-Fahdi,&nbsp;Mohamed A. K. El-Ghali,&nbsp;AbdulRazak A-Sayigh,&nbsp;AbdulRahman Al-Harthi,&nbsp;Mohamed S. H. Moustafa","doi":"10.1007/s12517-024-12094-0","DOIUrl":"10.1007/s12517-024-12094-0","url":null,"abstract":"<div><p>This paper presents a comprehensive lithofacies and microfacies analysis of the exposed Cenozoic (Late Paleocene to Early Eocene) Upper Jafnayn Formation in the Jafnayn area, Northern Oman. The study meticulously documents the color, lithology, grain composition, bed thickness, types, and nature of bed contacts and fossil content of the formation. Over 85 fresh rock samples from various lithofacies were collected for this analysis. The samples were treated with blue epoxy, thin-sectioned, and half-stained with potassium ferricyanide and alizarin red to aid in mineralogical identification. To accurately determine microfacies, quantify components, reconstruct origins, and build a depositional model for the Upper Jafnayn Formation, 300 points were counted per thin section using a point-counting method. This analysis identified five distinct facies and 16 microfacies, with ten containing quartz grains and six lacking quartz sand. The microfacies provide insights into the depositional environments of the Upper Jafnayn Formation: four represent backshoal conditions, seven indicate shoal environments, three correspond to foreshoal settings, and two exhibit characteristics overlapping between backshoal and foreshoal environments. The presence of Alveolinid foraminifera, red algae, and occasional coarse coral debris within the cleaner limestone sections further characterizes the formation. The diverse lithofacies and microfacies of the Upper Jafnayn Formation reveal a dynamic interplay between high-energy and low-energy depositional environments, influenced by sea level fluctuations. This comprehensive understanding of the formation’s depositional history is crucial for research teams aiming to identify potential hydrocarbon traps and reservoirs in the region.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142672538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the effects of different layering characteristics on the response of semi-sine hills","authors":"Mohammad Hossein Nateqi,&nbsp;Masoud Amelsakhi,&nbsp;Morteza Nateqi","doi":"10.1007/s12517-024-12120-1","DOIUrl":"10.1007/s12517-024-12120-1","url":null,"abstract":"<div><p>Investigating the phenomenon of topographic amplification and the seismic response of the site is an important issue that has already attracted the attention of many researchers. The studies and researches conducted in the field of topographical effects and also the phenomenon of the amplification of earthquake waves in passing through surface layers have shown that topography has a great impact on the amount of damage caused by earthquakes. The local topographic characteristics amplify the strong movements of the ground during an earthquake and ultimately cause great damages. In this article, the effects of a site (take, for example, one of the most common topographical forms in nature, such as a semi-sinusoidal hill) on the seismic response of the earth’s surface subjected to vertically propagating shear vertical (SV) waves have been studied using FLAC 2D, a two-dimensional finite-difference program. In the numerical modeling, the elastic linear behavior has been used. In this regard, in order to investigate the effects of layering on the response of semi-sine hills, two-layered and three-layered hills with different layering characteristics and thicknesses are considered the basis of this article. In this research, the effect of soil characteristics, layering thickness, and the position of the loose layer has been investigated. From the obtained results, it can be concluded that the characteristics and thickness of the layering and the position of the loose layer have effects on the general trend of amplification on top of the hills and de-amplification near the toe of hills in response to horizontal motion for acceleration, velocity, and displacement components.</p></div>","PeriodicalId":476,"journal":{"name":"Arabian Journal of Geosciences","volume":"17 12","pages":""},"PeriodicalIF":1.827,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142664438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}