Geofluids最新文献

{"title":"Tracking Deep Meteoric Fluid Circulation Along a Regional Detachment Fault Using Field Infrared Spectroscopy","authors":"Tom Brikowski,&nbsp;Chinomso Madubuike,&nbsp;Jeremy McDowell,&nbsp;Greg Greywall","doi":"10.1155/2024/7784177","DOIUrl":"https://doi.org/10.1155/2024/7784177","url":null,"abstract":"<p>Abundant evidence exists for deep crustal penetration of meteoric fluids along faults, including emergence of hot, dilute, and isotopically light geothermal fluids in extensional settings; however, the nature of the fluid conduits supporting this rapid circulation from surface to the brittle-ductile transition and back remains mysterious. Metamorphic core complexes (MCCs) are the sites of rapid exhumation of rocks from that depth, and their associated detachment faults are known loci of fluid migration. This study utilizes spot infrared (IR) spectroscopy of drill core and outcrop to unravel the fluid history of the late-Neogene Silver Peak-Lone Mountain MCC and detachment fault (SPLMDF) in SW Nevada. That history begins with Mesozoic regional burial metamorphism of Paleozoic sediments, minor late Mesozoic contact metamorphism by silicic intrusives, followed by upwelling of hot metamorphic fluids after detachment initiation (11 MYA), later circulation of moderate-temperature meteoric-geothermal fluids, and young (&lt; 5 MYA) hot epithermal fluids upwelling along detachment-cutting normal faults. Each of these stages is characterized by distinct changes in sheet silicate mineral crystallinity and hydration. These are conveniently summarized by maturity indicators based on IR absorption peak ratios, for example, illite spectral maturity (ISM). Burial metamorphism up to greenschist facies is indicated by steadily increasing ISM versus depth in core from a detachment-penetrating geothermal exploration borehole. A sharp decrease in ISM characterizes the detachment damage zone, accompanied by reappearance of smectite, zeolite, and abundant iron oxides, indicating much cooler alteration by meteoric-origin fluids. Low-ISM zones are concentrated in the damage zone ± 10 m from the fault, resulting from an accumulation of very narrow alteration bands (10–50 cm wide). About 1/3 of the SPLMDF fault trace exhibits this low-temperature circulation. Another third of the trace is overprinted by postdetachment epithermal alteration with extreme ISM, often in zones extending along the detachment near cross-cutting normal faults.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/7784177","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967828","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Hydrogeological Characteristics on the Development of Underground Space Resources in Valley Cities","authors":"Lizhong Zhang,&nbsp;Linde Liang,&nbsp;Jixiang Zhu,&nbsp;Tao Gan,&nbsp;Yamin Yang,&nbsp;Dun Wang","doi":"10.1155/2024/1052700","DOIUrl":"https://doi.org/10.1155/2024/1052700","url":null,"abstract":"<p>The development of urban underground space is a crucial aspect of current urban development. However, various factors pose challenges during the development process. In particular, in the valley cities of western China, groundwater has a significant impact on the utilization of underground space. This study focuses on understanding the influence of hydrogeological characteristics on the development of underground space in Ledu District, Haidong. Firstly, the hydrogeological characteristics of the aquifer in the study area are analyzed to determine the recharge and discharge characteristics. The dynamic changes in the groundwater table over time are then examined. Subsequently, the hydrochemical characteristics of groundwater are investigated to expound on the influence mechanism of groundwater on the development of underground space resources in Ledu District. The study reveals that the hydrodynamic effect of groundwater in the study area is substantial and has a significant physical scouring effect on underground structures. The fluctuation of groundwater levels affects the stability of buildings by increasing groundwater buoyancy. Additionally, this fluctuation also leads to engineering and environmental problems such as differential settlement and land salinization. The chemical characteristics of groundwater primarily impact the stability of building foundations through the corrosive effects of groundwater composition. This research clarifies the influence mechanism of groundwater on the development of underground space in typical valley cities of western China. The findings have practical significance for the evaluation, planning, development, and utilization of urban underground space resources in Haidong.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/1052700","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141967432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Crushing Technique for Measuring δ18O and δ2H Values of Fluid Inclusions (H2O) in Quartz Mineral Veins Using Cavity Ring-Down Spectroscopy","authors":"Akbar Aydin Oglu Huseynov,&nbsp;H. J. L. van der Lubbe (Jeroen),&nbsp;S. J. A. Verdegaal-Warmerdam,&nbsp;Onno Postma,&nbsp;Julian Schröder,&nbsp;Hubert Vonhof","doi":"10.1155/2024/5795441","DOIUrl":"https://doi.org/10.1155/2024/5795441","url":null,"abstract":"<p>Fluid inclusions in mineralized fracture infillings (i.e., veins) could preserve information about subsurface fluids like temperature and salinity. The isotopic composition of water in these fluid inclusions could provide direct evidence of the provenance of these mineral-forming fluids. So far, the isotope compositions of fluid inclusions have been mainly derived from carbonate veins and other precipitates, like speleothems. The aim of this study is to analyse the <i>δ</i>¹⁸O and <i>δ</i>²H isotopic compositions of aqueous fluid inclusions of quartz veins using a cavity ring-down spectroscopy (CRDS) analyser in combination with a moisturized nitrogen background and mechanical crusher. For this study, we analysed <i>δ</i>¹⁸O and <i>δ</i>²H values of fluid inclusions in quartz veins from three north-western European locations formed during the Variscan orogeny. Prior to crushing, the fluid-rich quartz fraction was separated from the pure quartz fraction, from other mineral phases and host rock by using conventional heavy liquids and magnet separation. Raman spectrometry detected some rare occurrences of hydrocarbon, methane, and nitrogen in the fluid inclusions. The samples were sequentially crushed to elucidate the potential impact of different fluid inclusion assemblages (FIA) on the <i>δ</i>¹⁸O and <i>δ</i>²H values. The results from single and sequential mechanical crushing, together with interlaboratory comparisons, exhibit reliable and consistent isotopic patterns across locations with high precision (for <i>δ</i>¹⁸O: 1<i>σ</i> SD &lt; 0.8<i>‰</i>; for <i>δ</i>²H: 1<i>σ</i> SD &lt; 1.5<i>‰</i>). The obtained data occur in three different clusters for three study zones, providing evidence for the presence of meteoric-derived fluids in the fold-and-thrust belts of the Variscan orogeny. These findings demonstrate that the CRDS approach can be successfully applied to quartz minerals, investigating fluid pathways within the upper crust and the formation of these secondary minerals.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/5795441","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141639569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Division and Effect Evaluation of Fracking Outburst Elimination Zones in Surface Extraction Wells of Coalbed Methane","authors":"Jianbao Liu,&nbsp;Zhimin Song,&nbsp;Bing Li,&nbsp;Jiangang Ren,&nbsp;Hongyan Zhang,&nbsp;Nuo Cheng","doi":"10.1155/2024/9813381","DOIUrl":"https://doi.org/10.1155/2024/9813381","url":null,"abstract":"<p>Surface hydraulic fracturing is an important measure for increasing reservoir permeability, which has advantages such as engineering safety and a large impact range and can be implemented ahead of the mine’s underground engineering. However, its underground outburst reduction range and effect are rarely reported, and there is a lack of connection with underground fracturing wells. Taking coalbed methane wells in the Lu’an Mining Area as an example, underground observation, microseismic monitoring, and numerical simulation methods were used to study the fracturing range and outburst control effect of surface wells. The fracturing zone of coalbed methane wells is approximately elliptical in shape, with the main fractures extending along the direction of the maximum horizontal principal stress. It can be divided into five zones: sand laying zone (radius of 140~150 m), fracture propagation zone (radius of about 180 m), fracturing fluid permeability zone (width of about 1 m), gas surge zone (width of 2~3 m), and final desorption zone (width of about 2 m). The stress around the fracturing zone increases along the direction of maximum and minimum principal stresses, while the stress value within the zone decreases, with a range of approximately 5~20% of the original geostress. The outburst reduction index <i>Δ</i><i>h</i>₂ in the fracturing zone significantly decreased after fracturing. The percent of <i>Δ</i><i>h</i>₂ (&lt; 150 Pa) increased from 38.3% to 100% after fracturing. A model for evaluating the effectiveness of surface fracturing and outburst prevention was proposed, and the model was used in Tunliu Mine. The results showed that the standard-reaching rate of extraction was high, and the danger of outburst could be completely eliminated. The research results can provide a reference for the arrangement of the coalbed methane wells and can also provide effective guidance for outburst prevention and control work during mining and excavation on a more macro scale. It provides a new idea and method for making up for the shortcomings such as the small impact range and safety hazards of underground fracturing.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/9813381","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of the Location of Concealed Pluton on the Spatial Variation Characteristics of Volatile Matter in Coal Seams","authors":"Yihao Li,&nbsp;Jingui Zhao,&nbsp;Wensheng Li","doi":"10.1155/2024/9455853","DOIUrl":"https://doi.org/10.1155/2024/9455853","url":null,"abstract":"<p>The lower the volatile value of coal, the higher the metamorphic degree of coal. As a vector, the spatial variation of the volatilization value of the coal seam be used to explore the location of concealed pluton and to characterize the maximum influence intensity of the magma thermal field. The eastern side of the Huyanshan intrusive pluton has amassed a large amount of C-P coal measurement and coal quality exploration data. The zonation distribution of coal seam volatile fraction data within the exploration area serves as an efficacious record of the intrusion process of the rock mass and a valuable resource for the exploration of the location of concealed plutons. Based on the data from 470 boreholes in the exploration area, contour maps of coal seams No. 02, No. 2, No. 6, No. 8, and No. 9; the true thickness contour maps of each coal layer; and the volatilizing profile map were created. The results indicate the following: (1) In the central region of the exploration area, from No. 9 to No. 8 to No. 6 to No. 2 to No. 02, the contours of volatiles in each coal seam exhibit a ring pattern, with the size of the ring and the size of the volatiles change regularly. This pattern strongly suggests that the concealed pluton is developed in the underlying layer of the coal seam. (2) According to the linear fitting of the relevant data, it is predicted that the concealed pluton is located at a depth of 65.4 m below the No. 9 coal seam. At a vertical distance of 159.1 m, the thermal field influence of the concealed pluton is lost, which aligns with the spatial distribution characteristics of volatiles in the coal seam as observed through drilling. (3) The occurrence of a significant interlayer slip between coal seam No. 6 and coal seam No. 2 in the overlying concealed pluton is indicated by the results of the hotspot migration analysis. The results are helpful to the search for magmatic-hydrothermal deposits and the exploration and development of coal and coalbed methane.</p>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2024-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/9455853","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and Antifiltration Performance of Organic Zirconium Crosslinker for Guar Gum-Fracturing Fluid","authors":"Yirong Chen,&nbsp;Yufang Wang,&nbsp;Wei Wei,&nbsp;Jiahui He","doi":"10.1155/2024/1364778","DOIUrl":"https://doi.org/10.1155/2024/1364778","url":null,"abstract":"<div>\u0000 <p>Aiming at the characteristics of low shear resistance and high filtration loss of guar gum-fracturing fluid, a high-efficiency organic zirconium crosslinker was prepared. In addition, the effects of different factors on the filtration coefficient and apparent viscosity of fracturing fluid were studied, and this study explores the micro mechanisms of various factors affecting the filtration coefficient from a molecular dynamics perspective. The results show that the antifiltration ability of guar gum-fracturing fluid is inversely proportional to the fluid viscosity. The increase of crosslinker content and reservoir pressure is beneficial to improve the viscosity and antishear ability of guar gum-fracturing fluid. When the crosslinker content is 0.25% and pressure is 30 MPa, the fracturing fluid parameters are 145 mPa·s and 2.1 × 10⁻² m³ · min^1/2, respectively, while the increase of reservoir temperature and the shear rate reduces the rheology and shear resistance of guar gum-fracturing fluid, so that the viscosity and filtration coefficient of fracturing fluid at 180°C and 200 s^-1 are 123 mPa·s and 2.3 × 10^-2 m³·min^1/2, respectively. This work not only paves a new avenue for synthesizing organic zirconium as a crosslinker but also provides an efficient measure to reduce the filtration of guar gum-fracturing fluid on the oil and gas reservoirs.</p>\u0000 </div>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/1364778","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141424812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study on the Evolution of Fracture Aperture of Single-Fracture Granite during Liquid Nitrogen Cold Shock Cycling","authors":"Haiping Niu,&nbsp;Weidong Yu","doi":"10.1155/2024/4023295","DOIUrl":"https://doi.org/10.1155/2024/4023295","url":null,"abstract":"<div>\u0000 <p>Fractures in hot dry rock (HDR) reservoirs are the locations where heating fluid flows exchange heat with the HDR matrix. Cold shock with liquid nitrogen is one method for stimulating cracks. This study investigates the evolution law of fracture aperture under cold shock with liquid nitrogen. The real-time high-temperature triaxial servo control rock testing machine was used to conduct permeability experiments to examine the fracture aperture of single-fracture granite during liquid nitrogen shock cycles at various temperatures. The effects of pore pressure, temperature, and shocking cycles on the fracture aperture are analyzed, and the difference in fracture aperture variation under liquid nitrogen cooling and natural cooling modes is compared. The results showed that (1) during liquid nitrogen cooling, the fracture aperture expands as pore pressure rises; the effect of pore pressure on the fracture aperture becomes more robust as the number of liquid nitrogen shocking cycles and initial temperature increases; (2) under 1-2 soaking cycles, fracture aperture decreases as the temperature rises. Under two or more soaking cycles, the fracture aperture first increases and then decreases with increasing temperature; (3) when the initial temperature of fractured granite is 100°C, the fracture aperture is not significantly changed by repeated cold soaking cycles. However, with a higher initial temperature, the fracture aperture develops with more liquid nitrogen cold soaking cycles. The liquid nitrogen cooling method is more conducive to increasing the fracture aperture than natural cooling. The experimental results can provide primary experimental data for future research into controlling the evolution of granite cracks.</p>\u0000 </div>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/4023295","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141298850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multistage Gold-Polymetallic Mineralization in the Bou Azzer District, Anti-Atlas, Morocco: Insights from Ore Microscopic, Geochemical, and Fluid Inclusion Studies","authors":"Amina Wafik,&nbsp;Basem Zoheir,&nbsp;Fouad Benchekroun,&nbsp;Rachid Benaouda,&nbsp;Mohamed Ben Massoude,&nbsp;Youssef Atif,&nbsp;Amin Beiranvand Pour,&nbsp;Shojaeddin Niroomand,&nbsp;Amal El Arbaoui,&nbsp;Abdelhak Karfal,&nbsp;Lhou Maacha","doi":"10.1155/2024/5579902","DOIUrl":"https://doi.org/10.1155/2024/5579902","url":null,"abstract":"<div>\u0000 <p>The Bou Azzer polymetallic Co-Ni-As±Au±Ag veins in the Central Anti-Atlas (Morocco) are significant sulfide ores hosted by Neoproterozoic ophiolites and are associated with felsic intrusive and subvolcanic phases. We report new mineralogical and fluid inclusion data to better understand mineralization’s formation processes and fluid evolution which are analyzed and merged with the existing published data. Gold-bearing sulfide-arsenide-quartz (±carbonate) veins in Bou Azzer exhibit mineralogical and fluid inclusion features similar to the epithermal and porphyry-style gold deposits. Modeling of widespread primary and pseudosecondary saline aqueous inclusions in the mineralized quartz veins suggests that circulating metalliferous brines, with estimated temperatures of ~275°C and pressures &lt; 550 bars and salinity &lt; 40<i>%</i>, precipitated sulfides in the veins. Gold was most likely transported as bisulfide complexes, and ore deposition was controlled by fluctuations in oxygen fugacity (<i>ƒ</i>O₂) upon fluid cooling. The systematic decrease in temperatures and salinities from an early prearsenide stage to a late paragenetic arsenide and sulfide stage was likely linked with extensive mixing with meteoric waters in a shallow hydrothermal environment. Available sulfur, oxygen, and hydrogen stable isotope data for the Bou Azzer sulfide-arsenide-quartz veins indicate variable fluid sources, primarily magmatic and metamorphic fluids. The wide range of the estimated mineralization ages (from 680 Ma to 210 Ma) and the spatial association with major shear zones and felsic intrusive stocks imply a significant role of the regional tectonic activities or reflect complex and superimposed mineralization episodes, corresponding to orogenic events spanned the Pan-African cycle to the Atlasic orogenesis.</p>\u0000 </div>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/5579902","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141264631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the Diffusion Law of Fluidized Filling Gangue Slurry in Goaf of Coal Mine Underground","authors":"Baoning Wei,&nbsp;Qingxiang Huang,&nbsp;Dengdeng Zhuang,&nbsp;Xin Cao,&nbsp;Bo Hui,&nbsp;Xiao Zuo,&nbsp;Mengbo Zhu","doi":"10.1155/2024/9925765","DOIUrl":"https://doi.org/10.1155/2024/9925765","url":null,"abstract":"<div>\u0000 <p>In response to the challenge posed by the limited capacity of postmining paste and original waste filling mining technology for small-scale waste rock treatment, which is incompatible with the requirements of modern high-yield mines producing millions of tons, fluidized filling mining technology in goaf presents a sustainable and environmentally friendly solution. This innovative method effectively addresses the balance between mining and filling operations while enabling large-scale waste rock management in coal mines. This article presents a model for predicting the spatial morphology of goaf and employs theoretical calculations to determine the residual space left after goaf caving. It unveils the fluidization filling approach for goaf caving, utilizing a “high- and low-level collaborative filling” strategy and taking advantage of various types of residual spaces within cavities and voids. Experimental investigations into gangue slurry diffusion in the goaf reveal insights into its diffusion patterns along three directions: horizontal, inclined, and vertical. The analysis also establishes correlations between porosity, space utilization rate, and the Talbol index. Furthermore, the research identifies the flow characteristics of fluidized filling slurry as consistent with the Bingham fluid behavior. A calculation formula for determining the diffusion radius of the filling slurry within cracks is provided. The study highlights four distinct flow stages in the process: stable laminar diffusion, transition from advection to turbulence, turbulence, and stoppage. To validate these findings, COMSOL simulation software is employed to simulate and analyze the diffusion patterns of gangue slurry within the goaf. The research outcomes offer valuable theoretical insights into the postgangue fluidization goaf filling technology and serve as a technical reference for the design of coal-based solid waste fluidization filling processes.</p>\u0000 </div>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/9925765","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141264632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fine Characterization of Nonmain Oil Layer Distributions in Complex Fault Block Oilfield and Its Development Model","authors":"Lei Xu,&nbsp;Xiutian Yao,&nbsp;Sen Yan,&nbsp;Zhang Wen,&nbsp;Jimei Xue","doi":"10.1155/2024/2183265","DOIUrl":"10.1155/2024/2183265","url":null,"abstract":"<div>\u0000 <p>Improving the oil production from nonmain oil layers is crucial for the complex fault block oilfields during the late stage of high water cut development to ensure stable production and capacity expansion. However, the developing characterization of the nonmain layers and their remaining oil distribution is still inadequate. Developing an efficient mode of development remains a challenge. This paper presents a detailed characterization of the sedimentary microfacies and architecture of a nonmain reservoir based on core and logging data analysis. A flexible injection-production development strategy model was designed and applied in the Hetan oilfield, located in the southeast of Zhanhua Depression of Bohai Bay Basin as an example. The results show that the nonmain oil layer of the Hetan oilfield is composed of estuary bar microfacies sand bodies. Deposits of various shapes are formed on the side or in front of the main body of the estuary dam, which constitutes the nonmain oil reservoir. The lithology is fine, the sand body thickness is small, and the plane heterogeneity is strong. The distribution is banded, potato-shaped, and fragmented. The nonmain oil layer has a small oil-bearing area of 0.1-1.0 km² and a high oil saturation of over 58%. The Hetan oilfield has a significant amount of remaining oil enrichment and considerable potential for production digging. To optimize production, a flexible injection and production adjustment scheme is proposed, which includes designing multitarget horizontal wells and utilizing various methods such as optimizing well spacing, coupled injection, and cycle injection. Field tests conducted in the area have shown an increase in the recovery factor of nonmain oil layers from 16.7% to 28.5%. This indicates that identifying and characterizing nonmain oil layers through detailed analysis of sedimentary microfacies and reservoir architecture is useful in the late-stage development of complex fault block reservoirs to maintain sustainable and efficient oilfield development.</p>\u0000 </div>","PeriodicalId":12512,"journal":{"name":"Geofluids","volume":"2024 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1155/2024/2183265","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141188557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}