Petroleum Exploration and Development最新文献

{"title":"Igneous intrusion contact metamorphic system and its reservoir characteristics: A case study of Paleogene Shahejie Formation in Nanpu sag of Bohai Bay Basin, China","authors":"Wenke LI,&nbsp;Xiaozhou WU,&nbsp;Yandong LI,&nbsp;Yan ZHANG,&nbsp;Xin ZHANG,&nbsp;Hai WANG","doi":"10.1016/S1876-3804(24)60026-1","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60026-1","url":null,"abstract":"<div><p>Taking the Paleogene Shahejie Formation in Nanpu sag of Bohai Bay Basin as an example, this study comprehensively utilizes seismic, mud logging, well logging, physical property analysis and core thin section data to investigate the metamorphic reservoir formed by contact metamorphism after igneous rock intrusion. (1) A geological model of the igneous intrusion contact metamorphic system is proposed, which can be divided into five structural layers vertically: the intrusion, upper metamorphic aureole, lower metamorphic aureole, normal sedimentary layers on the roof and floor. (2) The intrusion is characterized by xenoliths indicating intrusive facies at the top, regular changes in rock texture and mineral crystallization from the center to the edge on a microscopic scale, and low-angle oblique penetrations of the intrusion through sedimentary strata on a macroscopic scale. The metamorphic aureole has characteristics such as sedimentary rocks as the host rock, typical palimpsest textures developed, various low-temperature thermal metamorphic minerals developed, and medium-low grade thermal metamorphic rocks as the lithology. (3) The reservoir in contact metamorphic aureole has two types of reservoir spaces: matrix pores and fractures. The matrix pores are secondary “intergranular pores” distributed around metamorphic minerals after thermal metamorphic transformation in metasandstones. The fractures are mainly structural fractures and intrusive compressive fractures in metamudstones. The reservoirs generally have three spatial distribution characteristics: layered, porphyritic and hydrocarbon impregnation along fracture. (4) The distribution of reservoirs in the metamorphic aureole is mainly controlled by the intensity of thermal baking. Furthermore, the distribution of favorable reservoirs is controlled by the coupling of favorable lithofacies and thermal contact metamorphism, intrusive compression and hydrothermal dissolution. The proposal and application of the geological model of the intrusion contact metamorphic system are expected to promote the discovery of exploration targets of contact metamorphic rock in Nanpu sag, and provide a reference for the study and exploration of deep contact metamorphic rock reservoirs in the Bohai Bay Basin.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 320-336"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600261/pdf?md5=f7e4885b8d2e8309b299edfa86d1fb7a&pid=1-s2.0-S1876380424600261-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Types, composition and diagenetic evolution of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata: A case study of Mao-1 Member of Middle Permian Maokou Formation, eastern Sichuan Basin, SW China","authors":"Jinmin SONG ,&nbsp;Jiarui WANG ,&nbsp;Shugen LIU ,&nbsp;Zhiwu LI ,&nbsp;Ping LUO ,&nbsp;Qingchun JIANG ,&nbsp;Xin JIN ,&nbsp;Di YANG ,&nbsp;Shipeng HUANG ,&nbsp;Jianping FAN ,&nbsp;Yuehao YE ,&nbsp;Junke WANG ,&nbsp;Haoshuang DENG ,&nbsp;Bin WANG ,&nbsp;Jiaxin GUO","doi":"10.1016/S1876-3804(24)60028-5","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60028-5","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The types, occurrence and composition of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata of the first member of the Middle Permian Maokou Formation (Mao-1 Member) in eastern Sichuan Basin were investigated through outcrop section measurement, core observation, thin section identification, argon ion polishing, X-ray diffraction, scanning electron microscope, energy spectrum analysis and laser ablation-inductively coupled plasma-mass spectrometry. The diagenetic evolution sequence of clay minerals was clarified, and the sedimentary-diagenetic evolution model of clay minerals was established. The results show that authigenic sepiolite minerals were precipitated in the Si&lt;sup&gt;4+&lt;/sup&gt; and Mg&lt;sup&gt;2+&lt;/sup&gt;-rich cool aragonite sea and sepiolite-bearing strata were formed in the Mao-1 Member. During burial diagenesis, authigenic clay minerals undergo two possible evolution sequences. First, from the early diagenetic stage A to the middle diagenetic stage A&lt;sub&gt;1&lt;/sub&gt;, the sepiolite kept stable in the shallow-buried environment lack of Al&lt;sup&gt;3+&lt;/sup&gt;. It began to transform into stevensite in the middle diagenetic stage A&lt;sub&gt;2&lt;/sub&gt;, and then evolved into disordered talc in the middle diagenetic stage B&lt;sub&gt;1&lt;/sub&gt; and finally into talc in the period from the middle diagenetic stage B&lt;sub&gt;2&lt;/sub&gt; to the late diagenetic stage. Thus, the primary diagenetic evolution sequence of authigenic clay minerals, i.e. sepiolite–stevensite–disordered talc–talc, was formed in the Mao-1 Member. Second, in the early diagenetic stage A, as Al&lt;sup&gt;3+&lt;/sup&gt; carried by the storm and upwelling currents was involved in the diagenetic process, trace of sepiolite started to evolve into smectite, and a part of smectite turned into chlorite. From the early diagenetic stage B to the middle diagenesis stage A&lt;sub&gt;1&lt;/sub&gt;, a part of smectite evolved to illite/smectite mixed layer (I/S). The I/S evolved initially into illite from the middle diagenesis stage A&lt;sub&gt;2&lt;/sub&gt; to the middle diagenesis stage B&lt;sub&gt;2&lt;/sub&gt;, and then totally into illite in the late diagenesis stage. Thus, the secondary diagenetic evolution sequence of authigenic clay minerals, i.e. sepiolite–smectite–chlorite/illite, was formed in the Mao-1 Member. The types and evolution of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata are significant for petroleum geology in two aspects. First, sepiolite can adsorb and accumulate a large amount of organic matters, thereby effectively improving the quality and hydrocarbon generation potential of the source rocks of the Mao-1 Member. Second, the evolution from sepiolite to talc is accompanied by the formation of numerous organic matter pores and clay shrinkage pores/fractures, as well as the releasing of the Mg&lt;sup&gt;2+&lt;/sup&gt;-rich diagenetic fluid, which allows for the dolomitization of limestone within or around the sag. As a result, the new assemblages of self-generation and self-accumulation, and lower/","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 351-363"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600285/pdf?md5=00cecc328fe9e197b2dffc7aa52d9f71&pid=1-s2.0-S1876380424600285-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formation damage mechanism and control strategy of the compound function of drilling fluid and fracturing fluid in shale reservoirs","authors":"Jinsheng SUN ,&nbsp;Chengyuan XU ,&nbsp;Yili KANG ,&nbsp;Haoran JING ,&nbsp;Jie ZHANG ,&nbsp;Bin YANG ,&nbsp;Lijun YOU ,&nbsp;Hanshi ZHANG ,&nbsp;Yifu LONG","doi":"10.1016/S1876-3804(24)60034-0","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60034-0","url":null,"abstract":"<div><p>For the analysis of the formation damage caused by the compound function of drilling fluid and fracturing fluid, the prediction method for dynamic invasion depth of drilling fluid is developed considering the fracture extension due to shale minerals erosion by oil-based drilling fluid. With the evaluation for the damage of natural and hydraulic fractures caused by mechanical properties weakening of shale fracture surface, fracture closure and rock powder blocking, the formation damage pattern is proposed with consideration of the compound effect of drilling fluid and fracturing fluid. The formation damage mechanism during drilling and completion process in shale reservoir is revealed, and the protection measures are raised. The drilling fluid can deeply invade into the shale formation through natural and induced fractures, erode shale minerals and weaken the mechanical properties of shale during the drilling process. In the process of hydraulic fracturing, the compound effect of drilling fluid and fracturing fluid further weakens the mechanical properties of shale, results in fracture closure and rock powder shedding, and thus induces stress-sensitive damage and solid blocking damage of natural/hydraulic fractures. The damage can yield significant conductivity decrease of fractures, and restrict the high and stable production of shale oil and gas wells. The measures of anti-collapse and anti-blocking to accelerate the drilling of reservoir section, forming chemical membrane to prevent the weakening of the mechanical properties of shale fracture surface, strengthening the plugging of shale fracture and reducing the invasion range of drilling fluid, optimizing fracturing fluid system to protect fracture conductivity are put forward for reservoir protection.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 430-439"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600340/pdf?md5=daed80384c78d2a7380a7e063f26ab24&pid=1-s2.0-S1876380424600340-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme massive hydraulic fracturing in deep coalbed methane horizontal wells: A case study of the Linxing Block, eastern Ordos Basin, NW China","authors":"Fan YANG ,&nbsp;Bin LI ,&nbsp;Kunjian WANG ,&nbsp;Heng WEN ,&nbsp;Ruiyue YANG ,&nbsp;Zhongwei HUANG","doi":"10.1016/S1876-3804(24)60035-2","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60035-2","url":null,"abstract":"<div><p>Deep coal seams show low permeability, low elastic modulus, high Poisson’s ratio, strong plasticity, high fracture initiation pressure, difficulty in fracture extension, and difficulty in proppants addition. We proposed the concept of large-scale stimulation by fracture network, balanced propagation and effective support of fracture network in fracturing design and developed the extreme massive hydraulic fracturing technique for deep coalbed methane (CBM) horizontal wells. This technique involves massive injection with high pumping rate + high-intensity proppant injection + perforation with equal apertures and limited flow + temporary plugging and diverting fractures + slick water with integrated variable viscosity + graded proppants with multiple sizes. The technique was applied in the pioneering test of a multi-stage fracturing horizontal well in deep CBM of Linxing Block, eastern margin of the Ordos Basin. The injection flow rate is 18 m³/min, proppant intensity is 2.1 m³/m, and fracturing fluid intensity is 16.5 m³/m. After fracturing, a complex fracture network was formed, with an average fracture length of 205 m. The stimulated reservoir volume was 1 987×10⁴ m³, and the peak gas production rate reached 6.0×10⁴ m³/d, which achieved efficient development of deep CBM.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 440-452"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600352/pdf?md5=cac41c3ef217616cec053b6e456fbe15&pid=1-s2.0-S1876380424600352-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological characteristics and exploration breakthroughs of coal rock gas in Carboniferous Benxi Formation, Ordos Basin, NW China","authors":"Zhe ZHAO ,&nbsp;Wanglin XU ,&nbsp;Zhenyu ZHAO ,&nbsp;Shiwei YI ,&nbsp;Wei YANG ,&nbsp;Yueqiao ZHANG ,&nbsp;Yuanshi SUN ,&nbsp;Weibo ZHAO ,&nbsp;Yunhe SHI ,&nbsp;Chunlin ZHANG ,&nbsp;Jianrong GAO","doi":"10.1016/S1876-3804(24)60022-4","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60022-4","url":null,"abstract":"&lt;div&gt;&lt;p&gt;To explore the geological characteristics and exploration potential of the Carboniferous Benxi Formation coal rock gas in the Ordos Basin, this paper presents a systematic research on the coal rock distribution, coal rock reservoirs, coal rock quality, and coal rock gas features, resources and enrichment. Coal rock gas is a high-quality resource distinct from coalbed methane, and it has unique features in terms of burial depth, gas source, reservoir, gas content, and carbon isotopic composition. The Benxi Formation coal rocks cover an area of 16×10&lt;sup&gt;4&lt;/sup&gt; km², with thicknesses ranging from 2 m to 25 m, primarily consisting of bright and semi-bright coals with primitive structures and low volatile and ash contents, indicating a good coal quality. The medium-to-high rank coal rocks have the total organic carbon (TOC) content ranging from 33.49% to 86.11%, averaging 75.16%. They have a high degree of thermal evolution (&lt;em&gt;R&lt;/em&gt;&lt;sub&gt;o&lt;/sub&gt; of 1.2%–2.8%), and a high gas-generating capacity. They also have high stable carbon isotopic values (&lt;em&gt;δ&lt;/em&gt;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;1&lt;/sub&gt; of –37.6‰ to –16‰; &lt;em&gt;δ&lt;/em&gt;&lt;sup&gt;13&lt;/sup&gt;C&lt;sub&gt;2&lt;/sub&gt; of –21.7‰ to –14.3‰). Deep coal rocks develop matrix pores such as gas bubble pores, organic pores, and inorganic mineral pores, which, together with cleats and fractures, form good reservoir spaces. The coal rock reservoirs exhibit the porosity of 0.54%–10.67% (averaging 5.42%) and the permeability of (0.001–14.600)×10&lt;sup&gt;−3&lt;/sup&gt; μm&lt;sup&gt;2&lt;/sup&gt; (averaging 2.32×10&lt;sup&gt;−3&lt;/sup&gt; μm&lt;sup&gt;2&lt;/sup&gt;). Vertically, there are five types of coal rock gas accumulation and dissipation combinations, among which the coal rock-mudstone gas accumulation combination and the coal rock-limestone gas accumulation combination are the most important, with good sealing conditions and high peak values of total hydrocarbon in gas logging. A model of coal rock gas accumulation has been constructed, which includes widespread distribution of medium-to-high rank coal rocks continually generating gas, matrix pores and cleats/fractures in coal rocks acting as large-scale reservoir spaces, tight cap rocks providing sealing, source-reservoir integration, and five types of efficient enrichment patterns (lateral pinchout complex, lenses, low-amplitude structures, nose-like structures, and lithologically self-sealing). According to the geological characteristics of coal rock gas, the Benxi Formation is divided into 8 plays, and the estimated coal rock gas resources with a buried depth of more than 2 000 m are more than 12.33×10&lt;sup&gt;12&lt;/sup&gt; m&lt;sup&gt;3&lt;/sup&gt;. The above understandings guide the deployment of risk exploration. Two wells drilled accordingly obtained an industrial gas flow, driving the further deployment of exploratory and appraisal wells. Substantial breakthroughs have been achieved, with the possible reserves over a trillion cubic meters and the proved reserves over a hundred billion cubic meters, which is of great significance for ","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 262-278"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600224/pdf?md5=960223c0f39abac836cc4b34031678bf&pid=1-s2.0-S1876380424600224-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experiment of dynamic seepage of tight/shale oil under matrix fracture coupling","authors":"Meng DU ,&nbsp;Zhengming YANG ,&nbsp;Weifeng LYU ,&nbsp;Zhongcheng LI ,&nbsp;Guofeng WANG ,&nbsp;Xinliang CHEN ,&nbsp;Xiang QI ,&nbsp;Lanlan YAO ,&nbsp;Yuhao ZHANG ,&nbsp;Ninghong JIA ,&nbsp;Haibo LI ,&nbsp;Yilin CHANG ,&nbsp;Xu HUO","doi":"10.1016/S1876-3804(24)60032-7","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60032-7","url":null,"abstract":"<div><p>A physical simulation method with a combination of dynamic displacement and imbibition was established by integrating nuclear magnetic resonance (NMR) and CT scanning. The microscopic production mechanism of tight/shale oil in pore throat by dynamic imbibition and the influencing factors on the development effect of dynamic imbibition were analyzed. The dynamic seepage process of fracking–soaking–backflow–production integration was simulated, which reveals the dynamic production characteristics at different development stages and their contribution to enhancing oil recovery (EOR). The seepage of tight/shale reservoirs can be divided into three stages: strong displacement and weak imbibition as oil produced rapidly by displacement from macropores and fractures, weak displacement and strong imbibition as oil produced slowly by reverse imbibition from small pores, and weak displacement and weak imbibition at dynamic equilibrium. The greater displacement pressure results in the higher displacement recovery and the lower imbibition recovery. However, if the displacement pressure is too high, the injected water is easy to break through the front and reduce the recovery degree. The higher the permeability, the greater the imbibition and displacement recovery, the shorter the time of imbibition balance, and the higher the final recovery. The fractures can effectively increase the imbibition contact area between matrix and water, reduce the oil-water seepage resistance, promote the oil-water displacement between matrix and fracture, and improve the oil displacement rate and recovery of the matrix. The soaking after fracturing is beneficial to the imbibition replacement and energy storage of the fluid; also, the effective use of the carrying of the backflow fluid and the displacement in the mining stage is the key to enhancing oil recovery.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 403-415"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600327/pdf?md5=0defe36681387b6c6dc34bdfe45ca8b0&pid=1-s2.0-S1876380424600327-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development, challenges and strategies of natural gas industry under carbon neutral target in China","authors":"Caineng ZOU ,&nbsp;Minjie LIN ,&nbsp;Feng MA ,&nbsp;Hanlin LIU ,&nbsp;Zhi YANG ,&nbsp;Guosheng ZHANG ,&nbsp;Yichao YANG ,&nbsp;Chunxiao GUAN ,&nbsp;Yingbo LIANG ,&nbsp;Ying WANG ,&nbsp;Bo XIONG ,&nbsp;Hao YU ,&nbsp;Ping YU","doi":"10.1016/S1876-3804(24)60038-8","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60038-8","url":null,"abstract":"<div><p>In the mid-21st century, natural gas will enter its golden age, and the era of natural gas is arriving. This paper reviews the development stages of global natural gas industry and the enlightenment of American shale gas revolution, summarizes the development history and achievements of the natural gas industry in China, analyzes the status and challenges of natural gas in the green and low-carbon energy transition, and puts forward the natural gas industry development strategies under carbon neutral target in China. The natural gas industry in China has experienced three periods: start, growth, and leap forward. At present, China has become the fourth largest natural gas producer and third largest natural gas consumer in the world, and has made great achievements in natural gas exploration and development theory and technology, providing important support for the growth of production and reserves. China has set its goal of carbon neutrality to promote green and sustainable development, which brings opportunities and challenges for natural gas industry. Natural gas has significant low-carbon advantages, and gas-electric peak shaving boosts new energy development; the difficulty and cost of development are more prominent. For the national energy security and harmonious development between economy and ecology under the carbon neutral goal, based on the principle of “comprehensive planning, technological innovation, multi-energy complementarity, diversified integration, flexibility and efficiency, optimization and upgrading”, the construction of the production-supply- storage-marketing system has to be improved so as to boost the development of the natural gas industry. First, it is necessary to strengthen efforts in the exploration and development of natural gas, making projects and arrangement in key exploration and development areas, meanwhile, it is urgent to make breakthroughs in key science theories and technologies, so as to increase reserve and production. Second, it should promote green and innovative development of the natural gas by developing new techniques, expanding new fields and integrating with new energy. Third, there is a demand to realize transformation and upgrading of the supply and demand structure of natural gas by strengthening the layout of pipeline gas, liquefied natural gas and the construction of underground gas storage, establishing reserve system for improving abilities of emergency response and adjustment, raising the proportion of natural gas in the primary energy consumption and contributing to the transformation of energy consumption structure, realizing low-carbon resources utilization and clean energy consumption.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 476-497"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600388/pdf?md5=343b802a2db05113ac0a5f0ec44db14c&pid=1-s2.0-S1876380424600388-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing of natural gas migration by light hydrocarbons: A case study of the Dongsheng gas field in the Ordos Basin, NW China","authors":"Xiaoqi WU ,&nbsp;Chunhua NI ,&nbsp;Liangbang MA ,&nbsp;Fubin WANG ,&nbsp;Huichong JIA ,&nbsp;Ping WANG","doi":"10.1016/S1876-3804(24)60025-X","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60025-X","url":null,"abstract":"<div><p>Based on the analysis of light hydrocarbon compositions of natural gas and regional comparison in combination with the chemical components and carbon isotopic compositions of methane, the indication of geochemical characteristics of light hydrocarbons on the migration features, dissolution and escape of natural gas from the Dongsheng gas field in the Ordos Basin is revealed, and the effect of migration on specific light hydrocarbon indexes is further discussed. The study indicates that, natural gas from the Lower Shihezi Formation (P₁x) in the Dongsheng gas field displays higher iso-C₅₋₇ contents than n-C₅₋₇ contents, and the C₆₋₇ light hydrocarbons are composed of paraffins with extremely low aromatic contents (&lt;0.4%), whereas the C₇ light hydrocarbons are dominated by methylcyclohexane, suggesting the characteristics of coal-derived gas with the influence by secondary alterations such as dissolution. The natural gas from the Dongsheng gas field has experienced free-phase migration from south to north and different degrees of dissolution after charging, and the gas in the Shiguhao area to the north of the Borjianghaizi fault has experienced apparent diffusion loss after accumulation. Long-distance migration in free phase results in the decrease of the relative contents of the methylcyclohexane in C₇ light hydrocarbons and the toluene/n-heptane ratio, as well as the increase of the n-heptane/methylcyclohexane ratio and heptane values. The dissolution causes the increase of isoheptane values of the light hydrocarbons, whereas the diffusion loss of natural gas in the Shiguhao area results in the increase of n-C₅₋₇ contents compared to the iso-C₅₋₇ contents.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 307-319"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S187638042460025X/pdf?md5=a22c98c0d78674d08e4e91c322f3e982&pid=1-s2.0-S187638042460025X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discovery and petroleum geological significance of delta in the third member of Oligocene Lingshui Formation in southern Baodao Sag, Qiongdongnan Basin, South China Sea","authors":"Jianxiang PEI,&nbsp;Wei LUO,&nbsp;Shiyang GUO,&nbsp;Lu LIN,&nbsp;Keliang LI","doi":"10.1016/S1876-3804(24)60027-3","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60027-3","url":null,"abstract":"<div><p>Based on the 3D seismic data and the analysis and test data of lithology, electricity, thin sections and chronology obtained from drilling of the Qiongdongnan Basin, the characteristics and the quantitative analysis of the source-sink system are studied of the third member of the Upper Oligocene Lingshui Formation (Ling 3 Member) in the southern fault step zone of the Baodao Sag. First, the YL10 denudation area of the Ling 3 Member mainly developed two fluvial systems in the east and west, resulting in the formation of two dominant sand transport channels and two delta lobes in southern Baodao Sag, which are generally large in the west and small in the east. The evolution of the delta has experienced four stages: initiation, prosperity, intermittence and rejuvenation. Second, the source-sink coupled quantitative calculation is performed depending on the parameters of the delta sand bodies, including development phases, distribution area, flattening thickness, area of different parent rocks, and sand-forming coefficient, showing that the study area has the material basis for the formation of large-scale reservoir. Third, the drilling reveals that the delta of the Ling 3 Member is dominated by fine sandstone, with total sandstone thickness of 109–138 m, maximum single-layer sandstone thickness of 15.5–30.0 m, and sand-to-strata ratio of 43.7%–73.0%, but the physical properties are different among the fault steps. Fourth, the large delta development model of the small source area in the step fault zone with multi-stage uplift is established. It suggests that the episodic uplift provides sufficient sediments, the fluvial system and watershed area control the scale of the sand body, the multi-step active fault steps dominate the sand body transport channel, and local fault troughs decide the lateral propulsion direction of the sand body. The delta of the Ling 3 Member is coupled with fault blocks to form diverse traps, which are critical exploration targets in southern Baodao Sag.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 2","pages":"Pages 337-350"},"PeriodicalIF":0.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600273/pdf?md5=948a88aba3f5c2e85e675926890a750c&pid=1-s2.0-S1876380424600273-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140557554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microscopic experiment on efficient construction of underground gas storages converted from water-invaded gas reservoirs","authors":"Tongwen JIANG ,&nbsp;Huan QI ,&nbsp;Zhengmao WANG ,&nbsp;Yiqiang LI ,&nbsp;Jinfang WANG ,&nbsp;Zheyu LIU ,&nbsp;Jinxin CAO","doi":"10.1016/S1876-3804(24)60017-0","DOIUrl":"https://doi.org/10.1016/S1876-3804(24)60017-0","url":null,"abstract":"<div><p>Based on the microfluidic technology, a microscopic visualization model was used to simulate the gas injection process in the initial construction stage and the bottom water invasion/gas injection process in the cyclical injection-production stage of the underground gas storage (UGS) rebuilt from water-invaded gas reservoirs. Through analysis of the gas-liquid contact stabilization mechanism, flow and occurrence, the optimal control method for lifecycle efficient operation of UGS was explored. The results show that in the initial construction stage of UGS, the action of gravity should be fully utilized by regulating the gas injection rate, so as to ensure the macroscopically stable migration of the gas-liquid contact, and greatly improve the gas sweeping capacity, providing a large pore space for gas storage in the subsequent cyclical injection-production stage. In the cyclical injection-production stage of UGS, a constant gas storage and production rate leads to a low pore space utilization. Gradually increasing the gas storage and production rate, that is, transitioning from small volume to large volume, can continuously break the hydraulic equilibrium of the remaining fluid in the porous media, which then expands the pore space and flow channels. This is conducive to the expansion of UGS capacity and efficiency for purpose of peak shaving and supply guarantee.</p></div>","PeriodicalId":67426,"journal":{"name":"Petroleum Exploration and Development","volume":"51 1","pages":"Pages 203-212"},"PeriodicalIF":0.0,"publicationDate":"2024-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1876380424600170/pdf?md5=7d706d71cfb208105cdd74497f8023c4&pid=1-s2.0-S1876380424600170-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139749414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}