Based on the data of regional geology,seismic,drilling,logging and production performance obtained from 94 major petroliferous basins worldwide,the global coal resources were screened and statistically analyzed.Then,using established definition methods and evaluation criteria for coal-rock gas in China,and by analogy with the tectono-sedimentary and burial-thermal evolution conditions of coal rocks in sedimentary basins within China,the geological resource potential of global coal-rock gas was estimated mainly by the volume method,partly by the volumetric method in selected regions.According to the evaluation indicator system comprising 14 parameters under 5 categories and the associated scoring criteria,the target basins were ranked,and the future research targets for these basins were proposed.The results reveal that,globally,coal rocks are primarily formed in four types of swamp environments within four categories of prototype basins,and distributed across five major coal-forming periods and eight coal-accumulation belts.The total geological coal resources are estimated at approximately 42× 1012t,including 22× 1012 t in the strata deeper than 1 500 m.The global geological coal-rock gas resources in deep strata are roughly 232×1012 m3,of which over 90％are endowed in Russia,Canada,the United States,China and Australia,with China contributing 24％.The top 10 basins by coal-rock gas resource endowment,i.e.Alberta,Kuznetsk,Ordos,East Siberian,Bowen,West Siberian,Sichuan,South Turgay,Lena-Vilyuy and Tarim,collectively hold 75％of the global total.The Permian,Cretaceous,Carboniferous,Jurassic,and Paleogene-Neogene account for 32％,30％,18％,10％,and 7％of total coal-rock gas resources,respectively.The 10 most practical basins for future coal-rock gas exploration and development are identified as Alberta,Ordos,Kuznetsk,San Juan,Sichuan,East Siberian,Rocky Mountain,Bowen,Junggar and Qinshui.Propelled by successful development practices in China,coal-rock gas is now entering a phase of theoretical breakthrough,technological innovation,and rapid production growth,positioning it to spearhead the next wave of the global unconventional oil and gas revolution.

As a promising supplement of China's petroleum production, the lacustrine shale, compared with the marine shale, is characterized by higher clay mineral content, which has significant impacts on the hydrocarbon reservoir quality. Controlled by the paleo-lacustrine background and thermal maturity, the clay mineral contents vary tremendously in different shale systems. This study targets on three shale series formed in different basin types, namely the Lucaogou Formation shale (Junggar Basin), the Chang 7 Member shale (Ordos Basin), and the Qingshankou Formation shale (Songliao Basin), where the Junggar Basin was a saline lacustrine basin and the latter two were freshwater-brackish lacustrine basins. We find that the composition and content of clay minerals are considerably varied among the three shales that the clay mineral content of the Lucaogou formation shale is smaller than that of the Chang 7 Member and Qingshankou Formation, and the content of illite in the Chang 7 shale is lower than that in the Qingshankou shale. The occurrence of clay minerals has crucial effects on pore structures, that is the pore-filling clays has indiscernible contribution to the storage space, like in the Lucaogou shale, but those developing along the shale laminae can improve the storage capacities to form inter-granular pores and micro-fractures such as in Chang 7 Member and Qingshankou Formation. The development of clay mineral-related pores and fractures is controlled by thermal maturity (Ro) and affected by the content of terrigenous minerals. This pore structure alteration derived by the clay mineral occurrence types further affects the hydrocarbon contents. In the Lucaogou shale, the oil content is inversely proportional to clay mineral contents, while in Qingshankou Formation, the oil content is even higher than that of the adjacent felsic silt laminae due to the favorable development of micro-fractures and inter-granular pores in clay mineral laminae. The high clay mineral content in lacustrine shales in China make it necessary to investigate the clay mineral evolution to evaluate the hydrocarbon generation potential, pore structures, hydrocarbon contents, and hydrocarbon accumulation mechanisms in shale systems.

The first member of Cretaceous Qingshankou Formation in the Gulong Sag of Songliao Basin is rich in shale oil resources, which has become one of the most important exploration targets of lacustrine shale oil in China. Based on X-ray fluorescence element analysis, X-ray diffraction analysis, total organic carbon, rock pyrolysis, scanning electron microscope and nitrogen adsorption, the paleo-environment was reconstructed by comprehensive utilization of integrated prediction error filter analysis research method of chemical stratigraphy, and its relationship with organic geochemistry, mineralogy and pore structure was discussed. The results indicated that the first member of Qingshankou Formation was deposited in the environment with fresh water-brackish water, semi-deep/deep water and strong reduction. The evolution of paleo-environment during the deposition of Qing 1 member changed from bottom to top, with increasing water depth, decreasing salinity and oxygen content. Paleo-salinity was positively correlated with total organic carbon, residual hydrocarbon and carbonate mineral content. From bottom to top, the contents of carbonate and chlorite decreased, while the contents of plagioclase and clay minerals increased slightly. The pores were dominated by intra-illite pores, intra-I/S mixed-layer pores and intra-pyrite pores. Some intra-plagioclase pores and calcite dissolution pores were developed, and the organic matter pores is slightly few. Nitrogen adsorption data showed that the dominate pore size was 40-53 nm and 3-4 nm. This study clarifies the paleo-environmental evolution of the Gulong Sag, and may shed lights on lacustrine shale oil accumulation and sweet-spotting. Cited as : Guan, M., Wu, S., Hou, L., Jiang, X., Hua, G., Su, L. Chemostratigraphy and shale quality of the first member of Cretaceous Qingshankou Formation in the Gulong Sag, Songliao Basin. Advances in Geo-Energy Research, 2021, 5(3): xx-xx, doi: 10.46690/ager.2021.03.03

鄂尔多斯盆地南部铜川地区露头区中三叠统延长组长7段细砂岩、粉砂岩、泥质粉砂岩、粉砂质泥岩层序中发育有大量圆球状、椭球状、扁球状碳酸盐岩结核,对于其成因存在争议.对铜川地区多个剖面的结核开展宏观描述,在微观薄片观察基础上开展岩石矿物组成、稳定同位素、簇同位素以及微区同位素等分析,特别是选取一个结核开展了详细的解剖.结果显示结核成分以方解石为主,少量白云石;内部结构有差异,在球体横切面上明显分为两个圈层;碳同位素值正偏,由内部圈层向外部圈层降低;氧同位素与碳同位素变化趋势一致,计算结核形成古温度变化区间为28.6～76.5℃;簇同位素揭示结核中部形成温度为42.9℃.认为该类结核为早期发酵带内细菌参与甲烷生成作用形成,甲烷菌活动引起有机质碳同位素分馏,碳酸盐结核中方解石和白云石圆球粒可能是蓝细菌细胞方解石化或白云石化的结果.根据埋藏史,认为该类结核形成于成岩作用早期,后期在成岩过程中叠加生长,同心环层结构明显.

Pore structure is a major factor affecting the storage space and oil-bearing properties of shales. Mineralogy, organic matter content, and thermal evolution complicate the pore structures of lacustrine shales. In this study, the porosity evolution of organic-matter-rich shales from the Cretaceous Nenjiang Formation in the Songliao Basin, Northeast China, are investigated using thermal simulation experiments and in-situ scanning electron microscope analysis. Three findings were obtained as follows: 1) The pore system of shales from the Nenjiang Formation is dominated by inter-granular dissolution pores of plagioclase and intra-granular pores of illite-smectite mixed layers. Few organic-matter pores are observed. 2) New pores developing during thermal evolution are primarily organic matter pores and clay mineral pores, with diameters greater than 18 nm. Clay mineral pores with diameters of 18–50 nm are the principal contributors to porosity at temperatures between the low maturity stage and the oil-generation window, and organic matter pores with diameters of greater than 50 nm comprise the majority of pores generated between the gas-generation window and the high-/over-mature stages. 3) Porosity increases continuously with maturity, and the pore system varies at different maturity stages. Porosity evolution is controlled by illite content and organic matter abundance. Total pore volume correlates positively with illite content but negatively with organic matter abundance. These findings could provide guidance on shale oil evaluation in the Songliao Basin and assist in the ‘sweet-spotting’ of lacustrine shale systems across China.

Pore evolution in organic-rich shale is synchronically controlled by organic and inorganic diagenesis processes that are significantly different from sandstones and carbonates. Fundamental studies were conducted in characterizing pore evolution. However, pore evolution mechanisms and the main controlling factors for the particular pore size range have not been clarified yet. Herein, we conducted thermal simulation experiment, coupled with petrological, mineralogical, and organic geochemical tests on the organic-rich shales from the Permian Lucaogou Formation in Junggar Basin, China, to investigate the evolution of organic matter and mineral composition in different stages of pore evolution. For the first time, we discovered the relationship between evolution mechanisms and the particular pore size ranges. Eighteen nanometer was identified as the critical pore size boundary that connected pore evolution stages with the corresponding pore types. Pore sizes ranging in 2-18 nm, 18-50 nm, and >50 nm were separately controlled by the diagenesis process of day conversion, dissolution of nonday minerals, and thermal evolution of organic matter during the pore evolution process in the Lucaogou shale. Lucaogou shale demonstrated a three-phase pattern of pore evolution as thermal maturity increases. Porosity shows a slight decreasing trend at the first stage from low maturity to an oil window, followed by a rapid increase from the oil to gas window, and remains stable with a slight increase after entering into the high-mature stage. Different correlations are discovered between pore evolution and organic matter maturity in the particular pore size range, which sheds a light on the accurate formation evaluation in the Lucaogou shale for practical applications.

Carbonate concretion is an authigenic aggregation of minerals commonly found in sandstone and shale, especially in organic-rich shale. In the outcrop, large number of carbonate concretions developed in Chang 7 member in Tongchuan. Those concretions were studied in terms of stable isotope, clumped isotope to delineate its origin and sedimentary environment. Two types of concretions are identified. Type A concretionsmainly distribute in organic-rich shale. This concretion was divided into the inner circular layer and the outer circular layer. In the inner circular layer, the value of delta C-13 parts per thousand(VPDB) is 9.98 parts per thousand similar to 14.19 parts per thousand, and the value of delta O-18 parts per thousand(VPDB) is -13.32 parts per thousand similar to-10.07 parts per thousand. On the contrary, the delta C-13 and delta O-18 value of outer circular layer are4.74 parts per thousand similar to-0.59 parts per thousand,17.86 parts per thousand similar to-15.59 parts per thousand respectively. The formation palaeotemperature of different parts of concretion ranged from 28.6 to 76.5 degrees C. This may be due to methanogenesis arising from bacterial activities in the fermentation zone, and the fractional distillation of carbon isotope of organic matter was caused by the methane bacterial activities. The calcite and dolomite spherulites in carbonate concretions may be due to the calcilization and dolomitization of cyanobacteria in the early diagenesis. The type B concretions were distributed in the fine sandstone, silty sandstone, and silty mudstone. The internal structure of concretions is uniform. The carbon isotopic values were negative, and delta C-13 was -5.019 similar to-12.013 parts per thousand, and the delta O-18 values was -17.6 similar to-19.281 parts per thousand. The value of Sr-87/Sr-86 was in the range of 0.710072-0.710392. The temperature was established at 60.4 degrees C through clumped isotopes analysis. Based on isotopic analysis, the formation palaeotemperature at different parts of concretion was 55.4-65.6 degrees C. The origin of the concretion may be related to dehydroxylation in diagenesis, formed in the earlymiddle stage of diagenesis.

The characteristics of fracture propagation in heterogeneous tight sandstones are critical to volumetric fracturing, which is the key to unlocking unconventional resources in tight sandstones. Quantification of the influence of pre-existing pore systems and particle arrangements on the propagation of fractures is challenging due to inadequate imaging of the internal void systems in tight sandstones from three-dimensional (3D) aspect. In this study, the 3D geometry of tight sandstones from the Chang 7 member in the Ordos Basin is continuously imaged under different loading stresses, and the voxel resolution of the X-ray computed tomography is 2.5 mu m. The data set captured in this process shows the changes in the samples at the microstructural level as they approach fracturing. The data are stored as a time series of 3D images. The results demonstrate that (i) fractures propagate progressively and gradually link with pre-existing pores, resulting in macroscopic fractures with a maximum width of 250 mu m, while newly generated fractures could break up particles and may not follow the line of pre-existing fractures; and (ii) three stages were identified in the failure process of tight sandstones, with new fractures running at an angle of about 30 degrees to the general direction of the stress of compression. The total volumes of both the sample and pore-fractures, and the damage index, which were extracted from the 3D images, all increased when approaching fracturing. The final volume of pore-fracture systems could be 11 times that of the initial pore volume. All of these observations provide valuable insights and design guidelines for hydraulic fracturing in unconventional tight sandstones, and a quantified model of the dynamics and the morphology of fracture propagation with increasing stress approaching failure, which may shed light on dynamic critical transitions in the Earth's crust.

中国致密油主要分布在中、新生代陆相含油气盆地中,发育与湖相生油岩共生或接触、大面积分布的致密砂岩油或致密碳酸盐岩油.近年来,陆相致密油勘探开发取得重大进展,截至2018年底,中国陆相致密油已建成产能315.5×104 t,2018年年产量约105×104 t.中国陆相致密油以湖相富有机质页岩为主要烃源岩,多发育于淡水、半咸水-咸水环境,厚度一般为几十至几百米,有机碳含量为0.4％～16.0％,镜质体反射率为0.5％～1.3％,适宜的火山作用、低沉积速率、缺氧还原环境、海水入侵与水体分层是富有机质页岩形成的重要影响因素.中国陆相致密油储层类型包括致密砂岩、致密碳酸盐岩、致密混积岩和致密沉凝灰岩等,储集层非均质性强、物性差;覆压基质渗透率多小于或等于0.1×10-3μm2,以纳米级孔喉系统为主,孔喉半径小,主体直径40～900 nm,孔隙结构复杂;压力系数0.7～1.8,既有超压,也有负压;地层能量、原油品质变化大,原油密度0.75～0.92 g/cm3.中国陆相致密油地质资源量为178.20×108 t,技术可采资源量为17.65×108 t,主要分布在鄂尔多斯盆地、渤海湾盆地、松辽盆地、准噶尔盆地和柴达木盆地.提出"甜点区(段)"概念,"甜点区"多发育在宽缓背景下的局部微构造区,是指在平面上成熟优质烃源岩分布范围内,具有工业价值的致密油高产富集区;"甜点段"是指在剖面上源-储共生的黑色页岩层系内,人工改造可形成工业价值的致密油高产层段.源岩品质和源-储组合类型控制"甜点区"平面分布范围.资源评价方法、"六特性"测井识别、高精度三维地震、水平井平台式生产及人工油藏开发等"甜点区(段)"评价方法,可支撑致密油有效开发.

In unconventional petroleum reservoirs, such as shale gas, shale oil, tight oil, and tight gas reservoirs, the microscopic pore structure, namely, the size, geometry, distribution, and interconnected relations of the pores and throats of a shale rock, directly affects the porosity, storage, and permeability. Studies related to the microscopic pore structure of shale are considered important for evaluating shale resources and for elucidating their distribution characteristics; additionally, these studies aim to improve the productivity and recovery ratio of both oil and gas. Therefore, methods that can accurately characterize the microscopic pore structure of shale have received considerable attention. In this study, we used the electrodeposition method to fill the interconnected pores of a rock sheet with metal and then used selective dissolution of the rock portion of the rock sheet to obtain the metal complex of the pore-throat structure. The structure and morphology of the obtained metal complex, which represents the microscopic pore structure of the shale, are characterized by a scanning electron microscope (SEM). By combining electrochemical deposition and SEM images, we could directly observe the three-dimensional microstructure of the shale at a scale smaller than 50 nm with a large observation area. Additionally, the surface areas of the connected pores and throats of the shale were calculated.

华北克拉通西南缘高山河组是中元古代重要的地层单元之一,但其沉积时限和地层对比关系长期存在争论.本文对采自甘肃省华亭县马峡镇高山河组下部的凝灰岩进行了LA ICP-MS锆石U-Pb同位素年龄测定,获得凝灰岩样品的高精度年龄为1759±17Ma.结合区域资料和前人研究成果,初步将该地区高山河组的形成年代限定在1770～1600Ma之间,并进一步限定高山河组下部熊耳群火山岩系的形成时代介于1800～1770Ma之间.此为首次在华北克拉通西南缘高山河组获得高精度年龄,不仅确定了高山河组沉积时代应为长城纪,也为整个华北克拉通西南缘中元古代地层划分对比和地质演化及其进一步进行微古生物研究等地质问题奠定了重要的年代学基础.

Organic-matter-rich shales are the main target rocks for unconventional oil and gas exploration and development across the world. In China, shale-gas geological resources are estimated as approximately 110 x 10(12) m(3), with recoverable gas reserves of ca. 20 x 10(12) m(3). Recoverable shale-oil reserves are estimated as ca. 5 x 10(9) t. A total 35 important organic-matter-rich shale units have been recognized from Mesoproterozoic to Cenozoic strata across the entire China. These shales are categorized according to their origin under marine, marine-nonmarine transitional and lacustrine conditions. Shales of marine origin, with ca. 9 x 10(12) m(3) recoverable resources, dominate China's potential in terms of total volume of organic-carbon. Currently, the most favorable marine shales for oil and gas exploration are found in the Sichuan Basin within the lower Cambrian Qiongzhusi Formation and in the Wufeng-Longmaxi formations of uppermost Ordovician through lower Silurian. A fortuitous combination of of sea-level variations, of paleo-productivity, of tectonic activity causing development and migration of partially closed deep basin depocenters, and of sediment accumulation rates controlled the extensive deposition and distribution of organic-matter-rich shales in these Wufeng and Longmaxi formations. Organic-matter-rich shales in marine-nonmarine transitional facies associated with coal measures occur in North China within the Carboniferous and Permian, and in South China within the Permian. These Carboniferous Permian organic-matter-rich shales are important source rocks for the gas fields in the Ordos and Sichuan Basins. Abundant organic-rich shales are also widely distributed within coal-bearing elastics and coal-measure shales of fluvial, lacustrine, and swamp facies in Upper Triassic to Middle Jurassic successions of many basins. Lacustrine organic-rich shales were deposited during the Permian through Neogene in various freshwater to saline lake settings. Lacustrine organic-matter-rich shales are the main oil source rocks in the Songliao, Bohai Bay, Ordos and Junggar basins. Lacustrine algae contributed to the rain of organic matter; and the preservation of organic matter and distribution of organic-rich shale was controlled by lake currents, water depth and oxygen-poor conditions, with enhanced preservation when buried by turbidity currents. Algal blooms were partly induced by trace nutrients from volcanic ash falls in all of these lacustrine basins. Seawater intrusion into the freshwater lake of the Songliao Basin promoted some episodes of black shales. Saline lacustrine basins, such as middle Permian Junggar Basin, contain organic-rich dolomite mudstone that mainly formed during hot climate conditions when the lakes had high salinity and stratified water columns that deprived the bottom waters of oxygen, thereby preserving massive amounts of organic matter. Laminated calcite-rich mudstone in the saline lacustrine settings formed in more brackish waters under stable warm conditions and weak biological activity. The modeling of the factors controlling the distribution of organic-matter-rich shales within China's basins is important for the exploration and development of unconventional oil and gas resources.

Weathering crust reservoir has special characteristics.Combined with the discovered weathering crust reservoir in the world,the connotation of weathering crust reservoir was defined,three-level classification was made,and its characteristics and global distribution were present.The weathering crust reservoir can be subdivided into two types:uplift weathering crust reservoir and basement weathering crust reservoir.The weathering crust reservoir is distributed to almost all of the oil-gas province in the world and geologic eras.The lithology of the weathering crust reservoir includes clastic rock,carbonate,magmatic rocks,and metamorphic rock.The type of the reservoir space is included in pores or hole,fracture and fractured pores.The weathering crust of different li-thology forms different hierarchical structure and reservoir space combination,and large scale distribution.Multi-period large and medium sized unconformities developed in superimposed basins in China.It leads to wide distri-bution and great exploration potential of weathering crust reservoir in China. It is main to prospect basement weathering crust in the superimposed rift basins in eastern China,and uplifting weathering crust in the superim-posed craton-foreland basins in the middle and western China.

Tight oil in China is mainly distributed in Mesozoic-Cenozoic continental petroliferous basins, either generally occurs in tight sandstone or tight carbonate reservoirs which are paragenetic to or in contact with lacustrine petroleum source rocks. By the end of 2016, the continental tight oil in China has established an annual production capacity of 1.55 million tons, and a cumulative oil production of 2.52 million tons. In 2016, the continental tight oil production in China was about 800,000 tons. By analyzing the characterization of the tight oil in Ordos Basin, Songliao Basin, Jungar Basin, the organic-rich shale in China were formed in multiple geological periods including the Permian, Triassic, Jurassic, Cretaceous, Neogene, and Paleogene, in freshwater, semi-saline to hyper-saline lacustrine depositional setting. They are generally tens of meters to several hundreds of meters thick, have total organic carbon (TOC) contents of 0.4-16%, and thermal maturity of 0.4-1.4%. Algal bloom as results of volcanism, low sedimentation rate, transgression, and stratification of water body are prominent factors controlling the formation of organic-rich shales. Tight oil reservoirs in China mainly include tight sandstone, tight carbonate rock, tight sedimentary tuff, etc., all of which are characterized by strong heterogeneity and poor petrophysical properties, with in situ porosity and permeability generally no more 12% and 1 x 10(-3) mu m(2) respectively. They are also characterized by tight pore-throat systems of nano- to micro-scales, with pore throat diameters in the range of 80-1800 nm, and complex pore structures. The producing reservoirs have pressure coefficients between 0.7 and 1.8, covering under-pressure to over-pressure. Crude oil properties vary greatly with densities ranging from 0.75 to 0.92 g/cm(3). It is believed that the abundance and effectiveness of hydrocarbon supply controls the formation of oil saturation, and tight oil "sweet spots" are generally in or near the areas with high hydrocarbon expulsion intensities. In addition, the quality of the source rock and the type of source reservoir control the distribution of the "sweet spots", and storage space and movable fluid guarantee the formation of the "sweet spot" area of high oil saturation. "Sweet spots" are often developed in local mini-structural highs under a broad and gentle-sloped background. Continental tight oil in China has estimated geological resource of 14.66 x 10(9) tons with a technically recoverable resource of 1.45 x 10(9) tons. Tight oil is mainly distributed in Ordos Basin, Songliao Basin, Bohai Bay Basin, Junggar Basin, and Qaidam Basin, within the Mesozoic and Cenozoic formations. Overall China has a relatively large tight oil reserve and good exploration prospect.

复杂储层岩石矿物组成非均质性强,孔喉结构细小.储集空间有效性评价、岩石结构精细评价及流体赋存状态与运移规律评价是决定复杂储层油气勘探成效的关键.针对复杂储层的储集空间(孔喉、裂缝)、岩石结构(矿物、有机质)、流体特征3方面,建立了复杂储层多尺度数字岩石评价技术及工作流程.储集空间表征方面:二维大面积分析技术可建立跨越6～7个数量级的多尺度选取及非均质性评价;多尺度CT及FIB-SEM联用可精确刻画孔喉和裂缝的三维空间分布;电化学和显影剂技术可以有效地帮助分析微观孔隙连通性.固体组分分析方面:XRF及Qemscan联用可定量评价矿物组成与分布;三维FIB-SEM技术可以实现有机质形态和分布的定量分析.流体特性方面:荷电效应可用于微量残留有机流体的识别与表征;通过合成孔径、润湿性、表面微结构均可调控的纳米材料,开展地层条件下页岩油赋存及流动物理模拟研究,确定了单一因素对页岩油赋存及可动孔径下限的影响;利用分子模拟研究油气在无机、有机质纳米孔隙中的聚集机理与扩散潜力.复杂储层多尺度数字岩石评价技术体系和一系列具体应用可以有效地填补常规储层分析手段的不足,为页岩油气、致密砂岩油气储层以及深部油气储层等复杂储层有效性评价和含油气性定量评价提供技术支撑.

Abstract High heterogeneity and small pore throat characterize the mineral compositions of complex reservoirs. The evaluation of the effectiveness of reservoir space, the detailed evaluation of the rock structure, and the evaluation of fluid occurrence and migration all determine the possibility of oil and gas exploration within complex reservoirs. The technologies and workflows used for the multi-scale digital rock evaluation of complex reservoirs analyze the reservoir space (i.e., the pore throat and fractures), the rock structure (i.e., mineral and organic matter), and fluid characteristics. For the reservoir space, two-dimensional large-area analysis is sufficient to evaluate heterogeneity and multi-scale selection across 6–7 orders of magnitude. Three-dimensional space distributions of pore throat and fractures are precisely depicted through a combination of multi-scale CT and FIB-SEM. The developing agent facilitates the analysis of the micro-pore connectivity effectively. For the solid components, a quantitative evaluation of mineral composition and distribution is possible using Qemscan, and organic matter morphology and distribution are quantitatively assessed using the three-dimensional FIB-SEM. To characterize the fluid, charging effects may aid in the identification and characterization of residual, organic fluid traces. We perform the physical modeling of shale oil occurrence and migration by using nano materials that have adjustable pore sizes, adjustable wettability, and adjustable surface microstructure to understand the impact that each factor has on shale oil occurrence and the lowest pore sizes in which fluid can migrate. We use molecular simulations to observe oil and gas aggregation mechanisms and the diffusion potential in inorganic and organic nano pores. To supplement the conventional reservoir analysis, multi-scale digital rock evaluation, and its specific applications, provide technical proof for effective complex reservoir assessment, including shale oil and gas reservoirs, tight sandstone oil and gas reservoirs, and deep oil and gas reservoirs, as well as a quantitative oil-gas probability evaluation.

Lacustrine carbonate rocks have various occurrences.They commonly occur as the interbeds in clastic rocks with characteristics of multi-layers,thin individual layer and rhythm.Occasionally,they occur in mudstone and shale as thin layers of concretions or calcareous microfossils.Controlled by tectonic background,provenance and palaeoenvironment,the lacustrine carbonate rocks in China show widespatial-temporal distribution,which were firstly reported in the Permian,but mainly found in the Pa leogene.Based on carbonate and oxygen isotope analysis,different water environments during primary deposition and diagenetic process are concluded:(1) Well-related δ13C and δ18O with mostly positive δ13C values,indicating a closed saltwater or semi-saltwater lake environment;(2) Completely-unrelated δ13C and δ18O values with mostly negative δ13C values,indicating an open lake environment;(3) Seriously-positive δ13C values,indicating that during diagenesis,the environment was affected by the methane generation process,which was participated by archaebacteria.

Abstract A large number of micro–nanopores constitute the main reservoir space of shale oil and gas reservoirs. To evaluate a reservoir pore throat system's structure, it is of great significance to quantitatively characterize the pore distribution. There are two commonly used methods for characterizing the pore structure: mercury intrusion and gas adsorption analysis. The mercury intrusion method is to determine the pore size distribution by measuring the amount of mercury in the pores under different external pressure. The detection range of this method is pores with diameters of 3 nm–400 μm, and the optimal detection range is pores with diameters of 100 nm–100 μm. The gas adsorption analysis method is to measure the adsorption amount of nitrogen and other gases at the liquid nitrogen temperature. the optimal detection range of this method is pores with diameters of 0.4–100 nm. Because of the complex structure of porous materials, the results of different experimental methods are inconsistent, and the pore structure information provided by a single method is limited. Since different porous solid materials have different chemical and physical properties and different pore diameter range, it is necessary to select experimental methods for the target material. This paper introduces a new method of measuring pore distribution, which is a Low Field Cryoporometry NMR method. Based on the principle of the nanometer-confined effect, this method can measure mesoporous distribution of different porous materials and shale. The logarithmic pore diameter distribution and the pore diameter distribution histogram indicate that the shale sample's pore volume is mainly comprised of pores with a diameter of 80–500 nm, which is consistent with the pore statistical results of the SEM analysis. The porous size distribution (PSD) was obtained by Croporometry NMR (NMRC) for shale samples, which was compared with that from the measurements by Brunauer-Emmett-Teller Method (BET). This method enlarges the scope of the classical gas adsorption method, then can be used to study pore diameters from 10 nanometers to micron size. Furthermore, it provides an important reference to the study of the pore structure of shale oil and gas reservoirs.

The development of sedimentology depends on industrial exploration of mineral resources such as oil,gas, coal,sandstone type uranium deposit. Energy Sedimentology which becomes an important way for discovering re-sources and reducing cost is more and more important for resources exploration. Recently,the development of oil and gas sedimentary reservoir is supported by Energy Sedimentology,which ob-tained six significance progresses,established six grade measures such as remote sensing,seism and Nano-CT.Energy Sedimentology established new model of craton platform sedimentary reservoir and provided theoretical direction for global ancient hydrocarbon-bearing system. Genetic models of marine and continental facies fine-grained sedimentation were established,regularities of distribution of organic-rich shale were revealed,and important theoretical foundations of source rock evaluation and unconventional oil & gas exploration were provided by energy sedimentology. And dis-covering micro-nanoscale pore throat system of unconventional tight reservoir, guiding assessment of shale and tight reservoirs, studying coal-bearing stratum and guiding evaluation, revealing uranium mine gathering mechanism in sandstone and guiding evaluation,all these achievements can rely on energy sedimentology. Source-to-Sink Approach,marine and continental fine-grained sedimentology and ancient small craton carbonate sedimentology will become significant contents in the development of energy sedimentology. Reservoir heterogeneity, characterization of unconventional reservoir and limit of deep-reservoir will be a hotspot in the development of hydro-carbon sedimentology. Sequential deposition and mutualism regular research of different energy storage space, like gas,liquid and solid,are the key direction of resource exploration. Big data and technique innovation of sedimentolo-gy will provide new opportunity for energy sedimentology.

常规—非常规油气协同发展引发储集体类型的多样性,品质整体变差,孔隙结构更为复杂,亟需建立相对统一的孔隙结构评价方案,为储层评价与甜点区优选提供技术支持.基于岩石孔隙结构解剖,提出“孔隙结构四分法”评价方案,将孔隙系统分为毫米孔(大于1 mm)、微米孔(1～1 000μm)、亚微米孔(100～1 000 nm)及纳米孔(小于100 nm);明确了不同类型孔隙系统发育位置、流体作用力及流动机理,建立了对应的分析评价技术.解剖了克拉2气田巴什基齐克组常规砂岩、新安边油田长7段致密砂岩、川中大安寨段介壳灰岩、川南龙马溪组页岩4类储层,明确了各储层类型孔隙结构的差异性及不同级别孔隙所占比例,探讨了孔隙结构对储层物性、资源经济性及开发工艺的影响;孔隙结构分级研究需与储层有效性评价紧密结合,特征尺度决定流体相态与作用力,影响流体可动性及油气开发工艺.进一步加强孔隙分级评价关键界限值的研究,完善孔隙结构表征技术的融合,建立孔隙结构与岩性和产能的定量关系是未来研究的重点.