The characteristics of oil shale deposits in continental basins in China are wildly distributed. Taking Songliao basin,Fushun and Huadian Basin in the Dunmi fault zone,Junggar basin, and Ordos basin as examples,the authors analyzed four types of basins:discrete continental rift basin,transitional strike slip basin,convergent foreland basin, and intraplate craton basin,and summarized oil shale characteristics and their distribution. Among them,the oil shale of discrete continental rift basin deposited in the post rift thermal subsidence evolution stage has the characteristics of organic matter type Ⅰ,medium oil yield,stable thickness, and wide distribution area,which is easy to form super large oil shale deposits, while the oil shale of discrete continental rift basin deposited in the same rift has the characteristics of organic matter type Ⅱ₁-Ⅱ₂, medium oil yield, medium thickness, and small distribution area, which is easy to form medium oil shale deposits; the oil shale in the conversion strike slip basin has the characteristics of Ⅱ₁-Ⅱ₂ organic matter and medium-small overall distribution range, but the occurrence of deposits is quite different depending on the extent of the structural subsidence of the strike slip movement fault depression, which tends to form not only oil shale deposits with medium oil yield and huge thickness, but also oil shale deposits with high oil yield and thin thickness; the oil shale deposited in the continental molasse stage of convergent foreland basin has the characteristics of Ⅰ-Ⅱ₁ types of organic matter, high oil yield, large thickness, but limited distribution and large changes in stratigraphic occurrence, which is easy to form large oil shale deposits; the oil shale deposited in the stage of intracontinental depression of craton basin has the characteristics of Ⅰ-Ⅱ₁ types of organic matter, medium oil yield, stable thickness, and wide distribution area, which is easy to form super large oil shale deposits. Among all types of basins,deep lake environment, high system tract, and transgressive system tract are favorable for oil shale formation.

Jianchang basin, located in western Liaoning Province, is rich in oil shale resources. Based on the data of outcrops, drilling and laboratory analyses, distribution and petrological characteristics, the geochemical characteristics and sedimentary environment of oil shale were analyzed. The study shows that the oil shale is in the first, second and third members of Jiufotang Formation, totally nine ore groups. The average oil content and thickness of the third member of Jiufotang Formation are better than those of others. The average oil content of the oil shale is 5.15%, the average ash content is 81.9%, the total sulfur content is low, and the average calorific value is 5.19 kJ/g, belonging to medium-high calorific oil shale. The technically identified recoverable resources of oil shale and shale oil are 8.22×10⁸ t and 3.17×10⁷ t respectively in the area of Jianchang, Wujiazi, Jiufotang, Qidaoquanzi, and Daqingshan. It is predicted that there is 9.27×10¹⁰ t oil shale resources in Jianchang basin. There are abundant organic matter in immature-low mature stage, mainly type Ⅰ and type Ⅱ₁. During Jiufotang Formation, the climate was warm and humid, a large quantity of organic matter from land and lakes were deposited, and the sedimentary environment was in the state of freshwater and brackish reduction, which was conducive to the preservation of organic matter.

The study of Cretaceous continental paleoclimate has become an important reference for the international study of the earth environment system. The systematic sampling of the Lower Cretaceous Bayingebi Formation in Yin'e basin was made. Through the observation of lithology and analysis of sporopollen, the paleoclimate evolution and organic enrichment conditions were systematically studied. A total of 173 species belonging to 58 genera were identified, including 141 species belonging to 37 genera of gymnosperms, 11 species belonging to 6 genera of angiosperms, and 21 species belonging to 15 genera of ferns. Gymnosperms are dominant in the pollen assemblages with the pollen content over 90%. Coniferous forest is the main vegetation type, followed by coniferous and broad-leaved mixed forest, reflecting the north subtropical climate in warm temperate zone. The overall climate is semi-humid and humid with semi-arid in some layers. Semi-humid climate is the most favorable climate for the enrichment of organic matter in the study area, followed by humid climate.

In view of the forming mechanism of oil shale in Maoming basin, the authors studied the organic geochemical characteristics, and discussed the origin of organic matters and depositional environment of Eocene Youganwo Formation oil shale in Yangjiao mining area based on Leco, rock pyrolysis, oil yield, and biomarker analysis. The results show that the abundance of organic matter is high, the kerogen is type Ⅰ-Ⅱ₁, the average oil yield is 5.98%, and the quality of oil shale is fairly high. I_CP (3.73-4.37), OEP (7.59-9.57), low C₂₉ααα20S/(20S+20R), low Ts/(Ts+Tm),and T_max (428-434℃) indicate that the oil shale thermal evolution of Youganwo Formation is in immature stage. The gas chromatography (GC) of n-alkanes has the features of unimodal distributions with nC₂₇ as the mean peak. ∑C_21-/∑C₂₂₊ and ∑C₂₁₊₂₂/∑C₂₈₊₂₉ are low, I_CP and OEP are high. The content of high-carbon hopanes is high,while the content of tricyclic terpenes is low. No non-hoprii compounds such as oleane and lupane are detected. Combined with the relative content of C₂₇-C₂₈-C₂₉,all the above indicate that lacustrine algae, mixed sources of plankton and terrestrial plants are the main source of organic matter of the oil shale of Youganwo Formation. TOC/S (41.14-170.08), Pr/Ph (0.82-1.30), and rearranged sterane/sterane (0.06-1.10) indicate that the paleo-lake condition was fresh and reductive when oil shale deposited. In a subtropical-temperate warm-humid climate, high lake productivity is caused by aquatic organisms such as algae bloom, and reductive fresh water environment is favorable for oil shale mineralization in Youganwo Formation of Maoming basin.

In order to establish the reliable model between oil yield and total organic carbon (TOC) of oil shale to predict oil yield, it is very important to reveal the response mechanism between oil yield and TOC in different genetic types of oil shale of continental basins. In this paper, the response mechanism between oil yield and TOC in non-marine oil shale was studied by using the key parameters of borehole cores in various types of basins combined with sedimentology, organic geochemistry, and thermal simulation. The results show that an excellent correlation (R²=0.81-0.97) between oil yield and TOC exists in oil shales from different types of basins and sedimentary backgrounds. Firstly, the non-marine oil shale is divided into five genetic types, which control the relationship between oil yield and TOC. Secondly, three weight-loss stages of oil shales were presented during heating simulation, which clarifies the specific physical significance of oil yield and TOC parameters. Finally, the oil shale formed in similar basin and sedimentary background has similar organic matter source, so it has roughly equivalent hydrocarbon regeneration efficiency. The genetic types of non-marine oil shale, the physical significance of oil yield and TOC parameters, and the hydrocarbon regeneration capacity of oil shale were used to understand the internal relationship between oil yield and TOC of non-marine oil shale in China.

The paragenetic oil shale and coal are widely developed in continental basins of China. The authors took the oil shale and coal of the lower Cretaceous Muling Formation in Laoheishan basin as a study object, and studied the controlling factors of oil yield of oil shale and coal, combined with both industrial parameters (oil yield, ash content, volatile matter, total sulfur, and gross calorific value) and organic geochemical analyses (total organic carbon, Rock-Eval, maceral, and biomarker analyses). The oil shale and coal are classified into four types, including high oil yield oil shale (HOS), low oil yield oil shale (LOS), high oil yield coal (HC), and low oil yield coal (LC). The highest TOC and S₁+S₂ values are observed in HC, followed by LC, HOS, and LOS, all types are of type Ⅱ kerogen and in immature stage. The source of organic matter and depositional environment are the key controlling factors of oil yield in oil shale and coal. HC was deposited in mire with abundant input of terrestrial organic matter; in contrast, HOS was formed in limnology environment with moderate input of terrestrial organic matter. The floral assemblage is characterized by the presence of Pinaceae, Cupressaceae/Taxodiaceae, Araucariaceae, Podocarpaceae and ferns during the formation of oil shale and coal. These plants could provide abundant resinous and waxy organic matter, which lead to relatively high oil yield of oil shale and coal.

The geochemical characteristics and paleolimnological information of oil shale are the key evidence to reveal the rule of metallogeny and enrichment of oil shale. Based on the analyses of TOC, oil yield, rock pyrolysis, element, biomarker compound,and organic maceral, geochemical characteristics of oil shale in the 1^st Member of Qingshankou Formation in Well ZY1 in northern Songliao basin the were refinedly characterized, paleolimnological information recorded by the oil shale was analyzed, then the control effect of paleolake on organic matter enrichment of oil shale was discussed. The results show that there are 8 layers of medium-high quality oil shale in the 1^st Member of Qingshankou Formation, and the high quality oil shale is mainly in the lower part. The TOC of oil shale has good correlation with the oil yield. Seen from the thermal evolution, the oil shale is in the immature-low mature stage with high hydrocarbon potential. Abundant steranes and terpanes are detected from the oil shale samples. The organic matter type of oil shale is mainly Ⅰ, and the main source of organic matter is lake aquatic organisms dominated by lamalginite. The paleolacustrine productivity of the lower part can be divided into three cycles by geochemical parameters, correspondingly the water salinity of paleolake shows three cycles from semi-saline to saline, and the redox property of paleo-lake shows reduction-strong reduction-reduction. And the paleolacustrine productivity of the late cycle Ⅱ is the highest, corresponding to the highest water salinity and the strongest reducibility. It is suggested that the high lake yield caused by lake eutrophication is the material basis of organic matter enrichment of high-quality oil shale in the 1^st Member of Qingshankou Formation, and the strong reduction environment of bottom water controlled by salinity stratification is favorable for the accumulation of organic matter in high-quality oil shale.

This paper focused on the clastic rocks of the Middle Permian Zhesi Formation, well exposed in the Haoren Town, Suolun region of Inner Mongolia. Geochemistry and zircon geochronology analyses were conducted, in order to constrain the ages and origins of sediment provenance. The dating results show that the U-Pb ages of detrital zircons from the Zhesi Formation sandstone can be divided into six groups, i.e., 282-244 Ma, 352-294 Ma, 468-379 Ma, 513-482 Ma, 802-580 Ma, and 2 500-1 800 Ma, respectively. Geochemically, the sandstone samples have high SiO₂, and low Fe₂O₃, FeO, and MgO contents, indicating they were mainly deposited from felsic rocks. Rare earth elements and trace elements characteristics and tectonic distinguished diagrams suggest the sediment source region of the Middle Permian Zhesi Formation dominantly displays similar features with those of continental arc and active continental margin, with minor corresponding to passive continental margin. The former setting is the results of the amalgamation-collision of the Jiamusi-Mongolia block and northwards subduction of the south branch of the Paleo-Asian Ocean during different stages, while the later one probably reflects the tectonic setting of the generation of some basement rocks. Considering the facts that:1) the study region is located in the southeastern Xing'an block, far away form the North China craton; 2) the Zhesi Formation clastic rocks mainly consist of feldspar lithic sandstone, lithic feldspar sandstone, and lithic sandstone with relatively low structure and ingredient maturity, suggesting characteristics of near-source deposition; and 3) the coeval igneous rocks in the surrounding regions were all formed in subduction-related settings, it is proposed here that the Zhesi Formation was most likely deposited in a back-arc or inter-arc basin related with the northwards subduction of the south branch of the Paleo-Asian Ocean beneath the Jiamusi-Mongolia block, and their provenance was dominantly from the subduction-related igneous rocks in the southern margin of the Jiamusi-Mongolia block, with little contributions from ancient basement of the Jiamusi-Mongolia block.

Aiming at the controversial issues such as the sedimentary environment, time-limit of Linxi Formation, and the final closing time of the Paleo-Asian Ocean in Xingmeng-Songnen area,a comprehensive analysis was conducted for the lithology and paleontology of Linxi Formation in Hanmiao area of Arhorchin Banner, in particular,the trace elements, and the U-Pb dating of detrital zircon. The ratio of trace elements Sr/Ba is mainly distributed between 0.05 and 0.18 (average 0.12), the ratio of B/Ga is mainly distributed between 1.84 and 3.22 (average 2.50), and the V/Cr value is between 1.36 and 2.21 (average 1.81), which indicate that the sedimentary period of Linxi Formation was an anoxic freshwater lake environment. The freshwater bivalves and leaf-lime fossils are developed in Linxi Formation. The sandstone clastic zircons of Linxi Formation have multi-epoch provenance. The youngest age is 251 Ma, reflecting the lower sedimentary age in Late Permian. Based on the above characteristics, it can be inferred that the final closing time of the Paleo-Asian Ocean in the study area is the end of the Middle Permian, and the study area transformed into continental sediments during the Late Permian.

Based on abundant geological and geochemical data, the salt lake sedimentary characteristics of the Lower Ganchaigou Formation of Oligocene were studied to identify the major rock types and discuss the controlling factors of complex lithofacies, so as to restore the paleo-sedimentary environment and establish the sedimentary models. Salt lake can be divided into two types of sedimentary environments including basin margin and intra-basin, and five types of sedimentary facies zones are developed. The beach slope facies zone, steep slope facies zone and gentle slope facies zone are developed in the basin margin sedimentary environment, and the underwater high facies zone and the profound water facies zone are developed in the intra-basin sedimentary environment. There are three evolutionary stages from the bottom to the top of the upper section of the Lower Ganchaigou Formation:semi-salt lake, salt water lake, and salt lake, corresponding to three lithological associations of carbonate rocks and calcareous sandstone, anhydrite-rich carbonate rocks and mudstones, and thick-bedded salts and thin-bedded carbonates. The distribution of sedimentary lithofacies is controlled by the differences of chemical, biological and physical sedimentation, and the main controlling factors of sedimentation are climate, paleo-geomorphology,and tectonic movement.

A series of petroleum exploration discoveries have been made in Qixia Formation of Middle Permian in Sichuan basin, which has great resource potential. However, the previous research on the petrological characteristics and sedimentary environment of Middle Permian Qixia Formation in Guang'an area is weak. On the basis of geological survey, combined with petrology and petrography, the authors studied the carbonate rock characteristics, sedimentary facies types,and paleo-geographical distribution characteristics of Qixia Formation. The result shows that there are seven rock types developed in Qixia Formation in Guang'an area, including sparry bioclastic limestone, sparry granular limestone, microcrystalline bioclastic limestone, microcrystalline granular limestone, biofragmentary microcrystalline limestone, biofragmentary microcrystalline limestone containing biofragmentary microcrystalline limestone, and micritic limestone. The carbonate grains are mainly bioclastic, and spherules in some layers. Paleontological fossils are mainly trilobites, brachiopods, foraminifera, as well as echinoderms and algae. In the deposition period of Qixia Formation, the depositional environment was mainly a carbonate platform; in the later stage of Qixia Formation (Member 2), the marginal-platform shoals and intra-platform shoals were well developed, which provides favorable conditions for hydrocarbon accumulation in this area.

A better understanding of the Quaternary paleoclimate process in Songnen plain is of great theoretical significance for the study of the climate-influencing factors on the black soil degradation in this area. Seven sediments sections were collected from Guojia (GJ), Wangou (WG), Pingantun (PA), Yaofenshuiling (YP), Xidi (XD), Hujiadian (H),and Xiaojia (XJ) in the Changchun-Siping segment of Daheishan horst, the south margin of Songnen plain. The magnetic susceptibility, grain size,and chromaticity analyses indicate that the magnetic susceptibility of sediments is mostly characterized by increasing during drying or cold period,and decreasing during wet or warmer period. The color has a great influence on the magnetic susceptibility. The magnetic susceptibility of reddish brown sand or sandy clay is higher than that of light yellow or grayish green sand or sandy clay; while the magnetic susceptibility of light yellow or grayish green sand or sandy clay is higher than that of grayish black sand or sandy clay. The presence of carbonate or limestone in the source area makes the relationship between sediment chromaticity and magnetic susceptibility relatively complex. On the studied profiles, the magnetic susceptibility increases with the increase of grain size. Freeze-thaw or rainy can increase the grain size, and cause high magnetic susceptibility, however, in a warmer period, the magnetic susceptibility is reduced by the decrease of source supply. The three indicators comprehensively reflect that the seven sections experienced a paleoclimate environment process of a cold and dry in Early Pleistocene, cold and wet-warm and wet-cold and dry in Middle Pleistocene, and cool and wet in Late Pleistocene.

Many aspects of Sedimentology are promoted by Comparative Sedimentology in recent eras, which shows the great significance of Comparative Sedimentology to the development of Sedimentology. At present, it is widely used in the inference of the facies models, the prediction of sedimentary facies belts,and the prediction of reservoirs & their heterogeneity. Comparative Sedimentology is a branch of Sedimentology, which uses the selected variables of the compared object to build its spatio-temporal model, and further to predict the distribution of the dependent variables. Two steps should be included in a complete Comparative Sedimentology process:comparative modeling and inferential prediction; in other words, according to the analogy principle of comparative sedimentology, probability reasoning is carried out on the basis of identifying natural cycles and induced cycles. Its research methods include the local facies pattern analysis, the geometric morphology analysis, the sediment loading dispersion system analysis,and the simulation reconstruction, which are normally combined with sequence stratigraphy. The typical research results in recent decades have been comprehensively analyzed on the basis of the principles and methods of Comparative Sedimentology. It can be predicted that the further research of Comparative Sedimentology will concentrates on boundary conditions, multi-scale unification, and quantification to improve prediction accuracy.

The tempestites are developed in Eocene Pinghu Formation in Tiantai area in Xihu sag,and the discovery of tempestites has great paleo-graphical and paleo-environmental significances. According to core observation, the storm-generated sedimentary structures are identified, including scouring-filling structure, storm tearing structure, and hummocky cross-stratifications, etc. Through analyzing the lithofacies and sedimentary structures, two types of tempestites, near source and far source, are distinguished. The near source tempestites show incomplete storm sedimentary sequence units, and are dominated by storm-generated grave layers(A)+mud beds(E), indicating sedimentary environment of subtidal zone of tidal flat; while the far source tempestites show incomplete or complete storm sedimentary sequence units, and are dominated by graded members (B)+parallel laminations (C)+hummocky cross-stratifications(D), indicating shallow near storm wave base environment. The sequential depositional evolution of tempestites is from shallow sea shelf to tidal flat upwardly. The discovery of tempesites in the study area provides an important basis for the research of the evolution of paleo-environment.

The Carboniferous Donghe sandstone in Tarim basin is a typical deep-buried marine clastic reservoir in China, which has good physical properties and strong heterogeneity influenced by carbonate cements. In order to predict the beneficial zones of high quality reservoir more accurately, the authors studied the sedimentary characteristics and genesis of the carbonate cements in Donghe sandstone through core observation, variety of thin section identification, carbon and oxygen isotope, and cathodoluminescence analyses. It indicates the sandstones on foreshore and upper shore face are rich in oil, while the oil-free sandstones contain four types of carbonate cement:Ⅰ-biological burrow type, Ⅱ-bedding-laminae type, Ⅲ-thin calcareous sandstone intercalated in thick sandstone type, and Ⅳ-calcareous sandstone globular type. The carbonate cements include more calcite and some ferro-calcite, which usually fill in the intergranular and intragranular dissolved pores. The genesis of carbonate cements in Donghe sandstone is more organic acid decarboxylation in type Ⅱ and type Ⅲ lithologic associations; and some of the type Ⅰ and type Ⅳ are biogenesis and outcrop sedimentology. The key reason of heavy δ¹³C in the study area is the erosion and solution of Ordovician carbonate rocks from the eastern Lunnan low salience.

Experimental data of the major elements, trace elements and rare earth elements of the dark argillaceous slate from the Upper Permian Linxi Formation in Well Heifudi 1 of the northern Songliao basin were examined so as to discuss the geochemical characteristics, sedimentary environment and tectonic background of the Linxi Formation. The average content of major elements is SiO₂=65.05%, Al₂O₃=17.23%, CaO=2.58%, Na₂O=2.84%, and K₂O=3.29%. K₂O/Na₂O is 0.20-3.48, and A1₂O₃/(CaO+Na₂O) is 0.41-8.01. The ΣREE is between 80.68×10^-6 and 215.59×10^-6 (average 173.41×10^-6), the δEu negative anomaly is between 0.61 and 0.88 (average 0.70), and the Ce negative anomaly is between 0.91×10^-6 and 1.01×10^-6, relatively weak. The clastic rocks are characterized by LREE enrichment and HREE depletion. The trace elements are characterized by a loss of Nb, Ta, and Sr, and are relatively rich in Rb, Ba, La, Ce, Pb, Nd, and Sm. The elemental analysis of core samples and the results of w(TiO₂)-w(Ni)and La/Th-w(Hf)indicate that the sediment source of Linxi Formation is diverse, mainly from felsic rock of the upper crust with a minority of intermediate-basic igneous provenance. The results of trace element standardized spider web map, rare earth element chondrite standardized partition pattern,diagrams of K₂O/Na₂O-w(SiO₂), Th-Co-Zr/10, F₂-F₁ structural background discrimination,and geochemical parameters comparison indicate that the provenance of Linxi Formation in Well Heifudi 1 is mainly from active continental margin and continental island arc,which would like be formed in the marine-terrestrial transitional to terrestrial environment.

The Wunüfeng pluton is composed of alkaline granites,which is tectonically located at the NW Yalujiang fault in Ji'an area, Tonghua region. To determine its intrusive age and tectonic environment, mineralogical, petrological,and geochronological characteristics,a research of the pluton was carried out. The LA-ICP-MS zircon U-Pb age of sample JWNF01 is (110.50±1.60)Ma, belong to the late Early Cretaceous. The pluton has high content of SiO₂, Na₂O+K₂O, Al₂O₃ and low content of TiO₂, and belongs to high-K Calc-alkaline series. The A/CNK values are 0.98-1.00, belong to meta-to weak peraluminous rocks. The solidification index (I_S) is 0.80-3.20, reflecting that the rocks experienced high differentiation. δEu is 0.05-0.37, strongly depleted of Eu, LREE/HREE and (La/Yb)_N values are 7.13-24.68 and 7.01-39.20 respectively, indicating that LREEs are enriched and HREEs are depleted, clear fractionation of LREE and HREE. Meanwhile, the Wunüfeng pluton is clearly rich in LILEs (e.g., Rb, K, Th, U), slightly rich in HFSEs (e.g., Nd, Sm, Zr, Hf),and poor in P, Ti. The mineralogy, geochronology, petrology,and regional geological information show that Wunüfeng pluton belongs to high-K Calc-alkaline A-type granite, which was formed in an extensional tectonic background during post-orogeny period.

The structure of Tangyuan fault depression is complex,and its transformation is strong,which leads to the uncertainty of the original sedimentary subsidence center,and this, in turn, restricts the progress of oil and gas exploration. Starting from the calculation of denudation amount by using the stratigraphic trend method and the vitrinite reflectance method, the authors obtained the amount of stratum denudation of Baoquanling Formation,Dalianhe Formation, and Xin'ancun Formation, and restored the shape of the prototype basin in different periods combined with earthquake and structural features and the geological modeling technology. Through the calculation and recovery,it is considered that during Xin'ancun Formation period,the thickest part was in the eastern boundary,and the eastern sedimentary zone was formed by the influence of paleo-tectonics, and was divided by the middle uplift into two parts,the north and the south,the subsidence center was located in the middle section of the fault in the eastern boundary. During the Dalianhe Formation period,the two early subsidence zones gradually merged into one zone, the north of the eastern boundary,with some small subsidence zones in the west and south of the fault depression, and the thickest part was still located in the descending plate of the eastern fault zone. During the Baoquanling Formation period,the two early (eastern?) subsidence zones were completely merged into one zone,and the subsidence zone in the western part of the fault depression was formed and enlarged,thus the east and west subsidence centers were formed.On the above,the pattern of prototype basin,the distribution,and migration process of the sedimentation centers in different periods are finally clarified.

Black soil in middle and high latitudes is an important "stabilizer" for global agricultural production due to its high fertility and other good properties. The study of the formation and evolution of black soil in the world has flourished since the 19th century. However, the definition, characteristics, classification and research degree of black soil in different areas are different, which restricts the research of the influencing factors of black soil productivity and hinders the sustainable utilization of black soil resources to a certain extent. In this paper, the global black soil researches were systematically sorted out, the definition, characteristics, classification, and formation and evolution of black soil were analyzed, and the scientific research methods and development trend of black soil formation and evolution were discussed. Broad sense black soil includes mainly black soil and chernozem, meadow soil, albic soil, dark brown soil, and brown soil, etc. Its formation is mainly controlled by five natural factors:climate, topography, vegetation, soil parent material, and hydrology. The factors make the black soil different in nature and forming types, and the soil properties show certain different characteristics. The experiments such as spherical chemical analysis, sporopollen analysis, and particle size analysis are used to simulate the formation environment of black soil. Advanced scientific methods, such as model construction, spectral analysis, geographic information technology, image interpretation, and dynamic monitoring are used to predict the degradation of black soil, and the results provide a solid theoretical basis for the protection of black land.

High content of tuffaceous clastic rock reservoirs are widely developed in Tongbomiao Formation and Nantun Formation in the central oil-rich depression of Hailar-Tamucage basin,but the genetic mechanism is unclear. Based on the comprehensive analyses of core, logging, well logging and thin section data, combined with the volcanic events in Hailar-Tamucage basin and its surrounding areas, it is considered that the high tuffaceous clastic rocks developed in the middle oil-rich depression include mainly tuffaceous sandstone, tuffaceous mudstone, and tuffs. In different periods, the development characteristics of high content tuffaceous clastic rock reservoirs are different in different depressions. As a whole, the tuffaceous content in the reservoirs from Tongbomiao Formation to Nantun Formation is getting lower and lower. The high tuffaceous clastic reservoir is mainly developed in the sedimentary period of Tongbomiao Formation and the lower part of Nantun Formation. The volcanic material in the high content tuffaceous clastic rock reservoir is not derived from the basic volcanic activity in the fault depression period, but from the large-scale acidic volcanic eruption event in Daxing'anling area. There are two types of genetic mechanism of the high content tuffaceous clastic reservoir in Hailar-Tamucage basin:one is the direct air drop type of volcanic ash in the same sedimentary period, and the other is the water carrying type that the volcanic ash first dropped on the land and then deposited after being transported in the same sedimentary period. The pyroclastic material in the high tuffaceous clastic rock reservoir is easy to be dissolved by organic acid to form the secondary pores, which provided effective reservoir spaces for the deep oil and gas accumulation, and the volcanic eruption promoted the formation of high-quality source rocks, which is of great significance for oil and gas exploration.

In order to overcome the obvious limitations of the depth and breadth of single-hole data in previous reservoir description, the authors propose a method of well-seismic joint geological modeling. Firstly, based on the horizon data and fault data of fine seismic interpretation and combined with logging data,a structural model is established. Then the probability of the seismic inversion body is used to control the sedimentary microfacies, and the vertical probability distribution curves of each microfacies are classified and statistically analyzed. Further,based on the analysis of the variogram data, a sedimentary facies model is established through algorithm simulation of spatial distribution of microfacies. Finally, the reservoir attribute model is established by using facies control technology and geostatistical theory to analyze the characteristics of parameter regionalized variables. The verification results in the B1DD block of Salto oilfield in Daqing show that a large number of small faults are found through application of seismic data, the breakpoint combination rate is increased by 15%, and the prediction coincidence rate of sandstones over 2 m reaches more than 90%. The prediction accuracy of faults and sandstones between wells is improved, and the accuracy of geological models, especially the models between wells, is also improved through the application of this joint modeling method.

Drilling of salt paste layers is one of the problems of current drilling technology. During the drilling construction, there are problems such as the difficulty in safe drilling of salt paste and soft mudstone layers, control of well quality, and high probability of stuck drilling, etc. Based on the formation conditions of Halfaya oilfield in Iraq, the authors changed the casing sealing point of salt-gypsum interval,effectively controlled the casing leakage,and optimized the angle of directional trajectory well from 71.29° to 29.48°, thus avoided the well sections that are easy to form rock chip beds and the well stuck in the directional sections, hereby the drilling efficiency was improved by 23%. The shrinkage period of soft mudstone in Halfaya oilfield is determined to be 48 h approximately. Drilling according to the diameter reduction law effectively reduced the formation of mud packs at the bit and mud rings. Through this study,the principle of controlling the density of saturated brine drilling fluid according to the content change of gypsum rock and salt rock is determined, and the on-site maintenance technical measure for viscosity control of saturated saline drilling fluid is formed.

The sand-bodies of Fuyu reservoir in Songliao basin are thin in thickness, unstable in distribution, and great in lateral variation. To accurately identify and characterize the spatial distribution of single-layer sand-bodies and rationally and effectively design the drilling trajectory of horizontal wells are the keys to ensure the effective development of horizontal wells. By using pre-stack phased inversion,multiple inversion,and constrained sliding thresholds by encrypted isochronous frames,the thin sand-bodies are finely characterized. In consideration with the characteristics of the sand body of Fuyu oil layer in this area, combined with the structural fractures and the distribution of thin sand-bodies,the authors design the horizontal well trajectories through the reference wells to determine the encountered sand-bodies and their petroleum-bearing property, and the sandstone encounter rate of horizontal wells is 99.5%.

The stress change has an important influence on the irreducible water saturation in the process of coalbed methane development. A series of nuclear magnetic resonance (NMR) experiments were performed on the coal samples from different rank coal reservoirs, the T₂ cut-off value was calibrated by the empirical determination method of spectral pattern,the variation of irreducible water saturation with stress in different coal rank reservoirs was evaluated, and further, its dynamic changes with the development of coalbed methane in the study area were also predicted. The experimental results show that the irreducible water saturation has a strong stress sensitivity, and its change is the strongest at the initial stage of effective stress increase. Due to the difference of pore structure, the stress sensitivity is more intense in Baode block. The predicting result in Baode block shows that the total variation of initial irreducible water saturation affected by buried depth is smaller than that in Hancheng block because of the small variation range of buried depth in Baode block. In the process of coalbed methane development, the irreducible water saturation of shallow buried reservoirs has a stronger stress sensitivity, but the overall increase is basically the same at the end of the development process.

At present, the existing conventional oil and gas well production profile testing methods have limitations such as testing range and measuring technology,low construction success rate,and poor adaptability in coalbed methane wells. In order to make an improvement, a systematic design and development of coal-bed gas well production profile testing technology were carried out. Through the compact structure design and high integration, a set of coalbed methane logging instrument has been developed, which can simultaneously measure the temperature, pressure, magnetic positioning, thermal flow, probe gas, microwave gas, turbine flow, ultrasonic flow,and other multiple parameters. A multi-purpose one-time testing technology for single well coal bed methane production logging profile has been developed. A multi task and multi window portable ground system operation has been developed, and a new type of eccentric testing wellhead has also been developed and applied to coalbed methane well to realize continuous testing during workover. The technology was tested in three coalbed methane wells in north Shilou block, Ordos basin, the test data obtained are accurate and continuous,and the anti-interference ability are improved. The test results show that the 8^#+9^# coal seam in north Shilou block is the main gas and water producing layer.

Aiming at the gas and water distribution and control factors needed for the efficient and sustainable development of low-porosity and low-permeability tight sandstone gas reservoirs, a comprehensive analysis of gas reservoir geological and production dynamic data was conducted in the East 2nd area of Sulige gas field. The results show that:1) the geological structure and the intensity of hydrocarbon generation control the macro-pattern of gas-water distribution in this area, and the gas reservoirs are developed on the low-lying part or micro-structure near the source rocks; 2) the physical parameters of reservoir play a key role in controlling the gas-water distribution; 3) the sand bodies with good physical properties have less capillary resistance, and natural gas is more likely to displace the formation water in sandstone reservoirs to form gas layers. The porosity of the gas layers in the study area is between 7% and 14%, and the permeability is between 0.50×10^-3 and 2.00×10^-3 μm². The factors such as mudstone barriers complicate the gas-water distribution. The thickness increase of the mudstone barrier in the first Member of Shanxi Formation leads to the decrease of daily gas production but increase water production in the 8th Member of Shihezi Formation in the corresponding area. It is concluded that the production capacity of tight sandstone gas reservoirs is greatly affected by the development method. The pressure sensitive and velocity sensitive effects should be considered for a reasonable production allocation of gas reservoirs:the longer the production time is, the greater the production pressure difference is, the faster the gas well water production rate, and the larger the water production volume. The horizontal well development can increase the drainage area of gas wells, and it can, in turn, reduce the production pressure difference and the water-gas ratio, increase productivity, and extend the water-free or low-water gas recovery period and recovery ratio.

The volcanic rocks are widely distributed in the fault depression of the southern Songliao basin. After the recent breakthrough in the exploration of the middle-basic volcanic rocks in the south of Changling, the research on the characteristics of volcanic gas reservoirs has become the hot topic again. The volcanic reservoirs are characterized by vertical multi-periods and horizontal multi-phase zones with strong heterogeneity. Based on the data of several years exploration in the southern Songliao basin, many proxies have been applied to describe the characteristics of volcanic reservoirs from macroscopic to microscopic scales, such as core description, casting thin sections, and scanning electron microscope and CT scanning. Twelve kinds of effective volcanic reservoir types are recognized, and they are categorized into three groups. Among them,the widely development of two integrated reservoir types, "porosity + dissolution" and "pore + seam network", is the key point for the development of effective reservoirs in volcanic rocks. The controls of volcanic structure-lithofacies type, tectonic settings, exposure duration, and effects distance to hydrocarbon-generating source on the development of effective reservoirs in volcanic rocks are preliminarily summarized.

Deep oil and gas exploration is an important replacement area for oil and gas resources in the future. Since the oil and gas exploration of the Lower Carboniferous-Permian coal-series source rocks in Bohai Bay basin has made new breakthroughs, it has become a research hotspot in the deep oil and gas field. The high-yield condensate gas flow has been obtained in the newly deployed Well QG8 and Well YG1 in the Dagang exploration area, and the source identification is the key to deep oil and gas exploration. The analysis result indicates that the condensate from well QG8 and Well YG1 is light oil with low viscosity and density. The condensate has high pristane (Pr/Ph>2.8),and the stable carbon isotope (δ¹³C) of n-alkanes and aromatic hydrocarbons of Well QG8 condensate is -29.1‰ and -26.8‰ respectively. The δ¹³C₁ of natural gas is heavier, ranging from -39.7‰ to -36.4‰ with drying coefficient more than 0.8,and the heavy hydrocarbon content is higher, up to 16.2%,belonging to wet gas prone to dry. It is found that the characteristics of condensate oil and gas of Well QG8 and Well YG1 are similar in stable carbon isotopes in extracts (saturated hydrocarbons δ¹³C=-29.26‰—-26.87‰, aromatic hydrocarbons δ¹³C=-26.62‰—-24.15‰, natural gas δ¹³C₁=-43‰—-35‰,and crude oil physical properties of density is 0.757 1-0.840 2 g/cm³), indicating that the condensate oil and gas come from the Carboniferous-Permian coaly source rocks. It is confirmed that the Carboniferous-Permian coaly source rocks in Bohai Bay basin have hydrocarbon generation potential and oil-gas exploration prospect.

The physical characteristics and genesis of the upper part of the 3rd member of Eocene Shahejie Formation (E₂s₃^u) in Kenli L oilfield of Laizhou Bay sag in Bohai Bay basin were clarified by using a variety of analyses and testing methods, such as casting thin sections, SEM, X diffraction, pore permeability test and drilling test, combined with the related research results of regional tectonic setting and sedimentary system, the physical properties control factors of E₂s₃^u were discussed, and applied in oilfield water injection development. The results show that:the reservoir of E₂s₃^u with the average porosity of 28.9% and the average permeability of 762.7×10^-3μm² belongs to "high porosity-permeability" reservoir,the reservoir space is mainly primary intergranular pores with secondary intergranular pores, mold holes, and micro-fractures; the average width of the micro-fractures is 180 μm, the existence of the micro-fractures provided a highly efficient seepage channels, which makes drilling test pore permeability is obviously better than that through core test. The physical properties of high quality reservoirs are mainly affected by system tract, fault activity and burial, the thick net sandstone under transgressive system tract is the material basis of forming high-quality reservoirs; the developed micro-fractures improved seepage capacity; rapid burial slowed the drainage of reservoir pore water and the decline of reservoir physical properties. Based on high-quality reservoir development characteristics and production dynamic data, optimizing layered allocation of water wells, reducing uneven water flooding in the horizontal and vertical directions, and then Kenli L oilfield achieved balanced displacement.

Southeastern Sichuan basin and its marginal transition zone (hereinafter referred to as the basin-margin transition zone of SE Chongqing) is the focus of normal-pressure shale gas exploration in China. In order to understand the law of the shale gas enrichment in the southeastern Chongqing, to optimize the rough layers of horizontal well, and further guide the three-dimensional development and construction of the multi-layer system, the relationship between shale pressure system and the development of organic pores was studied by using the image quantitative characterization technology based on scanning electron microscope and the experimental analysis results of triaxial mechanics and liquid nitrogen adsorption. The results show that the organic pore size is small(1-30 nm) in the lower part of Wufeng-Longmaxi Formation shale,but the density of pore development is high(55.55-808.03 count/μm²). The organic pore size is high(30-50 nm) in the upper part,but the density of pore development is small(47.31-466.42 count/μm²). There is a significant positive correlation between pressure coefficient and roundness of organic holes. With the increase of fluid pressure in the pore, the pore will not be deformed by the overburden formation pressure, so that the pore can be better preserved. volume fractal dimension based on liquid nitrogen adsorption experiment show that the increase of fluid pressure in the pore can support the pore better, and ensure the difference of organic pore development is the common result of overburden formation pressure and pore fluid pressure. For the atmospheric pressure area, the pressure of overlying strata has important influence on pore development. For the overpressure zone, the increase of fluid pressure in the pore will slow down the deformation and disappearance of the pore. The realization of triaxial mechanics shows that the existence of Guanyinqiao Formation will increase the compressive strength of rock, thus forming a pressure partition in the vertical direction, resulting in the difference of pressure coefficient between the upper and lower layers, forming different subpressure systems, resulting in the difference of pore development characteristics.