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01 January 2019, Volume 39 Issue 3 Previous Issue    Next Issue

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Structure Deformation Characteristics of Wubaiti Area in the Eastern Sichuan Basin ZHOU Lu1,2,3, ZHANG Xinji2, ZHONG Kexiu4, WU Yong2,5, ZHANG Qiaoyi2, LIU Yi2 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180301 Abstract ( 133 )   PDF (300KB) ( 69 )   Save Based on the comprehensive analysis of drilling and logging data and the fine structural interpretation of 3D seismic data of Wubaiti area in the eastern Sichuan basin, the paper establishes a 3D structural model, studies the characteristics of structure deformation in the area by combining with typical seismic interpretation sections, and concludes that the structural deformation in the area is featured with zonation vertically and segmentation in the plane. 5 sets of structural layers are vertically separated by 4 sets of detachment layers. The structure below the Cambrian gypsum-salt bottom is simple with a few fractures in it and is represented by low-amplitude uplift; the structure between the top of the Cambrian gypsum salt layer and the bottom of the Silurian is controlled by the Cambrian gypsum salt layer, in which fault-propagation folds are developed; the structure between the Silurian bottom and the Permian bottom controlled by the Silurian shale detachment layer is represented by anticline; the structure between the Permian bottom and the bottom of 4th member of the Lower Triassic Jialingjiang formation controlled by the Permian coal detachment layer is represented by duplex and anticline; the structure above the bottom of the Upper Triassic Xujiahe formation which is consistent with the main structure and locally controlled by the gypsum-salt layer of the Triassic Jialingjiang formation is represented by wide and gentle anticline. According to the deformation differences among the Cambrian post-salt structures, the deformation can be divided into 3 segments such as southwestern segment, middle segment and northeastern segment in the plane. Combining the deformation degree of each structure with the characteristics of onlap and truncation of the top of the Sinian pre-salt paleo-uplift, it is considered that the pre-salt structure in the northeastern segment has the best oil and gas preserving conditions and can be the favorable target for deep strata exploration Related Articles | Metrics

Reef Flat Sequence and Geological Structure of Platform Margin in Lianglitage Formation in Well Zhong-2, Tarim Basin ZHAO Lina1, TAN Fei2, SHUN Yaobin2, SHA Xuguang1, WEI Huadong1, WANG Feiyang2, WANG Zhenyu2,3 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180302 Abstract ( 75 )   PDF (300KB) ( 334 )   Save Well Zhong-2 is the first exploration well drilled into the upper Ordovician Lianglitage formation on the southern slope of Tazhong area. The establishment of reef-flat combination sequence and the analysis on geological structure of platform margin on the southern slope of Tazhong area based on the data of core, thin section and 3D seismic are of great significance to understand geological features in the area and to guide next exploration. There are 7 medium-high-energy sedimentary cycles of grain shoal, reef knoll, micrite mound and thin interbedded interbanks in Lianglitage formation of Well Zhong-2 vertically with high overall sedimentary energy. 4 typical reef-flat facies combinations are developed in the formation including combination A (grain shoal→micrite mound→reef knoll→grain shoal), combination B (interbank→grain shoal→micrite mound→grain shoal), combination C (interbank→grain shoal→reef knoll→grain shoal) and combination D (interbank→grain shoal), and combinations of B and D are dominant. The geological structure of platform margin on the southern slope of Tazhong area is a typical platform margin of sedimentary steep-slope type which is similar to that of the eastern section of the northern slope and has a broader marginal belt with the width of 4~6 km. The reef flat facies is widely distributed in the inner side of the platform marginal belt. Well Zhong-2 is located at the transitional position from platform margin facies to foreslope facies. The size of a single reef/mount is relatively small and serious crush occurs to reef-building organism in the reef front or the area adjacent to the slope of the platform margin. The main part of reef flat facies is located in the area next to the inner side of the platform marginal belt in the well. It is suggested that the later exploration should revolve around these zones Related Articles | Metrics

Tectonic Transition Relationship between Shawan Sag and Western Well Pen-1 Sag and Its Geological Significance WU Songtao1, LIANG Yusheng1, ZHANG Lei1, TIAN Aijun2 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180304 Abstract ( 98 )   PDF (300KB) ( 113 )   Save Based on the seismic and drilling data and combining with geological sections, the paper discusses the the structural geometry and the characteristics of movement of the transitional zone from Shawan sag to the western Well Pen-1 sag by using fault-related fold theories. The study shows that a paleohigh exists in the transitional zone, which exhibits a NW-SE trending, irregular strip. Based on which, through the structural model establishment of the transitional zone from Shawan sag to the western Well Pen-1 sag, it is considered that the basement of the paleohigh had a pattern of “uplift plus semi-graben” and was controlled by both back-thrust reverse basement fault and extensional normal fault, and changed to a pattern of “sole uplift” after the Middle Permian. The forming process of the paleohigh can be divided into 5 periods such as the prototype period from the Late Carboniferous to Early Permian, the development period at the early Middle Permian, the peak period at the late Middle Permian, the inherited period from the Late Permian to Middle Jurassic and the reconstruction period from the end of the Middle Jurassic up to now Related Articles | Metrics

Controls of Abnormal Fluid Pressure on Tectonic Deformation in Northeastern Sichuan Basin FAN Huida, HE Dengfa, ZHANG Xuliang 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180305 Abstract ( 48 )   PDF (300KB) ( 33 )   Save To investigate the influences of abnormal fluid pressure on structural deformation in the northeastern Sichuan basin, on the basis of drilling and logging data obtained from 40 wells in the study area, the paper uses equivalent depth method to calculate fluid pressure in the shale section and corrects the pressure by combining with the actual measured fluid pressure to characterize the characteristics of the overpressure development in the study area and to match the variations of the fluid pressure with depth. The pore-fluid pressure ratio of different detachment layers in the northeastern Sichuan basin are calculated. The calculated pore-fluid pressure ratio is 0.38~0.72 for the gypsum-salt detachment layer in the Lower Triassic Jialingjiang formation, 0.48~0.78 for the shale detachment layer in the Lower Silurian Longmaxi formation, 0.61~0.87 for the gypsum-salt detachment layer in the Lower Cambrian Longwangmiao formation and 0.71~0.84 in the basement detachment layer, showing a feature of “lower in the east and higher in the west”. The pore-fluid pressure ratio of each detachment layer is used to obtain effective friction coefficient and the calculated effective friction coefficient of each detachment layer is 0.170~0.530, 0.130~0.320, 0.110~0.330 and 0.090~0.180 for Jialingjiang formation, Longmaxi formation, Longwangmiao formation and basement, respectively. Based on the through-well seismic profile interpretation, the intensity of the basement detachment layer is calculated as 0.060~0.110 by using structural wedge-related theories. Comparing the intensity with the effective friction coefficient, it is found that they are identical with each other, which can prove that the calculated effective friction coefficient of the basement detachment layer is reliable. When the fluid overpressure is not developed in the study area, the effective friction coefficient of the basement detachment layer should be 0.372~0.527, which indicates that the widely-developed fluid overpressure in the study area results in the reduction of the effective friction coefficient of the basement detachment layer by 79.1%~83.9%, indicating that the tectonic stress needed by shear action along the basement detachment layer significantly decreases Related Articles | Metrics

Quantitative Evaluation of Activities for Contemporaneous Reverse Faults and Associated Folds: A Case Study of Huwan District in Northwestern Margin of Junggar basin XIA Qinyu1,2, WU Shenghe2, FENG Wenjie3 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180306 Abstract ( 100 )   PDF (300KB) ( 233 )   Save The paper quantitatively analyzes the activities of the contemporaneous reverse faults and the associated folds in Triassic Karamay formation of Huwan district in the northwestern margin of Junggar basin by comprehensively using growth index and fault throw, and discusses the correlation between the activity intensities of the contemporaneous reverse fault and the associated fold. The research shows that the activity intensity of Karamay fault which is a primary-order contemporaneous reverse fault is much higher than those of other small-scale contemporaneous reverse faults. The analysis of strata denudation restoration indicates that the activity intensity of the associated folds gradually increased during the deposition of Karamay formation. It is further found that the parameters of the associated folds well correlate with those of the activity of contemporaneous reverse faults. The length, width, rising amplitude and activity intensity of the associated fold are linearly positively correlated to those parameters of the faults, the structural area of the associated fold exhibits an exponential relationship with the activity parameters of the fault, and the rising amplitude of the associated fold well correlates to the growth index and fault throw of the fault Related Articles | Metrics

Characteristics and Genesis of Low Oil-Saturation Reservoir in the First Member of Hutubihe Formation in Wellblock Lu-9, Luliang Oilfield REN Peng1, WANG Weifeng1, CHEN Gangqiang2 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180307 Abstract ( 87 )   PDF (300KB) ( 123 )   Save Based on the data of seismic, formation test, logging and core analysis, the paper systematically analyzes the characteristics of the low oil-saturation reservoir in the first member of Hutubihe formation in Wellblock Lu-9, Luliang oilfield. The results show that the reservoir is characterized by low amplitude, multiple stratigraphic series, one reservoir in one sand body and active edge and bottom water. The reservoir distribution is controlled by structure and lithology and relatively wide oil-water transition zone generally exists in the reservoir. The low oil-saturation reservoir formed far away from hydrocarbon generating center with complicated accumulation process, leading to insufficient differentiation of oil and water in traps, which is the main reason for the low oil saturation of the reservoir. Additionally, low structure amplitude, wide distribution of clay minerals and high saturation of bound water in the reservoir are the reasons resulting in insufficient pore water displacement by hydrocarbons and low oil saturation of the reservoir Related Articles | Metrics

Sedimentary Texture and Reservoir Distribution of Platform Margin Reef-Flat Zone in Changxing Formation of Northeastern Sichuan Basin YAN Zhanglei1,2, XING Fengcun1,2, DUAN Jinbao3, HU Huarui1,2, WU Siyue4 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180308 Abstract ( 67 )   PDF (300KB) ( 175 )   Save Using the data of outcrop, drilling, laboratory analysis and seismic, the paper compares the sedimentary textures and reef-flat reservoirs of 3 sets of platform margin zones developed on the east and west sides of Kaijiang—Liangping continental shelf and the west side of Chengkou—Exi trough during the Changxing Period of the Late Permian in the northeastern Sichuan basin, and identifies 2 sedimentary textures of migration-aggradation type and aggradation type. The platform margin zone of migration-aggradation type mainly consists of 2 platform margin zones of Yuanba—Longgang—Xinglongchang and Zhenba—Chengkou—Lichuan, the biological reef flat has an obvious steep-gentle alternating structure, the platform margin slope and reef flat in the gentle slope area are characterized by significantly migration and wide distribution, and obvious aggradation occurs in the steep slope area. The platform margin zone of aggradation type is dominated by the platform margin zone of Tiechanghe—Puguang—Luojiazhai, in which the geomorphology is different laterally, and platform margin reef flats are developed concentratedly and have no obvious migration. Both the palaeogeomorphology and sea level changes during deposition controlled the development of platform margin reef flat and the overall reservoir distribution. Biological reef flat is mainly distributed in the middle—upper parts of highstand system tract, dolomite reservoir was generally developed at the late HST period and the thickness of the dolomite reservoir in the steep slope area is larger than that in the gentle slope area. The reservoir distribution is featured with obvious vertical difference and segmentation. The dolomite reservoir tends to form in the platform margin zone of aggradation type in the first member of Changxing formation and slightly strong dolomitization is noted in the steep slope area. Contiguous dolomite reservoir tends to form in the migration-aggradational platform margin zone in which multiple rows of biological reef flat co-exist in the second member of Changxing formation, and relatively narrow dolomitized belts are distributed in the aggradational platform margin reef flat Related Articles | Metrics

Geometry and Kinematics of Wensu Swell in North Tarim Uplift CHEN Jiajun, HE Dengfa, SUN Fangyuan, HE Lei 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180309 Abstract ( 60 )   PDF (300KB) ( 83 )   Save Wensu swell is located in the northwestern margin of Tarim basin, which belongs to western segment of North Tarim uplift. As a part of paleo-uplift in the cratonic basin, Wensu swell is an ideal object for studying the deformation behaviors in the interior of tectonic plates. Based on drilling data, logging information, 2D seismic data, Digital Elevation Model（DEM）and geological map and combining with the stratigraphic texture of periphery areas, the paper characterizes the geometries of Shajingzi boundary fault and Wensubei fault detailedly, and establishes a geometric and kinematic model with the guidance of fault-related fold theories. The study results suggest that Wensu swell is an inherited upwarping zone controlled by Shajingzi fault, Wensubei fault and basement uplift. Shajingzi fault was developed as fault propagation fold mode at the early stage, then broke through along the forelimb of the fold at the late stage and transtensional faults occured during the late Quaternary. Wensu swell formed at the end of Early Ordovician; its structure was shaped under the influence of the closing of South Tianshan Ocean at the end of Permian; Wensu swell stepped in relative tectonic silence stage during Mesozoic and strongly deformed due to the South Tianshan orogenesis during Cenozoic. Wensu swell and the peripheral area are shortened by about 35.40 km totally. Fine fault analysis, especially the staged fault analysis can be a breakthrough method to analyze complicated structures Related Articles | Metrics

Phase Behavior and Rheological Properties of Emulsions Based on Janus SiO2/PS Nano-Particles CHEN Xi1,2, MA Desheng2, TIAN Maozhang2, SONG Xinmin2, WU Chaodong1, HAN Lu2, LIANG Fuxin3 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180310 Abstract ( 91 )   PDF (300KB) ( 250 )   Save Regarding microstate and rheological property, the paper studies the phase behaviors of the emulsions formed by the crude oil obtained from 81# combination station of Karamay oilfield and the aqueous dispersion system of Janus SiO2/PS nano-particles under the conditions of different mass fraction (CS) and different water-oil volume ratio (RWO). Setting CS=0.100%, when RWO≤7/3, stable water-in-oil emulsion is formed by the aqueous dispersion system of Janus SiO2/PS nano-particles and the crude oil, and both the droplet size and viscosity of the emulsion increase with the rise of the water-oil volume ratio; when RWO>7/3, the oil-water miscible liquid has 2 phases—the upper is water-in-oil emulsion and the lower is dominated by water, the viscosity of the emulsion decreases with the increase of the water-oil volume ratio. Setting RWO=7/3, when 0.080%≤CS≤0.300%, oil and water are mixed completely with the emulsion viscosity of more than 60 times of the crude oil viscosity, and the mixture becomes shear thinning at high shearing rate; when CS<0.080% or CS>0.300%, the oil-water miscible liquid has 2 phases and the emulsion viscosity decreases with the increase of the volume of separated water. Setting RWO=4/6, when 0.001%≤CS≤0.500%, oil and water are mixed completely with the emulsion viscosity of 55~75 mPa·s, and the emulsion becomes shear thickening at the shearing rate of 3.00~70.00 s-1. The results show that the aqueous dispersion system of Janus SiO2/PS nano-particles allows the crude oil to form stable, high-viscosity water-in-oil emulsion at relatively high water cut, and within a certain range of water-oil volume ratio, the higher the water cut, the higher the viscosity of the emulsion. The conclusion can provide a new idea for improving sweep efficiency in heterogeneous reservoirs Related Articles | Metrics

Pressure Behavior Analysis of Volume Fracturing in Horizontal Wells in Fractured Tight Oil Reservoirs WU Zhiqia, WANG Houkunb, WANG Ruic 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180311 Abstract ( 116 )   PDF (300KB) ( 144 )   Save Based on Green function, Mirror inversion and pressure superposition principle, a semi-analytical model for pressure behavior analysis is established for volume fracturing in horizontal wells in fractured reservoirs with box-type closed boundaries. This model uses the classical Warren-Root model to show the seepage relationship between matrix and fracture and the spatial distribution of fracturing system in the volume fracturing regions, and takes the pressure interference of adjacent main fractures into consideration. So the reservoir seepage characteristics can be described better and the interpretation parameters are more consistent with the actual situation. The paper uses the model to analyze the sensibilities to parameters such as fracture number, fracture half-length, fracture interval, storage ratio and interporosity flow coefficient. The results show that the response process of bottom hole pressure can be divided into 6 flow stages based on the double logarithm curve chart, i.e., linear flow of artificial fracture, interporosity flow of dual medium, the first radial flow, the second linear flow, pseudo-state radial flow and closed boundary flow. Fracture number has significant influences on the whole response process—the larger the fracture number and the producing pressure drop are, the higher the single well deliverability will be. The growth of producing pressure drop decreases with the increase of the fracture number. There is an optimal economic value in a volume fracturing horizontal well. The single well deliverability and the producing pressure drop at the early production stage will increase with the increase of fracture half-length. If the fracture interval increases, the effective time of the first radial flow will increase and that of the second radial flow will decrease. At the late production stage, the larger the producing pressure drop is, the smaller the growth of the deliverability will be; the smaller the storage ratio is, the more obvious the fluid channeling will be; the smaller the interporosity flow coefficient is, the later the fluid channeling occurs Related Articles | Metrics

Study on Energy Replenishment Mode Selection and Its Limit in Tight Oil Reservoirs HONG Yafei 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180312 Abstract ( 81 )   PDF (300KB) ( 240 )   Save The pore throats are narrow and fluid-solid coupling is obvious in tight reservoirs. Because the implementation results of waterflooding and gas drive are very different in different tight reservoir blocks, selecting reasonable energy replenishment modes is a difficult problem in tight oil production. The paper uses numerical simulation methods to study the effects of different energy replenishment modes for staged fracturing in tight reservoirs in horizontal wells, discusses the main controlling factors of the energy replenishment mode selection and proposes definite limits. The study shows that the difference of permeability is the key parameter to select energy replenishment mode. Compared with pore radius, pore throat radius has more impacts on permeability, which can influence the producing degree and development effect of tight oil reservoirs directly, and meanwhile, can reflect microscopic characteristics of the reservoirs, so it can be a parameter for energy replenishment mode selection. It is considered that the main pore throat radius of 1.5 μm can be used as the limit for energy replenishment mode selection in tight oil reservoirs Related Articles | Metrics

Recognition of Complicated Sandy Conglomerate Reservoir Based on Micro-Resistivity Imaging Logging: A Case Study of Baikouquan Formation in Western Slope of Mahu Sag, Junggar Basin LUO Xingping1, PANG Xu2, SU Dongxu1, LU Hui1, ZHANG Ni1, WANG Gang1 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180313 Abstract ( 85 )   PDF (300KB) ( 383 )   Save Regarding the problems of low resolution of conventional logging data which can’t effectively reflect grain size of sandy conglomerate and taking the sandy conglomerate reservoir of Baikouquan formation in Mahu sag, Junggar basin as an example, the paper proposes a method to automatically recognize lithologies of complex sandy conglomerate reservoirs by using micro-resistivity imaging logging. Firstly, according to the differences in grain size, the sandy conglomerate can be classified into mudstone, sandstone, fine conglomerate, small medium-sized conglomerate and big medium-sized conglomerate. Based on the core calibrating logs, the characteristics of the micro-resistivity imaging logging are analyzed and summarized for different lithologies. With the technology of image processing, 5 characteristic values such as contrast, relevancy, entropy, uniformity and energy of the sandy conglomerate samples are calculated through image gray scale transformation and gray scale co-occurrence matrix establishment. On the basis of multivariate statistics, Bayes discriminant method is used to build lithology discriminant functions for mudstone, sandstone, fine conglomerate, small medium-sized conglomerate and big medium-sized conglomerate and the lithologies of the rocks can be determined. The results show that the lithologies identified by the micro-resistivity imaging logging highly match with those obtained from core analysis and good identification effects have been gained Related Articles | Metrics

Geological Interpretation of Ordovician Carbonate Reservoir in Tahe OilfieldApplication of Imaging Logging Technology ZHANG Chenjia, FAN Tailiang, MENG Miaomiao, WU Jun 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180314 Abstract ( 76 )   PDF (300KB) ( 60 )   Save Formation micro-resistivity scanning imaging logging (FMI) can provide visualized and high-resolution images, which has obvious advantages in describing heterogeneous strata containing complicated reservoir spaces. Combined with the core and conventional logging data, FMI images are used to detailedly describe the key intervals of the Ordovician carbonate reservoir in 8 prospecting wells of Tahe oilfield, and a geological interpretation model is established for FMI logging. The model is used in the non-coring intervals and the lithologies of the Ordovician reservoir are identified, which is dominated by calcarenite, sand-clastic micrite, micrite and calcite dolomite; the reservoir spaces are composed by pores, caves and fractures. The sequence unconformity surfaces can be identified by using resistivity difference, reservoir space distribution and lithological and structural markers displayed in FMI images. Based on the single-well facies analysis and well tie correlation, it is considered that the sequence unconformity surface resulted from tectonic movement, karstfication and regressive erosional dissolution controls the development of the reservoir spaces Related Articles | Metrics

Tectonic Simulation Experiment of Fault Forming Mechanism in Kunbei Fault Terrace Belt WANG Haiqi1, DOU Xiaoyu2, WANG Lin3 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180315 Abstract ( 82 )   PDF (300KB) ( 174 )   Save Various conditions and stress mechanisms result in the complicated tectonic settings of the Kunbei fault terrace belt. 2 series of tectonic simulation experiments are designed for the primary-order and second-order main faults, and the third-order and other secondary order faults, respectively. The first series of experiments simulate the primary-order and second-order main faults and the results reveal that a series of unbalanced thrust fault systems are developed on the Kunbei fault terrace belt under the continuous compression of N-S trending tectonic dynamics during Himalaya orogeny, which highly matches with the 5 seismic interpretation sections in the study area. The second series of experiments simulate the third-order and other secondary order fault structures and suggest that these faults are controlled by the maximum shear stress, in which 2 fault systems including conjugate reverse fault and tearing reverse fault are developed, which matches with the characteristics of fault systems displayed on the time slices in the study area. The numerical simulation results can further verify the conclusions of the 2 series of experiments and show that the secondary fault systems can improve the accumulation properties of reservoirs. Wellblocks of Qie-16, Qie-6, Qie-12 and Qie-4 in Kunbei oilfield have been proved to be the hydrocarbon enrichment areas, which well matches with the experiment results and can be the guidance and references for oil and gas exploration Related Articles | Metrics

Well Test Response Charts of Sand Body Configuration in Fluvial Facies Reservoirs ZHANG Lijun, ZHU Guojin, WANG Shuai, XIAO Dakun, ZHENG Wei 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180316 Abstract ( 62 )   PDF (300KB) ( 176 )   Save Reservoir configuration study is the core of fine reservoir description and then fine characterization of reservoir heterogeneity can be realized. Based on the study of sand body configuration in fluvial reservoirs, numerical well test models are built for percolation resistance areas resulted from the superimposition of different sedimentary sand bodies of fluvial facies and the corresponding well test response charts are established. Based on which the reservoir connectivities of various sediments are determined. Through the well test analysis on sand body superimposition modes, the response characteristics of sand bodies are determined for different thickness and different positions. A case study in a certain oilfield of Bohai Bay has verified the geological configuration results by combining the studies of seismic, logging and sedimentation, which can provide basis for geological pattern study and well allocation in fluvial reservoirs Related Articles | Metrics

History and Current Situation of Shale Gas Exploration and Development MEN Xiaoxi1, HAN Zhihui2, WANG Lei1 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180317 Abstract ( 81 )   PDF (300KB) ( 188 )   Save Under the background of global access to difficult-to-produce reserves and taking the fossil energy as the main energy, the successful development of shale gas in North America sets off a gas revolution worldwide and the self-sufficiency of America’s natural gas supply has been realized. Shale gas is a huge resource in 21st century, which has the advantages of rich reserves, clean, cheap and long-term supply. However, in China and even in the whole world, the exploration and development work for shale gas is not enough and the utilization of shale gas is just the tip of the iceberg. The potential of shale gas resources in China is huge. If it can be developed successfully, not only can ease the shortage of oil and gas resources, but also can change the map of oil and gas resources and even the energy structure, and it is important for energy security and economic development of China. Economic development of shale gas is necessary and urgent to be done; China’s shale gas reserves are huge and the policy support and prospect for its exploration and development are pretty good. Meanwhile, there are still some problems such as complicated geological conditions and difficulties on key technologies. It is necessary to link successful experience of North America with the actual status of China’s shale gas reservoirs, then a shale gas exploration and development road with Chinese characteristics can be created Related Articles | Metrics

Geometrical and Kinematics Characteristics of Selibuya Fault Belt, Tarim Basin ZHANG Yong1, CUI Yongping2, LIU Changlei1 2018, 39 (3):  1-1.  doi: 10.7657/XJPG20180303 Abstract ( 105 )   PDF (300KB) ( 73 )   Save The Selibuya fault belt is one of the boundary faults on the southern margin of Bachu uplift, in which complex fault structures formed under the influence of muti-period tectonic activities in the basin. Studying the geometrical and kinematic characteristics of the Seriyabu fault belt is of great significance in exploring the nature and forming time of Bachu uplift and exploring the causes of structural deformation in the craton. Using fault-related fold theories and other seismic interpretation methods, the paper detailedly interprets and analyzes 8 2D seismic profiles nearly perpendicular to the strike of the Selibuya fault belt, re-depicts the geometry of the fault belt, establishes the 3D shape of the fault belt with 3D modeling techniques, and re-segment the fault belt according to fault assemblages and their distribution patterns. Combining the development characteristics of growth strata and unconformities, the paper also discusses the periods and relative intensities of the structural activities. The study suggests that the Selibuya fault belt is characterized by deep faulting whose activity is the main reason leading to the uplifting of the strata at the northern side of the fault belt. The Precambrian structure proves that the activities of the deep Selibuya faults were tensional at the early stage; according to fault assemblages and their distribution patterns, the Selibuya fault belt can be divided into the northern, middle and southern segments, all of which show stratified deformation patterns. Paleogene gypsum and the Middle Cambrian salt bed are detachment layers of Cenozoic and Paleozoic faults, respectively. The morphology of the growth strata indicate that the Cenozoic faults started their activities during the Quaternary and continued to the present. The development of the unconformity indicates that the basement faulting was active during the Middle-Late Permian with the activity intensity showing stronger in the north and weaker in the south in the fault belt. The Paleozoic active fault period occurred in the Miocene-Late Pliocene and its activity intensity showed weaker in the north and stronger in the south. The basement fault led to the overall rise of the strata, while the the faults of Paleozoic and Cenozoic resulted in the strong fold deformation of the strata Related Articles | Metrics