Differential Hydrocarbon Enrichment and its Main Controlling Factors in Depressions of the Bohai Bay Basin Differential Hydrocarbon Enrichment and its Main Controlling Factors in Depressions of the Bohai Bay Basin

Significant differential hydrocarbon enrichment occurs in depressions in a petroliferous basin.There are multiple depressions in the Bohai Bay Basin, and each depression as a relatively independent unit of hydrocarbon generation, migration and accumulation, contains significantly different hydrocarbon generation conditions and enrichment degree. On the basis of previous documents and a large number of statistical data, this work comparatively analyzed the differential hydrocarbon enrichment and its major controlling factors in depressions of the Bohai Bay Basin. The results show that depressions in the Bohai Bay Basin have various hydrocarbon enrichment degrees, and can be categorized into four types, namely enormously oil-rich, oil-rich, oily and oil-poor depressions. In general, the enormously oil-rich and oil-rich depressions are distributed in the eastern part of the basin along the Tan-Lu and Lan-Liao faults, whereas depressions in the western part of the basin are poor in hydrocarbons. Moreover, the vertical distribution of hydrocarbons is also highly heterogeneous, with Pre-Paleogene strata rich in hydrocarbons in the northern and western depressions, Paleogene strata rich in hydrocarbons in the entire basin, and Neogene strata rich in hydrocarbons in the off-shore areas of the Bohai Bay Basin. From early depressions in onshore areas to the late depressions in offshore areas of the Bohai Bay Basin, the source rocks and source-reservoir-cap rock assemblages gradually become younger and shallower, and the hydrocarbon resource abundance gradually increases. Hydrocarbon supplying condition is the key factor constraining the hydrocarbon enrichment for different depressions,while the main source-reservoir-cap rock assemblage, sufficient hydrocarbons and the transportation capacity of faults control the vertical distribution of hydrocarbons. The main factors controlling hydrocarbon enrichment are different for different layers. The hydrocarbon supplying condition of source rocks is the key controlling factor, whereas the source-reservoir configuration, the main sourcereservoir-cap rock assemblages, and the fault transportation are the main factors of hydrocarbon enrichment in the Paleogene, Paleogene and Neogene, respectively.

Influential factors and control of water inrush in a coal seam as the main aquifer

In this paper, a combination of field measurement, theoretical analysis and numerical simulation were used to study the main control factors of coal mine water inrush in a main aquifer coal seam and its control scheme. On the basis of revealing and analyzing the coal seam as the main aquifer in western coal mine of Xiao Jihan coal mine, the simulation software of PHASE-2D was applied to analyze the water inflow under different influencing factors. The results showed that water inflow increases logarithmically with the coal seam thickness, increases as a power function with the permeability coefficient of the coal seam, and increases linearly with the coal seam burial depth and the head pressure; The evaluation model for the factors of coal seam water inrush was gained by using nonlinear regression analysis with SPSS. The mine water inrush risk evaluation partition within the scope of the mining field was obtained,through the engineering application in Xiao Jihan coal mine. To ensure the safe and efficient production of the mine, we studied the coal mine water disaster prevention and control measures of a main aquifer coal seam in aspects of roadway driving and coal seam mining.

A comparative study of the main factors controlling geohazards induced by 10 strong earthquakes in Western China since the Wenchuan earthquake in 2008

Determining the main controlling factors of earthquake-triggered geohazards is a prerequisite for studying earthquake geohazards and post-disaster emergency response.By studying these factors,the geomorphic and geological factors controlling the nature,condition,and distribution of earthquake-induced geohazards can be analyzed.Such insights facilitate earthquake disaster prediction and emergency response planning.The authors combined field investigations and spatial data analysis to examine geohazards induced by seismic events,examining ten earthquakes including the Wenchuan,Yushu,Lushan events,to elucidate the main control factors of seismic geohazard.The authors observed that seismic geohazard occurrence is usually affected by many factors,among which active nature of the seismogenic fault,seismic peak ground acceleration(PGA),topographic slope and geomorphic height differences,and distance from the fault zone and river system are the most important.Compared with strike-slip earthquakes,thrust earthquakes induce more high-altitude and high-speed remote landslides,which can cause great harm.Slopes of 0°–40°are prone to secondary seismic geohazards,which are mainly concentrated 0–6 km from the river system.Secondary geohazards are not only related to seismogenic fault but also influenced by the associated faults in the earthquake area.The maximum seismic PGA and secondary seismic geohazard number are positively correlated,and the horizontal and vertical ground motions play leading and promoting roles in secondary geohazard formation,respectively.Through the research,the spatial distribution of seismic geohazards is predicted,providing a basis for the formulation of emergency response plans following disasters.

Controlling factors of remaining oil distribution after water flooding and enhanced oil recovery methods for fracturecavity carbonate reservoirs in Tahe Oilfield

Based on comprehensive analysis of core, well logging, seismic and production data, the multi-scale reservoir space, reservoir types, spatial shape and distribution of fractures and caves, and the configuration relationship with production wells in fracture-cavity carbonate reservoirs were studied systematically, the influence of them on the distribution of residual oil was analyzed, and the main controlling factors mode of residual oil distribution after water flooding was established. Enhanced oil recovery methods were studied considering the development practice of Tahe oilfield. Research shows that the main controlling factors of residual oil distribution after water flooding in fracture-cavity carbonate reservoirs can be classified into four categories: local high point, insufficient well control, flow channel shielding and weak hydrodynamic. It is a systematic project to improve oil recovery in fracture-cavity carbonate reservoirs. In the stage of natural depletion, production should be well regulated to prevent bottom water channeling. In the early stage of waterflooding, injection-production relationship should be constructed according to reservoir type, connectivity and spatial location to enhance control and producing degree of waterflooding and minimize remaining oil. In the middle and late stage, according to the main controlling factors and distribution characteristics of remaining oil after water flooding, remaining oil should be tapped precisely by making use of gravity differentiation and capillary force imbibition, enhancing well control, disturbing the flow field and so on. Meanwhile, backup technologies of reservoir stimulation, new injection media, intelligent optimization etc. should be developed, smooth shift from water injection to gas injection should be ensured to maximize oil recovery.

Main geological and mining factors affecting ground cracks induced by underground coal mining in Shanxi Province, China

As one of the largest coal-rich provinces in China,Shanxi has extensive underground coal-mining operations.These operations have caused numerous ground cracks and substantial environmental damage.To study the main geological and mining factors influencing mining-related ground cracks in Shanxi,a detailed investigation was conducted on 13 mining-induced surface cracks in Shanxi.Based on the results,the degrees of damage at the study sites were empirically classified into serious,moderate,and minor,and the influential geological and mining factors(e.g.,proportions of loess and sandstone in the mining depth,ratio of rock thickness to mining thickness,and ground slope)were discussed.According to the analysis results,three factors(proportion of loess,ratio of rock thickness to mining thickness,and ground slope)play a decisive role in ground cracks and can be respectively considered as the critical material,mechanical,and geometric conditions for the occurrence of mining surface disasters.Together,these three factors have a strong influence on the occurrence of serious discontinuous ground deformation.The results can be applied to help prevent and control ground damage caused by coal mining.The findings also provide a direct reference for predicting and eliminating hidden ground hazards in mining areas.

Analysis of main factors in partial mining subsidence

The partial mining subsidence is a technical method widely used in the mining under buildings. How to calculate the subsidence caused by the partial mining is the key to use this method. By using the numerical calculation method, the main factors affecting the subsidence caused by the partial mining were analyzed, which include the recovery ratio of the partial mining, the width of the mined strip, the thickness and the depth of the mined seam, the conditions of the overburden. The relationship between the partial mining subsidence and the main factors was given according to the calculated results, which provides a theory basis for design and application of the partial mining.

Main Controlling Factors and Accumulation Model of Chang 9 Reservoir in Northwest Ordos Basin, China

In northwestern Ordos Basin, the Triassic reservoir Chang 9 has favorable reservoir forming conditions, extensive reservoir development, and huge potential for oil exploration and exploitation. Studying the main controlling factors and accumulation model of Chang 9 reservoir in this area can provide a basis for the production targets, and assist in formulating reasonable development technology policy. In this paper, to explore and summarize the hydrocarbon accumulation model, the Chang 9 reservoir were analyzed from the aspects of oil source, fracture, oil migration, structure, lithology and reservoir physical properties for the main controlling factors in this area. Organic geochemical and geological comprehensive analysis that the oil-source of the Chang 9 reservoir in the northwest of Ordos Basin is derived from Chang 7 hydrocarbon source rocks. The fractures provide a sound channel for the "vertical multi-point filling" of the oil source from Chang 7 to Chang 9. The crude oil migrates vertically from Chang 7 to Chang 9, then expands horizontally to form a reservoir. Structures play an important role in controlling the distribution of reservoirs, the control by sand in small layer and physical property is also obvious. This paper creatively establishes the reservoir accumulation model of Chang 9 in northwest of Ordos Basin, which is characterized by Vertical multi-point filling, horizontal expansion becomes oil pool. It reveals the genetic mechanism of the development of Chang 9 multi-reservoir in the study area, which provides guidance for exploration and evaluation deployment.

Study on the Main Controlling Factors of the Early Ordovician Stromatolites Development in Liujiachang Area of Songzi City

The Early Ordovician stromatolites in the study area are mainly exposed at the bottom and middle and lower parts of the Second Member of Nanjinguan Formation,the top of the Fourth Member of Nanjinguan Formation,the middle of the Second Member of Fenxiang Formation and the bottom of the First Member of Honghuayuan Formation.In order to find out the controlling factors of Lower Ordovician stromatolites development in the study area,the analysis data of carbon,oxygen isotope samples,macro element samples as well as their variation characteristics are studied and then combined them with previous research results,which is eventually beneficial for reaching the conclusion:sea level change is one of the main factors controlling the formation of stromatolites.There are five sea level change cycles in the Early Ordovician period.The analysis of sea level change and accommodation space variation characteristics show that when the growth rate of the accommodation space is approximately equal to that of carbonate,the circulation of seawater is well,and the amount of light and oxygen is sufficient,so that the cyanobacteria organism can be multiplied in large quantities.The growth and development provide favorable conditions,and favorable conditions are provided for the growth and development of stromatolites;The peak changes in CaO content and CaO/MgO ratio indicate that the formation period of stromatolites is arid climate environment with high water temperature and large evaporation.Prokaryote reproduction is suitable for the environments with high seawater cleanliness.When the amount of land-based debris injected into the sea increases,the turbidity of water will lead to a large number of deaths of algae microorganisms that form stromatolites,and the stromatolitic microbial mats cannot be preserved.In addition,the growth and predation of macro-organisms play a restrictive role in the development of stromatolite-forming micro-organisms blue-green algae.According to the actual situa-tion of the development of the laminated rocks in the study area,what is the dominant function in the formation and decline of stromatolites between the evolution of metazoans and changing environments is discussed in the study.

Enrichment model and major controlling factors of below-source tight oil in Lower Cretaceous Fuyu reservoirs in northern Songliao Basin,NE China

Based on the geochemical,seismic,logging and drilling data,the Fuyu reservoirs of the Lower Cretaceous Quantou Formation in northern Songliao Basin are systematically studied in terms of the geological characteristics,the tight oil enrichment model and its major controlling factors.First,the Quantou Formation is overlaid by high-quality source rocks of the Upper Cretaceous Qingshankou Formation,with the development of nose structure around sag and the broad and continuous distribution of sand bodies.The reservoirs are tight on the whole.Second,the configuration of multiple elements,such as high-quality source rocks,reservoir rocks,fault,overpressure and structure,controls the tight oil enrichment in the Fuyu reservoirs.The source-reservoir combination controls the tight oil distribution pattern.The pressure difference between source and reservoir drives the charging of tight oil.The fault-sandbody transport system determines the migration and accumulation of oil and gas.The positive structure is the favorable place for tight oil enrichment,and the fault-horst zone is the key part of syncline area for tight oil exploration.Third,based on the source-reservoir relationship,transport mode,accumulation dynamics and other elements,three tight oil enrichment models are recognized in the Fuyu reservoirs:(1)vertical or lateral migration of hydrocarbon from source rocks to adjacent reservoir rocks,that is,driven by overpressure,hydrocarbon generated is migrated vertically or laterally to and accumulates in the adjacent reservoir rocks;(2)transport of hydrocarbon through faults between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downward through faults to the sandbodies that are separated from the source rocks;and(3)migration of hydrocarbon through faults and sandbodies between separated source and reservoirs,that is,driven by overpressure,hydrocarbon migrates downwards through faults to the reservoir rocks that are separated from the source rocks,and then migrates laterally through sandbodies.Fourth,the differences in oil source conditions,charging drive,fault distribution,sandbody and reservoir physical properties cause the differential enrichment of tight oil in the Fuyu reservoirs.Comprehensive analysis suggests that the Fuyu reservoir in the Qijia-Gulong Sag has good conditions for tight oil enrichment and has been less explored,and it is an important new zone for tight oil exploration in the future.

Study on Influencing Factors and Control Points of Design Estimate of Landscaping Engineering

In recent years,China’s landscaping projects have developed vigorously,and the growth rate of urban garden green space areas has been maintained at about 5%.Overall,with the development of the national economy and the support of macro policies,people’s demand for close to nature and beautify the environment is gradually increasing,which has brought new growth momentum for the development of the landscaping industry.Simultaneously,from the perspective of future economic development and urban development,the landscaping industry still has a lot of room for development.However,with the rapid development of landscape engineering,the problem of cost control of landscape engineering is becoming more prominent,the phenomenon of budget overestimation is common,and there are many factors affecting the cost of landscape engineering,which brings difficulties and challenges to the analysis of its influencing factors and cost management.How to scientifically analyze the influencing factors and control the cost has become an important link in the landscaping project.To solve the above problems,this paper takes the design stage of landscaping engineering as the background,takes the design estimate of landscaping engineering as the research object,through literature research and data collection,fully excavates the main influencing factors of the design estimate stage of landscaping engineering,analyzes the key points of cost control,and provides reference ideas and directions for the later cost management and control.

变化环境下西江干流水文情势演变及其驱动因素

为掌握变化环境下西江干流水文情势演变特征及主要驱动因素,通过识别径流序列突变点将径流序列划分为天然时期和变化时期,采用基于水文改变指标的变化范围法定量探究各水文指标改变度,借助水文变异程度和水文情势变化法(DHRAM)评估整体水文情势改变度,利用主成分分析法筛选最相关生态指标捕捉关键水文变量,并基于随机森林模型,结合残差分析法定量评估气候变化与人类活动对流域水文情势的影响。结果表明:西江干流4座水文站32个水文指标以中、低度改变为主,天峨、迁江、武宣、梧州站水文变异程度分别为64.70%、61.34%、51.70%、51.89%,基于DHRAM得到各站水文情势改变等级分别为3、3、2、3,综合判定4站整体水文情势改变度均为中度;中上游天峨、迁江站改变度比中下游武宣、梧州站高,应重点关注中上游生态保护;气候变化与人类活动均是西江干流水文情势变化的重要驱动因素,气候变化对天峨、迁江、武宣、梧州站水文情势变化的贡献率分别为25.65%、60.07%、50.29%、55.22%,气候变化对于西江流域中下游地区水文情势的影响大于上游地区。

四川盆地蓬莱地区灯影组四段超深层白云岩储集层特征及主控因素

作为四川盆地超深层油气资源的主力产层之一,灯影组超深层碳酸盐岩储集层发育特征及其控制因素亟待进一步厘清。选取四川盆地内最新勘探突破的蓬莱地区灯影组灯四段超深层白云岩为主要研究对象,在野外露头、钻井岩心、显微薄片、阴极发光、扫描电镜及物性测试数据等资料的基础上,开展了储集层特征及主控因素等方面的研究。结果表明:(1)蓬莱地区灯四段储集岩主要包括凝块石白云岩、叠层石白云岩、泡沫绵层白云岩和砂屑白云岩;储集空间主要包括砂屑白云岩的晶间孔、晶间溶孔和溶洞,凝块石白云岩、叠层石白云岩和泡沫绵层白云岩的原生格架孔洞和后期溶蚀作用形成的溶蚀孔缝等。(2)凝块石白云岩和叠层石白云岩多发育孔洞缝型和孔洞型储集层,均具有较好的物性,孔隙度能达到4%以上,但前者平均渗透率可达2.43×10^(-3)μm^(2),后者仅为0.35×10^(-3)μm^(2)。(3)综合分析成岩演化史,认为灯四段储集层先后经历了沉积—准同生阶段、表生阶段、浅—中埋藏阶段和深层—超深层埋藏阶段的成岩改造。(4)蓬莱地区灯四段储集层发育具有自台地内部向台地边缘逐渐减弱的分布规律,总体上显示“相—断裂—溶蚀”三元综合成储模式。本研究明确了四川盆地蓬莱地区超深层白云岩储集层的特征及主控因素,可为后续超深层油气资源勘探开发提供理论基础。

煤体注水渗流模型构建及微观主控影响规律

煤层注水技术是目前矿井除尘的主要技术手段之一,起到润湿煤体、源头减尘的作用.但随着开采深度的增加,煤体孔隙率相对较低,极大影响煤层注水的润湿效果.因此,为了提高煤层注水的效果,结合煤体固有属性、孔隙尺度等影响因素,首先,引入连通孔隙率,建立了包含孔喉、等效孔径、有效孔隙率、毛细管束、迂曲度、流动路径在内的渗流模型;其次,采用高精度射线显微镜(μ-CT)对内蒙古煤矿、同富新煤矿、梅花井煤矿、大黄山煤矿以及磁窖沟煤矿5个煤矿的不同变质程度煤进行扫描,三维重建可视化煤体微观有效孔隙结构,运用分形理论,提取煤体有效连通孔隙结构参数进行计算;再次,通过实验对5个煤矿不同变质程度的煤进行渗透率实测;最后,引入“敏感度”来表征每种影响因素对渗流量的影响程度,运用Morris筛选法,将数值分析法与渗流模型相耦合,定量筛选了煤体坚固性系数、迂曲度分形维数、有效孔隙率、体积分形维数、孔喉半径等主控因素,并分析了各主控因素对注水能力的影响规律.本研究建立了一个综合煤体坚固性系数、迂曲度分形维数、有效孔隙率、体积分形维数和孔喉半径的渗流模型.分析表明,影响注水能力的主控因素依次为煤体坚固性系数、迂曲度分形维数、有效孔隙率、体积分形维数和孔喉半径.注水能力与煤体坚固性系数呈正弦函数关系,随着有效孔隙率的增加,迂曲度分形维数和体积分形维数的减小,注水能力增强.研究结果可为进一步完善煤层注水渗流理论、增强煤层注水润湿效果,防治矿井粉尘灾害提供理论依据.

细粒沉积岩优质储集层发育主控因素分析:以渤海湾盆地沾化凹陷为例

为了深化对湖相细粒沉积岩储集层的认识,以渤海湾盆地济阳坳陷沾化凹陷渤南洼陷沙三下亚段(Es3L)为研究对象,利用岩心描述、薄片鉴定、扫描电镜观察、物性分析和测井曲线,揭示了储集层特征、分布规律及其主控因素。基于矿物组成、沉积构造和有机质含量,将渤南洼陷Es3L细粒沉积岩划分为6类岩相:富有机质纹层状灰质细粒混积岩(LF1)、富有机质纹层状长英质细粒碳酸盐岩(LF2)、富有机质层状灰质细粒混积岩(LF3)、富有机质层状/块状长英质细粒碳酸盐岩(LF4)、富有机质层状含长英细粒碳酸盐岩(LF5)、含有机质块状含长英细粒碳酸盐岩(LF6)。储集层的主要储集空间为粒间孔、晶间孔、溶蚀孔和层间微裂缝,储集层孔隙度主要介于0.67%~5.56%之间(平均值为4.93%),渗透率主要介于(0.02~4.87)×10^(-3)μm^(2)之间(平均值为0.59×10^(-3)μm^(2))。渤南洼陷Es3L细粒沉积岩储集层分布的主控因素包括岩相、沉积环境、成岩作用和有机质热演化。渤南洼陷Es3L的中下部的陆源输入水平低、水体盐度大、水体分层性强,主要发育岩相LF2和LF4,容易发育Ⅰ类和Ⅱ类优质储集层。渤南洼陷Es3L细粒沉积岩储集层处于中成岩A阶段,黏土矿物转化作用、溶蚀作用、重结晶和白云石化以及有机质热演化产生次生孔缝,改善了储集层物性。

莺歌海盆地莺北区HK29区三亚组一段沉积特征及储层主控因素

随着莺歌海盆地成熟区域及主力层系勘探程度日益提高,新区新层系成为日益关注的焦点。莺北区位于莺歌海凹陷北部,目的层三亚组一段具有较大的勘探潜力,但目前勘探程度较低,对其沉积体系及储层发育情况缺乏系统的研究。基于岩芯观察、镜下薄片鉴定以及地震、测录井、分析化验等资料分析,对HK29区目的层沉积相及其展布特征、储层特征等展开研究,探讨了储层发育的主控因素。结果表明:(1)HK29区三亚组一段主要发育物源来自海南岛的近源三角洲沉积,水下分流河道微相是有利相带;(2)三亚组一段储层岩性以长石岩屑砂岩和岩屑长石砂岩为主,孔隙类型以长石溶孔和粒间孔为主,总体表现为中—低孔、低渗—特低渗的特征;(3)储层物性主要受沉积作用和成岩作用控制,三角洲前缘水下分流河道砂体粒度粗、分选好,是发育有利储层的优势相带,压实作用是该区储层物性变差的直接因素,长石和岩屑的溶蚀是改善储层物性的关键因素。基于以上研究,提出HK29区三亚组一段“相带优、埋藏浅、溶蚀强”的优质储层形成机制,有效指导了莺北区领域勘探突破。

鄂尔多斯盆地西南部侏罗系延安组油气成藏条件及主控因素

鄂尔多斯盆地西南部油气资源量丰富,近年来在侏罗系延安组发现了一系列含油面积小、储量丰度高的岩性-构造油藏,油藏规模小,成藏主控因素不明确。为了揭示鄂尔多斯盆地侏罗系延安组油藏的成藏机理及主控因素,利用三维地震、镜下观测、光谱测试、测井等资料,对研究区侏罗系延安组油藏的油源条件、古地貌、构造及储层等特征进行综合分析,总结鄂尔多斯盆地西南部侏罗系延安组油藏古地貌控制下的成藏模式;同时从油源充注条件、不整合面与连通砂体、古地貌、构造和储层几个方面分析总结侏罗系延安组油藏的成藏主控因素。结果表明:鄂尔多斯盆地延长组长7段烃源岩生烃并排出油气,在剩余压差作用下,油气沿断层、裂缝和高渗透砂体侧向顺层、纵向穿层不断向上覆侏罗系延安组储层运移,并在构造高部位、上覆及侧向泥岩遮挡条件下聚集成藏。鄂尔多斯盆地西南部侏罗系延安组油藏是以晚期成熟—高成熟的油源充注为主,由古地貌主导的,断层及裂缝、沉积储层控制的岩性-构造油藏,其成藏规律为“古河控制、砂体输导、高点富集”,油藏在平面上呈“串珠状”分布。提出了鄂尔多斯盆地侏罗系延安组油藏基于不整合面、裂缝和河道高渗透砂体构建的三维输导网络体系,为其油藏的规模勘探开发提供了理论依据。

运用地理探测器和地理加权回归模型分析城市渍水成因

以武汉市青山海绵城市示范区为例,选取地表覆盖、水系统、雨水排水管网、地形4类共10个因子,采用地理探测器和地理加权回归(GWR)模型分析渍水成因。结果表明:①渍水的主要驱动因子是坡度标准差、高程标准差、硬化地表面积占比和坡度,且因子间两两交互均对引起渍水有增强作用,特别是硬化地表面积占比与其他主要驱动因子交互后增强作用明显;②除硬化地表面积占比对渍水以正向作用为主外,其他各主要驱动因子均表现出明显的空间异质性。研究结果有望为渍水成因分析提供一种全新的视角。

Geological Factors Controlling the Accumulation and High Yield of Marine-Facies Shale Gas: Case Study of the Wufeng-Longmaxi Formation in the Dingshan Area of Southeast Sichuan, China

The main geological factors controlling the accumulation and yield of marine-facies shale gas reservoirs are the focus of the current shale gas exploration and development research.In this study,the Wufeng-Longmaxi Formation in the Dingshan area of southeast Sichuan was investigated.Shale cores underwent laboratory testing,which included the evaluation of total organic carbon(TOC),vitrinite reflectance(Ro),whole-rock X-ray diffraction(XRD),pore permeability,and imaging through field emission scanning electron microscopy(FE-SEM).Based on the results of natural gamma ray spectrum logging,conventional logging,imaging logging,and seismic coherence properties,the exploration and development potential of shale gas in the Dingshan area have been discussed comprehensively.The results showed that(1)layer No.4(WF2-LM4)of the Wufeng-Longmaxi Formation has a Th/U ratio<2 and a Th/K ratio of 3.5–12.Graptolites and pyrite are relatively abundant in the shale core,indicating sub-high-energy and low-energy marine-facies anoxic reducing environments.(2)The organic matter is mainly I-type kerogen with a small amount of II1-type kerogen.There is a good correlation among TOC,Ro,gas content,and brittle minerals;the fracturing property(brittleness)is 57.3%.Organic and inorganic pores are moderately developed.A higher pressure coefficient is correlated with the increase in porosity and the decrease in permeability.(3)The DY1 well of the shale gas reservoir was affected by natural defects and important latestage double destructive effects,and it is poorly preserved.The DY2 well is located far from the Qiyueshan Fault.Large faults are absent,and upward fractures in the Longmaxi Formation are poorly developed.The well is affected by low tectonic deformation intensity,and it is well preserved.(4)The Dingshan area is located at the junction of the two sedimentary centers of Jiaoshiba and Changning.The thickness of the high-quality shale interval(WF2-LM4)is relatively small,which may be an important reason for the unstable production of shale gas thus far.Based on the systematic analysis of the geological factors controlling high-yield shale gas enrichment in the Dingshan area,and the comparative analysis with the surrounding typical exploration areas,the geological understanding of marine shale gas enrichment in southern China has been improved.Therefore,this study can provide a useful reference for shale gas exploration and further development.