Genetic mechanisms of high-quality tight siliciclastic reservoirs:A case study from the Upper Triassic Xujiahe Formation in the Yuanba area,Sichuan Basin,China

This study analyzed the petrological characteristics,diagenesis,pore types,and physical properties of the tight coarse-grained siliciclastic sequences in the third member of the Upper Triassic Xujiahe Formation(also referred to as the Xu-3 Member)in the western Yuanba area in the northeastern Sichuan Basin,China,based on the results of 242.61-m-long core description,292 thin-section observations,scanning electron microscopy(SEM),and 292 physical property tests.The types and genetic mechanisms of high-quality tight coarse-grained siliciclastic reservoirs in this member was determined thereafter.The research objective is to guide the exploration and development of the tight coarse-grained siliciclastic sequences in the Xu-3 Member.The results of this study are as follows.Two types of high-quality reservoirs are developed in the coarse-grained siliciclastic sequences of the Xu-3 Member,namely the fractured fine-grained sandy conglomerate type and porous medium-grained calcarenaceous sandstone type.Hydrodynamic energy in the sedimentary environment is the key factor controlling the formation of high-quality reservoirs.These high-quality reservoirs are developed mainly in the transitional zone with moderately high hydrodynamic energy between delta-plain braided channels and delta-front subaqueous distributary channels.The dolomitic debris(gravel)content is the main factor affecting the reservoirs’physical properties.The micritic algal debris and sandy debris in the dolomitic debris(or gravels)tend to recrystallize during burial,forming intercrystalline pores within.In the medium-grained calcarenaceous sandstones,intercrystalline pores in the dolomitic debris are formed at the early diagenetic stage,and a pore system consisting of structural fractures connecting intergranular pores,intergranular dissolution pores,and kaolinite intergranular micropores is developed at the late stage of diagenesis.The formation of intercrystalline pores in dolomite gravels and gravel-edge fractures,a pore system connected by gravel-edge and tectonic fractures,is closely related to the dolomite gravels in the sandy fine-grained conglomerates.

Depositional and Ecological Features of Permian Oxygen Deficient Deposits at Shangsi Section,Northeast Sichuan,China

Because oxygen deficient conditions enhance the preservation of depositional organic matter, analysis on paleooxygenation conditions of depositional environments becomes a routine work in evaluations of potential hydrocarbon source rocks. The article focuses on depositional and ecological features relating to oxygen deficient shelfal environments at the Shangsi （上寺） Section, as a part of multidiscipline collaboration to reevaluate the hydrocarbon potential of the Middle and Upper Permian, Guangyuan （广元）, Northeast Sichuan （四川） Province. Ichnofabric Zoophycos, sepiolite-bearing limestones （SBL） were interpreted as indicators of dysaerobic environments. Laminated calcareous and/or siliceous mudstones with pelagic ammonites and radiolarians were believed to be the deposits of anaerobic environments. When rhythmic succession was considered, average strategy was adopted for the oxygenation explanation of a given interval. The anaerobic condition in this Permian section was observed in the upper part of the latest Permian Dalong （大隆） Formation, in which siliceous mudstones with ammonite, radiolarians develop in association with lower U/Mo ratio, lower blomarker ratio of Pr/Ph, and the highest TOC content. The topmost Maokou （茅口） Formation, featured by thin-bedded calcareous and siliceous mudstones with ammonite, thin-shelled bivalves, and laminations would be deposits of the quasianaerobic condition. The middle part of the Members Ⅰ and Ⅲ of the Chihsia Formation is proposed to be dysaerobic condition as indicated by occurrences of SBL and ichnofabric features, with the Member Ⅲ being the severe dysaerobic condition.

Subdivision of Permian Fossil Communities and Habitat Types in Northeast Sichuan,South China

Recent achievement in hydrocarbon exploration in Northeast Sichuan （四川） demonstrated that Permian calcareous and argillaceous deposits are the major contributing source rocks. Reevaluation on the hydrocarbon potential of the Permian strata over the whole Yangtze region is thus to be desired. A comprehensive corroboration was carried out at the Shangsi （上寺） Section, Guangyuan （广元）, Northeast Sichuan, which is believed to be another promising area in South China. This article deals with the ecological and depositional conditions of the Permian strata in the section, including the Chihsia, Maokou （茅口）, Wujiaping （吴家坪）, and Dalong （大隆） formations, which share some similarities with those occurring in the broad Yangtze carbonate platforms. Five fossil communities of Mizzia-Permocaiculus, Hayasakaia, Inozoan, Ostracod, and Crinoid were identified in the Yangtze region and described in detail including their components and occurrence. On the basis of the fossil communities and depositionai features, 23 habitat types, mainly occurring from inner to outer shelves, were recognized at the Shangsi Section in order to reconstruct the depositionai conditions and accordingly to evaluate the paleoproductivity. In addition, the subdivision of Chihsia Formation in the section was revised, which would be of significance for the reconstruction of the Chihsian paleogeography in the study area.

A Study on the Conservation and Application of the Silk Industry in Nanchong City,Sichuan Province,China

40 years had passed since China implemented its iconic Open Policy and reform.In the past 40 years,the proportion of tertiary industry in large cities like Beijing,Shanghai and Guangzhou has surpassed that of the primary and secondary industries.Even small and medium cities are currently transitioning from the primary and secondary industries towards the second and tertiary industries.Following this transition,the old industrial edifices and buildings are gradually abandoned and neglected.This paper examines the feasibility of Nanchong’s transformation from the textile industry to tertiary or service industry through a comprehensive survey of the status,conservation and application of Nanchong industrial heritage,and explore the new direction for China’s industrial heritage.

Panda Tour in Sichuan

TheitinerarybeginsattheFengtongZhaiNatUreReserveinBaoxingCounty,220kilometersfromChengdu,thecaglulOfSichtal~.hoistheachomeofthegiantpandaandmostofChina’sremainingPandaPOPulationlivesinacsarea.AlOngthe600kilometerroute,touristScanvisitagiantPandafeedi...

Seismic Sedimentology Study in the High-Resolution Sequence Framework——A Case Study of Platform Margin Reef-Beach System of Changxing Formation,Upper Permian,Yuanba Area,Northeast Sichuan Basin,China

The Yuanba （元坝） area is considered another potential large-scale reef-bank gas field following the Puguang （普光） field. However, there are lots of difficulties on the spatial and temporal distribution of reef-beach and the detailed prediction of the effective reservoir in the sequence stratigraphic framework. In this paper, based on the seismic data, well, log and core, we conduct a high-resolution sequence division and build an isochronal sequence stratigraphic framework for the Changxing （长兴） Formation by the methods of wavelet transformation, FMI, etc.. Then, the corresponding relationship among the lithologic facies, logging facies, seismic facies, seismic attribute facies and reservoir of Changxing Formation were established through well-seismic calibration and geological-geophysical modeling. Furthermore, detailed study on the spatial and temporal distribution of microfacies of the reef-beach was carried out by means of seismic attribute extraction. Meanwhile,combined with impedance inversion, the spatial distribution of porosity of reef-beach reservoir was predicted. The results show that the revolution of the reef-beach system contains three stages which are initial bioclastic bank establishment stage, reef development stage and exposure stage. Also, porosity inversion shows that the region with high value of porosity is located in the reef cap, fore reef and back reef.Seismic Sedimentology Study in the High-Resolution Sequence Framework

Evidence of Thermal Evolution History of Northeast Sichuan Basin-(U-Th)/He Low Temperature Thermochronometry of Apatite and Zircon

（U-Th）/He dating is a newly developed low temperature thermochronometry, and it elaborately reflects cooling history of geologic body under low temperature. It can be applied to analyze thermal evolution of the sedimentary basin, combining with vitrinite reflectance and fission track. （U-Th）/He dating of apatite and zircon from drilling cores in Puguang （普光）-Maoba （毛坝） area and outcrops in Tongjiang （通江） area indicates that the Northeast Sichuan （四川） basin underwent great uplift and denudation during the Tertiary and the Quaternary. During the period, denudation rates changed from 74.8 to 172.5 m/Ma and denudation thickness was between 2 800 and 3 000 m, geotemperature gradually declined into the current temperature, passing through helium closure temperature of apatite. The uplift and denudation relate to new tectonic movement response in the Sichuan basin aroused by the Qinghai （青海）-Tibet plateau. Drilling samples above 4 000 m did not undergo closure temperature of zircon, but the samples nearly 4 000 m might approach closure temperature of zircon and all the samples underwent closure temperature of apatite. According to （U-Th）/He ages of zircon, it is concluded that the Northeast Sichuan basin began to uplift in the Late Jurassic. From the Late Jurassic to the Paleogene, Northeast Sichuan basin was in slow uplift and denudation, but the denudation of Puguang-Maoba area was earlier than that of Tongjiang area. （U-Th）/He ages of zircon indicate the denudation time of provenance areas. On the basis of paleodrainage characteristics, provenance transport and other related data, provenance areas of the clastie rocks are decided, which is worthy to be investigated further.

New Seismic Attribute Technology for Predicting Dissolved Pore-Fracture of Deeply Buried Platform Margin Reef-Beach System in Northeast Sichuan Basin, China

The large reef complexes of the Upper Permian Changxing Formation, with a significant breakthrough for petroleum exploration, are an important target for petroleum exploration in the Yuanba area of the Sichuan Basin in SW China. The storage space types of reef complexes are dominated by the dissolved pore-fracture（DPF）. However, using only single geophysical methods, it is difficult to predict effective distribution of DPF. Based on a combination of geological models and geophysics technology, this study proposes two new geophysical methods, including anisotropy coherence technique（ACT） and fracture intensity inversion（FII）, to research the characteristics of DPF by faciescontrolling in Changxing Formation in Yuanba area. Two major findings are presented as follows：（1） the characteristics of DPF varying with facies are the result of different diagenetic and petrophysical property. The intensity of DPF decreases from reef and bioclastic bank to interbank sea and slope;（2） ACT can qualitatively identify the distribution of DPF with no-directional and dispersed distribution, while FII can quantitatively characterize the intensity of DPF development within various sedimentary facies. When integrated into the geological study, ACT and FII can provide an effective way to predict the distribution of DPF in similar geological settings and the predicted DPF have been supported by the historical well data.

川东北普光地区下三叠统蒸发岩硫同位素地球化学特征及其指示意义

海相硫酸盐矿物的硫同位素研究不仅可以解析当时的古海水特征,还可为物质来源分析、地层对比及其沉积环境条件分析提供重要线索。川东北地区中-下三叠统海相蒸发岩地层中除大量膏-盐以外,还发育与石盐共伴生的硫酸盐型钾盐矿物杂卤石(被命名为“新型杂卤石钾盐矿”),因此,对该区域硫同位素的研究不仅可以为蒸发岩的沉积环境及其演化进行解密,还可为钾盐矿物杂卤石的物源分析提供证据。但当前对于研究区内硫同位素研究多存在于大时间尺度上的演化规律以及全球性的地层对比,对于杂卤石发育的嘉四-五段地层内δ^(34)S的高精度演化规律及其指示意义研究相对匮乏。本文利用川宣地1井中的硬石膏、杂卤石及二者的混合样品开展δ^(34)S的高精度分析。研究显示,硬石膏与杂卤石样品不存在明显的硫同位素分馏。同时,δ^(34)S结果证实,钾盐矿物杂卤石及其伴生硬石膏的物源主要是海水,但受到细菌还原作用和蒸发岩矿物沉淀的影响。此外,δ^(34)S演化规律与嘉四-五段地层的层序演化规律较一致,这表明δ^(34)S测试对蒸发沉积过程的沉积演化分析及区内地层的高精度对比具有重要意义,在杂卤石型钾盐矿勘查工作中可用于精细对比和矿层定位的重要手段。

川东北二叠系海相页岩硅质矿物成因机理

海相页岩中硅质矿物含量及成因往往与有机质丰度和可改造性存在密切关系。为揭示研究区二叠系海相页岩硅质矿物赋存特征及物质来源,对野外露头和钻井样品开展了系统的岩石学与元素地球化学分析,利用岩石薄片、扫描电镜、能谱分析、主量元素、微量元素等对吴家坪组-大隆组页岩中的石英赋存特征和成因进行深入解剖,认为:①硅质矿物主要包括4种赋存状态,即碎屑石英、石英胶结物、硅质生屑及石英脉体,硅质矿物来源为火山喷发-陆源物质输入、生物成因、深部热液成因三类;②硅质页岩主要沉积于拉张性海槽地堑区,吴三段及其他层段的Al、Ti和Th的含量低于上地壳,且吴一、二段和大隆组的碎屑石英为陆源输入成因,Al-Fe-Mn和Zn-Ni-Co三角图中吴家坪组-大隆组页岩样品落在生物成因和热液成因区,表明石英胶结物和石英脉体为生物及热液成因,且硅质矿物及水体营养化与有机质富集具有耦合关系。

川东北地区五峰组–龙马溪组页岩地球化学特征及有机质富集模式

四川盆地是我国页岩气开发的主力产区,川东北地区作为四川盆地的页岩气开发的接替区,备受关注。为了探究川东北地区上奥陶统五峰组–下志留统龙马溪组富有机质页岩的控制因素及富集模式。采用电感耦合等离子体质谱(ICP–MS)方法对川东北地区五峰组–龙马溪组14件页岩进行元素分析,并结合测井曲线特征,探讨五峰组–龙马溪组沉积体系、氧化还原条件、陆源碎屑输入、初级生产力和古气候关系。识别出了3个三级层序(SSQ1,SSQ2和SSQ3),海平面经历了由高—低—高—低的过程,结合页岩元素的w(V)/w(Cr),w(V)/w(V+Ni),w(Ni)/w(Co),w(Sr)/w(Cu),w(Sr)/w(Ba),T(℃)等参数,指示了五峰组-龙马溪组,经历了氧化—贫氧—缺氧还原—贫氧—氧化的淡水环境;气候经历了温暖湿润—干旱寒冷—温润湿润—干旱寒冷—温暖湿润演化过程,温度经历了降低—升高—降低—升高的过程。川东北地区五峰组-龙马溪组有机质富集模式可划分为Ⅲ阶段模式,第Ⅰ阶段,五峰组到龙马溪组底部沉积时期,有机碳逐渐增高阶段;第Ⅱ阶段,龙马溪组中部,有机碳富集阶段(甜点段);第Ⅲ阶段,龙马溪组上部,有机碳逐渐降低阶段。期望为川东北地区页岩气的勘探提供依据,下一步,将开展研究区重大地质事件对有机质富集的资源响应研究,深化页岩气富集模式。

川东北须家河深层气藏高效挖潜测试关键技术

川东北地区须家河陆相气藏储量超1000亿m^(3),前期主要采用小规模加砂压裂或酸压改造投产,未获得大的产能突破。由于须家河储层致密、高破裂压力导致施工排量受限,加砂难度大,改造效果差。通过开展挖潜井井筒作业保障技术研究,开发了须家河挖潜井井筒治理及精细控压技术,解决了原测试层共存、地压系数差异大导致井筒作业时井控难的问题以及施工作业承压问题。提出了一趟管柱多层挖潜思路,形成了大通径油管组合配套封隔器分段压裂管柱,140.0 MPa与105.0 MPa井口交互式作业可满足超高压大规模加砂作业以及后期生产要求;在YB6、YL15、YL171井应用,成功实现了三口老井的挖潜作业;在YL171井一趟管柱完成须四储层的分层压裂,在71.0 MPa的油压下日产量达到32.5万m^(3)。

近红外高光谱传感器在地震有关气体监测中的应用:以青藏高原东边界为例

为了促进高光谱技术在地震有关气体监测中的应用,本文选取对近地表信息敏感度较强的近红外高光谱传感器TROPOMI的二级产品数据,分析研究了青藏高原东北缘和川滇地区地震相关气体时空特征及其与构造和地震活动关系,评价了近红外传感器在地震有关气体监测中的应用效果和应用前景。结果表明:TROPOMI反演的研究区CH_(4)和CO气体在时间上呈现明显的季节变化,受气候变化、地貌、人类活动等影响;空间上在银川、渭河和四川盆地表现为高值,受地质背景、地形地貌和人类活动等因素影响。目前近红外高光谱传感器在时间分辨率和有效数据量上具有一定的局限性,但是相对于热红外高光谱传感器,近红外传感器可以较好地反映气体与近地表构造的关系。未来随着近红外高光谱传感器的应用和发展,近红外数据可以逐渐弥补热红外传感器数据对近地表信息敏感度低的不足,提高异常与地震关系的判断力。

川东北山地农村夯土民居建筑空间形态解析

川东北夯土民居拥有强烈的山地地域特色和浓厚的山水环境乡土气息,体现了巴蜀传统建筑文化品格,民居建筑空间是巴蜀文化传承和发展的重要载体。川东北山地农村地区夯土民居建筑空间在发展演变过程中形成了具有巴蜀文化特征的典型性空间范式和巴蜀历史文化特征元素,但未被系统地分析和归纳。通过对川东北山地农村夯土民居70余户进行调研和测绘,本文从民居建筑不同尺度层级下分别分析夯土民居建筑空间形态特征,总结川东北山地农村夯土民居建筑空间形态的基本特征。

川东北礁滩相碳酸盐岩储层酸化工艺优化

川东北地区的礁滩相碳酸盐岩气藏孔隙度和渗透率差异性大,非均质性强,储层酸化工艺设计方案针对性不强。利用酸液有效作用距离和酸蚀裂缝导流能力计算模型,建立一套酸化效果预测图版和工艺参数优选方法。结合川东北礁滩相碳酸盐岩储层特征,开展不同类型储层的酸化工艺参数优化设计,并进行现场实例验证。研究工作不仅对川东北礁滩相碳酸盐岩的高效开发具有指导意义,也为类似地质条件下的碳酸盐岩储层酸化工艺优化提供了理论和实践参考。

川东北客家龙舞文化节庆旅游开发研究——以国家级“非遗”安仁乡板凳龙为例

基于川东北地区龙舞文化具有代表特色的安仁乡板凳龙为研究对象。文章运用文献资料法和逻辑分析法等研究方法,对安仁乡板凳龙节庆文化旅游开发展开研究。主要历程:通过对安仁板凳龙与本土文化的融合现状、自然环境结合情况、乡土社会人文联系进行三维度分析,提出安仁乡板凳龙文化旅游开发设计思路。研究结果:对板凳龙制作从工艺文化、乡土舞台互动创新、民俗体验场景搭建三方面进行文化资源整合,提出建设安仁乡板凳龙旅游长廊设想。研究结论:可通过提高本土居民文化自信,拓宽板凳龙文化传播途径,获取政府支持项目以及确保文化原生性四方面保障安仁乡板凳龙文化旅游长廊的合理开发。

川东北地区大安寨段页岩油气资源评价与有利区优选

四川盆地是中国最具勘探潜力的非常规油气盆地之一,其中川东北地区的大安寨段地层发育富含机质并与薄层介壳灰岩互层的页岩,有生烃、含油含气的特征,具有页岩油气开发潜力。为明确四川盆地川东北地区大安寨段页岩储层的油气资源潜力,综合运用油气地球化学和地质学研究方法,对该地区的页岩油和页岩气的资源潜力进行评价,预测页岩油气的有利区。结果表明:大安寨段岩性主要为黑色页岩和介壳灰岩。其中,大二亚段为富含有机质的页岩层段;大安寨段累计厚度约为60~110m,埋藏深度约为1000~3600m;有机质类型以Ⅱ2型为主,有机碳含量介于0.42%~2.74%,平均值为1.18%;有机质成熟度为0.94%~1.84%,主要处于成熟—高成熟阶段;大安寨段页岩埋藏深度适中,有效厚度大,生烃潜力高,具备页岩油气成藏的基础条件;大安寨段页岩气和页岩油的有利区位于研究区西南部和东部,估算页岩气资源量为24543×10^(8)m^(3),页岩油资源量为10×10^(4)t。根据研究结果,分别优选研究区的页岩油气的Ⅰ类有利区带和Ⅱ类有利区带,可为大安寨段页岩油气勘探开发提供参考。

川东北地区“人口-经济-空间”城市化耦合协调性研究

为了探究川东北地区人口、经济、空间城市化耦合协调发展程度,文章通过构建人口、经济和空间城市化内在表征指标体系,借助熵权法计算各项指标的权重,运用耦合协调模型,对川东北地区人口、经济、空间城市化水平及其耦合协调度进行分析。结果表明:(1)川东北地区空间城市化主导了经济和人口城市化,但整体水平有待提升;(2)人口、经济、空间城市化区域差异明显,呈现出“南高北低”的趋势,且表现出圈层结构;(3)人口、经济和空间城市化两两耦合和三者耦合度整体较低,市域内差异也较大,呈现出以主城区为中心向四周递减的趋势;(4)从耦合协调度上看,川东北地区城市化耦合协调度较低,仅南充市顺庆区处于勉强协调阶段,而广元市和巴中市等地处于严重和重度失调阶段。川东北地区整体城市化水平不高,以空间城市化为主导,城市化耦合协调度较低,文章揭示其变化和差异的主要原因,为研究区城市化发展提供借鉴。

川东北地区家庭农场经营效率分析

分析经济欠发达的川东北地区各类型家庭农场经营效率,发现存在问题并提出建议,以促进家庭农场健康发展。以巴中市591个家庭农场为例,运用投入导向BCC模型对种植类、养殖类、种养结合类家庭农场经营效率进行计算。结果表明,家庭农场综合技术效率和纯技术效率有较大提升空间;养殖类家庭农场综合技术效率最高,为0.659,种植类最低;种植类和种养结合类家庭农场纯技术效率都较低,分别为0.628和0.602;3类家庭农场间规模效率差距较小,规模有效程度均较高。应引导农场主参加技术培训,提高农业生产技术,加强对中小型家庭农场扶持力度。