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.

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.

Process and mechanism for oil and gas accumulation, adjustment and reconstruction in Puguang Gas Field, Northeast Sichuan Basin, China

With the discoveries of a series of large gas fields in the northeast of Sichuan Basin, such as Puguang and Longgang gas fields, the formation mechanism of the gas reservoir containing high H2S in the ancient marine carbonate formation in superposition-basin becomes a hot topic in the field of petroleum geology. Based on the structure inversion, numerical simulation, and geochemical research, we show at least two intervals of fluid transfer in Puguang paleo-oil reservoir, one in the forepart of late Indo-Chinese epoch to early Yanshan epoch and the other in the metaphase of early Yanshan epoch. Oil and gas accumulation occurred at Puguang structure through Puguang-Dongyuezhai faults and dolomite beds in reef and shoal facies in Changxing Formation (P2ch) - Feixianguan Formation (T1f) in the northwest and southwest directions along three main migration pathways, to form Puguang paleo-oil reservoir. Since crude oil is pyrolysised in the early stage of middle Yanshan epoch, Puguang gas reservoir has experienced fluid adjusting process controlled by tectonic movement and geochemical reconstruction process controlled by thermochemical sulfate reduction (TSR). Middle Yan-shan epoch is the main period during which the Puguang gas reservoir experienced the geochemical reaction of TSR. On one hand, TSR can recreate the fluid in gas reservoir, which makes the gas drying index larger and carbon isotope heavier. On the other hand, the reciprocity between fluid regarding TSR (hydrocarbon, H2S, and water) and reservoir rock induces erosion of the reservoir rocks and anhydrite alteration, which improves reservoir petrophysical properties. Superimposed by later tectonic movement, the fluid in Puguang reservoir has twice experienced adjustment, one in the late Yanshan epoch to the early Himalayan epoch and the other time in late Himalayan epoch, after which Puguang gas reservoir is finally developed.

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。

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。

川东北滑坡地质灾害成因机制分析及治理方案探究

滑坡是一种常见的地质灾害现象,对人类生命和财产造成了严重的威胁。川东北地区因其地理位置和地质特点,常常受到滑坡地质灾害的侵袭。为了更好地应对这一现象,将对川东北地区的滑坡地质灾害进行分析和研究。通过分析滑坡地质灾害的成因机制,包括地质、地形、气候、人为因素等,结合相关资料和实际工作经验,提出了一些治理方法和实践措施,以期提供宝贵的经验,降低川东北滑坡地质灾害的风险,从而促进川东北地区的可持续发展。

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。

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。

川东北五市PM_(2.5)输送轨迹及潜在源区分析

基于全球数据同化预报系统数据(GDAS)资料和气象数据,分析川东北五市广元、巴中、达州、南充和广安PM_(2.5)的污染特征、传输途径和污染源分布。通过HYSPLIT后向轨迹模型模拟五市2015-2020年冬季(12-2月)的逐日48 h的气流后向轨迹,同时进行聚类分析,并使用潜在源贡献因子(PSCF)方法和浓度加权轨迹(CWT)方法识别川东北地区的PM_(2.5)的潜在污染源区,分析PM_(2.5)质量浓度的区域性污染特点及其输送特征。结果表明,研究期间川东北五市的污染物总体呈现下降趋势,其中PM_(2.5)和PM_(10)下降幅度较大,PM_(2.5)污染最严重的季节出现在冬季。后向轨迹表明,五市的污染轨迹均以近距离输送为主。通过潜在源区分析表明广元的主要源区为巴中和南充,巴中的主要源区位于广元南部、南充北部及达州中部地区,达州的主要源区为巴中南部、南充的东南部及重庆的北部地区,南充的主要源区在广元南部、巴中南部、达州的中南部、广安及重庆的中西部和遂宁,广安的主要源区主要在达州中部、南充及重庆的中部地区。

川东北地区腹泻牛群中牛病毒性腹泻病毒的分子流行病学调查及病毒分离鉴定

为了掌握川东北地区腹泻牛群中牛病毒性腹泻病毒(BVDV)的感染情况和主要流行基因型及亚型,采用RT-PCR方法对采集于川东北地区临床腹泻牛粪便样品进行了病原学检测。根据5'-UTR基因序列进行遗传变异分析和基因分型鉴定,并对RT-PCR阳性样品进行了病毒的分离鉴定。结果显示:97份腹泻样品中BVDV平均阳性感染率为9.28%,达州市的阳性率最高(13.04%)、巴中市的阳性率最低(5.26%)。在5'-UTR基因系统进化树中9份阳性样品均为BVDV-1型,包括BVDV-1a(n=2)和BVDV-1b(n=7),经细胞培养、RT-PCR检测、间接免疫荧光检测共分离鉴定出2株致细胞病变型BVDV。表明川东北地区腹泻牛群中均存在BVDV感染,流行的优势基因亚型为BVDV-1b,丰富了BVDV的分子流行病学资料,为川东北地区BVDV的综合防控提供了理论基础。

川东北地区茅口组岩溶储层测井特征及有效性评价

川东北元坝地区茅口组钻遇浅滩叠岩溶新类型储层,取得油气勘探突破。为了落实茅口组浅滩叠岩溶新类型储层的测井特征及有效性评价方法,结合岩心和电成像资料,分析垂向岩溶带测井特征,对储层类型进行定性识别,开展储层有效性评价。

建国初期川东北革命老区的传染病防治及启示

传染病是传统社会突出的社会问题。近代以来,川东北社会动荡、民生凋敝,始终未能有效开展疫病防治。建国初期,面对天花、霍乱、伤寒、痢疾、疟疾等多种传染病,在中国共产党领导下,川东北革命老区通过建立防疫体系、加强法治保障、扩大预防接种、消除顽固疫病、开展防疫宣传、整治城乡卫生、改善饮水卫生、加强饮食卫生等措施,防疫取得了巨大成就,到1956年,天花、霍乱、伤寒基本绝迹,其它传染病整体上得到有效控制,发病率、死亡率大幅下降,老区人民的生命安全有了坚实的保障。其启示有:防疫的政治之基,坚持中国共产党的领导;科学之策,坚持“预防为主”的原则;使命追求,坚持人民生命至上;力量源泉,坚持全社会力量整合。

三高条件对弹韧性水泥浆性能的影响及短期腐蚀机理

针对固井水泥石所处的高温高压含H_(2)S/CO_(2)腐蚀环境以及复杂工况,开展三高条件下弹韧性水泥浆的性能变化及短期腐蚀机理研究。基于弹韧性外掺料的3种主要类型,采用向G级油井水泥中分别加入10%橡胶粉末、0.3%玄武岩纤维以及10%丁苯胶乳的方式制备弹性水泥浆。通过力学性能测试、XRD、FTIR、MIP及SEM-EDS测试,分析弹韧性材料添加前后及腐蚀前后,水泥石的力学性能、孔径分布、水化产物类型及微观结构变化。结果表明,掺入3种弹韧性材料均有利于水泥石的脆度系数降低、韧性提高,其中玄武岩纤维最利于控制材料破坏时裂缝的发展,而丁苯胶乳最利于降低材料的弹性模量和保持较大的抗折强度。经过短期液相腐蚀后,水泥试样的力学强度均出现增长,特别是掺入玄武岩纤维和丁苯胶乳的试样。玄武岩纤维在该研究中的腐蚀条件下性能稳定,腐蚀反应生成的致密碳酸钙晶体堆积于玄武岩纤维与水泥基质界面孔隙处,引起了腐蚀后材料总孔容的减小及力学强度的大幅度增长。丁苯胶乳在水泥石中形成聚合物膜,覆盖及包裹水泥基质,可提高复合水泥表面的耐腐蚀性能。

天文轨道周期调制的海平面变化对生物礁发育的影响——以川东北地区晚二叠世长兴期为例

为探讨天文轨道周期驱动下全球海平面升降对生物礁发育的影响,选取湾滩河剖面长兴期自然伽马数据序列进行数据预处理、频谱分析、天文检验、滤波和调谐后,建立“浮动”天文年代标尺。文中基于旋回地层学、2种轨道调谐后的动态沉积噪音模型(DYNOT和ρ1)分析结果、La2010d天文调制方案以及长偏心率周期(405 kyr)与斜率长周期(1.2 myr)的正相关性可知,斜率长周期(1.2 myr)与海平面变化曲线具有相关性,该时期海平面变化受到轨道长周期(1.2 myr)驱动。无机碳同位素分析表明,轨道长周期(1.2 myr)驱动下的海平面升降影响着海洋环境的变化,进而影响着生物礁的生长发育。

乡野杂草多样性特征与保护策略——以四川东北丘陵区蚕华山村为例

【目的】乡野杂草是乡村生物多样性的重要组成部分,更是乡村生态系统的核心生物要素。长期以来,乡野杂草多样性的科学价值未得到足够重视,研究乡野杂草多样性特征及维持机制,并提出乡野杂草多样性保护策略,是乡村生物多样保护亟待解决的科学问题。【方法】选取四川东北丘陵区域典型传统村落蚕华山村为研究区域,对村落内乡野杂草种类及分布情况进行定性及定量调查。【结果】共记录乡野杂草65科188属263种,分布在院落、农田、水塘、沟渠、篱笆、崖壁、片林等21种不同类型的乡村生境中。分析发现,影响乡野杂草分布的主要环境因子为光照强度和土壤含水量,丰富多样的乡村生境类型为乡野杂草生长提供了多样化水热组合条件,而乡村生境多样性的维持与乡村生产生活方式密切相关。【结论】基于实证研究结果,在分析乡野杂草多样性维持机制的基础上,提出5项乡野杂草多样性保护策略:1)合理布局“三生”空间;2)修复重建“丘-田-林-塘-居”单元;3)保护乡村小微生境及构建立体生境网络;4)选用乡野杂草恢复乡村植被;5)传承传统乡村生态智慧。

川东北地区须家河组气藏储层显微图像数据集

四川盆地东北地区须家河组气藏具有良好的勘探开发潜力。本文收集和整理了研究区须家河组气藏碎屑岩储层的显微图像数据,以期对须家河组储层岩石学特征、成岩作用、储集空间和物性特征进行进一步研究。储层岩石类型主要为岩屑砂岩、岩屑长石砂岩和石英砂岩。储集空间可见粒间溶孔、剩余粒间溶孔、粒内溶孔、黏土矿物晶间(溶)孔及各种微裂缝。孔隙相对不发育,部分薄片(微)裂缝较为发育。经薄片下鉴定及观察,研究区须家河组砂岩储层主要经历了压实作用、胶结作用、溶蚀作用和构造破裂作用。本数据集的建立可为砂岩图像数据的对比分析和相关引用提供直接的途径,亦可作为智能识别岩性的标准。