Discovery and inspiration of large-and medium-sized glutenite-rich oil and gas fields in the eastern South China Sea:An example from Paleogene Enping Formation in Huizhou 26 subsag,Pearl River Mouth Basin

Based on the practice of oil and gas exploration in the Huizhou Sag of the Pearl River Mouth Basin,the geochemical indexes of source rocks were measured,the reservoir development morphology was restored,the rocks and minerals were characterized microscopically,the measured trap sealing indexes were compared,the biomarker compounds of crude oil were extracted,the genesis of condensate gas was identified,and the reservoir-forming conditions were examined.On this basis,the Paleogene Enping Formation in the Huizhou 26 subsag was systematically analyzed for the potential of oil and gas resources,the development characteristics of large-scale high-quality conglomerate reservoirs,the trapping effectiveness of faults,the hydrocarbon migration and accumulation model,and the formation conditions and exploration targets of large-and medium-sized glutenite-rich oil and gas fields.The research results were obtained in four aspects.First,the Paleogene Wenchang Formation in the Huizhou 26 subsag develops extensive and thick high-quality source rocks of semi-deep to deep lacustrine subfacies,which have typical hydrocarbon expulsion characteristics of"great oil generation in the early stage and huge gas expulsion in the late stage",providing a sufficient material basis for hydrocarbon accumulation in the Enping Formation.Second,under the joint control of the steep slope zone and transition zone of the fault within the sag,the large-scale near-source glutenite reservoirs are highly heterogeneous,with the development scale dominated hierarchically by three factors(favorable facies zone,particle component,and microfracture).The(subaqueous)distributary channels near the fault system,with equal grains,a low mud content(<5%),and a high content of feldspar composition,are conducive to the development of sweet spot reservoirs.Third,the strike-slip pressurization trap covered by stable lake flooding mudstone is a necessary condition for oil and gas preservation,and the NE and nearly EW faults obliquely to the principal stress have the best control on traps.Fourth,the spatiotemporal configuration of high-quality source rocks,fault transport/sealing,and glutenite reservoirs controls the degree of hydrocarbon enrichment.From top to bottom,three hydrocarbon accumulation units,i.e.low-fill zone,transition zone,and high-fill zone,are recognized.The main area of the channel in the nearly pressurized source-connecting fault zone is favorable for large-scale hydrocarbon enrichment.The research results suggest a new direction for the exploration of large-scale glutenite-rich reservoirs in the Enping Formation of the Pearl River Mouth Basin,and present a major breakthrough in oil and gas exploration.

Expression and clinical significance of pattern recognition receptor-associated genes in hand, foot and mouth disease

Objective:To explore which pattern recognition receptors(PRRs)play a key role in the development of hand,foot,and mouth disease(HFMD)by analyzing PRR-associated genes.Methods:We conducted a comparative analysis of PRR-associated gene expression in human peripheral blood mononuclear cells(PBMCs)infected with enterovirus 71(EV-A71)which were derived from patients with HFMD of different severities and at different stages.A total of 30 PRR-associated genes were identified as significantly upregulated both over time and across different EV-A71 isolates.Subsequently,ELISA was employed to quantify the expression of the six most prominent genes among these 30 identified genes,specifically,BST2,IRF7,IFI16,TRIM21,MX1,and DDX58.Results:Compared with those at the recovery stage,the expression levels of BST2(P=0.027),IFI16(P=0.016),MX1(P=0.046)and DDX58(P=0.008)in the acute stage of infection were significantly upregulated,while no significant difference in the expression levels of IRF7(P=0.495)and TRIM21(P=0.071)was found between different stages of the disease.The expression levels of BST2,IRF7,IFI16 and MX1 were significantly higher in children infected with single pathogen than those infected with mixed pathogens,and BST2,IRF7,IFI16 and MX1 expression levels were significantly lower in coxsackie B virus(COXB)positive patients than the negative patients.Expression levels of one or more of BST2,IRF7,IFI16,TRIM21,MX1 and DDX58 genes were correlated with PCT levels,various white blood cell counts,and serum antibody levels that reflect disease course of HFMD.Aspartate aminotransferase was correlated with BST2,MX1 and DDX58 expression levels.Conclusions:PRR-associated genes likely initiate the immune response in patients at the acute stage of HFMD.

Microstructure,mechanical properties and fracture behaviors of large-scale sand-cast Mg-3Y-2Gd-1Nd-0.4Zr alloy

In order to improve the ductility of commercial WE43 alloy and reduce its cost,a Mg-3Y-2Gd-1Nd-0.4Zr alloy with a low amount of rare earths was developed and prepared by sand casting with a differential pressure casting system.Its microstructure,mechanical properties and fracture behaviors in the as-cast,solution-treated and as-aged states were evaluated.It is found that the aged alloy exhibited excellent comprehensive mechanical properties owing to the fine dense plate-shapedβ'precipitates formed on prismatic habits during aging at 200℃for 192 hrs after solution-treated at 500℃for 24 hrs.Its ultimate tensile strength,yield strength,and elongation at ambient temperature reach to 319±10 MPa,202±2 MPa and 8.7±0.3%as well as 230±4 MPa,155±1 MPa and 16.0±0.5%at 250℃.The fracture mode of as-aged alloy was transferred from cleavage at room temperature to quasi-cleavage and ductile fracture at the test temperature 300℃.The properties of large-scale components fabricated using the developed Mg-3Y-2Gd-1Nd-0.4Zr alloy are better than those of commercial WE43 alloy,suggesting that the new developed alloy is a good candidate to fabricate the large complex thin-walled components.

Computational Investigation of Hand Foot Mouth Disease Dynamics with Fuzziness

The first major outbreak of the severely complicated hand,foot and mouth disease(HFMD),primarily caused by enterovirus 71,was reported in Taiwan in 1998.HFMD surveillance is needed to assess the spread of HFMD.The parameters we use in mathematical models are usually classical mathematical parameters,called crisp parameters,which are taken for granted.But any biological or physical phenomenon is best explained by uncertainty.To represent a realistic situation in any mathematical model,fuzzy parameters can be very useful.Many articles have been published on how to control and prevent HFMD from the perspective of public health and statistical modeling.However,few works use fuzzy theory in building models to simulateHFMDdynamics.In this context,we examined anHFMD model with fuzzy parameters.A Non Standard Finite Difference(NSFD)scheme is developed to solve the model.The developed technique retains essential properties such as positivity and dynamic consistency.Numerical simulations are presented to support the analytical results.The convergence and consistency of the proposed method are also discussed.The proposed method converges unconditionally while the many classical methods in the literature do not possess this property.In this regard,our proposed method can be considered as a reliable tool for studying the dynamics of HFMD.

Construction of Plant Expression Vector for Hand,Foot and Mouth Virus EV71-VP1 Gene and Its Expression in Tomato

EV71-type virus is one of the main pathogens causing the occurrence of hand,foot and mouth disease(HFMD),and VP1 protein,a factor that directly determines the antigenicity of the virus,has been isolated.The tomato was selected as a bioreactor for the production of an edible EV71 vaccine designed for the VP1 capsid protein.Using molecular biology techniques,the fusion gene EV71-VP1 was cut from vector PGEX-4T-2,a vector containing the p2300-EV71 gene with CaMV35S promoter and TL regulatory elements was constructed,and the hypocotyl and cotyledons of tomato were transformed using Agrobacterium(EHA105)-mediated method,screened,elongated and rooted,and finally 20 resistant tomato plants were obtained.Five transgenic positive seedlings were obtained by digestion and PCR assay,among which three plants were detected by RT-PCR to be capable of transcriptional translation at the RNA level.The experimental results aimed to explore new material support for the preparation of transgenic plant oral vaccines against EV71 infection and provide a theoretical basis for accelerating the development of transgenic plant vaccines in the future.

Tectonic-thermal history and hydrocarbon potential of the Pearl River Mouth Basin,northern South China Sea:Insights from borehole apatite fission-track thermochronology

The Pearl River Mouth Basin(PRMB)is one of the most petroliferous basins on the northern margin of the South China Sea.Knowledge of the thermal history of the PRMB is significant for understanding its tectonic evolution and for unraveling its poorly studied source-rock maturation history.Our investigations in this study are based on apatite fission-track(AFT)thermochronology analysis of 12 cutting samples from 4 boreholes.Both AFT ages and length data suggested that the PRMB has experienced quite complicated thermal evolution.Thermal history modeling results unraveled four successive events of heating separated by three stages of cooling since the early Middle Eocene.The cooling events occurred approximately in the Late Eocene,early Oligocene,and the Late Miocene,possibly attributed to the Zhuqiong II Event,Nanhai Event,and Dongsha Event,respectively.The erosion amount during the first cooling stage is roughly estimated to be about 455-712 m,with an erosion rate of 0.08-0.12 mm/a.The second erosion-driven cooling is stronger than the first one,with an erosion amount of about 747-814 m and an erosion rate between about 0.13-0.21 mm/a.The erosion amount calculated related to the third cooling event varies from 800 m to 3419 m,which is speculative due to the possible influence of the magmatic activity.

Analysis of the Effect of Mindfulness Meditation on Patients with Burning Mouth Syndrome

Objective:To explore the effect of mindfulness meditation on patients with burning mouth syndrome.Methods:60 patients with burning mouth syndrome in our hospital who were treated from January 2021 to December 2022 were selected for this study.The patients were divided into two groups of thirty cases each using the randomized numerical table method.The observation underwent psychological intervention and mindfulness meditation training,while the control group only received symptomatic care.The condition of the patients of both groups was observed and compared.Results:Upon receiving treatment,the patients in the observation group had lower Hamilton Anxiety(HAM-A)scores,and Hamilton Depression(HAMD)scores compared to the control group(P<0.05).The visual analog scale(VAS)scores of the observation group were also lower than those of the control group(P<0.05).Moreover,the efficacy of the nursing intervention in the observation group was higher than that of the control group(P<0.05).Conclusion:Psychological intervention and mindfulness meditation training can effectively improve the clinical symptoms of patients with burning mouth syndrome.Therefore,this treatment method should be popularized.

珠江口盆地白云凹陷东部古近系文昌组沉积演化特征

充分利用新三维地震资料,结合测井以及录井资料,对珠江口盆地白云凹陷古近系文昌组层序地层、沉积特征及沉积演化进行研究,重新建立文昌组三级层序格架内的沉积体系演化过程。结果表明:白云凹陷东部文昌组自下而上共划分为5套三级层序,分别对应于初始裂陷期(WCSQ1)、拆离裂陷早期(WCSQ2,WCSQ3)、拆离裂陷晚期(WCSQ4,WCSQ5)3个构造演化阶段;初始裂陷期为多个孤立的箕状半地堑,以发育缓坡轴向物源辫状河三角洲、陡坡近源扇三角洲和滨浅湖沉积为特征;拆离裂陷早期断裂活动强烈,湖盆迅速扩张,半深湖—深湖局限发育,沉积中心北移,北部番禺低隆起发育大型辫状河三角洲沉积;拆离裂陷晚期断裂活动减弱,湖盆逐渐萎缩,沉积中心稳定在白云凹陷中部,主要发育小型辫状河三角洲沉积,滨浅湖发育;大型辫状河三角洲及扇三角洲砂体是白云凹陷东部的有利储集体。

基于双特异纳米抗体FMDV血凝检测方法的建立

本研究利用基因工程方法将抗口蹄疫病毒(FMDV)纳米抗体Nb205和抗鸡醛化红细胞(cRBC)纳米抗体NbRBC48的基因片段连接,构建双特异纳米抗体Nb205-48,其相对分子质量为3.5×10^(4),能同时与FMDV和cRBC反应。利用Nb205-48成功建立了可用于FMDV抗原检测的血凝方法,该方法检测灵敏度为1μg/ml,与其他病毒无交叉反应,且批内和批间重复性好。分别采用血凝法和夹心ELISA方法对3批次FMDV抗原进行了检测,二者检测结果基本吻合。本研究建立了基于双特异纳米抗体Nb205-48的血凝检测方法,该方法具有较好的灵敏度、特异性和重复性,且简便、快捷、成本低,其检测结果与传统的FMDV定量检测方法的检测结果相关性好,为检测口蹄疫疫苗生产过程中FMDV抗原的含量提供了新方法。

2020-2022年丽水市儿童手足口病流行特征及病原谱分析

目的分析2020—2022年丽水市儿童手足口病(HFMD)流行病学特征和病原学监测结果,为HFMD防控提供科学依据。方法通过传染病报告信息管理系统收集丽水市HFMD发病资料,对流行特征进行分析,同时采用荧光定量PCR技术对收集的1558例标本开展病原学检测,探究2020—2022年HFMD肠道病毒病原谱的动态变化。结果丽水市儿童HFMD发病年龄主要集中在0~5岁,2020年发病主要集中在9月至12月,2021—2022年主要集中在4月至7月份。2020—2022年间丽水市累计报告HFMD病例为13611例,在1558例病原学标本中检出肠道病毒核酸阳性1032份,总阳性率为66.24%。其中肠道病毒A组71型(EV71)5份,总阳性率为0.32%;柯萨奇病毒A组16型(CoxA16)322份,总阳性率为20.67%;柯萨奇病毒A组6型(CoxA6)型494份,总阳性率为31.71%;柯萨奇病毒A组10型(CoxA10型)63份,总阳性率为4.04%;其他型别148份,总阳性率9.5%。2020—2022年间,EV71仅在2021年检出5例;CoxA16型阳性率分别为2.44%、21.54%和36.42%,2022年1月至8月和11月至12月为检出高峰;CoxA6型阳性率分别为49.78%、33.44%和12.76%,2020年8月至12月为检出高峰;CoxA10型阳性率只在2020年和2021年有检出,分别为4.00%、7.23%。结论除2020年HFMD流行月份整体延后外,其余年份流行特征类似于往年。2020—2022年丽水市HFMD的主要肠道病毒型别为CoxA16和CoxA6型,期间CoxA6型的优势已逐步被CoxA16取代。CoxA16为下一步防控工作的重点。

牛碱性成纤维细胞生长因子联合盐酸金霉素眼膏对正颌外科术后口角黏膜压力性损伤愈合的效果

目的:研究外用牛碱性成纤维细胞生长因子联合盐酸金霉素眼膏用于正颌外科术后口角黏膜压力性损伤愈合的临床效果。方法:选取温州医科大学附属口腔医院2018年6月—2023年9月行正颌外科术后发生口角黏膜压力性损伤的患者为研究对象,根据用药方式不同,将患者分为盐酸金霉素眼膏组(30例)、外用牛碱性成纤维细胞生长因子组(30例)和外用牛碱性成纤维细胞生长因子联合盐酸金霉素眼膏组(简称联合组)(30例)。比较3组患者的疼痛程度、张口度、愈合时间及满意度。结果:用药第5天,3组VAS评分均较用药前显著下降(P<0.05),张口度均较用药前明显增大(P<0.05)。用药第5天,3组VAS评分和张口度差异有统计学意义(H=13.921,P=0.001;F=8.569,P<0.001),其中与金霉素眼膏和外用牛碱性成纤维细胞生长因子组相比,联合组的VAS评分最低、张口度最大(P<0.05)。3组用药前后VAS评分和张口度的差值差异有统计学意义(H=18.292,P<0.001;F=6.720,P=0.002),且联合组的差值均为最大。3组愈合时间和满意度差异均有统计学意义(F=9.510,P<0.001;χ^(2)=8.940,P=0.011),其中联合组的愈合时间最短、满意度最高(P<0.05)。结论:外用牛碱性成纤维细胞生长因子联合盐酸金霉素眼膏可促进正颌外科术后口角黏膜压力性损伤的愈合,减轻术后疼痛,增大张口度,缩短愈合时间,从而提高患者的满意度。

2018年盐城市CVA6型肠道病毒全基因组分子特征分析

目的掌握盐城市肠道病毒CVA6型基因进化特征。方法对盐城市鉴定为CVA6型的肠道病毒,通过反转录聚合酶链式反应的方法扩增全基因组序列,扩增产物经纯化测序,采用相应的生物信息软件进行核苷酸及氨基酸序列比对、分子进化树构建以及重组分析。结果盐城市2018年共检测疑似疱疹性咽峡炎病例107例,肠道病毒核酸阳性率73.83%,其中CVA6、CVA16、其他肠道病毒分别占50.63%、5.06%、44.30%,未检出EV71。选取3株2018年疱疹性咽峡炎、3株2018年手足口病(流行月峰前、峰中、峰后)、1株2017年手足口病CVA6型代表株进行全基因组测序,遗传进化树显示:7株盐城株位于B进化分支B2基因亚群分支,3株疱疹性咽峡炎CVA6型代表株与2株2018年手足口病CVA6型毒株聚集成簇构成一进化小分支,2株手足口病毒株(2017年、2018年各1株)形成独立的进化小分支,形成2条传播链。选取2个进化小分支中疱疹性咽峡炎、手足口病CVA6型各1株,进行分子进化重组分析,均未发现明显的重组来源。结论2018年盐城市疱疹性咽峡炎的病原谱呈现遗传多样性,CVA6型肠道病毒为优势流行株,与手足口病的CVA6型肠道病毒可能有着共同的来源,盐城株未发现基因重组。

2013-2019年柳州市手足口病病原学监测结果及肠道病毒71型VP1基因特征分析

目的 分析2013-2019年柳州市手足口病病原学监测结果,掌握该地区手足口病的病原组成以及肠道病毒71型(EV71)的分子流行病学特征,为当地手足口病的防控提供科学依据。方法 采用实时荧光定量聚合酶链式反应(RTPCR)对收集的手足口病病例标本进行病原学检测。对重症或死亡病例的病原进行分型检测,选取2017年的5例EV71阳性手足口病重症或死亡病例标本进行VP1基因序列测定和特征分析。结果 2013-2019年柳州市共检测6 038例手足口病病例标本,肠道病毒通用型阳性标本4 210例(69.73%),其中EV71阳性659例(15.65%)、柯萨奇病毒A16型(Cox A16)阳性1 159例(27.53%)、其他肠道病毒阳性2 392例(56.82%)。2013年、2015年、2017年、2019年以其他肠道病毒为主(阳性率均>50.00%),2014年以EV71和其他肠道病毒为主,2016年、2018年以Cox A16和其他肠道病毒为主。2014-2019年重症或死亡病例的病原学分型显示,重症或死亡病例的主要病原是EV71、Cox A16、柯萨奇病毒A6型(Cox A6)、柯萨奇病毒A2型(Cox A2)。2017年该市手足口病重症或死亡病例中分离到的5株EV71毒株的病原基因亚型均为C4a亚型,毒株序列之间的核苷酸同源性为95.20%~100.00%,氨基酸同源性为97.50%~100.00%。结论 2013-2019年柳州市手足口病的优势病原发生了变化,主要病原由EV71逐渐转变为Cox A16和其他肠道病毒。引发重症或死亡病例的病原主要有EV71、Cox A16、Cox A6、Cox A2,EV71的优势基因型为C4a亚型。今后应进一步加强病原监测和相关分子流行病学研究,为落实手足口病综合性防控措施提供依据。

2019—2020年许昌市手足口病病原学监测结果分析

目的分析许昌市2019—2020年手足口病的病原体型别及分布,为手足口病的防治提供参考依据。方法采用Real-Time RT-PCR法,检测2019年1月1日-2020年12月31日间许昌市临床诊断手足口病例粪便、肛拭子、咽拭子、疱疹液标本的病毒核酸,并对监测数据进行分析。结果两年共检测标本540份,阳性409份,总阳性率75.74%,其中CA16阳性81份(占19.80%),EV71阳性11份(占2.69%),其他肠道病毒阳性280份(占68.46%),轻、重症病例肠道病毒阳性率差异无统计学意义(χ^(2)=0.37,P>0.05),不同年龄组构成比差异无统计学意义(χ^(2)=1.42,P>0.05)。结论许昌市2019—2020年手足口病的主要发病人群是3岁以下年龄组幼儿,优势毒株是其他肠道病毒,EV71型肠道病毒的阳性占比明显降低。

珠江口盆地白云凹陷古近系深层高变温背景下储层成岩作用与低渗致密化机制

珠江口盆地白云凹陷油气勘探逐渐从中-浅层韩江组-珠江组的常规储层转向深层-超深层珠海组-恩平组的低渗致密储层,特殊的高变地温地质背景使得储层成岩作用以及致密化机制与常规储层差别较大。综合运用铸体薄片鉴定、扫描电镜观察、物性测试、成岩过程重建和物性恢复等技术,系统分析了白云凹陷西北部低隆起-中部洼陷带古近系珠海组下段-恩平组砂岩储层的成岩过程及差异,结合构造演化背景、地层埋藏史和现今物性数据,研究了影响储层物性关系的主要因素以及储层致密化过程与机理。结果表明:珠海组下段-恩平组储层经历了较强的压实作用、2期碳酸盐胶结、3期硅质胶结和3期长石溶解作用。储层成岩作用过程中,地温梯度变化导致压实速率不同,经历不同开放-封闭体系的水-岩反应过程是不同区带物性差异的主要原因。压实作用是导致储层致密的主要因素,硅质胶结和碳酸盐胶结进一步增强了储层致密程度,溶解作用改善了储层物性。从低隆起到洼陷带,伴随地温梯度升高和埋藏深度增加,低隆起储层成岩阶段为中成岩A2期,斜坡带为中成岩B期,洼陷带为晚成岩期,成岩强度不断增加;成岩作用的差异使得储层物性演化显著不同。洼陷带储层在晚期烃类充注前已致密化,斜坡带储层在晚期烃类充注阶段逐渐致密,而低隆起区储层目前仍为低渗储层。斜坡带整体埋深小于5 km,且上覆地层具备良好封盖能力,是下部勘探的重点。

珠江口盆地潜山储层地质力学及压裂参数优化研究

珠江口盆地珠一坳陷惠州27-1井区作为潜山油气储层,压裂层段厚度大、层数多、非均质性强、压裂改造难度大,对于人工裂缝的在潜山储层中的拓展延伸规律认识困难。针对此问题,首先建立动态参数测井解释模型,并与静态岩石力学数据协同校正,建立一维岩石力学剖面;结合深部成岩理论,建立三维地质力学模型,真实模拟研究区块成岩环境;最后基于三维地质力学模型,研究排量、液量、砂比、前置液占比、射孔层位厚度等参数对裂缝纵向和平面延伸规律的影响,优化压裂设计。结果表明:惠州27-1区块,杨氏模量平均值为45.47 GPa,最大水平主应力平均值为100.91 MPa,最小水平主应力平均值为80.98 MPa,泊松比平均值为0.30。排量6~7 m^(3)/min、液量600~700 m^(3)、砂比10%~15%、前置液比例50%~60%、射孔厚度8~11 m为最优施工参数,为现场施工提供指导意见。

新冠疫情防控下手足口病肠道病毒的流行特征及变迁趋势

针对2019冠状病毒病(coronavirus disease 2019,COVID-19)疫情,在早期缺乏有效药物干预的情况下,大多数国家都采取了疫情防控措施,该措施的实施导致人们生活及行为方式的改变,减轻了COVID-19的传播.然而,这一策略对其他常见传染病的影响尚不清楚.本文通过分析疫情防控下手足口病肠道病毒的流行及变迁趋势,阐明实施疫情防控措施在减少手足口病肠道病毒流行方面非常有效,并对其基因变迁产生明显影响;探讨免疫力缺失和传染性疾病暴发之间的关系,提示疫情期间由于人们缺乏暴露于各种传染性病原体的机会导致免疫力缺失,未来可能出现多种传染病的共同流行,可为疫情大流行后常见及新发传染病的监测和防控、抗病毒药物和疫苗的研究提供启发.

虚拟影响者代言的有效性研究:基于消费者态度和口碑视角

虚拟影响者代言正在成为全球范围内品牌新兴的营销实践,对虚拟影响者代言的研究也因此成为新兴的研究领域。为了增加对虚拟影响者代言现象的理解,从消费者态度和口碑两个角度对虚拟影响者代言的有效性进行了验证。研究发现,在虚拟影响者的喜爱度、吸引力和受欢迎程度的作用下,虚拟影响者能够帮助提高消费者对被代言产品或品牌的态度和口碑。本研究的发现有助于理解虚拟影响者代言有效性的发生机制,对虚拟影响者代言的营销实践也有一定的参考意义。

天津市手足口病防控知识科普宣讲活动及效果评价

2023年6—10月,对天津市16个区进行分层抽样,抽取4个宣传地区及其24所托幼机构,对849位幼儿家长、705名校(园)医、129名社区医生开展手足口病防控知识科普宣讲活动,宣传形式包括家长课堂宣讲,校医、社区医生现场活动和答疑解惑,以科普文章制作转发、视频播放等形式传播,并针对现场宣讲活动人群开展问卷调查。科普宣讲活动后,手足口病日常预防知识知晓率及防控行为率明显升高。提出对于需要多次强化或不易记忆的日常防护知识,可采用科普宣讲和短视频循环播放相结合的方式。

南海东部富砂砾型大中型油气田发现与启示——以珠江口盆地惠州26洼古近系恩平组为例

基于珠江口盆地惠州凹陷油气勘探实践,通过烃源岩地球化学指标测定、储集体发育形貌恢复及镜下岩矿表征、圈闭封盖指标实测比对、原油生物标志化合物提取、凝析气成因判别及成藏条件解剖,系统分析惠州26洼古近系恩平组油气资源潜力、大型砂砾岩优质储集层发育特性、断裂圈闭有效性及油气运聚成藏模式,总结南海东部古近系富砂砾型大中型油气田的形成条件及勘探方向。研究表明:(1)洼内古近系文昌组发育“面积广、厚度大”的半深湖—深湖亚相优质烃源岩,具有“早期大量生油、晚期大量排气”的典型倾油型烃源岩排烃特征,为恩平组油气成藏提供了充足的物质基础;(2)洼内断裂陡坡带与转换带联合控制下近源规模性砂砾岩体储集层非均质性强,具有“有利相带-颗粒组分-微裂缝”三元分级控储特性,等粒、低泥质(含量小于5%)、高含量长石组分及近断裂组合的(水下)分流河道有利于甜点储集层发育;(3)稳定湖泛泥岩封盖下的走滑增压型圈闭是油气保存的必备条件,斜交主应力的北东及近东西向断裂控圈效果最优;(4)优质烃源岩-断裂输导/封堵-砂砾岩储集层时空配置共同控制油气富集程度,自上而下划分为低充满带、过渡带和高充满带3个油气聚集单元,且近增压型通源断裂带河道主体区利于规模性油气富集。研究成果为珠江口盆地恩平组规模性富砂砾型油气藏勘探指明了新方向,并实现了油气勘探重大突破。