河流相砂体的识别预测及其发育演化对古气候变化的响应是当前河流相沉积研究的热点.基于地震沉积学方法,采用三步走的河流相砂体识别预测方法(井震结合建格架→90°相位调整标岩性→切片属性辨砂体),在渤海湾盆地渤中坳陷石臼坨凸起南部(石南)新近系明化镇组下段(简称"明下段")识别出了顺直和蜿蜒河道砂、河道—堤坝复合体、点砂坝、河口坝、牛轭湖和决口扇6种河流相砂体.依据明下段泥岩颜色,结合藻类种属记录和孢粉记录分析,认为石南地区明下段沉积早期到中期经历了干湿交替→湿润主导的湿润化气候演变;而明下段沉积中期到晚期经历了湿润主导→干旱主导的干旱化气候演变.润湿化气候演变使得明下段沉积中期河流相砂体宽度和单层厚度减小、弯曲度增大,且带状孤立河道砂体更发育;而干旱化气候演变使得明下段沉积晚期流相砂体宽度和单层厚度增大、弯曲度减小,且带状河道—溢岸复合带和河口坝砂更发育.研究成果可为其他断陷盆地河流相砂体识别、预测提供参考,对指导构造活动相对较弱的湖盆萎缩期油气勘探实践具有一定的实践价值.

南黄海盆地迄今未获商业性油气突破,或与对其中-新生界3套湖相烃源岩的发育模式和生烃史研究薄弱有关.对来自3套烃源岩的41块样本进行岩石热解、微量元素、X衍射和色谱-质谱分析后发现,泰州组二段腐泥组含量高,为Ⅱ1型干酪根,以水生有机质输入为主,C27甾烷占优,受海侵影响碳酸盐矿物含量高,古水体还原性强且盐度高,利于有机质保存;阜宁组二段和泰州组二段古水体环境相似,但C28甾烷含量显著增高,为藻类为主和陆源为辅的双重有机质输入,是典型的湖相烃源岩;阜四段的C29甾烷含量占绝对优势,TAR比值高,为单一的陆源有机质输入,古水体偏氧化性且盐度低,不利于有机质的保存.烃源岩复杂的母质输入类型和沉积环境不利于对其热成熟度的评价,对以甾烷20S/(20S+20R)或Ts/(Ts+Tm)参数表达的"未熟"特征应谨慎.基于断陷型-拗陷型的构造背景转换分析,建立了潜力生油层的生烃过程,认为活跃的火山活动对烃源岩生烃有促进作用,且北部坳陷以早期生烃为主,南部坳陷存在早、晚两期生烃,以三垛组沉积时期生烃为主.研究对南黄海盆地下一步的油气勘探部署具有重要指导意义.

通过生烃模拟获取生烃动力学参数是近年来油气资源评价工作中极为重要的一个环节,利用地层热压生排烃模拟装置对南黄海盆地南二凹陷阜四段烃源岩进行了生烃模拟实验,并拟合了生烃动力学参数.实验及研究结果表明,阜四段烃源岩的生烃演化可分为3个阶段:第1阶段产烃量随温度上升快速增大,以产油为主;第2阶段产烃量随温度上升缓慢增加,为油、气同产;第3阶段产烃量随温度上升快速增大,主要是以生气为主.实验拟合出阜四段烃源岩的生油活化能为228 kJ/mol,生气活化能为280 kJ/mol.与常压-完全开放体系试验、金管-高压釜实验装置的实验结果对比,本次实验南黄海盆地阜四段烃源岩在地层热压条件下出现生油窗滞后现象,烃源岩样品在高成熟演化阶段依然具有较高的液态烃产率.阜四段生油活化能值较高,其内在原因是有机质受到烃源岩孔隙中高压水的“保护”作用以及受生烃空间的影响,延缓了烃源岩的热演化进程.综合前人实验结果分析,有限空间热压生烃模拟实验环境更接近于烃源岩在地层条件下的生烃条件,实验结果对南黄海盆地的油气资源潜力评价及油气勘探方向具有指导意义.

基于地貌、钻井、岩石测年和地震等资料,分析盆地地层分布、盆架结构、构造单元划分和裂陷迁移规律,结果表明东海盆地由台北坳陷、舟山隆起、浙东坳陷、钓鱼岛隆褶带和冲绳坳陷构成,是以新生代沉积为主、中生代沉积为辅的大型中、新生代叠合含油气盆地;古元古代变质岩系构成了盆地的基底.该盆地不仅是印度-太平洋前后相继的动力体系作用下形成的西太平洋沟-弧-盆构造体系域一部分,而且也是古亚洲洋动力体系作用下形成的古亚洲洋构造域和特提斯洋动力体系作用下形成的特提斯洋构造域一部分,晚侏罗世至早白垩世经历了构造体制转换,盆地格局发生重大变革,早白垩世以前主要受古亚洲-特提斯洋构造体制影响的强烈挤压造山和地壳增厚作用演变为早白垩世以来主要受太平洋构造体制控制的陆缘伸展裂陷和岩石圈减薄作用,经历侏罗纪古亚洲-特提斯构造体制大陆边缘拗陷和白垩纪以来太平洋构造体制弧后裂陷两大演化阶段.白垩纪以来太平洋构造体制的弧后裂陷演化阶段可细分为早白垩世至始新世裂陷期、渐新世至晚中新世拗陷期和中新世末至全新世裂陷期.

渤海Y构造浅层明化镇组储层发育,但已钻井证实该区储层含油气性有较大差异.高精度的地震流体检测结果对提高目标区明下段岩性圈闭钻探成功率意义重大.为研究目标区明下段储层含油气性,对目的层进行了一系列基于振幅类和频率类的叠后含油气性检测,但都无法对储层流体进行有效识别,可靠性较低.因此,转变研究思路,应用叠前流体检测技术,通过方法对比发现,在入射角小于30°时,直接通过叠前角道集提取出的流体因子对该区浅层油气较为敏感,与已钻井测井解释结果对应较好.应用该敏感参数进行储层含油气性预测取得了较好的效果.对类似地区叠前储层流体预测具有一定的借鉴意义.

为探讨断陷盆地陡坡带近源扇体的发育规律,利用三维地震资料和钻井资料,在"源—汇"理论指导下对秦皇岛A构造近源扇体展开研究.结果显示:石臼坨凸起的中生界火山岩潜山为秦皇岛A构造提供充足的沉积碎屑.提出"隐性古沟谷"概念,解决了物源区无古沟谷输砂的问题.在构造重新落实的基础上,结合古断距恢复和古地貌恢复识别出了平行断裂型古转换带.发育在坡折带上的古转换带可以作为古水系进入盆地的入口,从而确定陡坡带近源扇体的发育位置.在物源分析、注水口识别、古地貌恢复的基础上,建立了隐性古沟谷—平行断裂型古转换带控砂模式.在该模式指导下,利用基于灰度共生矩阵的属性优化技术,精细刻画了近源扇体的平面形态.已钻井QHDA1井打在了秦皇岛A构造"二台阶"上的扇缘部位,未钻遇扇体的根部,故而储层不发育.研究区有利勘探区带位于构造"一台阶"的扇根部位.

渤海地区新近系断裂体系复杂,受多期次构造运动影响,使得渤海油田的构造非常的破碎.在秦皇岛28构造的勘探评价过程中,发现局部地区断裂在平面呈现羽状分布,且存在掉向相反断裂带,这种特征是走滑断裂的依据之一,但仅依靠地质理论来确定是否存在走滑断裂是不客观的,需利用地震属性验证其客观存在性.在评价的过程中通过不同技术的组合应用及对比分析,发现常规的边缘检测、相干属性等技术很难对该区复杂断层进行有效识别.基于倾角中值滤波技术去除部分噪音的干扰,凸显断裂信息,应用最大似然属性技术识别出了较为清晰的“隐性走滑”断裂,结合平面特征,进一步落实构造,直接新增资源量约300万t.为扩大秦皇岛28油田的储量规模奠定了坚实的基础.在现今精细勘探阶段,推广应用微断裂识别技术,将会进一步提高复杂断块区断层系统解释的可靠性和精细程度,提高油田滚动勘探开发的钻探成功率.

渤海海域渤中凹陷深层具有大型天然气田形成的良好地质条件,渤中19-6大型凝析气田是渤海湾盆地迄今发现的最大的天然气田,储量超千亿立方米.利用大量岩心、薄片、测井及地球化学资料,对渤中19-6构造深层天然气成藏条件进行了系统分析.研究表明,渤中凹陷深层具有巨大的生气潜力,是大型凝析气田形成的物质基础;区域性稳定分布的东营组和沙河街组巨厚超压泥岩为大型凝析气田的保存提供了良好的封盖条件;首次在渤海湾盆地古近系孔店组发现巨厚裂缝一孔隙型砂砾岩储层,突破了在凹陷区深部寻找厚层砂砾岩储层的禁区,大大拓展了古近系油气勘探领域;通过对太古宇深埋变质岩潜山优质储层形成机制进行分析,提出多期次动力破碎作用使潜山内幕发育大规模裂缝体系和动力破碎带,是变质岩优质储层形成的关键.这些认识指导了渤中19-6构造大型凝析气田的发现,实现了渤海海域天然气勘探的突破,对渤海湾盆地深层天然气勘探具有重要指导意义.

渤海湾盆地渤中凹陷砂砾岩储层致密化成因及其与晚期油气侵位的关系一直没有得到合理地解释.为此,以渤中凹陷西南部地区古近系砂砾岩气藏为研究对象,利用物性、热史、包裹体等分析资料,确定油气首次成藏时间、划分油气充注期次、恢复成藏期储层物性,进而模拟压实作用对储层的影响,并结合包裹体、铸体、扫描电镜、X射线衍射等实验手段明确油气侵位关系,分析石英加大、黏土矿物转化、碳酸盐胶结等关键致密化作用发生的序列,探究储层致密化作用机理及其与油气充注的关系.研究结果表明:①该区深层砂砾岩油气充注至少可分为3期,早期包裹体为重质油,晚期包裹体气油比高;②首次油气充注期为距今5Ma,储层埋深介于2 500～2 800m,以中孔、中渗储层为主,储集物性较好,成藏后盆地快速沉降、充填,上覆地层增加厚度超过1 000 m;③首次油气充注后砂砾岩进入成岩快速演化期,埋深介于2 500～3 200m,是砂砾岩快速压实阶段,石英加大在油气充注后经历了两期强烈发育,减孔作用明显,压实减孔作用是储层致密化的重要机制;④埋深介于2 500～3 500 m为该区黏土矿物快速转化区间,花状及丝发状伊利石极其发育,对渗透率的大小产生了决定性的影响;⑤铁方解石及铁白云石沉淀于石英加大之后,使储层进一步致密化,以残余孔隙为主.结论认为,该区古近系砂砾岩气藏具有先成藏后致密的特点,尽管油气充注对储层成岩具有抑制作用,但后者仍然会导致储层的致密化.

为探讨CF油田热液活动对古生界碳酸盐岩储层的影响,对岩心、薄片、扫描电镜、阴极发光、碳氧锶同位素、流体包裹体等进行了综合分析.研究认为:碳酸盐岩储层中存在典型的热褪色、细密不规则诱导缝,发育鞍形白云石、硅质结核、自生石英等典型热液矿物;受热液影响的方解石阴极发光下发亮橘黄色光、δ18O值异常低、87Sr/86Sr值异常高,盐水包裹体均一温度明显高于地层温度;富含Mg2+的酸性岩浆热液流体沿断裂涌入地层,促使围岩发生白云石化作用,产生大量的晶间孔,同时溶蚀碳酸盐岩,形成大量的溶蚀孔隙;受热液流体作用影响形成的诱导缝可进一步沟通储集空间,改善了储层的渗透性,提升了碳酸盐岩储层储集性能.

渤海海域古近系广泛发育三角洲沉积体系,三角洲砂体是重要的油气勘探目标,对三角洲砂体地震响应特征分析以及边界的精细刻画有助于提高三角洲储层预测的准确率.以渤海辽东湾探区实际地震资料为基础,设计物理模型和参数,并对模型进行简化;制作了典型三角洲沉积模式下的物理模型,模型包括低位体系域、湖浸体系域和高位体系域共11套砂体.在实验室条件下,采集得到物理模拟三维地震数据体,并对其进行处理和解释,再分别利用常规振幅切片和谱分解技术识别砂体边界.结果表明,振幅切片对于砂体横向的岩性变化较敏感,而谱分解技术能够精细刻画出砂体的轮廓和边界.

B well field in Bohai Bay basin is affected by bidirectional sources,and its main source direction is uncertain due to the lack of research.In this study,forward modeling was applied to the study of the main source.The models were designed to simulate these two kinds of main control sources,verify the direction of the main source and the distribution of the reservoir by comparing the modeling re-sponse with the actual seismic reflection characteristics.In order to further demonstrate the conclusion that the western part of B well field is mud rich,the authors established different models by giving different wave impedance differences between the near source and the end of the progradation,and carried out forward modeling.Based on comparing the sandbody characteristics, the actual seismic re-flection characteristics and the forward modeling responses,the authors have reached the conclusion that the oil-bearing sandstones of the lower D2 Formation in B well is the distal end of progradation that comes from northwestern Shijiutuo Uplift,and Shijiutuo Uplift is the main source of the study area,which is the potential target for the high quality reservoir.

To study oil and gas generation activation energy of different samples under different pyrolysis experiments,open system anhydrous pyrolysis and confined system hydrous pyrolysis are performed on lacustrine shale source rock,raw rock and kerogen samples from Bozhong area.Source rock samples are from different sags and different intervals,and have different organic matter abundance,kerogen type and maturity.The results shows that kerogen type and maturity have important influence on oil generation activation energy,and mean oil generation activation energy increases as organic matter type becomes poorer and maturity is higher.Different sags,source rock intervals and sample type have no obvious influence on mean oil generation activation energy,but sample type influences the distribution.Hydrocarbon generation activation energy distribution of raw rocks is more concentrated than kerogen.Gas generation activation energy of mature source rocks is 11-17 kJ/mol higher than that of low mature source rocks.Compared with open system anhydrous pyrolysis,confined system hydrous pyrolysis has more concentrated activation energy distribution including primary and secondary cracking.Confined system hydrous pyrolysis of low mature source rock raw samples and mature source rock kerogen samples for oil and gas generation kinetics respectively are recommended.

利用近几年新取得的钻孔资料及地震资料,对崂山隆起的地层发育、构造演化进行了分析,并与下扬子陆区的苏南地区、浙西地区进行了对比.结果表明,崂山隆起有2个主要发育期,第1期为晚震旦世至中奥陶世,第2期为早三叠世;在这2个时期内,崂山隆起形成了以台地相为主的沉积,而浙西地区形成了深水盆地相沉积;晚奥陶世至志留纪期间是崂山隆起的构造加强期,中、新生代为崂山隆起的整体抬升期.崂山古隆起的形成一方面在该区形成了较厚的台地相白云岩等储层,为该区的油气富集提供了储集空间,另一方面继承性发育的古隆起为构造高部位,有利于周缘深水盆地或裂陷槽中形成的烃类向隆起区圈闭中运移成藏,有利于在崂山隆起形成大型油气田.

精细恢复陡坡带下降盘的微古地貌,探讨沉积期古地貌对沉积的控制作用.基于平衡剖面原理,提出构造-沉积恢复法:选取合适机制,对Q构造三维构造模型进行构造恢复和地层压实恢复,减小晚期构造运动对边界断层下降盘同沉积期古地貌的影响.实例对比表明,构造-沉积恢复法较传统的残余厚度法能够更准确地刻画盆地同沉积期的微古地貌特征.实际钻探结果证实,运用该方法恢复古地貌可以更精准地预测沉积体系和储层的分布,预测结果与实钻吻合良好,为渤海湾盆地Q构造区大型油田的发现提供了有力支持.

Sealed gold tube pyrolysis was carried out for 3 source rock samples from the third (E2s3) and first (E3s1) members of Shahejie Formation, and the third (E3d3) member of Dongying Formation in the Shanan Sag, and 2 source rock samples from the E2s3 in the Qinnan Sag in Bozhong area.These samples are lacustrine shale with a high organic matter content and low maturity, and contain type I kerogen.Minerals in the source rock samples are mainly clay minerals and contain a significant amount of calcite, quartz and feldspar.The gold tube pyrolysis experiments focus on liquid hydrocarbon generation.The mean hydrocarbon generation kinetics of E2s3, E3s1 and E3d3 source rock samples range between 219 and 222 kJ/mol, and the kinetics of all samples have a concentrated distribution.Samples from same sag but different intervals, and samples from different sags but same interval have no significant difference, but the samples with a relatively low content of clay minerals and a high content of calcite have a relatively higher mean hydrocarbon activation energy.Carbon isotopes of C14+ liquid products during peak hydrocarbon generation can be 11.3% heavier than extracts from unpyrolyzed samples, and oil-source correlation with extracts from low maturity source rocks must consider this.TOC loss of residual solids can reach up to 48%.It is necessary to restore organic matter abundance and kerogen type when evaluating high maturity source rocks with a high organic abundance and favorable organic type.

Many heavy oil reservoirs are discovered in Mesozoic buried hill and Neogene of Bohai sea in recent years,but oil-source correlation is difficult because the common used biomarkers become invalid due to severe biodegradation.Taking PL 9-1 oilfield in Bohai sea as an example,the influence of severe biodegradation on oil carbon isotope,biomarkers in saturated and aromatic hydrocarbon,and nitrogen containing compound is studied.A biodegradation index is introduced to quantify biodegradation level for the severely biodegraded oil.Results show that carbazole and gammacerane contents decrease when biodegradation becomes severe;the preferential biodegradation of C19 tricyclic terpane,C24 tetracyclic terpane and Ts results in the decrease of C19/C23 tricyclic terpane and C24 tetracyclic terpane/C26 tricyclic terpane index,and the increase of ETR index,respectively;4-methyl triaromatic steroids are the most reliable biomarker in severely biodegraded oil,C27 4-methyl triaromatic steroids,C29 4-methyl-24-ethyl triaromatic steroids and C29 4,23,24-trimethyl triaromatic dinosteroids are indicators of organic input and depositional environment for source rocks,and they can be used to distinguish oil source from the E2s3,E3s1 and E3d source rocks with the combination of whole oil carbon isotope;carbazole and crude oil properties reflect the hydrocarbon migration directions.Oil source of the Mesozoic buried hills and Neogene reservoirs of PL 9-1 oilfield are E2s3 and E3s1 source rocks in Bodong sag.Oil source of Neogene reservoirs is E3s1,with contribution of both Miaoxi and Bodong sags.The research results have significance for exploration of the study area and provide reference for oil-source correlation of severely biodegraded oil in Bohai sea and other similar areas.

In order to determine the provenance of sediments and play fairways in Lishui Sag,East China Sea Shelf Basin, we analyzed and characterized the provenances of the sediments in the sub-sags in eastern and western Lishui Sag through detrital zircon U-Pb dating and discussed the influences of different provenances on the physical properties of sandstone reservoirs in the Sag. The results show that sediments in the west sub-sag were mostly sourced from Minzhe Uplift Zone in the western part of the Sag where volcanic rocks are predominant with some intrusive and metamorphic rocks . The sand-stone formed by sediments sourced from this provenance has high plastic content and low resistance to compaction,thus porosity loss is relatively largeduring compaction processes. The sediments in the east sub-sag were mostly sourced from Yushan Uplift Zone in the eastern part of the Sag where sedimentary rocks and intrusive rocks are predominant. The sand-stone formed by sediments sourced from this provenance has low plastic content and strong resistance to compaction,thus porosity loss is relatively small during compaction. It is suggested that the provenance differences indeed have certain im-pact upon the physical properties of the reservoirs in the Sag.

针对渤海构造-岩性油气藏实际CRP道集出现的近道剩余多次波发育、地震分辨率偏低、道集不平以及AVO背景趋势异常等问题,提出了一套基于弹性反演的叠前CRP道集保幅处理技术,包括基于振幅拟合及信号匹配重构的剩余多次波压制技术、基于时频分析的Q补偿技术、动校剩余时差校正技术和AVO背景趋势校正技术.经过叠前保幅精细处理后的CRP道集数据,满足了精细构造解释和弹性反演的要求,达到了更好利用地震信息预测油气的目的.

This paper discusses the distribution laws and prediction methods of the subtle oil and gas reservoir in a sequence framework.Guided by the sequence stratigraphic theories,this paper studies the sequence stratigraphy features of Paleogene Dongying Formation in the southeast slope of the Qinnan depression in Bohai Bay in detail by using well drilling,logging and seismic data.Dongying Formation is divided into 3 third-order sequences,that is Sequence Dong 3 ,Sequence Dong 2 and Sequence Dong 1 .The depositional model of Sequence Dong 3 is constructed and the petroleum accumulation model of the subtle oil and gas reservoir is concluded.The research results show that in the late period of Sequence Dong 3 reservoir well developed and widely distributed with water level falling and the abundant material supplying, which can form a large-scale formation reservoir combined with the stable distribution of mudstone in Sequence Dong 2 .In the early stage,the water gradually rises and an overlap pinch-out lithologic reservoir can be formed.Below the thick mudstone of Sequence Dong 2 ,the main controlling factors of the petroleum accumulation for the subtle oil and gas reservoir are the sand distribution characteristics controlled by the change of lake level.The exploration potential is great in subtle reservoirs of the Qinnan depression.