The conductive model of complex shaly sandstones is used to describe the rock-electric characteristics, which is the key to reservoir saturation evaluation. At present, conductive models as a single factor are unable to accurately reflect the conductive property of complex shaly sandstones, which limits the evaluation precision of reservoir saturation. In this paper, by incorporating multiple factors of shale, pore structure, and conductive structure, a novel modified equivalent rock element model (MEREM) is developed to analyze the rock-electric characteristics and calculate the reservoir saturation in complex shaly sandstones. Our studies show that pore structure and shale significantly influence the conductive property of complex shaly sandstones. However, they have the opposite effect and may cancel out each other. Moreover, the conductive model presented here has achieved promising results in interpreting experimental data. Furthermore, the MEREM is extended to oil-bearing shaly sandstones, demonstrating that the rock resistivity at different saturation is sensitive to pore structure and shale. The MEREM is applied to predict the reservoir saturation, and the computed saturation is found to be well-matched with cores. Therefore, the proposed MEREM is good for interpreting rock-electric characteristics and the evaluation of reservoir saturation in complex shaly sandstones.

准噶尔盆地腹部八道湾组是侏罗系潜在的勘探接替领域.通过分析盆1井西凹陷八道湾组低位体系域砂体形成条件、沉积特征,结合成藏条件研究,提出了坳陷湖盆坡折之下发育低位体系域砂体,低位体系域砂体成藏条件优越:①盆1井西凹陷八道湾组发育1个完整的三级层序,凹陷周缘发育坡折,来自东部物源体系的辫状河三角洲向凹陷方向进积,在坡折之下的凹陷区卸载沉积物,为凹陷区低位体系域砂体的发育创造了条件.②盆1井西凹陷八道湾组发育低位体系域砂体,低位体系域砂体呈砂泥互层,侧向与三角洲平原河漫滩泥岩接触,顶底板和侧向遮挡条件较好,岩性圈闭条件优越,具有形成规模岩性圈闭群的条件.③盆1井西凹陷发育低孔特低渗低位体系域砂岩储层,局部发育的微裂缝改善了储层物性;凹陷发育二叠系风城组和下乌尔禾组2套烃源岩,烃源条件较好.④盆1井西凹陷周缘发育深浅2组断裂,在垂向上沟通八道湾组低位体系域砂体与二叠系烃源岩,有利于油气聚集成藏,勘探潜力大,为准噶尔盆地下一步天然气规模发现的有利勘探领域.

为了明确坳陷湖盆古地貌对沉积体系的控制作用,认识沉积体系展布规律,优选下一步勘探领域,以准噶尔盆地中部侏罗系三工河组二段为例,采用地层厚度法恢复了古地貌,细化了古地貌单元,并通过岩芯观察,识别了沉积微相,在此基础上,通过古地貌单元与沉积微相叠合分析,提出了坳陷湖盆沉积期古地貌对沉积体系、沉积微相和岩性圈闭的形成具有重要的控制作用.研究结果表明:准噶尔盆地中部三工河期为隆凹相间的古地貌格局,具有水下古低凸、水下古沟槽、古坡折和水下古平台等4类古地貌单元,发育湖泊-三角洲沉积体系,可进一步识别出水下分流河道、分流间湾、席状砂和砂质碎屑流微相.水下古沟槽充填水下分流河道微相砂体,水下古低凸主体部位发育分流间湾相泥岩,古坡折之下的水下古平台发育砂质碎屑流砂体.水下古低凸翼部发育的水下分流河道砂体向低凸方向超覆尖灭,水下古平台发育的砂质碎屑流砂体呈"泥包砂"结构,储层性质较优,岩性圈闭条件好,成藏条件优越,为下一步最有利勘探领域.

砂质碎屑流储层普遍非均质性较强,纵、横向变化快,储层预测难度大.因此,需要精细描述砂质碎屑流储层,以拓展油气勘探新领域.利用多属性融合技术预测砂质碎屑流储层面临属性优选,很难得到明确的解释结果.为此,利用GeoEast软件的核主成分属性优化技术与神经网络反演技术定性与定量预测砂质碎屑流储层,落实砂质碎屑流储层发育区.首先,分析砂质碎屑流地震响应特征,利用核主成分压缩技术定性预测砂质碎屑流;其次,利用敏感曲线(GR曲线)对砂质碎屑流储层的敏感性,利用神经网络反演定量预测砂质碎屑流有效储层的分布范围.结果表明,利用神经网络反演结果在平面上确定了 6个砂质碎屑流砂体,与钻井结果匹配较好.

为了明确准噶尔盆地白垩系清水河组是否发育低位体系域砂体、低位体系域砂体是否具有勘探潜力,对阜康凹陷清水河组低位体系域砂体形成条件、沉积特征和沉积模式进行了分析,并对成藏条件进行研究.结果 表明:准噶尔盆地白垩系清水河组底部为三级层序界面,且阜康凹陷沉降中心附近发育多级坡折,为低位体系域砂体发育创造了条件,并提出大型坳陷湖盆坡折之下发育多期低位体系域砂体,岩性圈闭条件优越.低位体系域砂体厚度大、面积广、储层优,侧向封堵条件优越,且研究区发育深层和浅层两组断裂,在垂向上构成"Y"形组合,可沟通烃源岩和低位体系域砂体,证实研究区低位体系域砂体成藏条件优越,为下一步岩性油藏最有利勘探领域.

为查明源储配置对致密油富集的影响,优选下一步致密油潜在有利区,在岩心和薄片观察的基础上,开展地球化学分析和扫描电镜、微米CT等测试,对川中地区大安寨段烃源岩和致密储层特征进行分析,并通过已知油藏解剖,对大安寨段致密油源储配置类型和平面展布进行了研究,发现源储互层式和上源下储式配置关系最有利于致密油富集.研究结果表明:川中地区大安寨段发育旁生侧旁生侧储储式、源储互层式和上源下储式等3种源储配置,烃源岩为最大湖泛期泥页岩,有机质含量0.54％～2.32％,干酪根类型以腐泥型为主,处于成熟—高成熟阶段;储集空间类型包括溶蚀孔洞和基质孔隙,分别发育于厚层介壳灰岩和中—薄层泥质介壳灰岩中,孔隙度0.38％～6.82％,平均1.67％,渗透率多低于0.1×10-3μm2,为特低孔致密储层.现有勘探实践证明油田源储配置关系以源储互层式和上源下储式为主,秋林、仪陇、渠县、李渡和广安地区以该类源储配置关系为主,为下一步致密油潜在有利区.

海洋地震资料普遍发育强能量表面多次波,传统表面多次波压制技术(SRME)能够预测出所有阶次表面多次波,但是各阶次表面多次波相互混叠.为了能够单独利用不同阶次的表面多次波成像,降低干涉假象对多次波成像的影响,需要将不同阶次的表面多次波分离出来.本文提出一种基于扩展SRME的海洋单阶次表面多次波分离方法.首先,应用SRME技术预测出混叠的所有表面多次波;其次,修改常规SRME技术的边界输入条件,将上一步求得的所有多次波进行升阶次处理;再次,预测出混叠的所有表面多次波与其升阶次后的表面多次波匹配相减求得单阶次多次波.以此类推,能够逐步分离出不同阶次的表面多次波.数值模型和某深海实际资料测试表明本方法的有效性,不同阶次表面多次波被有效分离,为后期多次波的利用奠定了基础.

为了进一步了解玛湖凹陷下二叠统风城组沉积环境,通过现代碱湖和主要碱矿进行调研,系统梳理了现代碱湖沉积特征,并与风城组沉积特征进行了对比研究,提出了现代碱湖沉积对玛湖凹陷风城组沉积环境具有可对比性.研究结果表明:玛湖凹陷风城组沉积期为一大型碱湖盆地,与世界上典型碱湖特征基本相近,自生矿物、沉积组合与演化过程大致相同,为形成于半干旱气候环境的闭流盆地,含碱层段一般为浅水环境成因,是碳酸盐型湖水蒸发浓缩的产物,与碱层互层的暗色细粒岩石不全为深水沉积产物.

为了弄清准噶尔盆地凹陷区是否发育有效砂体、岩性圈闭是否落实,基于岩心观察、重矿物分析、储层表征和地震反射特征分析等方法,分析了该盆地盆1井西凹陷下侏罗统三工河组二段(以下简称三二段)古地貌、沉积微相、储层性质和含油气性,评价了砂质碎屑流砂体的岩性圈闭条件,明确了准噶尔盆地三工河组下一步天然气勘探的方向.研究结果表明:①盆1井西凹陷周缘三二段发育坡折带,坡折带之上三角洲前缘砂体发育,在燕山期构造活动的触发下,滑塌至坡折带之下的半深湖形成砂质碎屑流砂体;②砂质碎屑流砂体厚度大,垂向上具有“泥包砂”结构,侧向与前缘相砂体之间存在泥质分隔带,封堵条件较好,岩性圈闭条件优越;③砂质碎屑流砂体储层物性好,属于中等—较好的储集层,砂质碎屑流砂体整体含油气性较好.结论 认为:①准噶尔盆地三工河组发育砂质碎屑流砂体,岩性圈闭条件优越,具有重要的油气勘探意义;②基于该研究成果,通过新钻井已取得了油气勘探重大突破,证实坡折带之下砂质碎屑流砂体岩性油气藏成藏条件优越,是该区下一步最有利的天然气勘探新领域.

以准噶尔盆地中拐地区上乌尔禾组砂砾岩储集层为例,利用铸体薄片、电子探针、扫描电镜、物性等资料,对陆相岩屑砂砾岩中发育的绿泥石膜微观特征、成因及其与储集性能之间的关系进行详细研究.结果 表明:上乌尔禾组绿泥石膜为偏富铁型,且具有双层膜结构,近颗粒一侧里层膜连续性好、致密、晶体小;近孔隙一侧的外层膜连续性差、疏松、晶体大;绿泥石膜由先存黏土膜转化而来,形成于温度小于70℃的早成岩阶段;绿泥石膜对碎屑石英的次生加大有抑制作用,但不能阻止自生石英晶粒在孔隙中沉淀,更不能阻止浊沸石、方解石胶结物的沉淀,也不能抑制机械压实作用,其对储集层孔隙保存贡献较小,对优质储层起指示作用.

志留系柯坪塔格组上3亚段是塔里木盆地塔中地区重要的海相碎屑岩勘探层系,综合运用钻井、测井、地震和实验分析资料,对沉积前古地貌、古盐度和水动力条件进行系统分析,进而明确了沉积体系类型和分布规律.研究发现,塔中地区志留系沉积前古地貌由北向南逐渐抬高,局部存在多个狭长低洼区和水下低隆,发育海侵背景下受古地貌控制的潮坪、河口湾和潮汐改造三角洲3种沉积体系,主作用水体类型和能量的差异形成了不同的砂体类型和沉积建造.潮坪沉积体系的砂体类型以潮下带潮汐水道和潮间带沙坪为主,其中潮汐水道具有完整的3层结构,垂直海岸呈条带状分布.河口湾发育水道和沙坝砂体,砂层中常见泥质薄层,砂体轴向与河口湾轴向平行且延伸较远.潮汐改造三角洲发育水下分流河道砂体,见硅质、燧石砾层及大型冲刷面.通过以上研究建立了塔中地区志留系潮坪—河口湾—三角洲沉积模式,并预测了有利砂体的展布.

为详细解剖水下分流河道沉积特征,探讨其岩性圈闭意义,采用多参数分析方法,对水下分流河道微相沉积特征进行了分析,提出了发育于不同古地貌单元的水下分流河道微相砂体由于物性存在差异而对岩性圈闭的形成具有重要意义.研究结果表明:研究区三工河组二段发育古低凸和古沟槽2种古地貌单元,古沟槽发育反旋回叠置型水下分流河道,低凸翼部发育正旋回叠置型水下分流河道.正旋回叠置型水下分流河道砂体物性自下而上逐渐变差,在侧向对反旋回叠置型水下分流河道储集体构成侧向遮挡,有利于形成岩性圈闭.在此基础上建立了岩性圈闭模式,将该模式应用到油田预探井井位部署中,取得了很好的效果.

准噶尔盆地中拐—玛南地区上乌尔禾组为扇三角洲前缘亚相沉积的砂砾岩,具有厚度大、横向变化快、岩石结构成熟度和成分成熟度均低的特点.砂砾岩储层的关键控制因素为泥质含量,根据泥质含量对上乌尔禾组砂砾岩进行划分,可以分为含泥砂砾岩和富泥砂砾岩.利用单一的测井曲线难以有效识别研究区的泥质含量,根据常规测井曲线的响应特征,利用中子测井曲线和声波时差测井曲线的幅度差来拟合砂砾岩储层泥质含量曲线,再经地震波形指示反演来预测砂砾岩优质储层的平面展布,实现了砂砾岩储层的定量化预测.经过钻井证实,这一方法预测结果符合率较高,油气显示良好,展示了本区良好的勘探前景.

为了弄清准噶尔盆地腹部白垩系清水河组沉积体系和微相砂体展布,落实下一步岩性油藏勘探领域,采用残余地层厚度法恢复了古地貌,识别了古地貌单元,并通过岩心观察、测井相和地震相分析,研究了沉积体系和微相发育特征,提出了水下古沟槽侧翼向低凸超覆尖灭的水下分流河道砂体有利于形成上倾尖灭型岩性圈闭,研究结果表明:石南低凸、夏盐低凸、三个泉低凸、石东低凸和滴南低凸侧翼水下分流河道砂体厚度5～20 m,平均孔隙度12％～28％,平均渗透率10～2 490 mD,侧向受低凸主体部位分流间湾和滨浅湖泥岩封堵,顶部发育“高伽马”泥岩,平均厚度20～60 m.低凸分布区发育深层和浅层2组断裂,深层断裂沟通二叠系烃源岩且与浅层断裂呈“Y”型配置,构成良好油气运移通道,证实5个低凸翼部成藏条件优越,为下一步岩性油藏最有利勘探领域.

Based on the data of cast thin section,SEM,Electronic probe,X-ray diffraction and petrophysical properties etc.,the paper detailedly studies the petrologic features and diagenesis of the Middle-Lower Permian clastics in the northwestern margin of Junggar basin,based on which,the influence of the diagenesis in alkaline environment on accumulative properties of reservoirs is discussed.The results show that the diagenesis in alkaline environment is commonly noted in the Middle-Lower Permian strata,such as tephra hydrolysis,tephra albitization,formation of zeolites and chlorite and so on.Various associated pores including alkaline dissolved pore of tephra,albitized associated pore and intercrystalline micropore in clay minerals are developed in alkaline environment.The influences of diagenesis in alkaline environment on the Middle-Lower Permian clastic reservoirs mainly include strong impaction of reservoir fluids resulted from alkaline fluids,i.e.,high reservoir compaction ratio in alkaline fluids,which is unfavorable for primary pore preservation;high authigenic mineral content of reservoir under the diagenesis in alkaline environment and local cementation with large pore reduction amounts;high pore increase efficiency due to the corrosion of alkaline fluid.Alkaline dissolved pore in tephra can be the important accumulation space.

The upper Wuerhe formation of Permian and Triassic Baikouquan formation in Mahu sag and its adjacent areas are a set of nearsource coarse deposits under the background of depression basin that are large-scaled shallow retrogradation fan-delta deposits under the background of gentle slope,and 13 lithofacies and 7 sedimentary microfacies are identified based on core observation.Muhiple fan deltas are developed on the slope of the sag,and the fan bodies connect with each other.The formation of this kind of large-scaled shallow retrogradation fan delta is closely related to 3 geological conditions.The first is that continuously uplifting periphery ancient mountains and sta-ble river systems provided sufficient provenance for each fan during deposition;the second is that there was a good paleogeographic background such as large basin,shallow water and gentle slope;the third is that continuous lake transgression and multi-stage slope-break are significant conditions for large-sized superposition and merging of sand bodies.A sedimentary model of large-scaled shallow retrogradation fan delta is established,which provides guidance for petroleum prospecting and reserves estimation in Mahu sag.

库车坳陷前陆区白垩系发育特低物性、强非均质性和高稳产砂岩储层,溶蚀作用显著,但成因机制尚不是很明确.利用高温高压热模拟实验还原了目的层在成岩演化过程中1种表生流体和2种埋藏流体环境下溶蚀作用差异,揭示了成岩矿物演化过程及储集空间结构变化特征.结果表明,表生成岩期大气淡水淋滤弱酸性流体环境(CO2饱和溶液,pCO2=1 MPa)溶蚀作用最为显著,长石类矿物发生明显溶蚀,石英和黏土矿物相对难溶,Na+、Ca2+和K+等离子析出明显,Si4+和Al3+析出较少,样品表面沉淀出较多的疑似多边形石英和铝硅酸类矿物;成岩晚期油气充注酸性流体环境(乙酸溶液,2 mL/L)溶蚀作用其次,易于溶解白云石、石膏和长石类矿物,Ca2+、Mg2+、Na+和Si4+等离子析出明显,样品表面无沉淀;成岩早—中期碱性流体环境(NaHCO3溶液,pH=7.46、HCO-3=0.6 mol/L)溶蚀作用相对较弱,石英、长石和部分黏土矿物均发生了不同程度的溶蚀,且随着温度、压力的增加,溶蚀作用程度增加.综合分析表明:表生流体是研究区砂岩储层溶蚀孔隙发育的关键因素,其次为有机酸和碱性埋藏流体.这一认识能够丰富致密砂岩储层孔隙成岩演化理论,为下一步寻找规模储层发育区和气田有效开发提供理论支撑.

Based on the comprehensive application of the data on formation test,core analysis and logging interpretation,the low limits of physical properties of effective sandy conglomerate reservoirs in the Lower Triassic Baikouquan formation on the northern slope of Mahu sag are determined by using the distribution function curve method and formation test method,and regression analysis method is used to match the lower limits of physical properties with depth.Based on which,lithofacies,sedimentary microfacies and diagenesis are analyzed by using the differences of reservoir physical properties.The results show that the lower limits of effective reservoir physical properties exhibit a trend of gradual decrease with the increase of depth in the study area;the development of effective reservoirs is mainly controlled by sedimentary microfacies and lithofacies,and weakly influenced by diagenesis.Microfacies of underwater distributary channel and braided channel are the most favorable areas for effective reservoir development,and tabular cross-bedding and trough cross-bedding are the most favorable lithofacies for effective reservoir development;the sandy conglomerate in the study area is mainly in the A stage of the middle diagenetic period,the secondary pores result from feldspar dissolved by organic acid which is liberated from thermal evolution of organic matter,which can improve reservoir physical properties,the effective reservoirs with the diagenetic faices of weak-compaction-weak-corrosion and unstable component corrosion are the most developed.

Based on the analysis of core facies, logging facies, seismic facies and analysis assay data, with the field practice induction of glutenite sedimentary,this paper draw conclusions that:Fan-fan delta glutenite sedimentary sys-tem under the control of contemporaneous reverse thrust show the progradation deposition on the whole in P 3 w. Indica-ting the phase-sequence characteristics called "Alluvial fan toe ( channel flow )-Alluvial fan middle/Fan delta plain (braided stream)-Fan delta front(distributary belt) - former fan delta/shallow lake (be mixed up with subaqueous fan)".with the development of such five typical glutenite sedimentary microfacies types as channel flow, debris flow/sandy debris flow, braided channel, underwater distributary channel, sectoral waterway. The cumulative effect of con-temporaneous reverse fault belt continuous uplifting and denudation, make the sedimentary of fan toe in alluvial fan thinning, with more and more obvious trend of contemporaneous reverse fault controlling the sedimentary facies differ-entiation. Shale content is the key control factors of glutenite reservoir quality under the extrusion background. The di-agenetic compaction cut hole effect in poor mud glutenite reservoir is weak, with the higher residual intergranular pore development and the higher development level of crush seam in coarse particles communicating intergranular pore, the reservoir quality of poor mud glutenite is best. Based on combination of reservoir space,the favorable reservoir facies belt can be divided into two types:primary intergranular pore-crush seam development zones and primary intergranu-lar pore-secondary dissolution pore development zones. The former mainly distributed in the fault zone-upper slope belt near structural high position, the latter mainly distributed in middle-lower slope belt.

在与传统沉积体系分析方法进行对比的基础上,提出了利用地震沉积学方法进行沉积体系分析.在对准噶尔盆地阜东地区层序地层划分的基础上,开展90°相位转换、地震属性分析、地层切片提取与分析等,最后通过岩心、露头、测井与录井等资料,并参考现代沉积模式进行地震沉积相分析,建立了地震属性平面特征与沉积相间的对应关系,并对沉积体系进行了分析.研究认为,地震沉积学沉积体系分析方法以层序地层格架为基础,保证了地层对比的等时性;充分利用了地震资料的横向分辨率,可识别地震垂向分辨率难以识别的薄层砂体;将地震属性分析与沉积学相结合,可预测砂体空间展布及其演化特征.