【作者】 张晓莉；

【导师】 薛春纪； 赵靖舟；

【作者基本信息】 长安大学 ， 地质工程， 2009， 博士

【摘要】 高分辨率层序地层学在陆相含油气盆地油气勘探与开发研究中已成为重要的理论热点，它以其全新的理论、概念和技术方法有效的指导了隐蔽油气藏勘探、储层精细对比及特征研究。本文从油田开发中后期对油藏精细描述的实际需要出发，将高分辨率层序地层学理论与方法应用于子北油田延长组储层描述研究中，通过建立高分辨率层序地层格架，研究小层砂体在层序地层格架下沿剖面和平面的展布规律，同时应用沉积学、储层地质学、石油地质学和油气测井等理论及方法，系统研究子北油田延长组沉积相特征、储层特征、储层非均质性特征，分析高分辨率层序地层与储层非均质性之间的关系，以期为子北油田随后的油藏数值模拟、剩余油分布状况分析和注采工艺调整提供可靠的地质模型。论文首次应用高分辨率层序地层学观点，将子北油田延长组长6—长1油层组划分出1个超长期、3个长期、15个中期、28个短期基准面旋回层序，识别出3类7个亚类的短期基准面旋回层序基本类型。应用高分辨率层序地层学的等时对比法则，在油田范围内对延长组进行高时间精度分辨率的地层划分与等时对比，建立了相应的层序地层格架，在地层格架下进行了砂体在剖面和平面上展布规律研究。研究表明，高分辨率层序地层学能很好地适用于陆相含油气盆地。该研究不仅解决了油田的实际生产需要，同时也验证了高分辨率层序地层学的广泛适用性，具有重要的理论意义。系统的储层研究表明，研究区延长组长6—长1储层成因类型主要为三角洲前缘水下分流河道砂体、河口坝砂体；三角洲平原分流河道砂体；辫状河河道砂体等；储集岩经受了压实、胶结、溶蚀等成岩作用的改造，成岩演化经历了早期成岩机械压实和化学压溶的孔隙缩小期、晚成岩早期的胶结作用孔隙缩小期、晚成岩晚期的溶蚀作用孔隙扩大期等三个成岩—孔隙演化阶段；孔隙类型主要为残余粒间孔、粒间溶孔、粒内溶孔、晶间孔隙，其中尤以残余粒间孔最发育，裂缝不发育。喉道类型以细喉占主要，孔喉连通性较差。储集岩排驱压力、中值压力较高，孔隙结构较差。储层总体上为低孔低渗储层，其中长2油层组物性最好。储层控制因素的综合分析得出，沉积环境和成岩作用是控制延长组储层发育及其储集性能的主要地质因素。沉积环境控制沉积微相分布进而控制储层砂体分布，辫状河河道、三角洲前缘水下分流河道、河口坝、三角洲平原分流河道等微相中砂体最发育，它们决定了储集岩的发育、分布及原始物性条件，其中河道砂岩储集物性最好，分流河道、河口坝次之；岩性上中—细粒砂岩属于好储层，细粒砂岩属于中等储层，粉细砂岩、粉砂岩属于较差储层。成岩作用中的较晚期溶蚀作用对岩石的储集性能有所改善。储层非均质性研究表明，研究区长2~3(MSC9)、长2~2(MSC10)、长2~1(MSC11)层间为弱非均质性，长6~3(MSC2)、长6~2(MSC3)、长6~1(MSC4)层间为较强至强非均质性，长4+5下部(MSC5+MSC6+MSC7)层间为强非均质性。延长组各小层间储层孔隙度差异明显，渗透率差异很明显，渗透率非均质参数差异较明显。高分辨率层序地层与储层发育及其非均质性关系研究表明，在子北油田延长组层序地层格架中，储集砂体主要发育于中期基准面旋回层序的分界面两侧，其中河道砂体、分流河道砂体主要分布在中期基准面旋回上升半旋回的下、中部，河口坝砂体分布在中期基准面旋回下降半旋回的中、上部。建立了5种与高分辨率层序地层学基准面旋回有关的储层非均质模式即：物性向上变差模式；物性向上变好模式；物性均匀变化模式；物性向上变差又变好模式；物性变化复杂的复合变化模式。它们与高分辨率层序地层学基准面旋回关系密切。更多还原

【Abstract】 The high resolution sequence stratigraphy having been extensively applied to oilexploration and development studies in continental oil-bearing basin and got hot throry.Dueto its bran-new theory,concepts and methods effective decide the concealed oil exploration,reservoirs careful correlation and characteristics research.In order to meet the needs ofreservoir heterogeneity characteristic at medium-late development strage,the paper for thefirst time applies the theory to reservoir characteristics of YanChang Formation in ZiBeioilfield and transver the theory and method to the whole reservoir research.Moreovercombined with the sedimentary,reservoir geology and petroleum geology systematicallystudied the sedimentary facies,the sequence stratigraphy,the distribution of sandbody,thereservoir characteristics and heterogeneity.For the first time,the Chang6-Changl oil-bearing beds of YanChang Formation aredivided into 3 long term,15 middle term and 28 short term base-level cycle sequences inwhich 3 types and 7 subtypes short term base-level cycle sequences are identified.Accuratehigh-resolution equitime correlation is made and sequence framework is established.Thedistribution laws of sandbody are studied in the sequence framework.The study shows thatthe high-resolution sequence stratigraphy can be applied quite well to continental oil-bearingbasin and not only meets the needs of the oilfield’s exploration and development but also is ofimportant theoretic value.Systematic reservoir study of Chang6-Changl oil-bearing beds of YanChang formationindicates that the main genetic reservoir sandstones are the delta front submerged distributarychannel sands,the channel barrier,the delta plain distributary channel and the braided streamchannel sands.The reservoirs weathered the diagenesis such as the compaction,thecementation and the dissolution.The mechanical compaction and the chemical pressuresolution at the early diagenesis maked the pore small.The cementation at early of the latediagenesis maked the pore small by filling.The dissolution at late of the late diagenesismaked the pore large.These are the main diagenesis-pore evolution strage.The main pore arethe remnant intergranular pores,intergranular solution pores,intragranular solution pores andintercrystal pores,of them the remnant intergranular pores being dominant.The crack doesn’t develop.The main throat is fine throat.The connection of pore-throat is poor.Theentry pressure and median pressure are more higher.The structure of pore is more poor.Thereservoirs are low porosity and low permeability.The physical property of Chang2 is the best.The sedimentation and digenesis controlled the reservoir.The medium-fine-grainedsandstones form good reservoirs,the fine-grained sandstones form medium reservoirs and thesiltstones form poor reservoir;Sandbodies mostly developed in stream channel and deltadistributary channel microfacies.They decided the development,distribution and physicalproperty of reservoir rock.The physical property of stream channel is good and thedistributary channel,the channel barrier are secondary;The dissolution developed at the latediagenesis improved the reservoirs property.The analysis of reservoir heterogeneity suggests that the interlayer heterogeneity of theChang2~3(MSC9)、Chang2~2(MSC10)、Chang2~1(MSCll)are more isotropic,Chang6~3(MSC2)、Chang6~2(MSC3)、Chang6~1(MSC4)and Chang 4+5(MSC5+MSC6+MSC7)are more serious.The differentia of porosity between each bed is obvious and thedifferentia of permeability between each bed is more obvious.The analysis of relationship between high-resolution sequence stratigraphy and thereservoir development and heterogeneity shows that in the sequence framework the reservoirsandstones mainly locate near the boundaries of the middle term base-level cycles,amongthem the braided stream channel sandstones,delta distributary channel sandstones distributein the lower to middle parts of the middle term base-level rise cycles and channel barriersandstones distribute in the middle to upper parts of the middle term base-level down cycle.Five heterogeneity models of different microfacies are founded:Pooring-upward pattern ofphysical;Gooding-upward pattern of physical property;Homogeneous pattern of physical;Pooring-upward and gooding-upward pattern of physical property;Complex pattern ofphysical property.They are closely relative to the changings of the high resolution sequencestratigraphy base-level cycles.更多还原