低渗小断块油藏资源丰富,然而低渗透油藏由于孔吼细小、渗透率低,常规注水开发不是行之有效的方法.注CO2可以大幅提高原油采收率,兼顾碳减排与提高采收率,是低渗透小断块改善开发效果的有效方式.胜利油田小断块、小砂体井网不完善,注CO2驱油难以实施,CO2吞吐技术通过注入-焖井-生产的方式开发,是一种井网不完善的小断块开发的有效方法.矿场实施CO2吞吐影响因素较多,需要进一步开展研究.本文通过数值模拟,研究了不同油藏条件下CO2吞吐效果,为矿场实施CO2吞吐提供指导.

In this paper it aims to gain new insights into clastic buried hill reservoirs. For this purpose, the Permian sandstone reservoirs in Upper Shihezi Formation, Gubei low buried hill, Jiyang depression, was taken as the object. Referring to the diagenesis in the process of burial-lifting-reburning of the reservoirs, with the aid of techniques like core observation, casting sheet observation, scanning electron microscopy（SEM）, cathode luminescence, carbon-oxygen isotope analysis and fluid inclusion. The results show that: It is found that the diagenetic evolution of the sandstone reservoir of Upper Shihezi Formation of Permian in Gubei buried hill of Jiyang Depression has gone through three stages from early to late. Stage I: Late Triassic and Early-Middle Jurassic, Gubei buried hill was uplifted and the Permian strata were denuded by the Indosinian movement, and the main diagenetic environment was shallow burial and uplift exposure denudation. The main diagenetic responses are feldspar dissolution, kaolinite cementation, stage（1） quartz cementation and limonite invasion. Stage II: Jurassic and Cretaceous, the sinistral strike-slip movement occurred in the Tancheng-Lujiang fault zone, the strong tectonic activity accompanied by active volcanic activity, and the hydrothermal activity associated with volcanic activity greatly affected the reservoir. The diagenetic response is the development of stage（1） carbonate cementation, stage（2） quartz cementation, pyrite, sericite, chlorite and long columnar apatite.Stage Ⅲ: Cenozoic, under the action of regional transtensional stress, the burial depth of Gubei buried hill increased, the maturity of organic matter increased, and the diagenetic environment was dominated by organic acid. The diagenetic response was mainly from carbonate cementation and quartz dissolution in stage（2） to carbonate dissolution and feldspar dissolution in late stage. The results of quantitative restoration of pore evolution show that the compaction and cementation in stages Ⅰ and Ⅱ have a great influence on the porosity, which decreases from 40% to 19%, and the diagenesis in early alkaline environment in stage Ⅲ has a destructive effect on the porosity of the reservoir, which decreases from 19% to 6.7%. After that, the porosity of the reservoir increased from 6.7% to 9.1% due to the dissolution reconstruction in acidic environment, and the secondary dissolution pores were developed and well preserved.

为明确沾化凹陷孤北洼陷沙沙一二段储层平面展布规律,确定物源方向及沉积边界,利用岩心、录井、测井和地震等资料,对孤北洼陷沙一、二段的扇三角洲、近岸水下扇、砂质滩坝和生物灰岩滩坝等沉积体特征、平面展布及演化规律进行了系统分析.结果表明:沙二段低位体系域孤北洼陷湖水较浅,整体为滨浅湖相沉积.埕东断层下降盘以发育近岩水下扇为主,在桩34井区发育厚层生物灰岩.沙一段为湖侵体系域,湖广水深,主要在湖盆中心部位沉积泥岩和油泥岩,在中央隆起带、东次洼以及孤北南斜坡沉积薄层生物灰岩滩坝等湖相碳酸盐岩.随着湖水深度逐渐变深,碳酸盐岩滩坝越来越薄,并且有向东部迁移的趋势.该研究对提高研究区沉积相类型及展布规律识别的准确度、指导下步滚动勘探方向具有重要意义.

桩海下古生界潜山受三期构造运动影响,断层复杂多样,沿断层发育多期裂缝,形成受断层控制的裂缝型储层.因此断层识别是研究碳酸盐岩潜山油藏储层分布规律的前提,受地震资料分辨率限制,相干、曲率识别断层技术难以适用于古潜山高陡断层识别.利用曲率蚂蚁体融合属性消除了地层倾角影响,清晰地反映了不同走向断层平面展布及纵向发育特征,极大提高了桩海地区下古生界潜山断层的识别效果,通过与常规地震解释对比,每平方千米可增加3～4条断层,有效指导了勘探开发部署.

通过构造特征、储层特征及油气分布特征的分析,总结了桩海地区下古生界潜山储集空间类型、有效储层发育控制因素、储层纵向发育规律及平面分布、试油试采、油藏类型等特征,指导了桩海地区下古生界潜山的勘探开发.

构造控砂一直为断陷盆地分析调查工作的重点和难点.综合井-震、岩心和镜下鉴定资料,以渤海湾盆地济阳坳陷沾化凹陷东部始新统沙四上亚段—沙三段(SQ1-SQ3)为例,探讨构造主导下的控砂机制和沉积充填过程,取得认识如下:1)Ⅰ级构造转换带奠定盆地宏观构造-沉积格局,多阶构造坡折叠合湖平面升降控制三级层序内部体系域之间的砂体加积与沉积体系旋回性变化,Ⅱ级构造坡折和次级断层控制体系域内局部输砂系统和砂体展布,陡坡带往往不利于碎屑物质注入湖盆;2)SQ1-SQ2存在孤北和孤南两个独立输砂系统,SQ3两个输砂系统合二为一,SQ1主要发育进退积不明显的、小而多的扇三角洲,SQ2开始发育三角洲、(半)深湖和滑塌砂体,SQ3主要发育大型三角洲,(半)深湖区广泛发育滑塌砂体;3)构造活动通过构造转换带、坡折带、次级断层和陡坡带等主导多断湖盆控砂机制和沉积充填过程,气候仅可强化或弱化前者的控制作用,但不会改变盆地充填过程.

针对桩海潜山下古生界断裂复杂、剥蚀严重的海相碳酸盐岩地层对比困难的情况,充分利用测井、录井、地震结合,运用层序地层理论与基准面旋回分析方法,精细地层识别,指出了桩海潜山下古生界3个区域和局部不整合面在地震上的上超、削截、顶超、下超等反射特征,系统分析总结了桩海潜山下古生界各层系进一步精细层序对比划分的钻井、录井、测井以及沉积上表现特点,为进一步研究地层、储层空间展布规律奠定了基础.

利用孤北洼陷沙三段铸体薄片及物性参数等资料,开展储层的岩石学特征及储层储集空间类型等研究,探讨了储层发育的主控因素.研究结果表明,研究区岩石类型以长石质石英砂岩及岩屑质石英砂岩为主,次生溶蚀孔为主要的储集空间.储层物性受到沉积、成岩作用的控制,致使不同区带储层物性存在差异,为指导孤北洼陷沙三段勘探开发部署提供了新思路.

In view of great vertical and horizontal changes of oil-gas reservoir of Tertiary fluvial facies in old 163 well field of Laohekou oilfield,complex and aggregated oil-gas reservoir and the characteristics of low precision interpretation of common seismicity,Jason logging constrained inversion is used in the seismic processing and sandbody description in the upper reservoir of this region.This technology can improve the seismic interpretation precision in this area by pre-processing of seismic reservoir,standardized adjustment of bore log and demarcation position overcom the shortcomings of Jason's initial model by GOCAD.The results show that it can recognize reservoirs within 3 to 6 m,solve the difficult problem of the thin-bedded alternation sandbody identification and receive better exploration and development efficiency.