【作者】 范广娟；

【导师】 马世忠；

【作者基本信息】 东北石油大学 ， 石油与天然气工程， 2011， 博士

【摘要】 在高分辨率层序地层学理论以及储层沉积学的指导下,以大庆油阳萨中密井网区萨葡油层为研究对象,利用岩心、测井等资料进行了高频等时层序划分,将研究区层段划分为1个长期基准面旋回层序、5个中期基准面旋回层序和58个短期基准面旋回层序。与此同时,针对距离很近的临井砂体差异大、甚至突变,砂体垂向切叠严重(最厚砂层达20m)、可分性极差这一复合砂体劈分难题,结合储层沉积背景,利用砂体成因分析、测井微相识别与组合等技术,对重点层段的复合砂体进行系统研究,提出了“识别厚砂条带一统计可分井数.标定劈分位置”的复合砂体劈分方法,对于切叠型复合砂体采用“按成因一参临井一定界线”的劈分原则,客观有效地解决了厚砂劈分的难题,为全区统层对比扫清了障碍,也为高分辨层序地层格架的建立和成因单砂体的准确识别奠定了坚实的基础。在高频等时成因地层格架的控制下,将研究区的沉积微相由原河道砂、表内砂岩、表外砂岩和尖灭区4种类型,细分为2相3亚相26种微相,特别是根据砂岩电性、物性、含油性等定量特征以及全区储层发育状况,将河道(曲流河道、分流河道和水下河道)细分为一类河道、二类河道和三类河道；结合表内、表外储层细分溢岸或漫流砂,前者细分为：表内粉砂级溢岸砂,表外粉砂级溢岸砂,泥粉级溢岸砂、粉泥级溢岸砂和河道间泥,后者细分为：一类席主体、二类席主体、一类席状砂、二类席状砂。从而建立起了泛滥平原、三角洲分流平原、三角洲前缘2相3亚相26微相测井微相模式,通过逐井逐层的精细识别与组合绘制了研究区层段短期层序平面沉积微相,不但清晰地揭示了短期层序内砂体的成因、规模与展布规律,还提出了密井网条件下“主河道砂体非均质性及分流河道砂体连续性”储层砂体新认识：(1)在泛滥平原和分流平原区识别出了典型的废弃河道砂体；(2)原连片砂体,实为可分或基本可分连续带状河道砂体；(3)原坨状不连续砂体,实为连续带状或枝状水下河道砂体。通过对河道砂体的重新认识,详尽揭示了短期层序内单砂体的成因、规模、形态、密度及同一微相内和不同微相间能量单元的变化和接触关系,同时也清晰反映了短期层序间河道发育程度、摆动方向和幅度、以及沉积环境、亚环境的变化。在58个短期旋回层序垂向沉积演化规律的基础上,提出了萨葡油层沉积体系演化模式,即(1)湖岸线顺源进退,相与亚相边界近平行于湖岸线,(2)沉积环境时而相对稳定,时而跨相、亚相或区带变化,(3)主体水系左右摆动幅度较大,且能量变化频繁,(4)湖浪作用强弱不定、持续时间长短不一。在对研究区各短期层序平面沉积微相精细刻画和定量统计分析的基础上,据萨中密井网解剖,提出了“大型河控浅水三角洲亚相带细分模式”,包括(1)泛滥平原区“特大、严重切叠、宽带状主河道砂体”沉积模式,(2)三角洲上分流平原区“大型、带状、断续可分一类河道砂体”沉积模式,(3)三角洲下分流平原“中型、独立、带状连续河道砂体”模式,(4)三角洲内前缘近岸区“中小型、连续、条带状水下河道.大面积泥质沉积”模式,(5)三角洲内前缘中岸区“小型、连续、窄条带状水下河道。河控带状席状砂”模式,(6)三角洲内前缘远岸区“窄小型、连续、干枝状水下河道(术端).河控席状砂”模式,(7)三角洲外前缘区“河控扇状席状砂”和(8)三角洲外前缘区“浪控席状砂”模式。该模式的建立进一步明确了萨中密井网区萨葡油层的河流.三角洲沉积体系类型和范畴。搞清了萨葡油层的储层发育程度及分布规律,对整个萨中地区储层空间分布模式的建立、成因单砂体的识别与预测以及丌发调整和剩余油挖潜提供了可靠的储层沉积学保障,同时对周边或与之相近的储层预测、剩余油研究具有极为重要的指导意义。通过精细储层研究,提出了密井网条件下高-特高含水期萨葡油层剩余油主控因素为层内非均质性和平面非均质性,剩余油的主要类型为原井网控制不住的窄小河道砂体型剩余油、废弃河道遮挡型剩余油、注采系统不完善型剩余油等,其中前两种剩余油类型为本次密井网揭示的重点。通过本次密井网解剖在45个(占短期层序总数77.6%)短期层序内共识别出414个(占95.4%)窄小型水下河道砂体,在13个陆上沉积的短期层序的河道砂体内共识别出71处废弃河道砂体。此外,还提出了剩余油的挖潜措施。更多还原

【Abstract】 Taking the SaPu reservoir in dense well pattern area of Sazhong in Daqing oilfield as the studied area and layer, under the guide of high resolution sequence stratigraphy theories and reservoir sedimentology, utilizing core and logging data, to systematically make division, layer unification and correlation of the high frequency isochronous sequences, the studied area and layer is divided into 1 long-term,5 mid-term and 58 short-term base level cycles, to set up the framework of the high resolution sequence stratigraphy. At the same time, according to the sand body division problem that the differences of the sand body on the near distance adjacent wells is obvious, even to be sudden varies, and that cutting-piling sand bodies are serious so that their divisibility is worst in vertically(the thickest sandstone layer is nearly 20m). Combining depositional setting of the reservoir, and utilizing formation cause analysis of the sand body and identification and combination of the logging microfacies, to systematically study the compound sand body in the dominant layer. To put forward divisional methods, that is "identification of the thick sand belt-statistics of number of the divisible well-standardization of the division location", in order to divide cutting-piling compound sand body, to adopt-’accordance to formation cause-reference to adjacent wells-delimitation’-divisional principle, to objectively and effectively resolve thick sand body division problem and to clear away barrier for layer unification and correlation of the whole studied area, and also to settle sound foundation for the establishment of the high resolution sequence stratigraphy framework and precise identification of the same formation cause single sand body.Under the control of stratigraphy framework of the high frequency and isochronal formation cause, sedimentary microfacies of the studied area are subdivided to 2 facies 3 subfacies 26 microfacies, instead of original four types which are channel sandstone、inner table sandstone、outer table sandstone and pitch out area, especially, according to quantitative characteristics of electric property、porosity and permeability、oiliness, to development condition of the reservoir of studied area, channel(meandering channel、distributary channel and under-water channel) are subdivided typeⅠ、-ⅡandⅢchannel. On the basis of inner and outer table reservoir, to subdivide overflow and sheetflood sandstone, the former is subdiviede inner table silt-sand、outer table silt-sand、mudsilt-sand、siltmud-sand and interchannel mud. The latter is subdivided sheet main bodyⅠandⅡ, sheet sandⅠandⅡ. To establish floodplai、deltaic distributary plain and delta front 2 facies 3 subfaices 26 microfacies logging microfacies models. By means of fine identification and combination of each well and layer, short-term sequences plane sedimentary microfacies of the studied area and layers are drew:Not only clearly reveal formation cause、scale and distribution of sandbody in the short term sequence, but also come up with new standpoints under the condition of dense well pattern, that are "heterrogenetity of the main channel sand body and continuity of the distributary channele sand body", which are (1) abandoned channel sand body is identified in the flood plane and distributary plane; (2) original connected thick sand body, in fact, they are divisible or broadly divisible continuous banding channel sand body; (3) original mound discontinuous sand body, they actually are continuous belt or dentritic under water sand body. Via these new viewpoints, exhaustively reveal formation cause、scale、shape、density、within the same microfacies and between different microfacies energy unit variation and connect relation, at the same time, distinctly reflect channel upgrowth degree、swing direction and amplitude and the change of depositional environment and sub-enviornment.On the basis of vertical depositional evolution of the 58 short term sequences, to propose depositional system evolution patterns of the SaPu reservoir, that are(1) lake shoreline advance and retreat along the source, facies and subfacies boundaries approximately parallel to the lake shoreline; (2) depositional setting sometimes relatively stable, sometimes stride facies and subfacies or region variation; (3) the amplitude of main river system swing is wide, and energy variation is often; (4) lake wave function is unsteady, time of duration also is long or short. On the basis of plane sedimentary fine draw and quantitative statistic analysis of the each short term in the studied area, according to anatomy of dense well pattern in Sazhong, to propose the depositional pattern that is "large shallow delta subfacies subdivision under the control of the channel", including (1) the flood plane "especially big-size、serious cutting-piling、wide banding main channel sand body " depositional pattern; (2) the upper distributary plane "big-size、banding and interruption dividable channelⅠsand body" depositional pattern; (3) the lower distributary plane "mid-size、independent、banding and continuous channel sand body" pattern; (4) deltaic internal front near-shore "mid-small size、continuous belt under water channel-large area mud deposition" pattern; (5) deltaic internal front mid-shore "small size、continuous narrow belt under water channel-channel controlled sheet-sand" depositional pattern;(6) deltaic internal far-shore "narrow-small、continuous dry dentritic under water channel(or channel ends)-channel controlled sheet-sand" pattern; (7) deltaic external front "channel controlled fan-shaped sheet-sand" and (8) deltaic external front "wave controlled sheet-sand" pattern. The pattern further confirm the type and scope of river-deltaic depositional system of SaPu reservoir in the dense well pattern area of Sazhong. It is clear that reservoir development degree and distribution regularity of the SaPu oil layer. It provide reservoir sedimentary guarantee for reservoir space distribution pattern establishment of the whole Sazhong area, identification and forecast of the same formation cause, development adjust and remaining oil development, meanwhile, it is of extremely important guidance significance for reservoir predict of the rim or similar with it, for the remaining oil research.By means of fine reservoir study, to put forward under the condition of dense well pattern, in the high to highest water flooding stage, the dominant factors of the remaining oil of the SaPu reservoir are herogenety in the layer and on the plane. The main types of the remaining oil is narrow and small channel sand body that is uncontrolled in the original well network, abandoned channel blocking and injection-productiion system is inperfeccable so on. The two former are the important points of the revelation under the dense well pattern.414 narrow and small channel sand bodies are indentified in the 45 short term sequences (occupy the total short term sequences of 77.6%).71 abandoned channel sand bodies are indentified in the 13 continental short term sequences in the this study in the dense well pattern condition. Beside also to propose remaining oil development measures.更多还原