吉林大情字井地区青三段Ⅻ砂组厚砂体成因及其对油气分布的控制作用

发布时间：2018-06-09 11:33

  本文选题：厚砂体 + 多物源区　； 参考：《东北石油大学》2017年硕士论文

【摘要】：大情字井地区是松辽盆地南部有利的含油区带,经历了多年的勘探开发,认识不断深入,随着技术方法的成熟多样和井网系统的不断加密,原有对物源体系、沉积相、油气富集规律的认识与一些新发现不断出现矛盾,制约着本区进一步的油气勘探开发,青三段Ⅻ砂组在本区储层条件最好,多口探井试油试采效果良好。为此,对物源、沉积体系、成藏模式的清楚认知是油田增储、增产所需要亟待解决的问题。本文在对全区研究的基础上,重点剖析了厚砂体的成因和油气富集规律。以沉积学、地层学为指导,利用岩心、钻井、测井、三维地震解释成果等多方面地质资料,综合测井曲线的韵律性及薄夹层分析、岩心观察等5方面对Ⅻ砂组厚砂体进行垂向可分性分析,结果表明厚砂体在垂向上可分,并根据公认的标准井乾深8井、乾107井的分层标准,对全区进行了达小层级别的地层划分与对比,建立了大情字井地区青三段Ⅻ砂组的层序地层格架。以区域沉积学方法为指导,结合重矿物、泥岩颜色等6方面资料系统分析,认为大情字井地区青三段Ⅻ砂组三源交汇,即西部通榆物源的西北分支、西南保康物源和南部怀德物源的东南分支。西部通榆物源古坡度最大,是主物源,南部怀德物源为次物源、西南保康物源对研究区的影响最弱。通过岩心观察,本区主要存在三角洲相和重力流相2种主要的相类型,特别是对厚砂体岩心的观察,认为厚砂体具有不同的成因特征,而其各种成因特征主要受控于物源体系的差异,主要分为:河口坝-河道退积叠置型、河口坝密集叠置、河道—河口坝密集叠置型、河道—河口坝分期叠置型等。以现代三角洲沉积学理论为指导,在地层等时格架控制下分析了物源、沉积相的展布特征,建立三角洲前缘的测井相模式,识别水下分流河道、河口坝、席状砂等沉积微相,厘定了研究区的相带展布,砂岩空间分布的总体特征受控于研究区沉积相带的展布,厚砂体主要分布于通榆物源控制地区和大部怀德物源控制区域以及保康物源近源处。在以上工作的基础上,基于油气成藏理论,在了解区域油水分布总体特征的基础上,对Ⅻ砂组进行密井网开发区和重点探评井区解剖,认为研究区主要发育断层—岩性油气藏、岩性上倾尖灭油气藏和背斜油气藏三种油气藏类型,其中断层—岩性油气藏占绝大多数,沟通烃源岩和厚砂体的油源断层即油源供给,是油气藏形成的先决条件,成藏关键期正向古构造的轴线为油气优势运移路径,其上、附近圈闭最有利成藏,有效储层特别是储层性质良好的厚砂体是形成油气藏的基础,厚砂体对于油气分布具有明显的控制作用,中等厚度(2~6m)、条带状、有利相带(河道、河口坝)的砂岩有利于油气成藏。
[Abstract]:The Dazhengzhijing area is a favorable oil-bearing zone in the south of Songliao Basin. After many years of exploration and development, the understanding is deepening. With the maturation of technical methods and the continuous infilling of well pattern system, the original provenance system and sedimentary facies, The understanding of oil and gas enrichment law is in contradiction with some new discoveries, which restricts the further exploration and development of oil and gas in this area. The reservoir condition is the best in the third member of Qingshan formation, and the oil testing and production testing effect of multiple exploration wells is good. Therefore, a clear understanding of the provenance, sedimentary system and model of reservoir formation is an urgent problem to be solved for increasing reservoir and increasing production in oil fields. Based on the study of the whole area, the origin of thick sand body and the law of oil and gas enrichment are analyzed in this paper. Under the guidance of sedimentology and stratigraphy, the rhythm of logging curve and the analysis of thin intercalation are synthesized by using the geological data of core, drilling, logging, 3D seismic interpretation and so on. The vertical separability analysis of thick sand body of sand group XII from five aspects, such as core observation, shows that thick sand body can be separated vertically, and according to the accepted standard for stratification of Qianshen 8 well and Qian107 well, The stratigraphic classification and correlation of the sub-strata in the whole area have been carried out, and the sequence stratigraphic framework of the third member of the Qinghai sand formation in Dazhengzhijing area has been established. Guided by the method of regional sedimentology and the systematic analysis of six aspects of heavy minerals and mudstone color, it is considered that the three sources of the Qinghai sand formation in the third member of the Qing Dynasty in Dazhengzhijing area are the northwestern branch of the Tongyu material source in the western part of the region. The southeastern branch of the southwest Baokang source and the southern Wyde source. The ancient slope of Tongyu was the largest, which was the main source, the southern Huaide was the secondary source, and the southwest Baokang had the weakest influence on the study area. Through core observation, there are two main facies types in this area, delta facies and gravity flow facies, especially the observation of thick sand body core. It is considered that thick sand body has different genetic characteristics. The genetic characteristics are mainly controlled by the differences of provenance systems, which are mainly divided into three types: estuarine dam-channel degradation superposition type, estuary dam dense superposition type, river-estuarine dam superposition type and so on. Based on the theory of modern delta sedimentology, the distribution characteristics of provenance and sedimentary facies are analyzed under the control of stratigraphic isochronous frame, and the logging facies pattern of delta front is established, and the sedimentary microfacies such as underwater distributary channel, estuarine dam and sheet sand are identified. The distribution of facies belt in the study area is determined. The overall characteristics of sandstone spatial distribution are controlled by the distribution of sedimentary facies belt in the study area, and the thick sand body is mainly distributed in Tongyu source control area, most of Huaide material source control area and Baokang source near source area. On the basis of the above work, based on the oil and gas accumulation theory, and on the basis of understanding the general characteristics of the regional oil and water distribution, the authors have dissected the dense well pattern development zone and the key exploration and evaluation well area of the XII sand formation. It is considered that the main fault lithologic reservoirs are developed in the study area. There are three types of oil and gas reservoirs in lithologic updip pinnacle and anticline, in which fault lithologic reservoirs account for the majority. The oil source fault that connects the source rock and thick sand body is the prerequisite for the formation of oil and gas reservoir. The axis of forward paleotectonics in key period of reservoir formation is the dominant migration path of oil and gas. On the top of it, the trap near the reservoir is the most favorable for reservoir formation, and the effective reservoir, especially the thick sand body with good reservoir properties, is the basis of forming oil and gas reservoir. Thick sand bodies play an important role in controlling the distribution of oil and gas. The sandstone with medium thickness of 2 ~ 2 ~ 6 m ~ (-1), zonal shape and favorable facies (channel, estuary dam) is favorable for oil and gas accumulation.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13
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本文编号：1999583