川中南部地区寒武系洗象池组层序地层及沉积相研究

发布时间：2018-07-24 09:06

【摘要】：近年来,川中南部地区上寒武统洗象池组因处于相同构造条件的下寒武统龙王庙组发现特大油气田而成为现今重要的勘探领域之一,但前人针对川中南部地区上寒武统洗象池组的研究并不多,故本次研究结合前人的研究成果,以川中南部地区为研究区,以上寒武统洗象池组为目的层,综合利用岩芯观察、薄片鉴定、地球物理解释(测井和地震)和孔渗实验测试等多种研究方法,对上寒武统洗象池组的层序地层进行识别和划分,并对研究区域内的沉积相类型及分布特征进行了详细的研究。本次研究取得了以下主要成果:(1)在层序划分方面主要是划分出了一个三级层序。上寒武统洗象池组划分为1个三级层序,即SQ1,洗象池组与下部高台组无沉积间断,整合接触,是三级层序SQ1底界面;洗象池组与上部桐梓组整合接触,该界面是三级层序SQ1顶界面;层序内部包含1个最大海泛面(mfs1),1个高位体系域早期-高位体系域晚期转换面((E-L)TS)。SQ1包含3个体系域,即TST、EHST和LHST。SQ1-TST底顶界分别为洗象池底界和mfs1;SQ1-EHST底顶界分别为mfs1和(E-L)TS;SQ1-LHST底顶界分别为(E-L)TS和洗象池顶界。缺失LST。在SQ1中,岩相、测井相和地震相的变化反映了1个完整的水进-水退沉积旋回。TST、EHST和LHST分别对应洗一段、洗二段和洗三段。(2)研究区域总体为局限台地沉积环境。此次共识别出了台坪、台内滩和泻湖三种亚相以及砂泥质云坪、云坪、砂屑滩、泥云质泻湖和云质泻湖五种微相。在沉积相分布上,洗一段主要发育局限台坪亚相,东部局部地区发育台内滩亚相。洗二段主要发育局限泻湖亚相,研究区中部和东部大面积发育台内滩亚相。洗三段主要发育局限台坪亚相,研究区东部大面积发育台内滩亚相。(3)研究区物性整体较差,不同沉积相带比较而言,台内滩具有明显较好的物性,台坪次之,泻湖最差。原因主要有三方面,一是台内滩的沉积环境为动荡的高能量环境使得台内滩亚相沉积的残余砂屑被淘洗干净,保留了较好的原生孔隙,而同期的局限泻湖亚相和局限台坪亚相因处在低能环境中,原生孔隙发育较差;二是后期的埋深溶蚀作用,对台内滩亚相粒间孔进行了建设性改造,酸性流体的充注使得原生孔隙进一步扩大;三是后期的构造运动产生的构造缝将后期埋藏溶蚀作用形成的粒间孔和溶洞连通起来,大大改善了台内滩亚相的物性。(4)研究区内有利的沉积相主要大面积分布在东部,西部磨溪构造因遭受后期的构造剥蚀而小范围的发育台内滩亚相。其中洗一段(SQ1-TST)在高石21井、合12井,广探2井和南充1井发育残余砂屑云岩和砂屑云岩为主的台内滩;洗二段(SQ1-EHST)在安平1井、磨溪21井-磨溪23井、高石23井-高石7井-高石8井、高石16井、女基井-女深5井和高石21井-合12井-广探2井发育台内滩;洗三段(SQ1-LHST)在安平1井、宝龙1井-女基井-磨溪23井、南充1井和高石21井-合12井-广探2井发育台内滩。
[Abstract]:In recent years, the upper Cambrian washing pool in the middle and southern Sichuan Province has become one of the most important exploration fields because of the discovery of large oil and gas fields in the lower Cambrian dragon Wang Temple formation at the same tectonic conditions, but the previous research on the upper Cambrian washing pool group in the middle and Southern Sichuan is not much. The south area is the research area, and the Cambrian washing pool is the target layer. The sequence stratigraphy of the upper Cambrian washing pool group is identified and divided, and the types and distribution characteristics of the sedimentary facies in the study area are identified and divided by a variety of research methods, such as core observation, thin slice identification, geophysical interpretation (logging and earthquake) and pore permeability test. The main achievements of this study are as follows: (1) the sequence division is mainly divided into a three order sequence. The upper Cambrian washing pool group is divided into 1 three order sequences, that is, SQ1, the washing pool group and the lower high platform group have no depositional discontinuity and integrated contact, which are the bottom boundary of the order SQ1 of the three order sequence; the washing pool group and the upper Tung The interface is integrated contact, the interface is the SQ1 top interface of the three order sequence; the sequence contains 1 most sea surface (mfs1), and the 1 high system domain early high system domain late transition surface ((E-L) TS).SQ1 contains 3 system domains, namely, TST, EHST and LHST.SQ1-TST bottom boundary are respectively the bottom of the wash pool and mfs1; SQ1-EHST bottom boundary is mfs1 and (E-L) respectively. The bottom boundary of 1-LHST is (E-L) TS and the top of the washing pool, respectively. The absence of LST. in SQ1, lithofacies, log phase and seismic phase change reflect 1 complete water to water retrograde sedimentary cycles.TST, EHST and LHST correspond to the washing section, washing two segments and three segments. (2) the study area is the limited platform sedimentary environment. This time the platform was identified and the platform was identified. Three subfacies of beach and lagoons and five microfacies of sandy muddy cloud flat, Yun Ping, sand chip beach, muddy lagoon and cloud lagoon. In the distribution of sedimentary facies, the main development restricted platform subfacies, the eastern part of the region developed the subfacies of the platform inner beach. The two segments of the washing area are mainly restricted lagoon subfacies, and the central and eastern part of the study area developed large area subtropical beach subfacies. Phase. The main development Limited Tai Ping subfacies in the three section of the study, the large area in the eastern part of the study area, the subfacies of the large area of the inner beach. (3) the study area has a relatively poor physical property. In comparison with the sedimentary facies, the flat beach has obvious good physical property, the platform is the second and the lagoon is the worst. The main reasons are three aspects, the first is the high energy environment of the sedimentary environment of the flat beach. The residual sand debris in the subfacies of the Taiwan beach is washed clean, and the better primary pores are preserved, while the primary pores are poorly developed in the limited lagoon and the Limited Taiwan plateau in the same period because of the low energy environment. Two is the later buried depth dissolution, and the intergranular intergranular pore in the flat beach is reformed and the acid fluid is filled. The primary pores are further expanded; three the structural seams produced by the later tectonic movement connect the intergranular pores and karst caves formed by later buried dissolution. (4) the favorable sedimentary facies in the study area are mainly distributed in the eastern part and the Western Moxi structure is subjected to late structural erosion. And a small range of development platform subfacies. Among them, SQ1-TST is in the high stone 21 well, 12 well, Guangzhou 2 well and Nanchong 1 well developed residual sand debris dolomite and sand crumb dolomite, and two segments (SQ1-EHST) in Anping 1, Moxi 21 - Moxi 23, high stone 23 well - 7 well - 7 well - Gao Shi 8, Gao Shi 16 well, female base well - female Shen 5 well and Gao Shi 2 1 well - 12 well - Guangzhou 2 well developed platform inner beach; washing three section (SQ1-LHST) in Anping 1 well, Baolong 1 - female base well - Moxi 23, Nanchong 1 well - 21 well - 12 well - 12 well - Guangzhou - 2 well development platform.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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