普光气田长兴—飞仙关组沉积微相研究

发布时间：2018-01-06 18:27

本文关键词：普光气田长兴—飞仙关组沉积微相研究　出处：《长江大学》2017年硕士论文　论文类型：学位论文

【摘要】：普光气田位于四川盆地东北部宣汉—达县地区,东邻清溪场—老君山构造带,北邻铁山坡气田,南为渡口河及罗家寨气田。普光气田是整装特大型碳酸盐岩气田,该气田是一个由二叠系长兴组和三叠系飞仙关组构成的、受沉积相控制明显的礁、滩型气藏。普光地区由上至下依次钻遇的地层为侏罗系、三叠系、二叠系、石炭系和志留系。其中,古生界缺失的地层有志留系上统,泥盆系全部和石炭系大部分,石炭系只残留中石炭统黄龙组,其它地层保存较为完整;中生界缺失上白垩统,其他地层保留较全;新生界基本没有沉积保留。由于多期构造运动的影响,地层间多发育不整合面,其中,志留系与石炭系、石炭系与二叠系、上下二叠统之间均是平行不整合接触;晚三叠世末期,受印支运动影响,四川盆地抬升成陆,扬子地台发生大范围的海退,形成以陆相碎屑岩为主的湖泊一三角洲一河流沉积。在岩心和野外地质露头剖面观察描述的基础上,从岩性、沉积相、电性、成岩变化4个方面对层序界面进行识别。飞仙关组形成时间为245~251Ma,时间跨度为6Ma;长兴组形成时间为251~253Ma,时间跨度为2Ma。在此层序时间规模的控制下,再结合层序的岩石学特征,地层叠置样式特征等把普光气田飞仙关组划分为2个三级层序与9个四级层序,长兴组划分为2个三级层序与5个四级层序。在层序划分的基础上,通过横向对比总结,结合地震剖面属性研究,建立本区长兴~飞仙关组层序地层格架,区内层序发育较完整,各层序地层的岩性和厚度存在变化,但仍具有良好的可对比性,各个层序都只发育有海侵体系域和高位体系域,不发育低位体系域和凝缩段。通过对区内取心井岩石薄片分析,指出长兴~飞仙关组含有较纯的沉积物质,主要为碳酸盐岩与少量泥岩,膏岩及其过渡岩类,而碳酸盐岩类中又以云岩类为主,次为灰岩类。根据沉积环境,结合钻井资料,认为研究区长兴-飞仙关组以发育碳酸盐岩台地为特征,结合威尔逊沉积模式,可划分出开阔台地、局限台地、蒸发~局限台地、台地边缘、台缘斜坡~陆棚五个相,并进一步划分出台坪、泻湖、台缘礁滩等八个亚相和相应的三十余个微相,各种相带交错分布。其中,台地边缘相的礁滩、鲕滩,开阔台地和局限台地相的台内滩、台内礁,以及局限台地相的台坪沉积是储层发育比较有利的相带。通过区内沉积微相横向对比,指出长兴期晚期和飞仙关期早期的沉积格局具有东浅西深的特点。研究区主体为台地边缘相,向西水体逐渐加深,变为台缘斜坡~陆棚相;在飞三期西部地区受填平补齐作用影响,与东部地貌差异缩小,整个研究区演变成碳酸盐台地,西为开阔台地,东为局限台地;至飞四期,持续的填平补齐作用使东西部的地势基本一致,而此时大规模的海退使得全区演变成台坪环境。依据颗粒岩地层厚度比、白云岩厚度、泥质含量等,开展研究区沉积微相展布的研究,并建立长兴组和飞仙关组沉积相模式。
[Abstract]:Puguang gas field is located in the northeast of Sichuan basin in Xuanhan Daxian area, east of Qingxichang - Laojun Mountain tectonic belt, North Tieshanpo gas field, the South and Dukouhe Luojiazhai gas field Puguang gas field is ready. Large carbonate gas field, the field is a Changxin formation of Permian and Triassic Feixianguan Formation, by the sedimentary facies control obvious reef bank gas reservoirs in Puguang area. From up to down in drilled formation in Jurassic, Triassic, Permian, Carboniferous and Silurian Paleozoic strata. Among them, the lack of upper Silurian, Devonian and Carboniferous, most of all, only the residue of Carboniferous Huanglong Formation of Middle Carboniferous strata, other more complete preservation of the Mesozoic; lack of Upper Cretaceous strata, other than the whole; Cenozoic sedimentary basic not retained. Due to the influence of multi period tectonic movement and formation of multi development of unconformity, the Silurian and the The Carboniferous, Carboniferous and Permian, are parallel unconformity between the upper and lower Triassic in two; three at the end of Late Triassic, the Indosinian movement, the uplift of Sichuan basin to the Yangtze platform, there is a wide range of regression, formed in the continental clastic dominated lake delta river to observe and describe the deposition. On the basis of the lithology, sedimentary facies, electricity in the core and field geological outcrops, diagenetic change of 4 aspects to identify the sequence boundaries. The Feixianguan formation time is 245~251Ma, the time span of 6Ma; Changxin formation time is 251~253Ma, the time span for the control of 2Ma. in this sequence time scale next, combined with the petrological characteristics of sequence stratigraphic stacking patterns, characteristics of the Puguang gas field, Feixianguan formation is divided into 2 three order sequences and 9 four level sequence, Changxin was divided into 2 three order sequences and 5 four level sequence. On the basis of sequence dividing By comparison, summary, combined with the study of the establishment of the seismic profile attribute, Changxin District, Feixianguan formation sequence stratigraphic framework, region sequence development is complete, the sequence stratigraphic lithology and thickness changes, but still has a good comparison, each sequence only developed in transgressive system tract and highstand system no domain, lowstand systems tract and condensed section. Through the analysis of coring wells rock slices of the region, pointed out that the Changxin Feixianguan sedimentary material containing relatively pure, mainly for carbonate and a small amount of gypsum rock and mudstone, transition rocks, carbonate rocks and dolomite in the main category, for limestone. According to sedimentary environment, combined with drilling data, it is concluded that the Changxin Feixianguan Formation in the development of carbonate platform is characterized with Werwilson sedimentary model, can be divided into open platform, restricted platform, evaporation ~ restricted platform, platform margin, platform margin slope Po ~ five shelf facies, and further divide the introduction of flat, lagoon, platform margin reef eight subfacies and corresponding 30 microfacies, various sedimentary facies in staggered distribution. Among them, the reef, platform margin shoal, open platform and restricted platform facies intraplatform, Taiwan reef. And the restricted platform facies plateau sedimentary reservoir facies is more favorable. The area of sedimentary microfacies of horizontal comparison, pointed out that the Changxin stage and early period of Feixianguan sedimentary pattern with East shallow deep in the West. The main research area for platform.marginal, west water gradually deepened into Taiwan edge slope ~ shelf facies; by tianpingbuqi effect fly three western regions, narrow and Eastern landform differences, the study area evolved into a carbonate platform, West open platform, restricted platform to fly east; four, tianpingbuqi force continued to make things is basically the same, and This massive regression makes the region evolved into a platform environment. According to the thickness of granular rock strata, dolomite, shale content, the study area of sedimentary microfacies, and the establishment of Changxin group and the Feixianguan sedimentary facies model.

【学位授予单位】：长江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.13

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