松辽盆地南部姚家组沉积体系分析

1、松辽盆地南部姚家组沉积体系分析        【中文摘要】本文通过岩心、地质录井、测井、地震等资料的研究,结合前人关于松辽盆地南部姚家组的成果,在一年多的系统资料收集与分析的基础上,编制了大量图件,厘定松辽盆地南部层序地层格架,对松辽盆地南部地区沉积特征及砂体分布有了较系统的了解,并对松辽盆地南部构造-沉积演化及姚家组沉积环境进行了系统研究。提出研究区内姚家组为1个层序单元(即层序),在该层序单元的内部结构中体系域发育完整,自下而上依次发育了低水位体系域、水进体系域、高水位体系域和水退体系域,其中低水位体系域砂体发

2、育。确定了研究区上白垩统中发育有冲积扇、辫状河、曲流河、网状河、三角洲和湖泊六种沉积相类型。并进一步可以识别出13种亚相和若干个微相。其中,辫状河河道、扇中辫状河道等沉积亚相分布广泛,特别是在研究区南部的边沿地带发育普遍。在研究区内上白垩统中,姚家组时期为坳陷发展阶段的晚期,结合姚家组单井相型分布特征可知,姚家组沉积期由西南到东北沉积相展布总体表现为冲积扇相-辫状河相-三角洲相-滨浅湖相的渐变特征。此外,本文对研究区内资料较全的白兴吐小区进行了解剖,并指出:姚家组沉积时期,区段内整体构成了以西北和东部为主要物源供给区的冲积扇-辫状河沉积体系。');【Abstract】 Songliao

3、 basin is a large-scale Mesozoic-cenozoic era sedimentary basin in northeast of our country,which is the fault-cols type of interior basin,filled by the cretaceous non-marine fragmentary rock which reached 7000m thickness in the basin.The south of the songliao basin is consist of southeast uplift zo

4、ne、the south of the center depression area and the west sloping zone and the north of southwest uplift zone,bounded by the baicheng city and tongliao city in the west、baicheng and harbin city in the north,siping city in the south and the frontier of the basin in the east,which spans the jilin,liaoni

5、ng and intermongolia provices,the deminsion the basin is about 13.4*104km2。The cover coat concludes baicheng group,huoshiling group of the Jurassic,shahe group、yingcheng group、denglongku group、quantou group of the under-cretaceous,qingshakou group、yaojia group、nenjiang group、sifangtai group and ming

6、shui group of the upper-cretaceous.This * aims at the yaojia group, researchs the depositional system,the character of the sedimentary facies and the source nature of the yaojia group deeply. It is clear about the different deposition system boundary and the mop characteristic, and it will play a vi

7、tal role in impelling the exploration and disposition of the oil and gas accumulation in south of the songliao basin.This * has carried on the unition and contrast of the stratigraphic position to the 48 drill holes in the entire district , and carried on the system lamination to the unlamination dr

8、ill holes, completed the statistics and the analysis of essential data of 48 drill holes in the Upper Crataceous Yao Jia group, such as the stratum depth, sand body thickness, mudstone thickness, the ratio of the sand body and strata thickness, and so on sandstone type. Based on this, has establishe

9、d Yao Jia group stratum depth isogram, the top burying depth isogram, the sandstone thickness isogram, the sand body distribution isogram and the ratio of the sand body and strata thickness isogram and so on in the entire district. This * has carried on the fine dissection to the main purpose strati

10、graphic position of the key deposition sector. Has established typical sectional drawing, the top burying depth chart, the stratum isopach map, the sand body distribution map, the ratio of the sand body and strata thickness isogram , the sandstone color district chart, the mudstone color district ch

11、art of the key land sector, has portrayed sedimentary facies throughgoing ruleof the main purpose stratigraphic position.Through the system acquisition and analysis of information, and on the foundation of establishing massive graphic document, weve obtained the systematic understanding to the local

12、 deposition characteristic and the granulated substance body distribution in the south of the songliao basin, and the understanding is as follows:Yao group is a sequence unit (that is, sequences) in which the systems tract is integral within the internal structure of the the sequence unit in the res

13、earch area, and it has a bottom-up development of lowstand systems tract, transgressive systems tract, highstand systems tract and relictional systems tract.In it the lowstand systems tract grows sand body. In upper Crataceouson of the research area the sedimentary facies type is rich, the growth ha

14、s six types ,and they are the alluvial fan, the braided river, the delta and the lake. And further may distinguish eleven kinds of subfacies and certain microfacies. Of them , the braided river course, the fan deposition subfacies distributions and so on braided channel are widespread, and they are

15、specially common in the boundary zone in the south of the research area. Yao Jia group is in the later period of the depression development phase ,from the single well distribution characteristic of Yao Jia group we can be possible to know that in Upper Crataceouson of the research area : overall performance of the sedimentary facies from the southwest to the northeast has a gradation characteristic like the alluvial fan - braided river - deltashore shallow lacustrine facies during the Yao Jia group depositional stage. In yaojia group depositional stage the information of the distri