Citation: | SU Dapeng, HE Jing, YAN Zhuoyu, SHEN Jiangyuan, MA Xiao, FU Heping, LI Xushen, ZHANG Daojun, LIU Xinyu, DONG Gang, YAN Guijing, XU Hong. RESTUDY ON PETROGRAPHIC CHARACTERISTICS OF DEEP TIGHT DOLOMITE IN WELL XIKE 1 OF SHIDAO, XISHA ISLANDS[J]. Marine Geology Frontiers, 2021, 37(6): 55-63. doi: 10.16028/j.1009-2722.2021.036 |
Six years after the discovery of tight dolomite and ferroan dolomite in Shidao island, further studies have focused on the petrographic characteristics. The latest sampling of the tight dolomite strata in well Xike 1 was completed, and the systematic routine rock slice grinding and polarizing microscope and scanning electron microscope identification were carried out, which provided a series of photos and understanding of identification analysis. The petrographic microscopic characteristics of deep dolomite under polarized light microscope were determined, and the characteristics of tight algal reef dolomite composed of microcrystallite-fine-crystallite-clotted micritic dolomite were revealed. They developed fine crystallite-fine-grained, clotted and biological structure. Fine grained dolomite idiomorphic to hypoidiomorphic, bright edge of fog center, 0.05~0.25 mm, multi-generation characteristics; The bioclasts are coralophyta and cellophyta dolomite, 2~3 mm, some 3~5 mm, a few 5~10 mm. The internal dolomite of the organism is mostly silt-crystal, growing or filling in the bioclastic pores. The dolomite in the algae is irregular, 0.3~0.5 mm, scattered and inlaid, involving opaque minerals. Massive and irregular clumps of micritic dolomite were found, and some clumps gathered together. The inside of the clumps was mainly filled with micritic dolomite and a small amount of organic matter, and cryptocrystalline structure was developed.Multiple depth dolomite content of 90%~95% or 95%~100%, under the mirror colorless, sometimes cloudy gray, flash prominent, complete cleavage, senior white interference color; Some of them contain 5%~10% fine crystalline calcite, semi-idiomorphic, 0.05~0.25 mm, scattered among dolomites. The silt-crystal calcite is idiomorphic to hemiidiomorphic granular, 0.01~0.05 mm, Mosaic distributed in the edge of the bioclasts or filled in the internal pores of the bioclasts; The scanning electron microscope (SEM) system analysis is mainly carried out on the tight dolomite samples, and the typical photos are selected to analyze the dolomite grain and filling characteristics. It is found that there are two kinds of filling styles, one is micrite filling outcrops in the pores and cracks between the fine-grained dolomite, the other is micrite area coverage on the fine-grained dolomite.
[1] | 刘宝珺. 沉积岩石学[M]. 北京: 地质出版社, 1980. |
[2] | 李鹏飞,李建明,斯尚华,等. 中扬子西部上震旦统灯影组碳酸盐岩储层特征[J]. 岩性油气藏,2010,22(2):37-41. doi: 10.3969/j.issn.1673-8926.2010.02.007 |
[3] | 倪新锋,陈永权,米永进,等. 塔北地区寒武纪深层自云岩构造-岩相古地理特征及勘探力向[J]. 岩性油气藏,2015,27(5):135-143. doi: 10.3969/j.issn.1673-8926.2015.05.023 |
[4] | 黄擎宇,刘伟,张艳秋,等. 白云石化作用及白云岩储层研究进展[J]. 地球科学进展,2015,30(5):539-551. doi: 10.11867/j.issn.1001-8166.2015.05.0539 |
[5] | 刘诗宇,胡明毅,胡忠贵,等. 四川盆地东部石炭系黄龙组白云岩成因[J]. 岩性油气藏,2015,27(4):40-46. doi: 10.3969/j.issn.1673-8926.2015.04.006 |
[6] | 许红,王修齐,张健,等. 四川盆地震旦系勘探突破与绵阳-长宁拉张槽的特征及对于下扬子区的意义[J]. 海洋地质前沿,2016,32(3):1-6. |
[7] | 王修齐,许红,宋家荣,等. 高石梯-龙王庙大气田发现与四川盆地震旦—寒武系油气地质特征及成藏[J]. 海洋地质前沿,2016,32(3):24-32. |
[8] | 许红. 中国海域及邻区含油气盆地生物礁的对比研究[J]. 海洋地质与第四纪地质,1992,12(4):41-52. |
[9] | 许红, 王玉净. 西沙中新世生物地层与藻类的造礁作用和生物礁演变特征[M]. 北京: 科学出版社, 1999. |
[10] | 许红,张金川,蔡峰,等. 西沙群岛中新世生物礁矿物相研究及其意义[J]. 海洋地质与第四纪地质,1994,14(4):15-23. |
[11] | 朱淑英,张滨峰,毕桂荣,等. 致密泥质白云岩孔隙分布研究[J]. 内蒙古石油化工,2014(4):130-131. doi: 10.3969/j.issn.1006-7981.2014.14.052 |
[12] | 熊金玉,李思田,唐玄,等. 湖相碳酸盐岩致密储层有机质赋存状态与孔隙演化微观机理[J]. 石油与天然气地质,2015,36(5):756-765. doi: 10.11743/ogg20150506 |
[13] | 王海生. 雷家地区湖相碳酸盐岩致密油储层微观特征[J]. 特种油气藏,2016,23(5):26-29. doi: 10.3969/j.issn.1006-6535.2016.05.006 |
[14] | 魏新善,陈洪德,张道峰,等. 致密碳酸盐岩储集层特征与天然气勘探潜力-以鄂尔多斯盆地伊陕斜坡东部奥陶系马家沟组为例[J]. 石油勘探与开发,2017,44(3):319-329. |
[15] | 许红,张金川,蔡峰. 西沙群岛中新世生物礁矿物相研究及其意义[J]. 海洋地质与第四纪地质,1994,14(4):16-23. |
[16] | 张道军,刘新宇,王亚辉,等. 西沙地区中新世以来碳酸盐岩的沉积演化及储层特征[J]. 地球科学(中国地质大学学报),2015,40(4):606-614. |
[17] | 许红. “十二五”油气重大科技专项《南海新生代生物礁储层对比研究》成果报告[R]. 青岛: 青岛海洋地质研究所, 2015. |
[18] | 翟世奎,米立军,沈星,等. 西沙石岛生物礁的矿物组成及其环境指示意义[J]. 地球科学(中国地质大学学报),2015,40(4):597-605. |
[19] | 王振峰,时志强,张道军,等. 西沙地区西科1井中新统—上新统白云岩微观特征及成因[J]. 地球科学(中国地质大学学报),2015,40(4):606-614. |
[20] | 曹佳琪,张道军,翟世奎,等. 西沙群岛礁白云岩化特征与成因模式分析[J]. 海洋地质,2016,38(11):125-139. |
[21] | 修淳,张道军,翟世奎,等. 西沙石岛礁相白云岩稀土元素地球化学特征及成岩环境分析[J]. 海洋通报,2017,36(2):151-159. doi: 10.11840/j.issn.1001-6392.2017.02.005 |
[22] | NA Q,XU H,SU D P,et al. Microscopic characteristics and geological significance of tight dolomite in well Xike-1,Xisha Islands,China[J]. China Geology,2019,2(4):458-466. |
[23] | 许红, 韩学辉, 李峰弼, 等. 一种基于缩微样品的生物礁岩心常规物性测试器装置: CN 106324217 A [P]. 2016. |
[24] | XU Hong,ZHANG Weiwei,WEI Kai,et al. Ferroan dolomites in Miocene sediments of the Xisha Islands and their genetic model[J]. Journal of Oceanology and Limnology,2018,36(1):165-180. doi: 10.1007/s00343-018-7136-3 |
[25] | 宋红瑛, 南海西部新近系生物礁碳酸盐岩孔渗层变化与成因特征研究[D]. 青岛: 中国海洋大学, 2012. |
Microscopic characteristics of various dolomites in the study area
Fine grain dolomite of 1 045 m,unipolarized light,800 µm
Density-forming powdery algal calcareous dolomite,typical biological lattice structure,powdery structure
Fine crystal mist core bright edge dolomite and clotted micritic dolomite
Mist core bright edge coagulated micrite - fine grained dolomite
Microcosmic characteristics of dolomite fillings