論後期構造運動對於渝東牛蹄塘組等頁岩氣資源潛力影響

Discussion Upon Gas Potential in Black Shale of Early Cambrian Niutitang Formation in East Chongqing, China

岳來群(Lai-Qun Yue) ； 曽保忠(Pao-Chung Tseng) ； 齊紅衛(Hong-Wei Qi) ； 陳清禮(Qing-Li Chen)

《臺灣鑛業》 68卷4期 (2016/12) Pp. 33-46

摘要

中國大陸渝東牛蹄塘組等下古生界黑色頁岩分布廣，厚度大，有機質（碳）含量高，生成於缺氧閉塞滯留淺海環境。牛蹄塘組等黑色頁岩後期曾受到加里東等多期次構造疊加、改造，致其產狀複雜，裂縫、節理發育。後期構造對下古生界頁岩氣成藏主要有兩種影響，當頁岩裂隙發育、其上無蓋層時，頁岩氣資源潛力小；當頁岩裂隙發育，游離氣含量高且頁岩層之上配置有較好的蓋層時，則頁岩氣資源潛力大。箱式褶皺是渝東頁岩氣藏成藏的區域構造條件，相當於儲層的頁岩富游離甲烷且構造裂隙發育進而導致岩石連通空間發育、泄流表面積加大是必要的物性條件，配置有裂隙不發育的上覆富泥質頁岩是必要的蓋層條件。由此分析，除卻龍馬溪組頁岩，牛蹄塘組黑色頁岩也應具有較大的頁岩氣成藏潛力。在勘探開發中，應將牛蹄塘組頁岩氣與其它下古生界黑色頁岩氣、常規天然氣、緻密砂岩氣、碳酸鹽岩氣等統籌考慮。箱式褶皺（背斜）及區域性北東向斷裂附近有一定埋深的頁岩層是重要的遠景區。

關鍵字

黑色頁岩 ； 環境 ； 構造疊加 ； 頁岩氣 ； 蘊藏模式

並列摘要

The black shale has been taken as source rocks and important reservoir for petroleum development especially in north America through the fracturing technology. In China, the universities and government departments etc. jointly launched the shale gas research project particularly about shale gas exploration and development since 2008. In practical terms, these studies (including this paper) are primarily aimed at the development shale gas in East Chongqing (Yudong area) for the sake of two accounts which both in geologically strong late-reformation of structure in the basins of upper Yangtze area and in economically provincial demands. This research are already provided conditions such as professional knowledge and related research experience, seismic data and ongoing field well drillings. The principles of this study comprehensively contain field investigations and indoor analysis that including microscopic rock identification, petrophysical measurement and the porosity of hydrocarbon content analysis etc. The black shales in Niutitang and Longmaxi Formations pertained to Lower Palaeozoic and are widespread in Yudong, their layers are thick. The Niutitang Formation shale can fully represent other Lower Palaeozoic shales in lithology such as Longmaxi Formation shale etc during this study and especially for being concise and comprehensive discussing. There is a higher organic content in it which formed in marine anaerobic and block stagnation environment. Because of complicated geological structure, strong microheterogeneity and sharp lateral variation of Lower Palaeozoic shales in Yudong, the detail survey in field and core geology as well as laboratory experimental studies of course belong to basic issues. The Fracture and free gas here in shales benefited from tectonic superimpositions and reworking are key problems. The results of this study are followings: first, rich organic matter is material conditions; and then, Fracture and free gas enrichment are necessary conditions; the third,＂box fold＂ and caprock etc. which resulted from the tectonic movements are the essential preservation conditions and reservoir identifications of shale gas. The conclusions of this study are there surely has been a good gas resource potential and it is deserved to progress further geological survey although it is complicated in occurrence and underwent tectonic movements in Mesozoic and Cenozoic. The black shales, tight clastic and carbonate rocks in Yudong should be overall programmed in future geologic explorations and fracture developments. As a reservoir forming model of black shale gas in Lower Palaeozoic in Yudong, it is firstly summed up by this paper and it will be useful for studies and commercial developments in this kinds of shale exploration bidding blocks.

並列關鍵字

black shales ； environment ； structural superposition ； shale gas ； reservoir mode