渝南地區(qū)龍馬溪組筆石頁巖相與頁巖氣成藏關(guān)系探討
發(fā)布時間：2018-09-12 09:44
【摘要】：渝南地區(qū)龍馬溪組發(fā)育筆石頁巖相,且具有較好的頁巖氣成藏地質(zhì)條件。本文以渝南地區(qū)龍馬溪組筆石頁巖為研究對象,通過資料收集-野外地質(zhì)調(diào)查-實(shí)驗(yàn)測試-理論分析,對研究區(qū)龍馬溪組古生物化石發(fā)育特征、頁巖氣成藏條件及筆石生物對頁巖氣成藏貢獻(xiàn)等問題展開系統(tǒng)研究,結(jié)果表明:研究區(qū)構(gòu)造簡單,地層出露較好。龍馬溪組下部泥質(zhì)深水陸棚沉積,發(fā)育炭質(zhì)頁巖、泥質(zhì)頁巖、鈣質(zhì)頁巖,上部為灰泥質(zhì)淺水陸棚沉積,發(fā)育鈣質(zhì)頁巖、粉砂巖,夾透鏡狀灰?guī)r。綦江觀音橋剖面共識別出20屬71種筆石化石,其中奧陶系五峰組5屬8種,志留系龍馬溪組17屬63種,劃分7個筆石帶。奧陶紀(jì)晚期的冰期海退事件及志留紀(jì)初的全球氣候變暖事件,影響筆石的發(fā)育和保存條件,最終導(dǎo)致龍馬溪組下部筆石豐度高,上部筆石豐度低,與實(shí)測剖面有機(jī)碳含量自下而上逐漸降低的特點(diǎn)相對應(yīng),兩者具有良好的相關(guān)關(guān)系。且研究區(qū)筆石體碳元素含量極高,圍巖碳元素含量低。因此筆石豐度為控制源巖有機(jī)質(zhì)豐度的主要因素,筆石為頁巖氣形成提供了物質(zhì)基礎(chǔ),為頁巖氣主要生烴母質(zhì)。研究區(qū)五峰組內(nèi)腕足類化石以礦化立體-半立體保存,形成于有機(jī)質(zhì)含量低的層位中;龍馬溪組筆石化石多以有機(jī)質(zhì)壓扁薄膜狀態(tài)保存,形成于高有機(jī)質(zhì)含量儲層中;龍馬溪組中上部發(fā)現(xiàn)黃鐵礦化筆石化石,發(fā)育于有機(jī)質(zhì)含量相對較低的還原層位。因此,炭質(zhì)薄膜的筆石化石可反映研究區(qū)具有高有機(jī)碳含量的特征。研究區(qū)五峰組內(nèi)腕足類化石和龍馬溪組的黃鐵礦化的筆石化石由于填充及交代作用,有效孔隙少,對儲層孔隙貢獻(xiàn)有限。有機(jī)質(zhì)壓扁薄膜保存的筆石化石表面發(fā)育大量微孔-過渡孔,呈圓-不規(guī)則孔穴狀,筆石體內(nèi)胞管邊緣、中軸兩側(cè)仍存保留有一定的空間�？傮w看來,筆石的有效孔隙度相對較好,開放性好,可形成一定的孔隙空間及內(nèi)表面積;層間間隙發(fā)育且連通性較好,可提供一定的儲集空間和滲流通道。筆石生物化石殘余有機(jī)碳可發(fā)育大量筆石有機(jī)質(zhì)孔,主要為納米級的孔隙,保存較好,很難被充填,且可形成巨大的內(nèi)表面積,為頁巖氣的吸附提供大量的吸附點(diǎn)位,從而成為吸附氣的重要載體。同時筆石通過控制TOC的含量影響孔隙整體發(fā)育,尤其是微孔-過渡孔的發(fā)育,為游離氣和吸附氣提供了大量的賦存空間。因此,筆石化石是有利于頁巖氣賦存的重要因素。本論文研究成果對筆石與頁巖氣成藏關(guān)系及渝南地區(qū)筆石頁巖相頁巖氣的勘探具有參考價(jià)值。
[Abstract]:Graptolite shale facies are developed in Longmaxi formation and have good geological conditions for shale gas accumulation. Taking graptolite shale of Longmaxi formation in Yunan area as the research object, the development characteristics of paleontological fossils of Longmaxi formation in the study area were studied by data collection, field geological survey, experimental test and theoretical analysis. The conditions of shale gas reservoir formation and the contribution of graptolite organisms to shale gas accumulation are systematically studied. The results show that the structure of the study area is simple and the strata are well exposed. In the lower part of Longmaxi formation, shaly shales, calcareous shallow water shelf deposits, calcareous shale, siltstone and lenticular limestone are developed in the lower part of Longmaxi formation. A total of 71 species of graptolites belonging to 20 genera have been identified in the Guanyinqiao section of Qijiang, including 5 genera and 8 species of Ordovician Wufeng formation and 63 species of 17 genera of Silurian Longmaxi formation, which are divided into 7 graptolite zones. The late Ordovician sea retreat event and the early Silurian global warming event affected the development and preservation conditions of graptolite, which resulted in high graptolite abundance in the lower part of Longmaxi formation and low graptolite abundance in the upper part. The results show that the organic carbon content of the measured profile decreases gradually from the bottom to the top, and there is a good correlation between the two. The content of carbon element is very high and the content of carbon element in surrounding rock is low in the study area. Therefore graptolite abundance is the main factor to control the organic matter abundance of source rocks and graptolite provides material basis for shale gas formation and is the main hydrocarbon source material of shale gas. The brachiopod fossils in the Wufeng formation of the study area are mineralized stereoscopically and semi-stereoscopically, and formed in the low organic layer, while the graptolite fossils of the Longmaxi formation are mostly preserved as organic matter flattened thin films and formed in the reservoirs with high organic matter content. Pyrite graptolite fossils were found in the middle and upper part of Longmaxi formation. Therefore, the graptolite fossils of carbonaceous films can reflect the characteristics of high organic carbon content in the study area. The brachiopod fossils in the Wufeng formation and the pyrite graptolite fossils in the Longmaxi formation have little effective pores due to filling and metasomatism and limited contribution to the reservoir porosity. A large number of microvoids and transition pores are formed on the surface of graptolite fossils preserved by organic matter flattened thin films, which are circular and irregular holes, with the cell margins in the graptolite body, and there is still some space on both sides of the central axis. As a whole, the effective porosity of graptolite is relatively good and open, which can form a certain pore space and internal surface area, and the interlayer gap is developed and connectivity is good, which can provide a certain reservoir space and seepage passage. The residual organic carbon of graptolite fossils can develop a large number of graptolite organic pores, mainly nanoscale pores, which are well preserved and difficult to be filled, and can form a huge internal surface area, which provides a large number of adsorption sites for the adsorption of shale gas. Thus it becomes an important carrier of adsorption gas. At the same time, graptolite influences the development of pore by controlling the content of TOC, especially the development of micropore-transition pore, which provides a lot of space for free gas and adsorption gas. Therefore, graptolite fossils are important factors conducive to the occurrence of shale gas. The results of this paper have reference value for the relationship between graptolite and shale gas accumulation and the exploration of graptolite shale gas in Yunan area.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P618.13
本文編號：2238631
[Abstract]:Graptolite shale facies are developed in Longmaxi formation and have good geological conditions for shale gas accumulation. Taking graptolite shale of Longmaxi formation in Yunan area as the research object, the development characteristics of paleontological fossils of Longmaxi formation in the study area were studied by data collection, field geological survey, experimental test and theoretical analysis. The conditions of shale gas reservoir formation and the contribution of graptolite organisms to shale gas accumulation are systematically studied. The results show that the structure of the study area is simple and the strata are well exposed. In the lower part of Longmaxi formation, shaly shales, calcareous shallow water shelf deposits, calcareous shale, siltstone and lenticular limestone are developed in the lower part of Longmaxi formation. A total of 71 species of graptolites belonging to 20 genera have been identified in the Guanyinqiao section of Qijiang, including 5 genera and 8 species of Ordovician Wufeng formation and 63 species of 17 genera of Silurian Longmaxi formation, which are divided into 7 graptolite zones. The late Ordovician sea retreat event and the early Silurian global warming event affected the development and preservation conditions of graptolite, which resulted in high graptolite abundance in the lower part of Longmaxi formation and low graptolite abundance in the upper part. The results show that the organic carbon content of the measured profile decreases gradually from the bottom to the top, and there is a good correlation between the two. The content of carbon element is very high and the content of carbon element in surrounding rock is low in the study area. Therefore graptolite abundance is the main factor to control the organic matter abundance of source rocks and graptolite provides material basis for shale gas formation and is the main hydrocarbon source material of shale gas. The brachiopod fossils in the Wufeng formation of the study area are mineralized stereoscopically and semi-stereoscopically, and formed in the low organic layer, while the graptolite fossils of the Longmaxi formation are mostly preserved as organic matter flattened thin films and formed in the reservoirs with high organic matter content. Pyrite graptolite fossils were found in the middle and upper part of Longmaxi formation. Therefore, the graptolite fossils of carbonaceous films can reflect the characteristics of high organic carbon content in the study area. The brachiopod fossils in the Wufeng formation and the pyrite graptolite fossils in the Longmaxi formation have little effective pores due to filling and metasomatism and limited contribution to the reservoir porosity. A large number of microvoids and transition pores are formed on the surface of graptolite fossils preserved by organic matter flattened thin films, which are circular and irregular holes, with the cell margins in the graptolite body, and there is still some space on both sides of the central axis. As a whole, the effective porosity of graptolite is relatively good and open, which can form a certain pore space and internal surface area, and the interlayer gap is developed and connectivity is good, which can provide a certain reservoir space and seepage passage. The residual organic carbon of graptolite fossils can develop a large number of graptolite organic pores, mainly nanoscale pores, which are well preserved and difficult to be filled, and can form a huge internal surface area, which provides a large number of adsorption sites for the adsorption of shale gas. Thus it becomes an important carrier of adsorption gas. At the same time, graptolite influences the development of pore by controlling the content of TOC, especially the development of micropore-transition pore, which provides a lot of space for free gas and adsorption gas. Therefore, graptolite fossils are important factors conducive to the occurrence of shale gas. The results of this paper have reference value for the relationship between graptolite and shale gas accumulation and the exploration of graptolite shale gas in Yunan area.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：P618.13
【參考文獻(xiàn)】
相關(guān)期刊論文 前10條
1 徐國盛;徐志星;段亮;袁海鋒;張武;;頁巖氣研究現(xiàn)狀及發(fā)展趨勢[J];成都理工大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年06期
2 方曉思;侯靜鵬;;四川綦江觀音橋志留紀(jì)微古植物、幾丁蟲及其地層意義[J];地層古生物論文集;1988年02期
3 戎嘉余;再論志留紀(jì)年代地層的統(tǒng)、階層型研究[J];地層學(xué)雜志;2005年02期
4 張?jiān)獎?王志浩,馮洪真,駱天天,B.-D.Erdtmann;中國特馬豆克階筆石地層述評[J];地層學(xué)雜志;2005年03期
5 張雪芬;陸現(xiàn)彩;張林曄;劉慶;;頁巖氣的賦存形式研究及其石油地質(zhì)意義[J];地球科學(xué)進(jìn)展;2010年06期
6 楊振恒;李志明;王果壽;騰格爾;申寶劍;;北美典型頁巖氣藏巖石學(xué)特征、沉積環(huán)境和沉積模式及啟示[J];地質(zhì)科技情報(bào);2010年06期
7 李娟;于炳松;郭峰;;黔北地區(qū)下寒武統(tǒng)底部黑色頁巖沉積環(huán)境條件與源區(qū)構(gòu)造背景分析[J];沉積學(xué)報(bào);2013年01期
8 周玉增;;頁巖氣成藏淺析[J];科技創(chuàng)新與應(yīng)用;2013年06期
9 趙群;王紅巖;劉大錳;姚艷斌;楊慎;劉德勛;;中上揚(yáng)子地區(qū)龍馬溪組頁巖氣成藏特征[J];遼寧工程技術(shù)大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年07期
10 聶海寬;張金川;馬曉彬;邊瑞康;;頁巖等溫吸附氣含量負(fù)吸附現(xiàn)象初探[J];地學(xué)前緣;2013年06期
，本文編號：2238631
本文鏈接：http://sikaile.net/kejilunwen/diqiudizhi/2238631.html
最近更新
教材專著
