CHARACTERISTICS OF GEOTEMPERATURE FIELD AND MATURITY HISTORY OF SOURCE ROCKS IN LUNPOLA BASIN, XIZANG(TIBET)
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摘要: 西藏伦坡拉盆地是在燕山期基底上发育的拉张型老第三纪陆相盆地。形成时间晚于中国东部新生代沉积盆地.它在始新世未发生短暂抬升,渐新世求突告结束,之后长期抬升剥蚀,沉积时间短。伦坡拉盆地具有典型热盆的特点,受区域异常热流影响,地温梯度高于50℃/km;其地表温度随青藏高原隆升而大幅降低。独特的构造、沉积演化史及地温场特征,导致了盆内牛堡组二、三段烃源岩成熟快、门限浅,利于油气生成和排运。但盆地后期改造复杂,裂缝发育,勘探证实原生油气藏破坏明显,对保存大规模的油气储量不利。Abstract: Lunpola Basin, developed on Yensan basement, is an extensional Eogene continental basin. It started relatively later than other Cenozoic basins in eastern China, ended at the end of Oligocene Epoch, and then uplifted until present. Its deposition period was short. It also took place a short uplifting period at the end of Eocene Epoch. Lunpola Basin is a typical HOT Basin, in which geothermal gradient was higher than 50℃/km, and temperature was decreased as Qingzang plateau elevating. Special characteristics of structure, sedimentary history and geotemperature field made source rocks of Niubao formation in the basin bury shallow and mature fast. All of those are favorable for hydrocarbon generation and expulsion. But Petroleum exploration has shown that Lunpola Basin was reformed by succeeding structure and fracture and the primary reservoir was damaged. So it is unfavorable for preserving great amount reserves of oil and gas.
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Key words:
- geotemperature field /
- thermal evolution /
- source rocks /
- Lunpola Basin
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[1] 徐思煌,梅廉夫,邓四新.西藏伦坡拉盆地烃源岩生、排烃史模拟[J].地球科学——中国地质大学学报,1996,21(2):179-183. [2] 雷清亮,付孝悦,卢亚平.伦坡拉盆地第三纪陆相盆地油气地质特征分析[J].地球科学——中国地质大学学报,1996,21(2):168-173. [3] 罗本家,戴光亚,潘泽雄.班公湖-丁青缝合带老第三纪陆相盆地含油前景[J].地球科学——中国地质大学学报,1996,21(2):163-167. [4] 康文华,李德禄,白嘉启.西藏地热异常带的划分及构造控制[A].中国地质科学院地质力学研究所.地热专辑(第二辑)[C].北京:地质出版社,1989. [5] 孙鸿烈.青藏高原的形在演化[M].上海:上海科学技术出版社,1996. [6] D A Wood. Relationships between thermal maturity indices calculated using arrhenius equation and Lopatin method: applications for petroleum exploration[J].AAPG, 1988,72(2):115-134.
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