鄂尔多斯盆地中央古隆起东部古岩溶地貌小型沟槽的识别

作    者:高建荣,徐旺林,郭彦如,赵振宇,刘俊榜,张延玲,张月巧
单    位:中国石油勘探开发研究院鄂尔多斯分院
基金项目:中青年创新基金(项目编号2010-A-26-12)资助
摘    要:
鄂尔多斯盆地中央古隆起东部奥陶纪末古岩溶地貌发育,古地貌中沟槽的准确刻画识别对研究油气成藏和提高勘探成功率具有重要意义。沟槽在地震上的响应主要是槽的深度而不是宽度,当地层倾角大于5毅时,沟槽的响应特征模糊;而当地层倾角小于5°时,槽的侵蚀深度在10~5m,它的地震同相轴相位会反转。如果侵蚀深度在30~10m,那么它的同相轴增益会增大;如果侵蚀深度大于30 m,它的同相轴会呈复波型。利用井数据和实际地质资料建立沟槽充填模型,应用全波场数值模拟技术生成叠后偏移剖面,结合地震响应特征分析,推测描述了中央古隆起东部马家沟组五段中、下组合中小型沟槽的分布。
关键词:鄂尔多斯盆地;奥陶系;风化壳储层;岩溶沟槽;全波场正演模拟

Identification of Small Karst Paleogrooves in Eastern Central Uplift, Ordos Basin

Author's Name: Gao Jianrong, Xu Wanglin, Guo Yanru, Zhao Zhenyu,Liu Junbang, Zhang Yanling, Zhang Yueqiao
Institution: Research institute of Petroluem Exploration and Development PetroChina
Abstract:
Ordovician karst landforms are wide distributed in eastern Central Uplift, Ordos Basin. The accurate characterization and identification of small karst paleogrooves is important to approach hydrocarbon accumulation and improve success rate of exploration. The seismic response of paleogrooves is the depth of the grooves instead of the width of them. It is shown that as the dip angle is more than 5°, the seismic response is unclear. As the erosion depth of them is at 10 m to 5 m, seismic phase axis is reversed. As the erosion depth of them is at 30m to 10m, the seismic phase axisgaining even increases. As the erosion depth is greater than 30m, the seismic displays compound waves. By this method, a group of the middle and small karst paleogrooves have been effectively identified and confirmed in the Middle array of Ordovician Majiagou 5 Submember using well data and available geologic data and post-stack migration profiles.
Keywords: Ordovician; Weathering crust reservoir; Karstified groove;Full-wave field modeling; Ordos Basin
投稿时间: 2012-03-13  
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