柴达木盆地七个泉地区Q32井水下扇分析
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摘要
研究一个地区的古地形特征及构造演化规律,是寻找和分析各类扇体、三角洲的前提和基础。扇体因其自身内部结构与周围地层不同,岩性和倾角与围岩也存在差异,这就使得利用地震属性对扇体内部结构、外形特征和发育规模进行分析成为可能。沿层地震属性特征分析是确定扇体发育规模以及刻画扇体空间展布特征的有效手段。七个泉地区位于柴达木盆地的边缘,岩性尖灭、地层削蚀尖灭发育,同时受阿拉尔物源和阿尔金山前的陡坡近物源影响,在不同地质历史时期发育了众多不同类型的沉积体,包括冲积扇、近岸水下扇、扇三角洲、浊积扇、辫状河三角洲等,也是在柴达木盆地寻找各类岩性(地层)圈闭最为有利的地区之一。Q32井水下扇的发现,首先是从研究E31、E32时期古地形和古构造特征入手,并利用地震属性、沿层切片等技术手段对所发现的沉积体的内部结构、外形特征和分布范围进行描述和论证,最终被钻井证实,为今后开展(岩性)地层圈闭研究提供了有益的借鉴。
Studying the palaeotopographic feature and rule of structural evolution in an area is the precondition and foundation to look for and analyze various fans and deltas. Different in internal structure of fan with surrounding beds, there is difference in lithology and dips with surrounding beds, which becomes possible that utilizes seismic attributes to analyze the internal structure, configuration and development size of fan. The feature analysis of horizontal seismic attribute is an effective tool to determine the development size of fan and describe spatial distributing feature of fan. The Qigequan area is situated in the margin of Qaidam basin, where developing the lithologic and stratigraphic erosion pinchouts; and at the same time, affected by Alar source area and Arjin piedmont steep-slope near source area, developing various different types of sedimentary bodies in different geologic epochs, including alluvial fan, near-shore underwater fan, fan delta, turbidite fan and braided river fan, which is one of the most prospective areas for looking for various lithologic (stratigraphic) traps in Qaidam basin. The discovery of underwater fan in Q32 well started firstly from studying palaeotopographic and palaeotectonic feature in E31 and E32 epochs, used such technical tools as seismic attributes and horizontal slices to describe and demonstrate the internal structure, configuration and distribution range of discovered sedimentary bodies that are finally proved by drilling results, which provided meaningful reference for following development of study on (lithologic) stratigraphic traps.
Studying the palaeotopographic feature and rule of structural evolution in an area is the precondition and foundation to look for and analyze various fans and deltas. Different in internal structure of fan with surrounding beds, there is difference in lithology and dips with surrounding beds, which becomes possible that utilizes seismic attributes to analyze the internal structure, configuration and development size of fan. The feature analysis of horizontal seismic attribute is an effective tool to determine the development size of fan and describe spatial distributing feature of fan. The Qigequan area is situated in the margin of Qaidam basin, where developing the lithologic and stratigraphic erosion pinchouts; and at the same time, affected by Alar source area and Arjin piedmont steep-slope near source area, developing various different types of sedimentary bodies in different geologic epochs, including alluvial fan, near-shore underwater fan, fan delta, turbidite fan and braided river fan, which is one of the most prospective areas for looking for various lithologic (stratigraphic) traps in Qaidam basin. The discovery of underwater fan in Q32 well started firstly from studying palaeotopographic and palaeotectonic feature in E31 and E32 epochs, used such technical tools as seismic attributes and horizontal slices to describe and demonstrate the internal structure, configuration and distribution range of discovered sedimentary bodies that are finally proved by drilling results, which provided meaningful reference for following development of study on (lithologic) stratigraphic traps.
引文
[1]赵秀歧.洪泽凹陷管镇次凹水下扇地震识别技术.石油地球物理勘探,2005,40(增刊)
[2]亓雪静.利津油田砂砾岩扇体发育特征及储层评价.石油地球物理勘探,2006,41(4):410～414
[3]李廷辉等.关家堡滩海区近岸水下扇体研究及勘探意义.石油地球物理勘探,2005,40(5):561～564
[2]亓雪静.利津油田砂砾岩扇体发育特征及储层评价.石油地球物理勘探,2006,41(4):410～414
[3]李廷辉等.关家堡滩海区近岸水下扇体研究及勘探意义.石油地球物理勘探,2005,40(5):561～564
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