琼东南盆地北礁地区梅山组丘形反射特征

发布时间：2018-05-07 13:50

本文选题：北礁凹陷 + 梅山组　；参考：《海洋学报》2017年12期

【摘要】：目前琼东南盆地北礁凹陷中中新统梅山组顶部丘形反射引起广泛关注,但对其成因有不同认识。本文通过高精度二维、三维地震、钻井资料,研究丘形反射的特征。研究表明北礁地区梅山组顶部发育近东西向展布的长条形丘体,丘间为水道,丘内为中-弱振幅的地震反射,与西南部强振幅水道砂岩形成鲜明的对比,波阻抗反演揭示丘内为低波阻抗,属泥岩范畴。梅山组塑性丘内地层发生重力扩展,在其上覆的脆性地层(强振幅砂岩和弱振幅泥岩)发育多边形断层,反推出梅山组形成于深水环境,丘为泥丘,沉积环境分析也认为北礁凹陷中中新世为半深海沉积,梅山组的丘-谷分别对应上覆地层的谷-丘,认为是底流剥蚀/沉积成因。本文的研究对南海北部丘形反射的认识有重要意义,并可降低油气探勘风险。
[Abstract]:At present, the mound reflection at the top of Miocene Meishan formation in Beijiao sag of Qiongdongnan basin has attracted wide attention, but the origin of it is different. In this paper, the features of mound reflection are studied by using high precision two-dimensional, three-dimensional seismic and drilling data. The study shows that the top of Meishan formation in the north reef area is formed near east-west distributed long strip mound, with a channel between the hills and a medium-weak amplitude seismic reflection in the mound, which is in sharp contrast with the strong amplitude watercourse sandstone in the southwest. Wave impedance inversion reveals low wave impedance in the mound, which belongs to mudstone category. Meishan formation developed polygonal faults in the brittle strata (strong amplitude sandstone and weak amplitude mudstone), which formed in deep water environment, and the mound was mud mound. The analysis of sedimentary environment also shows that the Miocene in Beijiao sag is semi-deep-sea, and the mound-valley of Meishan formation corresponds to the valley-mound of the overlying strata, which is considered to be the origin of bottom flow denudation / sedimentation. The study in this paper is of great significance to the understanding of hilly reflection in the northern part of the South China Sea and can reduce the risk of oil and gas exploration.
【作者单位】：西北大学大陆动力学国家重点实验室;广西师范学院北部湾环境演变与资源利用教育部重点实验室;
【基金】：国家科技重大专项(2011ZX05025-006-02) 国家自然科学基金(41390451) 国家自然基金地区项目——北部湾海陆过渡带生态环境演化机理及其情景模拟研究(41361022) 广西创新研究团队项目——北部湾海陆交互关键带与陆海统筹发展研究(2016JJF15001)
【分类号】：P618.13;P631.4

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