东辛地区营26断层变换带形成机制模拟

发布时间：2018-04-04 00:33

本文选题：东辛地区　切入点：营断层变换带　出处：《中国石油大学学报(自然科学版)》2017年01期

【摘要】：为了分析叠覆型断层变换带的形成机制,揭示变换带内断裂体系的发育规律,根据区域应力机制设计相应的张扭及底辟复合作用实验装置,从湿度不同的砂、黏土及砂泥混合物中选取微湿的细砂作为实验材料,并与应力场数值模拟相结合,对东营凹陷东辛地区营26变换带沙河街组沉积期进行构造物理模拟。结果表明:营1与营31断裂是沙河街组沉积前由NE10°的伸展作用同时形成的两条平行断裂,二者向两侧的伸展位移在叠覆带边缘诱导出一条与伸展方向呈50°斜交的张扭性变换断层,随着二者叠置程度的增大,变换断层的发育程度也增大。之后,区域性的右旋走滑运动形成一系列雁列式分布的变换断层,其优势走向与剪切应力场方向一致,后期的底辟作用加剧了断裂系统的复杂程度。断层的转折端、交汇和分叉处以及次级断层形成的局部小断块内,最大主应力和最小主应力差值较大,为低级序断层的优势发育区。另外,平面上斜交的剪切断层在不同方向的走滑活动造成的局部断块的掀斜运动加剧了低级序断层复杂程度。
[Abstract]:In order to analyze the formation mechanism of overlapping fault transformation zone and reveal the development law of fault system in the transformation zone, the corresponding experimental apparatus of tension-torsional and diapir composite action was designed according to the regional stress mechanism, from the sand with different humidity,In the mixture of clay and sand, the micro-wet fine sand is selected as experimental material and combined with the numerical simulation of stress field to simulate the sedimentary period of Shahejie formation in Ying26 transform zone of Dongying depression.The results show that the Ying1 and Ying31 faults are two parallel faults formed at the same time by the extension of NE10 掳before the deposition of Shahejie formation.The extensional displacement of both sides induces a tension-torsional transformation fault which is oblique to the extension direction at the edge of the overlay zone. With the increase of the degree of superposition between the two faults, the development degree of the transformation fault also increases.The regional dextral strike-slip movement resulted in a series of geese distributed transformed faults whose dominant strike was consistent with the direction of shear stress field and the later diapir increased the complexity of the fault system.The difference between the maximum principal stress and the minimum principal stress in the turning point of the fault, the intersection and the bifurcation, and the local small fault block formed by the secondary fault is large, which is the dominant development area of the low-order fault.In addition, the tilting movement of local fault blocks caused by the strike slip in different directions of the oblique shear faults on the plane intensifies the complexity of the low-order faults.
【作者单位】：中国石油大学地球科学与技术学院;海洋国家实验室海洋矿产资源评价与探测技术功能实验室;中国石化胜利油田有限公司东辛采油厂;
【基金】：国家科技重大专项课题(2011ZX05011-003)
【分类号】：P618.13;P542

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