三肇凹陷断层垂向分段生长与扶杨油层油源断层的厘定

Vertical Segmentation Growth of Fault and Oil Source Fault Determination in Fuyang Oil Layer of Sanzhao Depression

野外观察、典型地震解剖和物理模拟证实,只要岩石存在能干性差,断层具有典型垂向分段生长特征.岩石能干性差异决定断层演化历经3个阶段:下部断层形成、断裂上下分段和贯通性断裂形成.以三肇凹陷为例,应用岩石力学特征和断层相关褶皱理论,证实扶杨油层砂岩层段普遍形成断裂,青一段泥岩阻止下部断层向上传播,从而形成断层垂向分段生长现象.结合油藏精细解剖表明,三肇凹陷扶杨油层"倒灌"运移的主要油源断层是成藏期活动、沟通源储且垂向分段生长的断裂.

It is proved that fault possesses a typical characteristic of vertical segmentation growth if there is competent difference by field observation,typical seismic analysis and physical modeling.Fault evolution can be divided into three stages by competent difference：formation of lower fault,segmentation of upper and lower faults and formation of throughgoing fault.Taking Sanzhao depression as an example,rock mechanical properties and fault related fold theories prove that there widely exist faults in sandstone layer of Fuyang oil layer,whose propagation is stopped by mudstone in Qingshankou FormationⅠ member,leading to the vertical segmentation growth of fault.Combining fine reservoir anatomy,it can be concluded that the main oil source faults of the＂reversed＂migration in Fuyang oil layer must have been active in hydrocarbon migration and accumulation period,connecting oil source and reservoirs,and featuring vertical segmentation growth in Sanzhao depression.