东辛油田营13断块区调节带特征及成因探讨

营13断块位于3条二级断层交汇处,3条断层均消失于调节带内及附近。该断块内油气富集程度很高。通过分析断层走向变化、断层终止关系及断层间的相对位置,识别出营13断块斜向背斜调节带。营13调节带位于两条倾向相对断层之间的断层叠覆段,呈半背斜形态,其枢纽线走向与断块边界断层走向斜交;与周围地区相比,调节带内次级断层密度增大,走向发生明显变化;剖面上,由下至上,随着叠覆断层叠覆程度的增加,半背斜枢纽线走向与断块边界断层走向间夹角逐渐减小并趋于平行;断块边界断层断距向调节带内部逐渐减小;平面上,断层末端呈发散状消失或终止于传递断层。调节带的形成与两条断层的横向生长叠覆及相互作用有关。调节带发育特殊的构造样式,研究调节带对优化勘探开发部署有重要意义。

A discussion on characteristics and origin of an accommodation zone in Ying13 fault-block, Dongxin oilfield

Ying13 is a petroleum-prolific fault-block located at a cross point of three second-order faults which all disappear in an accommodation zone and near it.The accommodation zone in Ying13 block is recognized by analyzing the faults' displacement directions,termination relationships and relative locations.It is located between two faults with opposite dips and shaped as a semi-anticline,and its axis oblique to the strike of the block boundary faults.Minor faults in the zone are closer in development and more changed in strike than those in the surrounding areas.Vertically from lower to upper,the axis tends to parallel to the boundary faults as their overlapping in creases.The offsets of the two boundary faults gradually decrease into the accommodation zone.Laterally,these faults splay or terminate at transfer faults.The formation of the accommodation zone is related to growth,overlapping and interaction of the two faults.In terms of its special structural style,the research on it is meaningful for optimization of exploration and development.