华北中原油田盐丘构造的成因机制

本文结合华北中原油田三维地震构造图和实地考察结果,通过半定量的构造模拟实验,探讨了该油田犁状正断层和盐丘构造的成因机制。结果证明犁状正断层和盐丘构造的形成受岩性、位移边界条件和拉张应力场三大环节控制。犁状正断层和盐丘构造生成在岩石圈地壳部分,从已探明的本区岩石种类分析,构造主体的岩性为脆性;构造区下部的软底边界(较厚的盐岩层),为该类型构造的形成提供了向下位移边界条件;拉张应力场是本构造区的主驱动力。

MECHANISM OF FORMATION OF THE SALT-DOME STRUCTURES IN ZHONG-YUAN OIL FIELD OF NORTH CHINA

This paper discusses certain problems related to the mechanism of formation of the salt-dome structures and listric normal fault in Zhong-Yuan oil field, North China. In order to explain such mechanism, we have conducted a series of modelling tests related to tectonic phenomena of salt-dome and listric normal fault. The experimental results indicate that formation of salt-dome was controlled by mechanical and physical properties of rock, vertical displacement boundary condition of the basement, and tensile stress field. In our modelling, it has been observed that the development of listric normal fault usually varies with depth. During formation and evolution of salt-dome and listric normal fault, they are subjected from regional tensile, derived from the inplate movement or that between block and plate combined with the shear-tensile stress from the upward gravity gliding of the rock salt formation.