The Relationship between the Time Difference of Formation Water Infiltration Rate, Tectonic Movement, and the Formation Pressure Coefficient

Abstract

The study of formation pressure holds great significance for both exploration and development. The formation pressure coefficient is a crucial parameter in geology, encompassing various aspects. Numerous models exist to explore its influencing factors, yet they remain highly controversial. Our research has gathered data on formation pressure states and tectonic movement rates from dozens of large sedimentary basins worldwide. We delved into the patterns of formation pressure changes during basin deposition, subsidence, and tectonic uplift, taking into account the permeability of formation water. The findings reveal that during the Neogene and beyond, rapid deposition or tectonic uplift can cause the infiltration of formation water to lag behind tectonic movements, resulting in overpressure. Conversely, if recent tectonic movements are slow, formation water will complete its infiltration process ahead of tectonic changes, bringing the formation pressure to a hydrostatic state. Consequently, we have concluded that abnormal formation pressure primarily depends on the rate of tectonic movements during the Neogene and Quaternary periods. This study also proposes four formation pressure models, paving the way for a comprehensive understanding of formation pressure within a unified theoretical framework.