Abstract: As the key target for oil and gas exploration and development in the Yingqiong Basin, the Miocene reservoir rocks are deeply buried in offshore blocks and have rarely been cored. Consequently, insufficient research has been implemented on their mechanical parameters. In this study, full-waveform acoustic logging curves are used to calculate the rock mechanical parameters of Miocene reservoir rocks. Specifically, whole-rock mineral analysis, physical property analysis, and mercury intrusion
experiments are conducted to identify the key factors that influence the rock mechanical parameters. The Miocene reservoir rocks
feature a Young’s modulus range of 20-50 GPa, a Poisson’s ratio range of 0.1-0.35, an internal friction angle range of 20°-35°,
and a tensile strength range of 5-30 MPa. Laterally, heterogeneity of mechanical parameters is seen in the same layer. Vertically, these mechanical parameters present a weak positive correlation with the burial depth. Four factors are demonstrated to be crucial for rock mechanical parameters, namely rock porosity, clay mineral content, brittle mineral content, and pore radius. The results of this study provide reliable basic data for the simulation of insitu stress field, evaluation of reservoir fractures, and optimization of the target fracturing scheme. Moreover, the results of this study provide a theoretical basis for evaluation of geological and rock mechanical parameters of deeply buried reservoirs.

Key words: rock mechanical, parameters, deep rock, main controlling factors, Yingqiong Basin, log interpretation