Evaluation and Development Characteristics of Pore Structure in a Canyon Channel System Controlled by Multiple River Source Inputs: A Case Study in <scp>LDX</scp> Area of the Western South China Sea

ABSTRACT The LDX area in the Yinggehai Basin hosts canyon channel reservoirs in the Huangliu Formation's Second Member, characterised by high temperatures, pressures and multi‐phase fluid influx, complicating pore structure evaluation. An integrated approach combining petrophysical measurements, thin section analysis, mineralogy, electron microscopy, granulometry and well‐log data was used to study compositional and structural impacts on pore networks. Key findings include: (1) Two high‐permeability pore types, linked to large pores and good sorting or strong dissolution; (2) Improved rock volume modelling using RT, DEN and CNL logging enhances calcite correlation and mineral content accuracy; (3) The median particle size ( M ) inversion model based on the classification of particle size sample has high precision, and the sorting coefficient ( S o) is segmentally correlated with M ; (4) The pore structure type recognition model, based on the feature fusion of skeleton knowledge‐driven and diagenetic sensitivity curves by multi‐modal learning, has good continuous recognition ability in well profiles and (5) High‐quality pores dominate thick sandstone at the base, while the middle section is poorer, with some quality pores in the east branch and canyon intersection during the top stage. This study enables continuous pore structure evaluation and summarises development patterns under multi‐source canyon systems, advancing understanding of pore evolution and reservoir impacts in the LDX area.