Log-based fault-fracture reservoir identification and porosity evaluation in Binchang area

A fault-fracture unit, as an irregularly distributed geologic body or unit of scale with cracks associated with folds or faults and pores in rock matrix, turns up in a brittle fracture zone where there are tight sandstones reworked by rupture, leading to improved porosity and permeability. This reservoir type plays a significant role in hydrocarbon accumulation in tight sandstones. To address the challenges of natural fracture identification, reservoir parameter estimation, and high-quality reservoir prediction in Binchang area, the southern Ordos Basin, we use core and log data to investigate the inner structures and log responses of fault-fracture units as well as the relationships between lithologic and petrophysical parameters and spatial crack distribution in fault-fracture reservoirs. We thereby establish the geologic model of fault-fracture reservoirs and the methods for reservoir identification and classification and reservoir parameter evaluation. Automatic reservoir identification, classification, and hierarchical evaluation with high accuracy are implemented using conventional well logs and formation conductivity micro-imaging logs, and fracture parameters are extracted from formation conductivity microimages. The efforts lay a solid foundation for effective reservoir identification and subsequent drilling site deployment and hydraulic fracturing design.