| Summary: | Reservoir rock mechanics plays a key role in oil and gas field development. The relationship between lithology, temperature, fluid and confining pressure and the mechanical properties of sandstone reservoirs and the influence mechanism of each factor were discussed using rock mechanics tests, X-ray diffraction, cast thin section and scanning electron microscopy analyses of core samples from the Funing Formation in the Jinhu Sag of Subei Basin. Lithology is a decisive factor for the mechanical properties of sandstones, which are related to particle size, quartz content, clay mineral content, particle contact and cement content. The influence of temperature on the mechanical properties of sandstones is segmented. At 25-100 ℃, minerals expand and contract, while interlayer water escapes. At 100-180 ℃, thermal cracking is dominant. As the oil-water ratio decreases, the mechanical parameters of sandstones change regularly, and the weakening of sandstone strength is related to pore fluid pressure, partial saturation and chemical effects. Artificial measures in oilfield development have a significant impact on the mechanical properties of sandstone reservoirs, and attention should be paid on sand production prediction and wellbore stability analysis.
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