The relationship between the compressive strength and gravel content of buried hill sandstone in Bozhong depression and the penetration depth of perforating bombs

The buried-hill glutenite reservoirs in the Bozhong sag are characterized by strong heterogeneity and tight lithology, making reservoir reformation challenging. To address this, perforation tests were conducted under simulated complex reservoir pressure conditions to analyze the main factors affecting the perforation depth in glutenite reservoirs. The research results indicate that, under the same conditions, the penetration depth of perforating charge in glutenite is much smaller than in pure sandstone. When the strength of glutenite exceeds 150 MPa, the penetration depth of ultra-deep penetrating perforating charge underground is less than 200 mm, posing a significant challenge to whether current domestic and international perforating charge can effectively penetrate contamination zones. As the gravel content increases, the perforation depth exhibits a decreasing trend. For every 10% increase in gravel content, the average penetration depth decreases by 4.7%, and the rock compressive strength and gravel content are the main factors affecting penetration depth. Due to the tight lithology of the glutenite reservoirs, the rocks themselves are less affected by stress, which poses a minimal impact on the penetration depth of the perforation borehole. The research results provide a valuable guidance for optimizing and designing perforation completion schemes in glutenite reservoirs.