It causes some reduction in reflection velocity owing to Shaximiao Formation contains oil and gas, which makes the Formation is without a determination velocity demarcation line with mudstone.

• 文章通过野外露头、岩心观察描述,结合钻井测试等综合研究,指出沙溪庙组储层属低孔低渗储层,储层非均质性较强,测井响应具有低伽马、高时差特征。