摘要
By anatomy of 19 gas reservoirs in Xujiaweizi Depression, it was considered that gas cap rocks are mainly K1d2 mudstone cap rocks and tuffite and mudstone cap rocks on top of K1yc1. Relation between reserve abundance and sealing captivity of caprocks in 19 natural gas reservoirs was direct. Through the displacement pressure of cap rocks forecast, it was considered that tuffite and mudstone cap rocks on top of K1yc1 and K1d2 mudstone cap rocks mainly sealed gas reservoirs distribution region with middle reserves abundance, gas reservoirs distribution region with high and low reserves abundance were less, and there were no gas reservoirs distribution region with especially low reserves abundance.