鄂西渝东JZ1井志留系致密砂岩气层解释

四川盆地天然气资源丰富,是中国石化强力推进的五大增储上产区块之一。随着勘探工作的深入,在盆地东部鄂西渝东区,已有井在志留系非常规致密砂岩层中钻遇天然气显示,并获工业气流。其中JZ1井进入志留系后,发现多套非常规致密气层,完井后对其中显示最好的一层进行压裂改造获得了稳定工业产能。通过对JZ1井产气致密砂岩层研究后认为,气层基岩孔隙度低、渗透性差,但由于致密砂岩储层横向展布稳定,在地层裂缝较发育的区域布井开发,能够获得一定规模的非常规天然气产量。

Interpretation of Tight Sandstone Gas Reservoirs of Silurian System of Well-JZ1 in Western Hubei and Eastern Chongqing

Because of its rich reserves of natural gas, Sichuan Basin has been promoted by SINOPEC as one of the five blocks with great potentials of increasing production and reserves. As the exploration pushes on, detecting equip- ment has already spotted readings of natural gas and industrial gas flow has been captured during the drilling of un- conventional tight sandstones of silurian system in the eastern part of the basin stretching from the west of Hubei to the east of Chongqing. During the drilling of well No. JZ1 in particular, a large number of unconventional tight gas reservoirs were discovered and a stable output was obtained through fracturing transforms of the one reservoir with the richest reserve after the well was completed. The studies on the tight sandstone that contributes to the gas pro- duction of well No. JZ1 find out that the layer has low porosity and poor permeability in bedrocks but reservoirs＂ sta- ble horizontal expansion makes it possible to extract fairly large amount of unconventional natural gas in the districts with developed fractures.