Quantitative Study on Sealing Ability of Ultra—Pressure Caprock

According to theory of low-velocity seepage and the true information of ultra-pressure caprock of the first section in Nenjiang group in Songliao Basin, the essence factor forming ultra-pressure in caprock is discussed in this paper, it is adsorption resistance of capillary for water in caprock. It has been confirmed that the sealing ability of the ultra-pressure of caprock is equal to twice as much as ultra-pressure value of fluid in the pore of caprock, the total sealing ability of ultra-pressure caprock is equal to the sum of displacement pressure and twice ultra-pressure value of caprock. The forming time of ultra-pressure caprock, effectiveness of ultra-pressure caporock for sealing hydrocarbon and evaluating method are researched, and take the regional caprock of the first section in Nenjiang group to the east of Daqing placantiline in Songliao Basin as example, the effectiveness that the ultra-pressure caprock seals the oil and gas coming from the source rock of Qingshankou group is studied, the significance of ultra-pressure caprock for to protect hydrocarbons is generally discussed.