Re-discussion on the reservoir formation by pressure-suck filling

The dominant water consumption reaction in sandstones was figured out by determining variables in the mineral alteration in sandstone reservoirs, on this basis, the conditions of major water consumption reaction and its correspondence with oil-generating window were analyzed to reveal the petroleum geological significance of water consumption reaction. The kaolinitization of feldspar plays a dominant role in the water consumption reaction during diagenetic stage, which corresponds to the hydrocarbon-generating window, and the acid hydrocarbon-bearing fluid produced by source rocks facilitates the kaolinitization reaction. Water consumption causes the pressure drop and porosity increase in the reservoir formation in the compartment sandstone, at the same time, huge pressure difference between source rocks and reservoirs comes about because strong pressure built up in the source rocks owing to hydrocarbon generation, and the oil and gas are pushed and sucked into the reservoir sands. The universality of the kaolinitization water consumption suggests this “pressure-suck” mode is very important for reservoir formation. This mode of the Jiyang depression can be used to explain the origin of similar reservoirs across the world, and guide exploration for oil and gas.