超压背景下自生石英形成的化学动力学模型

A new kinetic model for authigenic quartz formation under overpressure

为了准确模拟超压背景下自生石英含量随时间的变化规律，以Walderhaug时间一温度双控化学动力学模型为基础，考虑超压对自生石英形成的抑制作用，建立适用于超压背景下自生石英形成的时间．温度．压力多控化学动力学模型，并通过在莺歌海盆地的实际应用验证模型的正确性。莺歌海盆地中央坳陷区新生界石英砂岩中自生石英的形成受到了超压的抑制，通过引入超压抑制因子，建立了适用于超压背景下自生石英形成的化学动力学模型，根据莺歌海盆地石英砂岩中自生石英含量和压力实测资料，确定了超压抑制因子数值，在此基础上实现了对自生石英形成演化史的准确模拟，模拟精度远高于Walderhaug经典模型。模拟结果表明，压力系数为1．7～2．0的超压可使自生石英含量降低2．72％-4．72％，有利于深层超压带优质储集层的发育。

To model the change of authigenic quartz content precisely in geological history, a new kinetic model combining time, temperature and pressure was established considering the retardation of overpressure to the formation of authigenic quartz on the basis of Walderhaug＇s kinetic model including time and temperature. The model was tested to be practically applicable in the Yinggehai Basin. The Cenozoic quartzarenite in the central depression of the inggehai Basin was affected by overpressure during the formation of authigenic quartz. The overpressure inhibiting index was determined based on the measured pressure and authigenic quartz content. The model with overpressure inhibiting index can simulate the evolution of authigenic quarzt much better than Walderhaug＇s model. Overpressure sandstones with a pressure coefficient between 1.7 to 2.0 can cause the total amount of authigenic quartz to drop by 2.72% to 4.72%, which would result in high-quality reservoirs in deep overpressured formation.