库车坳陷异常高压流体充注成因分析与预测

GENESIS ANALYSIS OF THE OVERPRESSURE CAUSED BY FLUIDS CHARGE IN KUCHE DEPRESSION

通过分析流体充注增压所需要的地质条件(包括源岩排烃与储层封闭的时间配置、源岩与储层的空间配置、沟通源岩与储层的疏导体系以及流体充注动力等条件),证实了流体充注可对库车坳陷中生界储层增压。通过比较范德瓦耳斯非理想气体热力学方程、Redlich-Kwong状态方程、理想气体方程的摩尔数密度—压力曲线和实际摩尔数密度—压力状态,得到了100℃地层条件下实用的流体充注增压公式;利用该实用公式估算了对克拉2封存箱进行流体充注后的实际增压量,证实了流体充注对库车坳陷中生界储层超压具有较大贡献,据此认为流体充注是库车坳陷中生界储层异常高压形成的主要因素之一。

After the necessary conditions for pressure increase by fluids charge were considered, it was proved that the Mesozoic reservoir in Kuche depression have the necessary conditions to increase its pressure by fluids charging. These necessary conditions are the collocation of gas generation and fluid compartment sealed in period, the collocations of the source rock and reservoir layers in space, the drainage system connecting the source and reservoir and the dynamics of charge. Through the comparison of the mole density-pressure curves of Van der Waals, Redlich-Kwong and ideal gas thermodynamics state equation, a practical equation for pressure increasing was established. Use this equation to estimate the mole amount of the charged fluids in Kela 2 department, the result suggested that fluids charge has made a great contribution for the overpressure of the Mesozoic reservoir. The conclusion was that the fluids charge is one of the main factors for pressure increasing of the Mesozoic reservoir in Kuche depression.