【摘要】 柴达木盆地南翼山油田中浅层油藏具有异常低压、常压和异常高压并存的特征。针对南翼山油田中浅层压力分布特征,从封存箱流体性质和封闭性入手,结合压力预测和封存箱空间展布特征,剖析南翼山油田的中浅层流体压力封存箱组构模式,阐明南翼山油田浅层流体压力封存箱特征。研究表明,南翼山油田中浅层油藏封闭性良好,原油油质轻、黏度低、饱和烃m(∑nC21-)/m(∑nC22+)值反映出较好的封闭条件。从预测压力系数和实测压力系数连井剖面可以看出,南翼山油田中浅层异常低压和常压-弱异常高压封存箱具有垂向叠置、顺层分布的特征,异常低压封存箱中由于差异充注,造成断层附近出现局部异常高压带。封存箱组构模式为:底板为具有毛细管压力和异常压力双重封闭机制的上干柴沟组烃源岩;顶板为上油砂山组咸化沉积的夹膏盐岩层的泥岩和泥灰岩;具有侧向封堵作用的逆冲断层面、岩相和储集层物性渐变为封存箱的边板。更多还原

【Abstract】 The middle-shallow reservoir of Nanyishan oilfield in Qaidam basin is characterized by the coexistence of abnormal low pressure, normal pressure and weak abnormal overpressure. Aiming at the characteristics, this paper presents the constitutive model and feature for the fluid pressure compartment of such a reservoir in this area. The study shows good reservoir sealing ability in the reservoir, which is also reflected by its light crude oil, low viscosity, saturated hydrocarbon value of m(ΣnC21-)/m(ΣnC22+). It is suggested from the multi-well section with predicted and measured pressure coefficients that the abnormal low pressure and normal pressure-weak abnormal overpressure fluid compartment is characterized by vertical superimposition and along-bedding distribution, where local abnormal overpressure belt occurs near the faults due to differential fluid charging in the abnormal low pressure compartment. The constitutive model for the compartment is as follows: the bottom is the Upper Ganchaigou source rocks with capillary pressure and abnormal pressure dual sealing mechanism; the top is the Upper Youshashan formation with saline sediments of shale and marl interbedded with gypsum layers; while the edge is shaped by the gradual changes into such a compartment from thrust fault interface with lateral sealing, rock facies and reservoir physical properties.更多还原