疏松砂岩油藏出砂机理物理模拟研究

Physical Simulation of Sanding Production Mechanisms in Unconsolidated Sandstone Reservoirs

利用玻璃板填砂平面模型,在室内对地层出砂进行了实验研究,分析了疏松砂岩油藏出砂机理,并对影响地层出砂的非均质性、粘度、渗透率和流体渗流速度等因素进行了分析.结果表明,大孔道的形成是一个在主流线上分枝发展的“灾变”过程.在临界出砂速度以上,随流速的增加,出砂速度迅速增大;胶结强度越高,出砂量和出砂速度越小;在相同的渗流速度下,渗透率越大,出砂量越小;随着原油粘度的增加,出砂量增加.出砂量的变化表明,胶结程度和水力冲刷是影响油层出砂的重要因素.大孔道一旦形成,油井含水率增加,油藏的采收率降低36%.

The sand-packed glass plate model is adapted The effects of sanding production are investigated to study the sanding production mechanism. through the research of formation sanding production in laboratory. The factors influencing heterogeneity, mobilization, permeability and the fluid velocity are analyzed. The experiment results show that macroscopic throats forming is a ＂catastrophic＂ process in main stream line. Above a critical sand producing velocity, with the increment of the flow velocity, sand producing velocity increases quickly, and cementation intension is much higher, the content and velocity of sand producing is smaller than before. Under the same percolation flow velocity, the content of sand producing is smaller with the bigger permeability. The content of sand producing increases with the increasement of crude oil viscosity. The variety of a sand producing content manifestation proves that cementation intension and the hydraulic sand washing are important factors which affect formation sanding production. The macroscopic throats in formations once forms, water cut in oil well increases, and oil recovery reduces by 36 percent.