火山岩储层启动压力梯度影响因素研究

火山岩储层做为我国重要的勘探目标和油气储量的增长点,对其渗流特征进行研究具有重要意义。以实验为手段,具体地研究了火山岩储层启动压力梯度的影响因素。研究表明,在脆性较大、裂缝较发育的火山岩储层中启动压力梯度相对较小;火山岩储层的渗透率越低,启动压力梯度越大;无论岩性如何,火山岩储层的启动压力梯度都随束缚水饱和度的增加而增大;对同一块岩芯,含水饱和度越高,启动压力梯度值越大。综合而言,裂缝不发达,束缚水饱和度较高的火山岩储层中,由于渗透率较低,如果含水饱和度较高,则会产生较高的启动压力梯度,从而大大降低生产井的产能。鉴于启动压力梯度对渗流机理的影响,研究工作必将对火山岩油气藏的开发产生普遍的积极意义。

STUDY ON INFLUENTIAL FACTORS OF THRESHOLD PRESSURE GRADIENT IN VOLCANIC RESERVOIR

As the main exploration targets and the important source for oil and gas reserves,it is of great importance to study fluid flow in volcanic reservoir. Through experiments, this paper specifically studies the influential factors of threshold pressure gradient. Study shows, threshold pressure gradient is smaller in reservoirs with more fractures; the lower the permeability, the higher the threshold pressure gradient; no matter what the lithologic character is, threshold pressure gradient goes the same with irreducible water saturation; for the same core, the higher the water saturation, the bigger the threshold pressure gradient. In all, for reservoir with higher irreducible water saturation and fewer fractures, due to the lower permeability, if they have high water saturation, they will correspondingly have high threshold pressure gradient, and this will largely reduce the productivity of production wells. In view of the influence of threshold pressure gradient on flow mechanism, this study will definitely has a universial, positive and significant role in volcanic reservoir development.