板桥凝析油气藏水锁伤害实验研究

EXPERIMENT RESEARCH ON WATER LOCKING INJURY IN BANQIAO CONDENSATE OIL-GAS RESERVOIR

低渗透特低渗透油藏普遍存在着水锁损害,而且渗透率越低,水锁伤害越严重。采用来自大港板桥油田的岩样,通过水锁效应对岩样渗透率影响的实验研究证实了水锁效应是导致板桥凝析油气藏损害的主要因素之一。通过实验,认为气水对岩层润湿性的差异、孔喉细小造成较大的毛管压力以及束缚水饱和度与原始含水饱和度间差别较大是造成水锁效应的主要原因。在此基础上,定量评价了水锁程度,并给出了水锁伤害的预防原则。

Water locking damage exists generally in low permeability oil reservoir, and lower permeability, water locking damage is more severe. Through the experiment research on the influence of water locking effect on rock sample permeability by adopting the rock sample of Banqiao, Dagang oilfield, it verifies water locking effect is one of the main injured factors in Banqiao condensate oil-gas reservoir, the main reasons which caused water locking are the difference of gas and water to terrane wettability, small pore throat causing larger capillary pressure and a larger difference between irreducible water saturation and original water saturation. And then the degree of water locks is evaluated quantitatively and the prevention principles of water locking injury are given.