复杂岩性气藏自吸水能力及特征实验研究

Experimental study on the water absorption ability and characters of complex lithologic gas reservoir

柴达木盆地某地区基岩层和E1+2层储层见水速度快,为研究该地区气藏的水锁伤害机理,本文采用室内岩心实验,对该地区复杂岩心水的自吸能力及特征进行了研究,研究结果表明:(1)水与储层岩心接触会自发的进入,刚开始接触时吸水速度较快,随着时间的推移,吸水速度逐渐降低;(2)渗透率相对高的岩心刚开始自吸速度呈直线上升,而到后期几乎不吸水;而渗透率低的岩心自吸水速度一直很慢,前后变化不大,能够持续长时间的吸水;(3)该地区储层吸水能力极强,通过自吸水可以达到高的含水饱和度,从而造成强水锁,因此自吸水是该地区气藏水锁伤害的主要原因之一。

The speed of water breakthrough in bedrock and E1 ＋2layers in the area of Chaidamu basin is high,in order to analyze the water blocking in this kind of reservoir,through the methods of in-house core flow experiment to analyze the water absorption ability and characters of complex lithologic core.The experimental results show that（1）water will spontaneously flow into when contact with the reservoir core,in the beginning, the rate of absorbing water is fast, with the passage of time, the rate is gradually reduced.（2）For the relatively high permeability core,self-absorption rate in a straight line up at first,but to late almost no water absorption. Low permeability core self-priming rate has been very slow, there have little change between before and after,water can be sustained for a long time.（3）The area of the reservoir water absorption ability is extremely strong, can reach high water saturation and cause strong water lock through water absorption,so the water absorption is one of the main causes of gas reservoir water locking damage in the region.