更新－２
中文
所以用水基泥浆取出的岩心，对储层内共存水饱和度不能给出可靠的估算。
另一方面，用油基泥浆取心，对于那些含有不流动的共存水的油层，则可以确切的估算它的共存水饱和度。
其它用天然气洗井取心的方法，也是一种得到油层水饱和度的可靠方法。
用天然气作取心液时，岩样内所含的水分在天然气中汽化的数量一般是不明显的。
另外，还有一种称之为蒸发法的技术，曾有人建议用它来确定储层的共存水饱和度。
此法只限用于水湿岩石，而且在此情况下确定的也不是共存水饱和度，而是在水还不会流动时最大的水饱和度。
在进行室内的相对渗透率试验时，储层的共存水饱和度的大小是很重要的。
室内实验指出，对优先油湿的岩心，只要其存水饱和度小于20%的孔隙体积，那么共存水饱和度对相对渗透率是没有影响的。
对优先水湿的岩石，共存水饱和度则对测出的水油相对渗透率特性是有决定性影响。
因此，对这些亲水岩样，在实验开始时的间隙水饱和度应设法接近于储层的共存水饱和度。
英文
Cores cut with water-base mud cannot give a reliable estimate of the reservoir connate water saturation.
On the other hand, cores cut with an oil filtrate mud can give an accurate estimate of connate water saturation for those formation containing immobile connate water.
Another reliable technique for obtaining reservoir water saturations utilizes gas-cut cores.
Any evaporation of water contained in the core sample by the gas is generally insignificant.
Another technique, termed the evaporation method, has been proposed for determining the reservoir connate water saturation
This method is limited to water-wet rocks, however, and even in this case determine not the connate saturation but the maximum saturation at which water flow does not occur.
In performing meaningful laboratory relative permeability tests, the magnitude of the reservoir connate water saturation is important.
Laboratory experience has shown that the connate water saturation in preferentially oil-wet cores has no effect on the relative permeabilities as long as the connate saturation is less than about 20 percent PV.
In preferentially water-wet rock, the initial water saturation has a definite effect upon the measured water-oil relative permeability characteristics.
Therefore, in these rocks the interstitial water saturation at the start of testing should closely approximate the reservoir connate water saturation.
