利用核磁共振测井资料评价致密储层可动水饱和度

NMR Logging Evaluation of Mobile Water Saturation in Tight Reservoir

新场须四段储层岩性较为复杂,包括岩屑砂岩、钙屑砂岩和灰质砾岩,属致密碎屑岩储层,具有复杂的气水关系。针对其储层特征,以岩石弛豫特征和气水弛豫特征为理论基础,对致密碎屑岩储层的气水弛豫特征进行分析。充分利用汞饱和度资料、测试资料,并结合核磁共振岩心实验横向弛豫时间T2分布谱特征,对致密碎屑岩储层复杂岩性的T2气水分布界限值进行标定。形成了粗中砂岩、细粉砂岩、钙屑砂岩、灰质砾岩储层的核磁共振可动水饱和度评价技术。建立了以核磁共振T2气水分布界限为依据的致密碎屑岩储层流体性质判别技术。储层致密化是致密碎屑岩储层气水弛豫分布特征的主要影响因素。

The reservoir of Xingchang T3 X4 is complex in lithology, which contains lithic sand- stone, calcarenaceous sandstone and calcarenitic conglomerate, and pertains to tight clastic reser- voir with complex water-gas relation. Based on the features of rock relaxation and water-gas relaxation, analyzed is the water-gas relaxation of the tight clastic reservoir. With the data of Hg saturation and test values as well as the distribution characteristics of NMR logging transverse-relaxation-time T2 of core testing, demarcated is the T2 value of water-gas contact in the above res- ervoir. Given is the evaluation technique of NMR logging evaluation of movable water saturation in medium-grained sandstone, fine-grained sandstone, calcarenaceous sandstone, as well as calcarenitic conglomerate reservoir. Established is the discrimination technology of fluid property in the tight clastic reservoir on the basis of T2 value of water-gas contact. The compactness characteristic of the tight clastic reservoir has great effect on the distribution of water-gas relaxation. These technologies bring higher coincidence rate which indicates the success of using NMR logging in exploratory development of the tight clastic reservoir.