【摘要】 相比于常规储层,缝洞型油藏灰岩储具有集体结构复杂、缝洞尺度差异大、裂缝起主要沟通作用等特点,使用常规方法研究其流动特性和流体分布规律异常困难.该文采用自行研制的核磁共振（NMR）在线驱替装置对塔河奥陶系油藏15块致密基质灰岩岩芯进行了压力敏感性实验,获得了高压及流动状态下岩芯的横向弛豫时间（T₂）谱变化情况.在此基础上分析了灰岩在压敏实验过程中微裂缝尺寸、孔隙度及渗透率的变化规律,并与常规测试分析结果进行了对比.结果表明:NMR在线检测技术可以定量测量岩芯孔隙及微裂缝的变化,为岩芯渗透率变化规律提供微观解释.更多还原

【Abstract】 Compared to the conventional reservoirs, karstic carbonate reservoir has more complex structure, larger difference in the size of fracture cavity, and the property that the fracture functioning mainly as a way for communication. It is difficult to study flow characteristics and distribution in karstic carbonate reservoir with the conventional methods. In this paper, we had built an on-line NMR instrument to test the stress sensitivity of 15 Tahe Oilfield tight matrix limestone cores. The T₂ spectrum was measured at each stage. On the basis of the T₂ spectra measured, the pore size, porosity and permeability changes of the limestone rocks were determined. It was shown that the on-line NMR measurement technology can be employed in the laboratory tests to provide microscopic information on the changes of core permeability.更多还原