应用核磁共振技术研究吐哈盆地低渗透储层渗流能力

Nuclear magnetic resonance technology in percolation study of low permeability reservoir in Tuha Basin

应用核磁共振等实验技术对低渗透岩心的可动流体饱和度分布进行了定量测试,评价了储层流动能力,建立了可动流体饱和度与孔隙度、渗透率的回归关系,研究了影响储层渗流能力的因素;通过研究全直径岩心不同驱替阶段核磁共振弛豫时间谱的变化规律,探讨了低渗透储层渗流机理。研究表明:各类储层渗流能力差异较大,储层沉积微相、物性及微观孔隙结构决定了渗流能力的大小,注水驱替过程中剩余油主要分布在较小的毛管孔径中。

The technology of nuclear magnetic resonance is used to quantitatively test the distribution of movable fluid saturation in low permeable core, to evaluate the flowability in reservoirs, to establish the regression relationship between movable fluid saturation and porosity and permeability, and to study the influence factors of reservoir percolation ability. The percolation mechanism in low permeable reservoirs is investigated through studying the law of NMR relax time in different displacement stage of full core. The study shows that, the percolation difference in various reservoirs is quite different, the percolation ability depends on sedimentary subfacies, petrophysical property and microscopic pore structure, and residual oil mainly distributes in small capillary pores in waterflooding process. This study may guide the drawing of oilfield adjustment plan.