辽河盆地荣兴屯地区中生界火山岩储集性能研究

RESERVOIR PROPERTIES OF MESOZOIC VOLCANIC ROCKS IN RONGXINGTUN REGION, LIAOHE BASIN

运用火山岩岩石薄片、铸体薄片、扫描电镜、孔、渗及压汞分析等多种分析测试手段研究了辽河盆地荣兴屯地区中生界火山岩储集性能 ,认为 :(1)火山岩储集空间以次生孔缝为主 ,原生孔缝大多已被充填 ;(2 )孔喉狭窄 ,平均连通孔喉半径一般在 0 .10 0～ 0 .5 0 0 μm左右 .孔喉分布主要有单峰型和平峰型两种 ;(3)孔隙组合类型有微裂缝型、微裂缝 -孔隙型和孔隙型 3种 ,并以前两种类型为主 ;(4)孔隙度值在 1.0 %～ 16 .3%之间 ,渗透率在 0 .0 12× 10 -3 ～12× 10 -3 μm2 ,属低孔特低渗储集层 ;(5 )储层非均质性强 ,渗透率级差为 10 0 0 ,突进系数为12 .41,变异系数为 2 .3.根据上述特点提出了火山岩储集层划分方案 ;(6 )由于孔 /喉比值较小 ,火山岩储集层的压汞退出效率较高 ,平均达 47.9% 。

The testing methods, such as the volcanic rock thin section, the casting thin section, the scanning electron microscope and the porosity, permeability and mercury injection, are used in this paper to make researches into the reservoir properties of the Mesozoic volcanic rocks in the Rongxingtun region, Liaohe basin. The research results are used to draw the following six conclusions: (1) The reservoir space of the volcanic rocks is mainly composed of secondary pores, while the primary pores are often filled. (2) The pore throats are narrow, with the mean radium of an open pore ranging between 0.100-0.500?μm. The pore throats are distributed in the following two patterns: mono_peak and flat peak. (3) The major three pore assembly types are shown below: microfissure, microfissure_pore and pore, and are dominated by the first two types. (4) The porosity varies between 1.0%-16.3%, and the permeability between 0.012×10 -3 -12×10 -3 ?μm 2. In this case, this reservoir is featured by the low porosity and the super_low permeability. (5) The reservoir is characterized by strong heterogeneity, low permeability gradation: 1?000, abrupt injection coefficient: 12.41 and variation coefficient: 2.3. The features mentioned above have been used to make a plan to classify the volcanic rock reservoirs. (6) Because of the relatively low ratio between pore and throat, the seceding efficiency of the volcanic rock reservoirs is relatively high, whose average value reaches 47.9%, showing the potential of a high oil and gas productivity.