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

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 μm². 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.