Abstract:

Reservoir spaces of the Tertiary volcanic rocks in Oulituozi region, Liaohe Basin are generally developed in trachyte, tufflava, lava, trachydacite, brecciated trachyte, proclastic rocks, brecciated lava and can be divided into two main types. Primary pores include vesicles, inter-crystal pores, inter-breccia pores, cooling joint; the secondary porosity includes solution fissures, voids and structureal fissures. Vesicles and solution pores are the most important pore types in this area which occupy 65%～70% of the total amount of the porosity. Based on the statistics of mercury method and image plane scanning associated with the ratio curves of porosity and permeability, the reservoirs could be divided into four types. Type-Ⅰ and types-Ⅱ are favorable reservoirs. Four evolution stages of the reservoir spaces have been identified in Oulituozi region. Favorable reservoir spaces were mainly formed in the first and second stages.

Key words: Oulituozi region, volcanic rock reservoir, primary porosity, secondary porosity, fissure, evolution stage