CHARACTERISTICS OF MESOZOIC VOLCANIC RESERVOIR ROCKS AND THEIR MAIN CONTROLLING FACTORS IN THE CENTRAL BOHAI SEA

Based on the latest data from drilling cores, thin sections and tests of physical properties, the characteristics of the Mesozoic volcanic reservoir spaces and their controlling factors in the Central Bohai Sea area are studied in this paper. The results suggest that: The volcanic reservoir space in the study area includes primary pores, dissolution pores and fractures, among which dissolution pores and structural fractures dominate; Volcanic rock facies, fault activity and weathering process jointly control the formation of high-quality volcanic reservoirs, and the outburst facies zone near-crater is the one with best reservoir physical properties. The fractures formed by the continuous activity of large faults are one of the key factors to the formation of high-quality reservoirs, while the long-term weathering and leaching make the reservoirs further improved in physical properties. The risk of oil and gas exploration in volcanic rocks can be effectively reduced if drilling is made in the craters near fault zone.