Time and space matching relation among accumulation essential factors of gas reservoirs in volcanic rock and its controlling to gas accumulation: A case study of deep strata of Xujiaweizi region

Abstract

Gas source rock of K1sh, traps of volcanic rock and transport pathway of fault are three main factors that influence Xujianweizi gas reservoirs in volcanic rock. By studying the time and space matching relation of the three factors, we find that traps of volcanic rock can directly contact gas source rock of K1sh, or a distance can exist between gas source rock of K1sh and traps of volcanic rock, however, traps of volcano rock are all connected with gas source rock of K1sh by faults. The time matching relation among gas source rock of K1sh, traps of volcanic rock and faults is the best from the end of K1q to the middle of K1qn, the end of K1n and the end of K2m. It is favorable for gas to accumulate in a large scale. According to the study of relation between time and space distribution of gas reservoirs of volcanic rock, gas source rock area of K1sh, traps of best and better volcanic rock and the distribution of faults spacely controlled the distribution and formation of gas reservoirs of volcano rock. The end of K1q to the middle of K1qn, the end of K1n and the end of K2m are main accumulation periods of gas reservoirs of volcano rock in Xujiaweizi region. The good matching relation among three accumulation essential factors is the basic cause for the formation of large and medium gas fields in volcanic rock.