EFFECT OF LGNEOUS ROCKS ON OIL-GAS ACCUMULATION IN THE EASTERN LINQING DEPRESSION

A massive volcanic activity prevailed in Meso-Cenozoic in the eastern Linqing Depression, due to the tectonic rifting caused by plate subduction in the Yanshan and Himalayan periods in the eastern part of North China. In this paper, drilling and geophysical data are collected to calibrate and describe the igneous rocks, and to define the distribution pattern of different layers of igneous rocks. The relationship between the igneous rocks and oil-gas accumulation is also discussed. The results show that the igneous rock is the source of heat which can promote hydrocarbon generation. The vesicular and crevasse developed around the igneous rock can act as the effective reservoir. The igneous rock intrusion and eruption, which pierced the sedimentary cover, can provide channel for oil and gas migration, and igneous rocks can become a regional cap to prevent oil-gas escape to form traps under certain conditions. However, the superposition of the multiphase heat will damage oil-gas structures and reservoir properties on other side.