Present Research Status of the Deep Fluid and Their Effectiveness on Oil/Gas Generation
Based on the isotopic characteristics of the deep fluid that entered into the basin, two different kinds of style can be recognized. Under the high oxygen fugacity condition, the fluid is composed of CO2+H2O (rich CO2 fluid); under the low oxygen fugacity, the fluid is composed of CH4+H2+H2O (rich H2 fluid). The formation of hydrocarbon from organic matter degradation is a lacking hydrogen process; the H2 rich fluid can compensate the hydrogen in this process, and increase the production rate of hydrocarbon. The CO2 rich fluid can rebuild the pore space forming a mixed pore network composed of both original and derived pores and improving the physical properties of the reservoir.