Investigation of Liquid Movement Affected by Underground Faults and Fracture Distribution

摘要

In carbonate rock area, the movement of underground liquid is very complicated and is difficult to predict. According to the well data of petroleum exploration in Lunnan area, liquid movement is affected by the distribution of underground fracture and faults, which become the major concern of liquid movement investigation. In Ordovician of Lunnan area, the depth of fracture is 5000m. Moreover, during geological evolution, the distribution of fracture is controlled by many factors, such as depth, temperature, confining pressure, tectonic movement, etc. Core analysis show that rock cracked within 200m below the surface of Ordovician. The deeper it was, less fracture developed. Also, the distribution of fracture along layer is complicated, and four types of fractures are discovered. Parameters of model are determined, distribution of fractures are investigated by numerical simulation of cracking probability. According to the results, liquid distribution is predicted, and liquid movement is analyzed. Compared with the results of liquid test in wells, it is found that liquid moved through faults and accumulated to fracture areas. Faults are channel-ways of liquid movement and high fracture probability areas near faults are favorite areas for liquid accumulation. This method can be applied to other carbonate rock areas, especially, those with violent faults activity. Finally, some conclusions are drawn and some advice is proposed on liquid movement investigation in carbonate area.