As Tahe fractured-vuggy carbonate reservoir has many fractured-vuggy units

pressure systems and seepage units

its oil-water relation is complex and the water body energy distribution is unbalanced. Therefore

studies on the water intrusion process before water seepage is conducted for the elastic drive unit oil wells in single fracture and single hole reservoir with closed bottom water. There exists a connected water body. The fluid expands elastically in the dissolved hole. As time goes on

the water intrusion is inevitable due to the pressure decay of the reservoir during the mining process and begins at some point. Based on the characteristics of the fracture-cavity reservoir

the intrusion water is considered as the bottom water

and the elastic water flooding continues to supply the insufficient of the formation energy. According to the Poiseuille’s equation

the pressure of the karst cave before water breakthrough and the incremental rate of the cumulative oil production in the dissolved pores both decrease exponentially with time

following the rules of rapid in the early stage and slow down in the later stage. Meanwhile

combining the improved material balance method of reservoir engineering to calculate the water influx during the elastic driving period before water breakthrough. Taking well-TH12523 as an example

water intrusion occurs during its elastic mining stage

and the elasticity and the water body drive together. The actual measured incremental rate of the measured oil production and the karst pressure varied with in the whole mining process are consistent with the dynamic prediction results of the reservoir .