Elastic Exploiting Experimental Study of Filled Limestone Cave

摘要

Limestone cave is a kind of important oil and gas reservoir space in the Tahe oilfield, which is one of relatively simple reservoir types. In this paper, experimental simulation study of elastic exploiting in the filled large-scale cave reservoir is conducted. Physical model and mathematical model are established. Experimental researches at different filling degree, different matrix permeability, and different production are carried on. The experiments use a simulation method of single rate, thus overcome the impact of too fast current speed induced by no backpressure at the end of the core. The results show that: for filled cave model, oil production rate mainly impacts the pressure difference between the bottom of stuff and the inside of cave. The filler permeability mainly impacts the speed of energy recharge rate inside the cave. Cumulative pressure drop has a linear relationship with accumulate flow rate in the cave. Current speed and flow conductivity have less significant influence at the unit pressure difference liquid producing capacity. The unit pressure difference liquid producing capacity is mainly affected by filling degree. Through the elastic exploiting simulation of filled cave, the pressure variation regular in the filler and cave is obtained. Thus it provides a supplementary basis for the control of production rate and the supplement of reservoir energy at production practice in oilfield.