Baimiao Gas Condensate Wells Anti-condensate Damage Mechanism And Co <sub> 2 </ Sub> Throughput To Lift Anti-condensate Injury Research

In the course of gas condensate reservoir development, with the formation pressure ( or bottom-hole pressure) declined below the dew-point pressure, the retrograde condensation phenomenon will appear. The retrograde oil will condensate from gas and accumulate near the wellbore, which will damage the formation permeability and form the distribution hopper of the formation pressure, retrograde oil saturation and formation permeability, and these three distribution hoppers will strongly affect the development efficiency of the gas condensate reservoir.The paper studies the damage mechanism of the retrograde oil in condensate gas reservoir by experiment, especially considering the effect of slippage effect, fluid absorption, water sensitivity of the rock, imbibition of the liquid on the damage of the formation permeability. And the paper gives out the required pressure gradient of relieving the liquid lock.By establishing the relationship of oil saturation and pressure, the paper deduce the formula of the dynamic contaminative skin factor and the condensate block radii, and evaluate the damage degree of the retrograde oil to the formation. Based on the analyzing of the mechanism that CO2 Huff-Puff relieves retrograde condensation damage, the paper use the single well numerical simulation model to study the feasibility that CO2 Huff-Puff eliminates the damage of the retrograde condensation contamination for baimiao gas condensate reservoirs, especially simulating the effect of difference CO2 injection rate, CO2 injection volume and stew-well hours on relieving the damage of the retrograde condensation contamination for baimiao gas condensation reservoir.