Experimental Study Of Acoustic Blocking Removal

In the oil field development, reservoir plug is an important factor leading to well productivity decline, which seriously restricts and affects oil field development. Acoustic plugging removel technology has some field application effect though, but mostly experimental conditions limit the research in-depth. Through indoor experiments, this paper further studied permeability changes and the sound wave attenuation after the sound waves treating with different parameters under different permeability. In our laboratory, usable sonic band is wide, and acoustic frequency band is from 0.8 KHz to 135KHz. We polluted the core of different permeability segment with drilling fluid and removeled the pullution using acoustic waves of different frequency, and we also studied the factors of sound intensity, treating time and the initial permeability on the effect of law of core plug removal. Finally we studied the acoustic attenuation law in water, coarse sand and fine sand with saturated water. The results of the study show that with acoustic frequency increasing, first the core direct recovery rate and pollution recovery rate increase, then decrease, and there exists an optimal Acoustic blocking removal frequency. The optimal frequency. is 28KHz for the core of 30×10~-3μm~2 and core of 600×10~-3μm~2, and the optimal frequency. is 1.2KHz for the core of 1500×10~-3μm~2.The effects of treating time on Acoustic blocking removal are significant,and the optimal duration is 30min in our experiments The acoustic power(sound intensity) is bigger, the Acoustic blocking removal is better.The Acoustic attenuation coefficient is very small in the water but it is big in coarse sand and fine sand with saturated water. The acoustic power(sound intensity) is bigger, the sound attenuation is larger, and the Particle size has little influence on it.