oa Review Of Using Acoustic And Seismic Waves For Stimulation Of Oil Reservoirs: Methods And Results

Numerous observations, accumulated during the development of various oil fields<br>show that seismic waves generated from earthquakes and even traffic noise may affect oil<br>production. Elastic waves are observed to exert an influence on the permeability of the<br>saturated porous medium. In some cases application of waves may appreciably increase<br>the permeability of reservoirs and the mobility of oil. The effect of elastic waves on the<br>permeability of saturated media has been confirmed in numerous laboratory experiments.<br>Two different kinds of applications have arisen from these findings. In the first, highpower<br>ultrasonic waves are applied for downhole cleaning of scales, precipitants, mud<br>penetration, etc. in the near well-bore. In many cases ultrasound effectively removes the<br>barriers to oil flow into the well. The ultrasonic method is reported to be successful in<br>40-50% of the cases studied. In the case of successful treatment, the effect of improved<br>permeability may last for several months. However, this method has a very local effect.<br>A second method is used to stimulate the reservoir as a whole. Here seismic frequency<br>waves are applied at the earth surface by arrays of Vibroseis-type sources. This method<br>has produced promising results; however, further testing and understanding of the<br>mechanisms is necessary. An advantage of using elastic waves for stimulation of oil and<br>gas reservoirs is the ecological safety of this method.