Enhancement of Liquid Flow Through a Porous Medium by Ultrasonic Radiation

Abstract

A new method to enhance the oil production rate is irradiation of the near-wellbore region by an ultrasonic source. The limited success for the application of ultrasound in well stimulation to date, however, is due to the lack of understanding of the physical mechanisms between an acoustic wave field and a porous medium. In this paper the mechanism in which ultrasonic radiation deforms the walls of the pores in the shape of travelling transversal waves, is studied. A quantitative description of the mechanism indicates that these waves induce a net flow of the liquid inside the pores, identical to peristaltic transport. Numerical calculations show a damping effect of liquid compressibility and a strong influence of pore wall hardness and power output on the net flow rate induced. The occurrence of a flow induced by ultrasound has been confirmed by laboratory experiments. In these experiments a water velocity of almost 1 cm/s through a rubber capillary of 0.15 mm radius could be induced by an ultrasonic source of frequency of 20 kHz. By a comparison between the trends observed in the experiments and the theoretically predicted trends, the role of the peristaltic transport mechanism in acoustic well stimulation is discussed. P. 239

Experimental study of ultrasonic radiation on growth kinetic of asphaltene aggregation and deposition

“…(mole fraction) 0.0172 iC 4 (mole fraction) 0.0070 nC 4 (mole fraction) 0.0265 iC 5 (mole fraction) 0.0179 nC 5 (mole fraction) 0.0179 C 6 (mole fraction) 0.0927 C 7 (mole fraction) 0.0752 C 8 (mole fraction) 0.0919 C 9 (mole fraction) 0.0740 C 10 (mole fraction) 0.0557 C 11 (mole fraction) 0.0466…”

“…[7][8][9] Over the past decades, the ultrasound method as an economical and environmentally friendly technology has attracted much interest for prevention and treatment of small deposits in the wellbore, production facilities, and near wellbore region. [10][11][12][13][14] Recently, ultrasonic waves have been introduced as a useful method for enhancing oil/heavy-oil production, crude oil upgrading, and prevention or removal of asphaltene deposits from the wellbore and near wellbore region. [13,[15][16][17][18][19][20][21] In the following part, the most relevant studies on application of ultrasonic waves in oil industry are presented.…”

“…Later, Aarts et al investigated the effect of ultrasonic radiation on the enhancement of liquid flow in the porous medium. [10] In 2000, Roberts et al [8] carried out a study to determine the role of using ultrasonic energy in formation damage reduction. Their results demonstrated that ultrasonic cleaning may be a viable method for treating paraffin problems in the nearwellbore region.…”

Study on frequency optimization and mechanism of ultrasonic waves assisting water flooding in low-permeability reservoirs

“…For instance, the ultrasonic wave is able to effectively reduce the viscosity of heavy oil through aquathermolysis reaction, but such effect becomes pale in the light oil stored in low-permeability reservoirs due to the low viscosity in its nature [28] , [29] . Recently, the ultrasonic wave has also been proved to change the relative permeability of oil in low-permeability reservoirs [30] , [31] , [16] , [32] , [33] , [34] , [35] . In addition, with high energies, the ultrasonic waves may also change the microstructure of cores [36] .…”

Effect of Ultrasound on Rate of Flow through Porous Media

“…Reddi and Challa 5) and Reddi and Wu 6) reported that ultrasonic waves can increase not only the mobility of liquid ganglia but the porosity of the soil as well, resulting in a decrease in viscosity and buoyant pressure. Aarts et al 7) studied the mechanism of induced net flow by ultrasound. Poesio et al 8,9) found that ultrasound has a significant effect on the pressure gradient and temperature of core samples at constant liquid flow rate.…”