Читать книгу Acoustic and Vibrational Enhanced Oil Recovery - George V. Chilingar - Страница 17

In the classic book on wettability, Donaldson and Alam (2013) [13] pointed out that Earth tides activate the motion of fluids by continued expansion and contraction as simple harmonic oscillation resulting from diurnal tides. This effect was much greater earlier in geologic history because the moon was much closer to the Earth. Currently, the moon is moving away from the Earth at ≈3 cm/yr. Thus, the Earth tides were more rapid and energetic, resulting in greater dilation and the compression of rocks. According to Donaldson and Alam, in a 10-m-thick reservoir, with a radius of 100 m, an elastic change of porosity of 0.1% will result in an oscillatory motion of 294 bbl of fluid. Such motions could reduce the oil saturation to zero over geologic time, leaving only a trace amount of oil behind.