Crack-containing core model shock tube stoneley wave experiment method

Abstract

The invention discloses a crack-containing rock core model shock tube stoneley wave experiment method. The experiment method comprises the following steps: S100, preparing a crack-containing rock core model, and determining a crack inclination angle; S200, performing stoneley wave measurement on the crack-containing rock core model by using a shock tube, and changing the relative position of the crack and a sound pressure measurement point to obtain sound pressure values at different measurement point positions so as to establish a sound pressure change diagram of sound pressure along with the change of the measurement point positions; S300, determining the position of a crack center in the sound pressure change diagram; S400, determining the position of an attenuation starting point before the stoneley wave passes through the crack and the position of an attenuation ending point after the stoneley wave passes through the crack in the sound pressure change diagram; and S500, according to the sound pressure corresponding to the attenuation starting point position and the attenuation ending point position, calculating the relative attenuation amplitude before and after the stoneley wave passes through the crack.

Description

technical field [0001] The invention belongs to the field of oil and gas exploration and development, and in particular relates to a Stoneley wave experiment method for a rock core model shock tube containing fractures. Background technique [0002] In carbonate rock, volcanic rock, and tight clastic rock reservoirs, the matrix permeability is often very low, and various fractures play a leading role in oil and gas flow. Therefore, accurate identification and evaluation of fractures is of great importance for oil and gas exploration in complex reservoirs. Significance. The parameters of fracture evaluation mainly include fracture density, dip angle and width. It is relatively easy to calculate fracture density and dip angle by using imaging logging, but it is difficult to accurately obtain fracture width, which is also one of the main challenges in logging reservoir evaluation at present. . [0003] The wellbore Stoneley wave passes through the fractured reservoir, and the...

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Problems solved by technology

In addition, in the Stoneley wave experiment of the fractured shock tube, due to the acoustic reflection of different fracture interfaces, the Stoneley wave does not attenuate monotonously along the direction of Stoneley wave propagation (from the top surface of the core to the bottom surface of the core). Yes, Stoneley waves fluctuate in local positions, which brings great difficulties to the experiment

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