A Downhole Ultrasonic Vibration Cementing System and Its Vibration Cementing Method

Abstract

The invention discloses a downhole ultrasonic vibration cementing system and a vibration cementing method thereof, which belong to the field of oil and gas well engineering. The downhole ultrasonic vibration cementing system includes: a casing string that can be lowered into the preset position of the oil and gas well, a centralizer is installed on the casing string, and a sealing isolation plate is installed on every other casing string of the centralizer, sealing Perlman generators are arranged symmetrically and circularly on the isolation plate; the ultrasonic vibration cementing system uses rubber plugs and displacement fluid to suppress pressure, forcing the rubber plugs to move down, and the displacement fluid squeezes the cement slurry pre-injected into the casing string; The extruded cement slurry flows through the shrinking spray chamber and nozzle of the Pallman generator, causing it to vibrate ultrasonically. The multi-segment Pallman generator can generate long-distance high-frequency vibration, acting on the casing Pipe strings, well walls and cement slurries. The invention has the advantages of simple design, low processing cost, improved vibration effect, cleans the mud cake on the cemented surface, shortens the initial and final setting time, and further improves the cementing quality.

Description

technical field [0001] The invention relates to the field of oil and gas well engineering, in particular to a downhole ultrasonic vibration cementing system and a vibration cementing method thereof. Background technique [0002] Well cementing is one of the most critical parts in oil and gas exploitation engineering. Excellent cementing technology and process can improve the quality of well cementing and prolong the life of oil and gas wells. Vibration can reduce the perfusion voids, remove the mud cake on the cemented surface, strengthen the effect of turbulent flow, suppress the annular air channeling, improve the bonding strength of the cement surface, shorten the gelation time of the cement, reduce or even eliminate the static shear force of the cement slurry, so it can be passed Vibration cementing can effectively improve the cementing quality. However, the existing vibration cementing technology still has the problems of weak vibration intensity and uneven vibration d...

AI Technical Summary

Problems solved by technology

However, the existing vibration cementing technology still has the problems of weak vibration intensity and uneven vibration distribution.

For example, the widely used low-frequency hydraulic pulse vibration cementing tool has low vibration frequency and no significant effect of ultrasonic high-frequency vibration, and is usually installed on the casing string near the bottom of the well. When uploading, it gradually weakens, which makes the vibration intensity in the middle and long distance of the casing weak, which affects the cementing quality

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