ISSN: 0149-6115
Page Count: 12

Ultrasonic Method for Evaluation of Annular Seals for Wells and Instrument Holes

Yesiller, N
Assistant professor,Wayne State University,MI,

Edil, TB
Professor and associate professor,University of Wisconsin,WI,

Benson, CH
Professor and associate professor,University of Wisconsin,WI,

Abstract

An ultrasonic testing method employing the pulse-echo inspection technique was developed to assess the integrity of annular seals surrounding casings (i.e., instrument tubes or well casings). This nondestructive testing method permits testing a seal from inside a casing without disturbing the casing, seal, or formation. Seals constructed with cement-based and bentonite-based sealants surrounding various types and sizes of casings can be evaluated using the method. An evaluation is conducted by sending and receiving ultrasonic waves using a single piezoelectric transducer and commercially available hardware (a pulser receiver and a waveform analyzer). A probe was designed and constructed for downhole testing. Differences in the ultrasonic responses of the materials in contact with a casing are analyzed to determine the presence of different materials (seal or defects filled with air or water in a seal) outside a casing.

Keywords:
annular seals, well seals, instrument boreholes, ultrasonic method, nondestructive testing, cement, bentonite, casing, cross contamination

Paper ID: GTJ11417J
DOI: 10.1520/GTJ11417J
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