The Novel Compensated Sector Cement Bond Logging Technology and Application

The eight-sector cement bond logging tool is an effective logging technique to evaluate the quality of cement bond, which can identify the local deficiencies in the radial direction of the cement bond and the all-round cement bond status of the casing circumference. However, with the increase in the number of deep petroleum exploration and high-angle wells, the cement bond logging tool faces the problem of inaccurate scaling due to the response deviation of the excitation and reception transducers under high-temperature and high-pressure (HPHT) environment, as well as the impact of distortion of acoustic amplitude signal measurement caused by the eccentricity of the instrument. A compensation sector cement bond logging technology is proposed to address the problems faced by existing instruments. An excitation transducer has been innovatively added to the other end of the traditional eight sector cement bond logging tool. The acoustic signals emitted by two sets of excitation transducers pass through the bonding layer and are respectively received by 8 sectors of the receiving transducer. The proposed method in this paper eliminates the differences between transducers in high-temperature and high-pressure environments, and reduces the impact of eccentricity on the instrument, which calculating the acoustic amplitude attenuation of each sector through compensation measurement. The actual logging data show that the compensated sector cement bond logging technology can solve the influence of acoustic amplitude attenuation value errors caused by the factors of tool eccentricity and HPHT environment. The bonding situation of the cement sheath-casing interface is accurately displayed.