TY - CONF

T1 - Evaluation of Cement-Casing & Cement-Rock Bond Integrity during Well Operations.

AU - Lamik, Abdelfattah

AU - Thonhauser, Gerhard

AU - Ravi, Krishna

AU - Prohaska-Marchried, Michael

AU - Pittino, Gerhard

AU - Antretter, Thomas

PY - 2021/5/27

Y1 - 2021/5/27

N2 - This paper presents the results of laboratory static and dynamic tests on casing-cement-rock systems exposed to axial loads under ambient conditions. A new testing method has been developed.The casing-cement-rock system mostly fails due to tension and shear stresses. In various applications such as HPHT, deep-water, (steam) injection or geothermal wells, the cement-casing bond is exposed to cyclic thermomechanical loads resulting in casing elongation, contraction, expansion and subsequently in cyclic radial and axial stresses at the cement-casing-rock system. Cement is a brittle material which can fail when subjected to repeated application of stresses lesser in magnitude than the statically determined strength. A novel atmospheric test cell has been designed and constructed. In order to achieve the fatigue limits of the cement-casing bond, a set of testing procedures has been established. Several tests are conducted to evaluate de-bonding. The focus on de-bonding is achieved by allowing the casing to move through the test while preventing any cement movement. Thus, when a force is applied in the axial z-direction - either the casing is pulled out (tension) or pushed down (compression) - the casing has enough space to move in both directions. The advantage of this testing method is that different stress ratios can be applied during the test.

AB - This paper presents the results of laboratory static and dynamic tests on casing-cement-rock systems exposed to axial loads under ambient conditions. A new testing method has been developed.The casing-cement-rock system mostly fails due to tension and shear stresses. In various applications such as HPHT, deep-water, (steam) injection or geothermal wells, the cement-casing bond is exposed to cyclic thermomechanical loads resulting in casing elongation, contraction, expansion and subsequently in cyclic radial and axial stresses at the cement-casing-rock system. Cement is a brittle material which can fail when subjected to repeated application of stresses lesser in magnitude than the statically determined strength. A novel atmospheric test cell has been designed and constructed. In order to achieve the fatigue limits of the cement-casing bond, a set of testing procedures has been established. Several tests are conducted to evaluate de-bonding. The focus on de-bonding is achieved by allowing the casing to move through the test while preventing any cement movement. Thus, when a force is applied in the axial z-direction - either the casing is pulled out (tension) or pushed down (compression) - the casing has enough space to move in both directions. The advantage of this testing method is that different stress ratios can be applied during the test.

KW - cement bond

KW - cycling loading

KW - well integrity

KW - testing cell

KW - Low cycle fatigue

UR - https://doi.org/10.2118/202186-MS

M3 - Paper

SP - 1

EP - 13

ER -