Reliability assessment of ultra-deep oil and gas wellbore casing using data statistics and numerical simulations

Ultra-deep oil and gas wells have become a new development trend in onshore exploitation. However, wellbore casing is with high failure risk due to the harsh environment. It essential evaluate reliability of casing. This paper assesses operational using data statistics numerical simulation. Firstly, theoretical model for analysis established, variables are determined, including rock mechanics, cement ring, string strength factors. Subsequently, considering random distribution variables, many analyses performed determine parameters variables. Eventually, Monte Carlo based simulations carried out obtain residual The production ultra-deep well depth 6.5 km China as an industrial case used illustrate present study. observed that this study can be useful guide more accurate assessment