esearch on roduction rofile evaluation method for shale gas wells based on distributed Fiber-Optic Temperature Sensing (DTS)

Aiming at the challenge of achieving full-wellbore continuous monitoring and quantitative evaluation of shale gas well production profiles, this study develops an evaluation method based on distributed fiber-optic temperature sensing (DTS). By comprehensively considering the effects of fluid thermal convection in the wellbore, wellbore-formation heat exchange, and the Joule-Thomson effect on wellbore temperature distribution, a forward model of wellbore fluid temperature is established to accurately characterize the depth-dependent temperature distribution of the wellbore. On this basis, with model parameters as inversion variables, a squared error objective function between DTS-measured temperatures and forward-calculated temperatures is constructed, and the Bayesian inversion method is employed to solve the key parameters of the production profile, realizing the quantitative inversion of gas-water two-phase production for each producing layer. Field verification is conducted using an actual shale gas well: results show that the average absolute error between forward-calculated temperatures and DTS-measured temperatures is 0.05°C, indicating a high overall profile agreement; the gas and water two-phase production obtained by inversion is consistent with the on-site production dynamic recognition law, verifying the accuracy and reliability of the proposed method. This research provides effective technical support for the engineering application of DTS technology in production dynamic monitoring and development optimization of shale gas wells.