Principle: Based on Rayleigh scattering to capture acoustic signals along the wellbore. Application: DAS is used to detect and locate leaks, monitor cement integrity, and identify mechanical issues within the well. Vertical seismic profiling (VSP) using DAS An initial test DAS-VSP survey using the permanent sensor cables installed at Ketzin had revealed that superior data quality can be achieved with sensor cables cemented in place compared to other installation methods (Daley et al. Based on this, a. Maintaining well integrity is a critical aspect of safe, efficient, and economically viable oil and gas production. In oil drilling, well logging is.