oa Velocity Modeling and Static Corrections for Complex near-Surface - from Alternative Solutions to Improve Seismic Imaging in Muglad Basin

An important part of statics solution is determination of the velocity and depth of the near-surface<br>layer. This information can be obtained from an uphole survey, Refraction First break methods and<br>sometimes from shallow refraction reciprocal surveys. Uphole surveys provide the most reliable results<br>but the spatial coverage of this method is always limited. Shallow refraction reciprocal surveys are only<br>effective for a certain geological situations. Refraction First break method are recently attractive, but<br>the methods recently used are heavily depend on the refractor data quality.<br>By using of first breaks picks in a range of given CDPs for apparent velocity and intercept time, the<br>velocity and depth for weathering and near-surface layers can be well estimated based on a local<br>constant layer assumption. By repeating this process for all CDP ranges, a good refine of a 2D/3D<br>velocity model can be built. This method improves refraction statics solution.<br>This paper will present uses of a reasonable amount of direct arrival and refraction picks data from 2D<br>and 3D Surveys in Muglad Basin to extract the apparent velocity and intercept time from overall<br>behavior of the picks, Replicating this process on multiple locations across the survey, to build an initial<br>velocity depth model to be used in calculating the velocity and depth of weathering layers accurately as<br>an alternative way to solve one of the main challenges in static correction process.