Print this pageAAPG GEO 2010 Middle East
Geoscience Conference & Exhibition
Innovative Geoscience Solutions – Meeting Hydrocarbon Demand in Changing Times
March 7-10, 2010 – Manama, Bahrain
Velocity
Modeling and Static Corrections for Complex near-Surface - from Alternative Solutions to Improve Seismic Imaging in Muglad Basin
(1) Exploration, Petro Energy-E&P. Co.ltd, Khartoum, Sudan.
An important part of statics solution is determination of the velocity and depth of the near-surface layer. This information can be obtained from an uphole survey, Refraction First break methods and sometimes from shallow refraction reciprocal surveys. Uphole surveys provide the most reliable results but the spatial coverage of this method is always limited. Shallow refraction reciprocal surveys are only effective for a certain geological situations. Refraction First break method are recently attractive, but the methods recently used are heavily depend on the refractor data quality.
By using of first breaks picks in a range of given CDPs for apparent velocity and intercept time, the velocity and depth for weathering and near-surface layers can be well estimated based on a local constant layer assumption. By repeating this process for all CDP ranges, a good refine of a 2D/3D velocity model can be built. This method improves refraction statics solution.
This paper will present uses of a reasonable amount of direct arrival and refraction picks data from 2D and 3D Surveys in Muglad Basin to extract the apparent velocity and intercept time from overall behavior of the picks, Replicating this process on multiple locations across the survey, to build an initial velocity depth model to be used in calculating the velocity
and depth of weathering layers accurately as an alternative way to solve one of the main challenges in static correction process.