Gas prediction through the LMR method using post-stack inversion and multi-attributes, F3 cube, North Sea, Netherlands

摘要

Shallow gas can be considered as an indication of deep hydrocarbon reserves. In addition, if shallow gas accumulation is large enough, it could be considered a commercial gas field. Therefore, it can be an exploration tool, although it can be hazardous when positioning the platform at seabed or when drilling a borehole. In order to reduce the risk of shallow gas hazards, bright spot analysis has to be done. Bright spots are one of the direct hydrocarbon indicators (DHI) indicating the presence of gas. Bright spot analysis especially for gas sand is used to differentiate between false bright spot and bright spot. In order to delineate lateral variation of the seismic features of interest, post-stack attributes as envelope and RMS amplitude have significant results. Moreover, Lambda-Rho and Mu-Rho cubes are created using multi-attributes after applying post-stack inversion on 3D seismic data to predict the presence of gas. Since P-impedance inversion is sensitive to lithology, fluid, and porosity, it is difficult to discriminate each effect from the others and the results will be ambiguous. In order to reduce this ambiguity, facilitating and enhancing reservoir details using seismic inversion, therefore, the Lambda-Mu-Rho (LMR) method will be used to reduce the interpretation ambiguity as Mu-Rho is sensitive to lithology (matrix) and Lambda-Rho is sensitive to the fluid.