| Popis: |
Yammama formation of Lower Cretaceous period in Southern Iraq deposited massive bioclastic limestone of carbonate ramp, in which the mound-shoal complex (MSC) is the dominant reservoir contributor. Seismic attributes expression and the sedimentary evolution analysis can be used to better understand the deposition and distribution of the MSC. We summarized the seismic response characters of bioclastic limestone by analyzing seismic amplitude, phase etc., and then realized the seismic attributes expression of the MSC in the bioclastic limestone by multi-attribute blending and 3D visualization etc., revealing its stratigraphic sequence and sedimentary evolution. The MSC is characterized as high porosity as well as high permeability, resulting in low velocity, low density and low acoustic impedance in rock properties, and local strong reflections in seismic responses. The distribution of the MSC is mainly located at structure-high with periodic deposition on both wings of the anticline. This paper indicates that the MSC, the dominant reservoir of Yammama bioclastic limestone in the Lower Cretaceous period, is mainly controlled by micro-facies, and formed in the carbonate ramp of shallow water, which can deepens the understanding of its seismic attributes expression, spatial distribution as well as the sedimentary evolution. |
