AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Aggradational Slope Channel Complexes: An Important Reservoir Element in Pliocene in the Rakhine Basin, Offshore Myanmar
(1) Hangzhou Research Institute of Petroleum Geology, Hangzhou, China.
Aggradational slope channel complex is one kind of deepwater slope channel complexes which are the most important sedimentary architecture elements in Pliocene in Rakhine Basin. This study is carried out under the guidance of the relationship between the seismic response and deepwater reservoir. The strong amplitude attributes on 2D and 3D seismic data are applied to deduce coarse sediments existing in slope channel complexes. Technologies that include analysis of seismic reflected configuration, extracting amplitude attribute, coherence slice analysis, geoanomaly processing and 3D visualization are used for distinguishing aggradational slope channel complexes from background. Many detailed descriptions, involving the external shape, the nature of internal fill, and reservoir characters are executed.
Observed aggradational slope channel complexes are located in the downslope restricted portion of confined slope channel systems where the erosional ability of slope channel weakens and isolated channels forms. This study revealed that aggradational channel complexes are richer in reservoir than erosional confined channel complexes and erosional/aggradational confined channel complexes. Various sand-rich sub-environments, such as sandy channel complex axis, inside levee deposits that change in several kilometers in an aggradational confined channel complex, can be identified. Sands on channel complex axis connected with sandy inside levee deposits. The lateral accretion packages on convex bank are associated to continuous lateral migration during channel evolution. Three aggradational confined channel complexes that individual sand body with an area exceeds 100 sq km, range from 7km to 16km in the down-current direction and usually no more than 10km in width, are detected in Pliocene in Rakhine Basin. They comprised by 3 to5 layers vertically and connected with one another, mean accumulative thickness are bigger than 30m. Results suggest that aggradational slope channel complexes might be High-rate, high-ultimate-recovery reservoirs and be considered as one of the most favorable targets in the Rakhine Basin.