General ideas to explain the hydrocarbon distribution, considering different scales and kinds of reservoir compartmentalization. The structural approach has always been very important in Talara Basin. The tectonics, of course, plays a very important role in determining the first-order reservoir compartmentalization. However, for secondary recovery projects, Sedimentology and Stratigraphy begin to increase in importance--in characterizing smaller-scale heterogeneities. In any case, the integration of these three disciplines is vital for better models that aim to incorporate different scales of reservoir heterogeneities.