Research on the Sand Body Structure and Interlayer of Fan Delta Front in the Typical Outcrop

The research on the model of internal sand body structure has become a fundamental work of modern reservoir description, which is established by the detailed information measured from the typical outcrop which is similar to... [ view full abstract ]

The research on the model of internal sand body structure has become a fundamental work of modern reservoir description, which is established by the detailed information measured from the typical outcrop which is similar to the reservoir underground, thus to guide the exploration and development effectively. In the guidance of high-resolution sequence stratigraphy and base-level cycle recognition, the cross-sectional configuration of sand under micro-phase scale is established based on the phase sequence features measured in the modeling area. The results show that the sand body structure of underwater distributary channels of fan delta front can be divided into two types which are cutting and additive type of the main channel and additive type of the main channel side edge. The typical characteristics of cutting and additive type is the multi-layer and puzzle-link structure composed by a number of underwater distributary channels sands depositing vertically, representing the sand body configuration of the main waterway zone in the fan delta front distal region. The thickness of the single sand body is 1~5m and the thickness ratio is greater than 20, which connects well with each other in the vertical and horizontal direction. On the whole, the mudstone interlayers are not developed, with a smaller number and thin layer thickness. The structure of additive type performances like multilayer cake, composed by the underwater distributary channel sands deposed vertically and the underwater channel sands or sandbars deposited laterally, on behalf of the main sand body configuration developed in the proximal end of the fan delta front. The thickness of the single sand body is 1~3m and the thickness ratio is greater than 44, with a good lateral continuity. The mudstone interlayers are well developed which performance as a great number, large frequency and vertical density, thinning out significantly in the lateral direction.