Study On Hydrodynamic Force Of Representative Sedimentary Phenomena Of S?15+16 Unit In Saertu Oil Field

The dissertation begin with the sequence stratigraphy of S ? 15+16 unit in Saertu oil field, explicit the distribution of sediment microfacies of the small layers of S? 15+16a and S?15+16b. Then, the space-time pattern of sedimentary facies is concluded. The paper study the paleogeomorphology. At firt recover the paleogeomorphology, then discuss the domination for the sedimentation. The most important part is the sedimentary hydrodynamic cause of formation of the representative sedimentary phenomena.The paper includes the the following aspects at the base of preliminary work.1. The paleogeomorphology control the distribution of microfacies of shallow-water delta. The paleogeomorphology is recovered before the study of microfacies of shallow-water delta. There are many methods of recovering for paleogeomorphology. For example, the method of the strata thickness, recovering of denudation quantity, the decompaction correction, the paleo-water-depth correction. The paper recover the paleogeomorphology according to sequence stratigraphy principle. The lithology of shallow-water is fine, the lithology focus on fine sandstone, siltstone, nudstone. The compaction parameters of sandstone is different from that of mudstone. So the paper applys the hierarchy compaction method, and it is ideal for the paleogeomorphology before sediment of small layers. In the paleo-water-depth correction, it is used the experential means.2. Shallow-water delta inner front is made of bifurcate channnel pattern. The single channel has the characteristic of meander river. The unique hydrodynamic condition of the conjunction of single channel and multiple channels form the special sediment construction. The paper is based on the present theory. The subaquatic distribution channel has its distinct depositional envirenment. Split-flow system and converge-flow system are both controled by hydrodynamic force. So the subaquatic distribution channel can be divided into fractions.3. There are wedgelike sand bodys along subaquatic distributary channel. The top and bottom of the wedgelike sand body is mudstone. It is different in geomorphology, lithology and microfacies from the subsea natural barrier. But they all restrict the channel, so it is called subsea natural barrier type wedgelike sandbody.4. Through the plans and profiles of porosity of SII 15+16b, the physical property of erosion pit is better than other sand bodys in subaquatic distribuatry channel. And it is the same conclusion by the analysis of the permeability model. All is concluded that the physical property is better in hydrodynamic strong area of the underwater distributary channel.