Study Of Sedimentary Characteristics And Favorable Zones Prediction Of Shahejie Formation In Shulu West Slop

Shulu west slop is located in the southern edge of Jizhong depression and it is a west slop of Shulu sag which is a typical half garben with big fault in the east. The resources conversion of Shulu west slop is low and the exploration potential is high. The pre-research target was mainly focused on the structural trap, hence, it is significant to carry on researches on subtle traps for making a breakthrough in the petroleum exploration in Shulu west slop.On the basis of observation and description of core, combining the analysis of the regional geologic settings, applying the principle and methodology of high-resolution sequence stratigraphy, reservoir sedimentology, petroleum geology and both using the geology and geophysics then, following the research path of point(well) -line(profile) -plane(planar map) -tract(temporal evolution and special distribution)- point(potential sand bodies), the depositional system’s planar distribution and formation-lithological trap were studied and the potential zones were predicated in this thesis.The achievements of this thesis are as follows,1. For the depositional features of fault basin slop, the Shahejie formation was divided into two second-order sequence and six third-order sequence by the application of the high-resolution sequence stratigraphy and recognition of the Shahejie formation sequence boundary. Based on the third-order sequence, the formation has the features of western high and eastern low, southern steep and northern gentle.2. By the recognition of core, log and seismic data, the depositional system of Sahejie formation was delta-lacustrine system. The depositional system was fan delta-lacustrine system during the third member of Shahejie formation deposited and it changed to braided delta-lacustrine system during the the second and first member of Shahejie formation deposited.3. According to the break of slop, Shulu west slop was divided into two parts, the outer zone and the inner zone. The stratigraphic traps and stratigraphic-lithologic traps mainly developed in the outer zone while the lithologic traps and structural traps mainly developed in the inner zone.4. The distribution of Shulu west slop stratigraphic-lithologic traps has features of multiple layers distribution in vertical and traps connected together in plane. The main control factors for formation-lithological trap were unconformity, sedimentary facies and fault. The mixed traps were controlled by the multi factors.5. According to the controlling factors, the distribution of source rock and migration path, the hydrocarbon in the slop accumulated in the structural traps of inner zone in the first place, so the structural traps were the zones which have high enrichment of hydrocarbon. While the stratigraphic traps and lithologic traps like unconformity zones and fan delta sand body were the zones for hydrocarbon enrichment and they were the potential zones for the future exploration and development.By the research of depositional system and stratigraphic-lithological traps in Shulu west slop, the sedimentary facies, plane distribution and vertical evolvement features were analyzed, the trap features were summarized and the potential zones were predicted. The next step of progressive exploration and development direction was pointed out.