EVALUATION OF JURASSIC RESERVOIR STRUCTURE AND TRAP IN SANQUAN UPLIFT BASED ON FINE SEISMIC INTERPRETATION

The Jurassic in the Sanquan bulge of Luliang Oilfield, Junggar Basin, China is rich in oil and gas resources. However, the area is located in a desert area and its geological features are very complex. Therefore, the use of seismic data for reservoir prediction is an effective method. In this study, the three-dimensional seismic data system was used to carry out the fine fault characterization, structural interpretation, reservoir characterization and trap evaluation of the Jurassic strata. The research results show that the use of coherent horizontal slices can effectively realize fault recognition. The fault system of the Sanquan Uplift can be subdivided into two groups, one group is in NE-SW direction, the other group is in NW-SE direction. The study area is dominated by normal faults, which can be subdivided into two stages, the first stage is the early Yanshanian fault, and the other is the middle-late Yanshanian fault. The structural interpretation results show that different provenance sources of the Jurassic Toutunhe Formation have different seismic response characteristics. The source in the northwest direction shows a poorly continuous medium-weak reflection in the seismic axis, while the north-east source shows a superimposed feature and a moderately strong reflection with good continuity in the seismic axis. The argillaceous barrier zone between the two provenances showed blank reflection characteristics. According to regional seismic and geological fine interpretation, sedimentary reservoir research and reservoir profile analysis, we found that the Jurassic trap types are mainly: (1) Toutunhe Formation lithological traps developed on the perimeter; (2) The fault block, nose or fault anticline traps developed on the anticline belt of the Jurassic Xishanyao Formation. Finally, we identified the anticlines and fault anticlines traps in the Toutunhe Formation and the fault block traps in the Xishanyao Formation.