Comprehensive Research On Ji Yuan Oilfield Chang 9 Reservoir Characteristics

Ji Yuan oilfield began to explore in 1970. Since 2003, in the lower part of the Triassic Yanchang reservoir, the exploration obtain a large breakthrough. This paper used the collected geological materials, core data, log data, production performance data and results of previous studies for Chang 9 reservoir`s stratigraphic division and correlation, sedimentary microfacies study, logging data interpretation, reservoir characteristics study and so on. Finally gets the following conclusions.(1) In the study area, Chang 9 reservoir is delta plain depositional system. The main source direction is Northeast and Northwest. The sand body distribution of the four small layer Chang 911、Chang 912、Chang 921 and Chang 922 is strictly controlled by sedimentary facies;(2) Study area Chang 9 reservoir`s rock style is Feldspar lithic sandstone、 Lithic feldspathic sandstone and Feldspar sandstone. Detrital component is mainly quartz and feldspar. Sand grain size is mostly fine, poor sorting and medium psephicity. There are tiny pores developed, pore structure is complex. According to reservoir characteristics, established a unified standard which divide the reservoir into four categories. Most reservoir is class II and III;(3) Using the information of production and oil testing, extracting a variety of geological parameters which were related to production, made the relevant analysis with the oil testing and production information. Use production capacity parameters, the effective thickness and oil saturation method to predict the production. Find out that multiplication- method is better;(4) Predict 17 favorable areas, inculuding 1 class III areas. Totaling Chang 921 prediction area 32.95 km2, Chang 912 prediction area 32.82 km2, Chang 911 prediction area 185.12 km2. Provide the geological basis for the future development of the Ji Yuan oilfield.