HuanJiang Oilfield Chang8Reservoir Evaluation And Potential Area Prediction

HuanJiang oilfield began to explore in1967. Since2003, 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 Chang8reservoir’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, Chang8reservoir is delta depositional system. The main source direction is Northeast, Northwest and Southwest. The sand body distribution of the two small layer Chang81and Chang82is strictly controlled by sedimentary facies;(2) Study area Chang8reservoir’s rock style is Lithic feldspathic 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, in reference to the Changqing oilfield reservoir evaluation standards, 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) Predict9favorable areas, inculuding2class I areas,4class II areas and3class III areas. Totaling Chang82prediction area31.85km2, predict reserves8,208,100tons. Chang81prediction area116.59km2, predict reserves25,849,700tons. Provide the geological basis for the future development of the HuanJiang oilfield.