| The Su372 region in the Ordos Basin is located in the central and western part of China.It is located in the northern part of the western part of the Sulige gas field in the Ordos Basin.The research area is about 1824km2.According to the collected data,the study shows that the Su372 region is rich in natural gas resources.In terms of reservoir deposition,the predecessors have conducted extensive research on the horizon above the Shanxi Formation,and the research on the Shanxi Formation,especially the Taiyuan Formation,is relatively weak.Therefore,the exploration and development of the deep strata in the Su372 region is very arduous.In view of the significance and existing problems of the above research,this paper takes Su 372 region as the research area,takes Shanxi group and Taiyuan group as the research object,and uses the knowledge of geological basic discipline as the theoretical guidance,using static data such as logging,microflakes and cast thin sections,the sedimentary facies and sand bodies of the Shanxi Formation and the Taiyuan Formation were studied in depth.Combined with the existing stratigraphic division scheme in the Sulige area,based on the characteristics of the electric line curve,based on the comparison of the stratum thickness comparison method and the sedimentary cycle,the Taiyuan component is divided into two sections,Tai 1 and Tai 2;Shanxi Group it is divided into Shan 1 and Shan 2,and Shan 1 and Shan 2 are subdivided into three sub-sections respectively,and closed and contrasted in the whole research area,which laid the foundation for the subsequent research work.Through the analysis and test of reservoir samples,combined with the identification method of thin slice identification,the petrological characteristics,void structure characteristics and physical properties of the reservoirs in the study area are analyzed and summarized.Among them,the porosity of Shanxi group is mainly concentrated between 3.0%and 7.0%,with an average of 5.06%.The permeability is mainly concentrated at 0.001×10-3?m2?0.1×10-3?m2,and the average value is 0.235×10-3?m2;Taiyuan Group Most of the porosity is between3.0%and 8.0%,with an average of 5.06%.The permeability is mainly concentrated at0.005×10-3?m2 to 0.2×10-3?m2,and the average value is 0.13×10-3?m2,which belongs to the dense layer.The drilling facies,logging,earthquake and other data are used to identify the sedimentary facies markings of the target horizon.Based on this,the logging phase,single well phase,plane phase analysis and cross-section phase of the study area are studied.The types of sedimentary facies such as the meandering river and the barrier coast were identified.It was determined that the Shanxi Formation was mainly a continental sedimentary system combining lake delta and river.The Taiyuan Formation was mainly a set of barrier coastal sedimentary systems,and the sedimentary microfacies were detailed analysis.The sand body distribution is controlled by the sedimentary facies.According to the sand body distribution in the study area,the sand body of the Shanxi Formation is controlled by the river sedimentary facies.For the sand body parallel to the river course,there are mainly three large-scale sand belts in the research area.The performance is better;perpendicular to the river course,due to the barrier of the mudstone formation on the river bank,the continuity of the sand is poor,and the thickness variation between wells is also large;the sand body of the Taiyuan Formation is mainly deposited by the barrier sandbar,isolated Output,overall continuity is poor. |
PDF Full Text Request