Depositional Microfacies Study Of Putaohua Oil Layer In Zhou 13 Block

During the exploration stage, the study of the depositional facies chiefly refers to magnafacies and subfacies. However, in the development stage of oil field, which is after the stage of development well patter, the study of the sedementary facies must be implemented in microfacies. Depositional microfacies is indispensable content for reservoir study, which reflects the formation of the depositional rock with the same depositional conditions and is the base formation unite of depositional system. Moreover, it is also the basis of a single-well and multi-well reservoir evaluation. Depositional microfacies is of great significance to oil field development. It determines the macro-distribution of the reservoir sand body and the seepage barrier and controls the seepage variation of fluid in the reservoir sand body. Therefore, in the development stage of oil field, the depositional microfacies study is very important and indispensable in the geological study.In this research, Zhou 13 block is a newly developed block. Through the study on the division and correlation of reservoir, sedimentary facies, the distribution of sedimentary facies in this block, the further in-depth research work will be carried out. Furthermore, combined with the modern sedimentology, reservoir geology, sequence stratigraphy, petroleum geology as well as well logging geology, the depositional microfacies in-depth study will be improved greatly. Select a well with good curve, entire layers, easily divided and rightful boundary as the hierarchical standard well and divide the deposition unit in the research area. Subdivide original 5 sublayers of Putaohua oil layers into 8 deposition unit. By the correlation method of combining sedimentary cycle correlation, hierarchical control and discriminating different sedimentary facies association, 8 sedimentary units of 733 wells in the research area are finely correlated. The study of sedimentary microfacies is based on the fine division and correlation of sedimentary units. On the basis of the core observation and description, a great number of facies markers such as mudstone color and sedimentary structure are found. According to the various facies markers combined with the depositional background of the study area, sedimentary facies of single well in 5 coring wells are finely analysed and the sorts of the depositional subfacies and microfacies are determined. By applying the principle of the electrofacies, summarize typical logging curve characteristics of the same depositional microfacies and establish electrofacies scheme for various depositional microfacies. According to the electrofacies scheme, electrofacies of each deposition unit of 733 wells are finely recognized, microfacies of each deposition unit are combined in flat and eight depositional units of flat sedimentary microfacies map were drawn up and analysed.It provides a favorable reference for Zhou 13 block to adjust the encryption scheme, aided analyze the distribution of remaining oil, as well as develop quickly.