Evaluation And Study On Reservoir Characteristics Of Yan'an Formation About North-eastern Part Of West Block In Mahuangshan Area

Ordos basin is an important industrial base, which is rich in Petroleum, natural gas, uranium and coal. Mahuangshan block which is located in the west middle Tian huan depression in Ordos basin. The study area is an mainly layers for exploration and development for North China Branch of Sinopec rich in sand-body in Yan an formation. However, the factors including sand-body changes quickly, complexity of diagenesis, unclear controlling factors for distribution of favorable reservoir directly affect the exploration and development's effects of oil and gas. So it is necessary for making study for the characteristics and evaluation of reservoir under aforementioned case.Based on summing up and collating the previous studies, combination of advanced technologies and method to carry out scrutiny, this paper takes the drilling analytics, the geophysical well logging, the seismology, the experimental data and the traditional geology method to study the characteristics of Yan an formation by using available exploration and production data in study area. By analyzing of the sedimentary features and features of sand-body distribution for reservoir in Yan an formation, we can divided Yan an formation into fluvial facies and alluvial flat parfacies. There into, the sand-body which have a certain capacity is mainly including the channel bar and alluvial flat deposit. Based on study of petrologic characteristics, properties characteristics and pore structure in Yan an formation, we regard that the lithology of study area is mainly with sub-lithic sandstone and the pore types is mainly with shrink-type, neck type and narrow sheet. Moreover, the study shows that the reservoir property is clearly under the control of composition of reservoir rocks, sedimentary facies, reservoir diagenesis and tectonic activities and so on. The first is lithogenesis during the factors of thin out porosity and permeability, the second is compaction and clay mineral filling. Towards to the good permeability, pore throat development is the most important factors and the next is particular denudation. The paper takes advantage of log data to interpret the formation parameters and study the parameters distribution, and then identify the liquid, draw the reservoir section and talk about feature of oil layer distribution. According to physical property and pore structure, the author got the criterion of reservoir classification and defined 4 container rock. Based on the study of sedimentary facies, reservoir parameters and sand plane distribution, the author comprehensively evaluated the character of Yan-8, Yan-9, Yan-10 reservoir formation for north-eastern part of west block in Mahuangshan area, the study shows thatâ…¡,â…¢type of reservoir is mainly ,â… -type reservoir is only in Ningdong 8 - Dadong 19 - Ningdong 108 wells development zones. Finaly the author pointed out the available up-growth block.