Characteristics And Controlling Factors Study Of Sandstone Reservoir From Dongying Formation In Liaodong Uplift

In recent years, several large oil-gas fields, such as Jinzhou9-3?Jingxian1-1?Suizhong36-1 and Lvda 6-2, have been found in petroleum exploration and development of Dongying formation in Liaodong bay area, which is one of the most important oil and gas production regions of the Bohai sea. The study area, Liaodong uplift, is located in the eastern area of Liaodong bay. Current research indicates that relatively low exploration degree of study area, such as less drilling, weak geological study and not enough understanding of reservoir characteristics, reservoir types and reservoir controlling factors, have seriously restricted its next exploration.In order to solve the above problems, this study makes full use of core observation, well logging interpretation and the regional sedimentary background information based on the former achievements and it finally figures out Dongying formation are formed in delta and lakes sedimentary environment, which's skeletal sand bodies include debouch bar, underwater distributary channel and branch channel. Furthermore, with the aid of reservoir microscopic research methods such as core analysis, thin sections identification, SEM observation, this study identifies the pore type and pore structure characteristics and analyzes pore throat combination types and pore throat size distribution.Based on the modern testing method, like polarizing microscope, scanning electron microscope, rock pyrolysis, x-ray diffraction, temperature measuring of fluid inclusions and so on, the study has did a detailed research on the petrologic characteristics of reservoir, the types of the diagenesis and characteristics of the diagenesis evolution. It turns out that the main rock types of the reservoirs of Dongying formation are lithic arkose and feldspar lithic sandstone, the compaction and cementation are major factors to destroy the pore reservoir and the dissolution is an important diagenesis in reforming the reservoir physical property. Inaddition, the formation time of reservoir in study area is between early diagenesis B stage and middle diagenesis A stage. The amount of primary pore are controlled by the sedimentation and the transformation of primary pore and the contents of secondary porosity are determined by diagenesis.Based on the study area characteristics of sediment, diagenesis, pore structure, we have got reservoir classification and evaluation. In general, the study area is given priority to?high quality reservoirs, followed by ?medium reservoir, ?poor reservoir and ?class poor reservoir. During the process of reservoir classification evaluation, it is to be found that the reservoir of low second member of Dongying formation is relatively better for its sandstone are thick and corresponding property are high, followed by that of third member of Dongying formation and that of upper second member of Dongying formation.