Research Of Sedimentary Facies And Reservoir Characteristics Of Lower Shihezi Formation Of Permian In Tongxu Area

South of North China basin is one of the oil and gas exploration potential basin in our country, but has not obtained the breakthrough of the oil and gas exploration, the upper Paleozoic is widely containing coal bearing strata with abundant natural gas resources is the the main oil and gas exploration layer.This paper akes Lower Shihezi Formation in Tongxu area of southern North China Basin as the research object, sedimentary geology and petroleum geology theory as the instruction, through the comprehensive outcrop geological investigation, drilling core observation, thin section identification research, according to the "stratigraphic evolution, sedimentary evolution, reservoir evolution” research ideas, promoting the sedimentary micro facies and the planar distribution characteristics in the system, appraising the target strate, and predicting the favorable areas.The main results and understanding are as follows:1. Through the basic recognition of regional tectonic setting and regional structural characteristics of the southern North China basin, divide and contrast the strata in Tongxu area and research the planar distribution, the Lower Shihezi Formation is divided into 1st member, 2nd member and 3rd member, and study the rules of the plane distribution in the system.2. Based on outcrop observation and drilling core observation, combined with rock color, sedimentary structures, profile structure and so on, Lower Shihezi Formation in Tongxu area can be divided into delta deposition, the subject developing delta plain sedimentary, further identified such sedimentary microfacies, include distributary channel, depressions, natural levee, crevasse splay and peat swamp.3. Based on sedimentary facies analysis, research the planar distribution and vertical characteristics. Research shows that the plane has deposited by the north to the south of the facies distribution characteristics. It mainly develops distributary channel; vertical, large thickness, coarse grain, planar or banded distribution, better continuity.4. Studied the clastic reservoir genesis and reservoir forming factors of the Lower Shihezi Formation. Through the study area's core thin section identification, scanning electron microscope(SEM), pressure mercury data analysis, the reservoir of Lower Shihezi formation is low porosity and low permeability.5. Based on the research of reservoir forming conditions of Lower Shihezi formation in Tongxu area, appraising the target strate, and predicting the favorable areas.