Research About The Sedimentary Characteristics Of The Dongying Formation In The Shallow Sea Of Shengli Oil Field

Chengdao oil field in Shengli sea area is one of the most important oil gas accumulation zones of Shengli oil field(SNP), meanwhile Dongying formation is a main oil zone of Chengdao eastern slope with significant explosion improvement in current. Mainly based on principles of sedimentology, along with the seismic data, logging data, drilling and core data, this research makes comprehensive analysis on the sedimentary system of Dongying formation of Chengdao oil field in Shengli sea area. Specifically in this research, the main aiming positions of sand group Ed IV are fine deconstructed, the sedimentary system and sedimentary facies types are determined, the control factors of reservoirs is critically analyzed, furthermore, based on these preparations, the prediction of favorable reservoirs is made with geophysical methods.The sedimentary type of Dongying formation of Chengdao eastern slope has diversity. According to the characteristics of petrology, granularity, sedimentary tectonics, electrofacies and seismic facies, this paper indicates that the facies type of sublacustrine fan, fan-delta, braided river delta and slump turbidite deposits are mainly developed in this area. Furthermore, through point-line-plane analysis, this paper gives critical analysis on the single wall facies, section facies and plane facies of research area, the portrait evolution pattern of Dongying formation id determined, which is specifically, from Ed V+VI poor sand half deep-whole deep lake facies to Ed III rich sand braided river delta facies, then sand-dirt mixed Ed I+II fluvial facies. based on the sedimentary characteristics of verified sedimentary facies types developed in Chengdao eastern slope and analysis on its distribution pattern, combining with the analysis of sedimentary control factors, the sedimentary model of slope break in Chengdao area is built as slope break belt + cleugh controlled.After the sedimentary system and characteristics is determined, this paper analyzes the control mechanism of ancient landform, provenance and base level onto the growth of sand group Ed IV reservoir. It is particularly pointed that under the control of cleughes, due to the injection of river stream, channel turbidite fans are widely grown on the sand group Ed IV in the lacustrine transgress period. This paper also researched on the influences of sedimentary, diagenesis and tectonic movement on to reservoir physical property. At last, according to the sedimentary pattern, this paper gives deep analysis onto the earth physical character istics of favorable sand body; the favorable reservoir is also described precisely with the technology of natural gamma deduction.The achievement of research in this paper is applied on the practical explosion of Shengli Oil field, four exploratory wells are allocated with the guidance of this research, and significant economic benefit is successfully achieved.