The Paleogene Stratigraphic Framework And Distribution Of Sand Bodies In Changdi-Kendong Area Of Shengli Sea Area

Changdi-Kendong area is located in the copulae of Jiyang Depression and Tan-Lu fault zone, connecting through Kendong fault, Gudong fault and Wuhaozhuang fault with Zhanhua sag in the west, reaching Zhuangxi buried hill zone in the north, bordering Kendong 12 faults in the south and gently inclining to Zhuangdong sag in the east. A large buried hill drape structure nearly NW trending is formed by the northern slope of Kendong buried hill, Gudong buried hill drape structure and Changdi buried hill drape structure in different sequences. There are a great many of source sags along its perimeter that make for oil and gas formation and accumulation. Meanwhile, well developed faults, fragmented stratums and the complex structure in this section are serious constraints to the gas and oil exploration and development in this work area. Based on the seismic data, logging data, drilling and calling data, the research makes division on the palaeogene stratums of Changdi-Kendong area, conducts relevant studies on the provenance system and sedimentary system on this basis and concludes that the palaeogene system of Changdi-Kendong area is characterized by the time-spatial revolution of the coexistence of multiple sources, inheritance and development.Under the guidance of sequence stratigraphy theories and on the basis of the seismic and logging data, the palaeogene system in the research area is divided into 2 second order sequence(equivalent to lower Es3 – lower Es2 and upper Es2 – Dongying Formation) and is further divided into 6 third order sequence(sequence I – sequence VI).The analysis of provenance system and paleocurrent direction are performed based on the type distrubution characteristics of debris, lithology and lithofacies change, rock compositional maturity index and diplog. The analysis indicates that in Es3 and Es2 sedimentary period, Changdi low uplift and Kendong western uplift are primary provenances while Gudong uplift is secondary provenances; in Es1 sedimentary period, Kendong western uplift is primary provenance while Gudong uplift is speculative proverence; in Dongying Formation sedimentary period, the primary provenance is located in the northern part of Kendong uplift.Under the control of sequence stratigraphic framework and provenance system, the sedimentary facies symbols in the research zone are systematically summarized that Shahejie Formation mainly developed sedimentary facies including fan delta, beach bar, turbidite fan and shore shallow lake, while Dongying Formation in the north of Kendong mainly developed fan delta and shore shallow lake sedimentary facies from such aspects as petrologic features, grain structure features, sedimentary structure, fossil specimens and geochemical characteristics.On the basis of the comprehensive study on the sequence stratigraphic framework, provenance analysis and sedimentary facies type research, the distribution characteristics of various sedimentary facies in different sedimentary periods are studied and a sedimentary model is ultimately developed through employing the research idea of “point – line – surface”, conducting the core facies analysis, section facies analysis, glutenite percentage composition analysis and referring to mudstone color zoning map.