Ordos Basin Extending Leader 7 Accumulation Control Factors Analysis, And The Evaluation Of The Target

Base on the previous study of sediment source in Chang7, With the mathematical geological statistics method,the article analysis and identify the deposition zone parent rocks on study of light and heavy mineral typomorphic characteristics.Through the detailes anatomy of the reservoir sand body, Chang7reservoir of genetic types of sand bodies are mainly Delta the leading edge of the underwater distributary channel, mouth bar sand body, stacked underwater distributary channel sand body and delta front gravity flow form slump turbidite sand body, sandy debris flow sand. With the research on the reservoir characteristics of Chang7formation, Chang7is defined as ultra low permeability reservoir and its physical property is relatively poor. And corrosion pores, pore throat distribution, sorting, the most favorable diagenetic facies cementation-microporous particle Kong Chengyan phase, dissolution and solution pore porous into rock phase. Chang7reservoir can be further evaluated into five types.the first type reservoir is the best of the Chang7sandstone reservoir. The type of Ⅱa、 II b is the main reservoir. fluid inclusion study indicate that the main accumulation period in Chang7is the early Cretaceous and continuous charging characteristics.Stages of hydrocarbon generation and expulsion antiquities restoration table In Late Cretaceous Chang7better reservoir properties, is advantageous to the oil and gas migration and accumulation; reservoir type for lithologic reservoir. The excellent source rock distribution control the distribution of oil and gas. A good reservoir space is supported by the widespread distribution of sandy debris flow sand body、turbidite sand body and delta-front underwater distributary channel sand body. Abnormal pressure for Chang7reservoir is the mainly transport power. There are a lot of crack、microcrack is the important pathways of oil and gas migration. Combine the research results and Chang7exploration, we find the three next favorable exploration target area in Heshui-Ningxian and so on.