The Process Of Structure-sedimentary And Their Correlation Of The Cambrian Peroid In The Central Uplift Belt, Tarim Basin

There are thick dolomites in the Lower Cambrian series in the Central Uplift Belt, Tarim basin, and dolomites develop secondary porosity, such as pore,fracture,hole, so dolomites can be high quality reservoir; There are thick plaster stone and salt rock in the Middle Cambrian series, and plaster stone and salt rock can be high quality cap rock; In addition, Tarim basin is rich in high quality carbonate source rock, and three conditions form good allocation about source rock, reservoir and cap rock, which make dolomites below salt rock have good exploration potential.Based on the theory and method of structure geology, through the systemic analysis on seismic data, the author research on characteristic of structure geometry and kinematics, and its dynamics mechanism; Then, have the research on sediment feature and distribution of sedimentary facies based on the theory of the correlation between structure and sedimentation; Finally, evaluate and analyze forming condition of reservoir and cap rock developing in different sedimentary facies, and make some conclusion such as:(1)There are a series of half-grabens in the Lower-Middle Cambrian Series in the Central Uplift Belt, and they are lie in Bachu uplift and the southwestern area of Tazhong uplift, their strike is NW-SE, and the trend is NE-SW.(2) Based on the particular basement, tectonic movements, for example extension and compression are the main factors of forming half-graben. The high tape of residual gravity anomaly is accord with the distribution of half-graben, the strike of magnetic anomaly and half-graben is concordant.(3)The half-graben controls directly the sedimentary of the Low-Middle Cambrian. The lagoon in the half-graben deposits dolomite plaster stone and plaster stone; The downslope in the half-graben deposits plaster stone and salt rock interbedded; The top in the half-graben deposits red salt rock and mud stone. On the basis of analyzing lithology and thickness of rock, evaluate the cap rock of the Middle Cambrian: The lagoon is distributed area of thick bed cap rock, the downslope isdistributed area of medium bed cap rock, and the top is distributed area of thin bed cap rock, All of them can seal off hydrocarbon effectively.(4)There deposits lime- dolostone,dolostone,plaster dolomite and salt dolomite from the deep water to shallow water in the half-graben. Be based on the analysis on the diagenesis, tectonic movement and denudation, the author evaluates the carbonate reservoir: lime- dolostone developing in the lagoon of the half-graben is the best reservoir, then plaster dolomite and dolostone developing in the downslope of the half-graben is the better reservoir, and salt dolomite developing in the top of the half-graben is the medium reservoir.