The Study Of Sandbody Distribution Of Taiyuan Formation In Tabamiao Area

Reservoir description is a new technology used for oil or gas field exploration and exploitation which developed from the seventy's, it becomes more and more important in modern time. Sandbody distribution is one aspect of reservoir description. Based on the theories of sedimentary, petroleum geology, reservoir geology, well logging geology, reservoir properties and stochastic modeling method, by analysis of distribution of sedimentary microfacies, characteristic of sandbody distribution and reservoir physical property, favorable blocks are evaluated in Tabamiao area. Results showing: Firstly, the Tabamiao area is located at Yishan slope stripe in the north of Ordos basin, the main compositions of sandstone are coarse sand and gravel, grain separation is good, the types of grain contact are string contact and sagging contact. Secondly, analyzing and exactly describing the cores of Taiyuan formation, according to analysis of the symbols of the sedimentary structure, section framework and log data, it is concluded that Taiyuan formation is a seashore environment with barriers. It has tidal facies in member 1 and has barriers facies, lagoon facies and tidal facies in member 2, planning sedimentary microfacies of both members. Thirdly, By distributing the sandbody in longitudinally and over a section plane, elaborate contrasting the sandstones between wells and studying the connectivity and distribution of sandstone, it shows that sandbody distribution is subjected to sedimentary microfacies. The sandbars in barriers facies have better continuity and thickness than the sandbars in tidal facies on both aspects. Fourthly, by analyzing the relationship betweens container rock genetic model and logging response model in base of sedimentary microfacies, upgrowth characteristics and distribution rules of container rock are concluded, three-dimensional sandstone model which reflect the reservoir characteristic of Taiyuan Formation is upbuilded by use of stochastic modeling method and spline Interpolation. Fifthly, reservoir properties is distributed by use of information of geology, core and logging data, it is shown that distribution of reservoir properties is subjected to sedimentary microfacies. Sixthly, making use of sedimentary microfacies, characteristics of sandbody distribution, reservoir properties distribution and gas test, favorable blocks of Taiyuan Formation are evaluated in Tabamiao area, in order to the next exploration and exploitation.