Study On Geological Modeling Of Upper Guantao Formation In South Part Of Chengdao Oilfield

With a complex oil-water system, a strong heterogeneity and an obvious contradiction between layers after waterflooding, the Upper Guantao Formation in the southern Chengdao field faces many problems. Establishing three-dimensional geological model is of high precision, it is necessary to establish the idea of model are as follows: first, using core, drilling and logging data with seismic information for fine stratigraphic correlation and studying the structural features, thus setting up the 3D structural model of the reservoir. Second, through rock texture, sedimentary structure, sedimentary rhythm and electrofacies to analyze sedimentary environment, then further classify the microfacies by studying the single well facies of core well. The deterministic reservoir modeling can be used to establish the sedimentary facies model of the reservoir and analyze the microfacies distribution in the plane. Third, to reinterpret reservoir parameters as porosity, permeability and oil saturation by reinterpretation of logging, and establishing the reservoir parameter models under the control of microfacies, as well as studying the distribution of these parameters in space.Several achievements have been obtained as follows: (1) the geological model of the upper member of Guantao formation in Chengdao oilfield is set up on the basis of geological data, well logging data and seismic data, which ensures the accuracy of the model;(2) According to core analysis as well as well logging data, the upper member of Guantao formation is divided and correlated as 7 sand sets and 32 layers in total, and a 3D structural model is established by studying the structure with a well-seismic unified method;(3) The facies marks indicate that the sedimentary type of the studying layers is fluvial facies, and the types of its sedimentary microfacies are divided, in addition, analyses about single-well facies of sealed coring wells and profile facies of some sections are carried out. By studying the sand body distributing character, the plain distribution information of sedimentary facies is gotten, and the sedimentary microfacies model is set up by determinable modeling method. (4) The lithofacies model of the survey region is set up with sequential indicator simulation method. (5) The reservoir parameter model is set up with the stochastic modeling technology under the control of sedimentary microfacies model, which gets a consistence between the distribution of reservoir attributes and sedimentary microfacies of the corresponding sand body.