Geological Modeling Of SZ36-1 Oilfield In Bohai Bay

SZ36-1 oilfield locates in Liaodongwan sea area in Bohai, and it is the biggest offshore oilfield in China. At present, it faces lots of problems, for example, interlamination contradictory is prominent, water cut rate is more and more rapid, and the oil production decline is becoming faster. The aim of reservoir geology modeling for SZ36-1 oilfield is making it clear that how main pay formations and reservoir physical property distribute, at the same time, further describe sandstone distributing regularities in vertical and horizontal direction., make it clear how residual oil distributes, and then provide reliable geologic base for overall system adjustment of the I stage of SZ36-1 oilfield.This research center is building 3D heterogeneous geology modeling, applying with seismic data, wave impedance inversion data, time-to-depth conversion data, well logging interpretation data, geologic correlation research results, microfacies analysis research results, combining with reservoir bed analogy results, outcropping data, referring to oilfield production performance data, making a scrutiny into the reservoir formation, structure, reservoir bed, connected component, oil and water relationship and reserves, etc. Finally, with geology modeling software Petrel, build delicate 3D geologic model. In the course of delicate geologic correlation, we observed that formation thickness becomes thicker and thicker along precipitation facies, so we use cycle comparison combining with formation thickness trend and the combination comparison of well and seismic, and take sub-layer as sedimentation unit (simulation unit), considering characteristic of lake facies delta deposit, sub-layers are delicately compared, using cycle comparison, level control table, combining with the method of equaltime formation frame restraint. In the course of single sand body comparison, we take the compared method of microfacies distribution control according to sand and resistance similarity, fully considering the deposit characteristic of sand body. In the real model building, we take inverting shale content data as constraint condition of deposit micro-facies simulation, and then build rock facies model with sequence instructor simulation. Reservoir properties parameters models are made by control of facies model. Permeability is the key parameter of the reservoir bed properties, it is most sensitive for space, therefore Method of sequential Gaussian collocated co-simulation is used in Permeability modeling.The following achievements are obtained in this research: (1) Using high resolution sequence stratigraphy theory, according to production seismology explanation and reservoir bed inversion, delicately compare each sub-layer and justify stratigraphic position again; (2) According to bore logs shape of development wells and lithologic characteristic, subdivide individual well deposit micro-facies for development wells, and compose deposit micro-facies flat sheet for every sub-layer; (3) The emphasis of this modeling is delicately describing sub-layer, the interbed and barrier bed. After comparing and delicately dividing, 25 sub-layers and 20 interbeds and barrier beds are made, and multiwell model of delicate dividing layer is built. At the course of sublayer division, several breakpoints were adjusted, and geologic correlation of the well near the fault becomes more advisable. (4) Through this geology modeling and the subsequent reservoir numerical simulation, distribution pattern of residual oil and characteristic in I stage of SZ36-1 oilfield are finely behaved..