Research On3D Visualization System For Multi-source Heterogeneous Reservoir Models Based On OSG

In the oil industry,3D visualization technique is a powerful instrument for us tounderstand and describe the features of many surface and subsurface phenomenon, it canconvert the complex seismic and logging data into intuitive graphical images. In this way, thetrue3D form can be used to express the morphological characteristics of undergroundreservoir structures, petrophysical property and well path distributions, etc.Today, certain progress has been made in the3D visualization reservoir system.However, most softwares are only limited to read the data format file ruled or generated bytheir own systems, reutilization and studying on the geological results of other foreignreservoir softwares are not available. To some extent, this will restrict the scope of reservoirvisualization. In order to find a solution to read and render the un-compatible geologicalresults of different reservoir softwares, the following two aspects need to be considered: onone hand, the grid model data of the geological results exported from different reservoirvisualization softwares are dramatically different in respects of the grid storage format andsorting. Furthermore, the large-scale grid model tends to occupy lots of storage space and thecomputational burden is high, which will limit the rendering rate. Meanwhile, in the processof moving, rotation, scaling, the “pop” or “jump” phenomenon will appear. On the other hand,the data of well trajectory model is given in the form of coordinate sets. Nevertheless, the“line” form seems slightly dull, and the “cylinder” form requires too much computation forcorner smoothing. To solve these above problems, using the open source3D graphicsrendering engine Open Scene Graph (OSG) and taking the reservoir data as target, this paperdesigned a3D visualization system for multi-source heterogeneous reservoir models. The keytechniques are as follows:1. The paper parsed reservoir models from different software in respects of the grid dataorganization and content in the oil industry and designed common-interface engines to readand render different reservoir models for better expansibility and independence.2. It implemented the hidden surface removal algorithm of the heterogeneous gridmodels, which optimized the original mesh model data to reduce the amount of data flowinginto3D graphic engine and improved the rendering rate of reservoir model without causingany display differences. 3. It rendered3D well trajectory using the plane and triangulation method, where thearbitrary trajectory can be automatically processed and the curve section does not need to besmoothed. The method is simple and efficient.4. Based on the trackball, such functions as reservoir model roaming, scaling, movingand point-of-view operation became available. By studying the segment interpolation methodand the coordinate data conversion method, this system was capable of3D reservoir modelcolor display, and its reservoir model display effect was greatly improved.Based on the theory and methodology given in this paper, a preliminary3D visualizationsystem for multi-source heterogeneous reservoir models was constructed. Different softwares,formats and scales of reservoir geological results were used in system testing. Experimentalresults show that the system is well-functioning and stable. It can read and build the reservoirgeological results from different softwares and has desirable rendering effect.