Research On Spatial Information Retrieval Methods For Petroleum Geology

The business activities in petroleum geology have strong spatial characteristics.Petroleum geologists often attach spatial objects when performing information retrieval on petroleum geological data.However,spatial objects in petroleum geology involve vertical stratigraphic space,which is different from geographic spatial objects.Therefore,geographic information retrieval cannot be directly applied to spatial information retrieval in the field of petroleum geology.The thesis takes the retrieval requirements of spatial and text themes in petroleum geology as the starting point,and explores the spatial information retrieval methods suitable for petroleum geology further on the basis of the research on the spatial data and geographic information retrieval framework of petroleum geology,so as to meet the demand for spatial information acquisition.The research status of spatial information retrieval models,hybrid indexing technology and spatial information retrieval system both domestically and internationally was analyzed in the thesis.A spatial information retrieval framework for petroleum geology was designed,and the main technical methods and related theories used were introduced.The key research contents are as follows.1.The framework of petroleum geological spatial information retrieval is studied,and the definition of spatial information retrieval model is given.Firstly,the quintuple of the spatial information retrieval model is defined to realize the comprehensive ranking of the retrieved text topics and spatial topics.Secondly,aiming at the potential semantic relationship between documents and terms in petroleum geology,a text correlation calculation method based on the nonlinear fusion of BM25 model and LDA model is proposed,which verifies the effectiveness of the model on the petroleum geology dataset.Finally,a comprehensive spatial and textual correlation calculation model is designed,and a spatial information retrieval model for petroleum geology is established.2.A hybrid spatial index structure is designed,and a three-layer hybrid index structure based on text-space is constructed by combining inverted indexes.A two-dimensional R* tree index structure is adopted for sparsely distributed geological spatial entities in horizontal space,and a three-dimensional R* tree index structure is adopted in the three-dimensional geological space below the relatively densely distributed secondary structural units to realize a two-level mixed spatial index structure.Using a space-based hybrid index structure with better performance,the R* tree spatial index is preferred,and the inverted index is further constructed on this basis to realize the retrieval optimization of spatial theme and text theme.3.A prototype system of petroleum geological spatial information retrieval is developed,and the retrieval results are visualized.Firstly,PGSIS,a prototype system for spatial information retrieval in petroleum geology,is designed and developed,which is based on the spatial information retrieval framework and spatial information retrieval model in petroleum geology.By integrating the above research results,the spatial information retrieval is completed and the retrieval results are visualized,thus verified the feasibility of the retrieval method.