Designing a conceptual model for geochemical geodatabase of oil wells: A case study of Gachsaran Oilfield

Due to the necessity of identification and need assessment phase in the creation and the development of Geodatabase and Geographic Information System (GIS), designing a concept model is being introduced as its first phase of the study. Conceptual data modeling using ERD (Entity-Relationship Diagram) method, by defining entities, attributes, and the relationship between spatial and non-spatial entities. In this study, using the ERD method, a spatial database structure is designed for geochemical data of oil wells. Petroleum geochemical data is used for oilfield exploration, management, production, and development. In an oilfield, the most basic spatial entity is the wells. Other spatial entities in this study are field boundaries, sectors, and formations. Non-spatial entities were defined in separate tables, including oil samples and parameters derived from the geochemical analysis of samples in the Gachsaran oilfield. The ER diagram was designed using SAP Power Designer Software by establishing a 1 to N relationship between the well and all entities as well as determining the primary key and foreign key for each relationship. 11 entities were identified to create the data model.The result of applying the conceptual model before creating the Geodatabase is the logical structure of the database; also, spatial data modeling ensures the success of creating and developing a Geodatabase and WebGIS. As a result, the designed conceptual model simplifies the creation of a spatial database for display, processing, query and analysis of geochemical data of oil wells.