Research And Application Of Knowledge Base System In Logging Field

Logging is the main way to obtain geological and engineering data during the exploration and development of oil,and is an important part of oil field development.Logging comprehensive interpretation is a key part of well logging.It uses computer to process the logging information into geological information and visually displays it in the form of a graph or a data table.It is one of the important means to determine and evaluate the hydrocarbon reservoir.However,due to the hidden nature of the underground reservoir,there are a lot of uncertainties and empirical problems in the log interpretation process,which brings great difficulties to log interpretation work.It is an important research direction in the field of well logging interpretation to share and reuse domain knowledge based on the knowledge base system and improve the intelligence of logging interpretation software.The current knowledge in the field of well logging interpretation is becoming more and more abundant,the interpretation accuracy requirements are continuously increasing,and the requirements for logging interpretation workers are also constantly increasing.However,experts with rich basic knowledge and experience have a long history of formation and experience may be lost.Therefore,how to store domain knowledge in a displayed and structured way and apply it to well logging interpretation to reduce the difficulty of well logging interpretation is an important issue for logging interpretation work.In this paper constructs an ontology-based logging interpretation knowledge base and rule base for the problems in logging interpretation and the characteristics of knowledge.It also studies the inference mechanism based on domain rules and carries out experimental verification on the CIFlog platform.This paper adopts the ontology-based knowledge representation method to construct a well logging interpretation knowledge base.Through the research on well logging interpretation,a knowledge organization model for well logging interpretation is established,and a domain ontology construction method based on well logging interpretation flow is proposed.The method is to guide the preliminary construction of the field of on-line interpretation.By studying the relevant technology of reasoning,formally describing the rules of well logging interpretation and establishing the field of well interpretation field,and based on the established ontology field model of well logging interpretation,the reasoning in well logging interpretation process was realized.And through experiments,the accuracy and effectiveness of the rules are verified.Finally,based on the ontology knowledge base and rule base in the well logging interpretation field,combined with the logging interpretation processing software,the knowledge base system based on well logging interpretation is realized.The system provides persistent storage of ontology models,ontology analysis,and intelligent selection of parameters in log interpretation.It also verifies the effectiveness and feasibility of the knowledge base system in log interpretation using the single-porosity logging shaly sand evaluation process as an example.