Identification of downhole conditions in geological drilling processes based on quantitative trends and expert rules

Abstract

In drilling processes, faulty downhole conditions often lead to drilling performance degradation and even serious accidents, such as the blowout, and well collapse. To improve the drilling efficiency and enhance the process safety, a new downhole condition identification method is proposed for geological drilling processes based on quantitative trends and expert rules. A knowledge base that associates the quantitative trends and downhole conditions is established based on variational trends extracted from the historical data and rules summarized from the drilling operation manual. When the new data arrive for online monitoring, the variational trends are extracted, and then, the downhole condition is identified by comparing such trends with each rule in the knowledge base. The effectiveness and practicality of the proposed method are demonstrated by industrial case studies with real drilling process data.