Prediction Method on Wellbore Stability Based on Analytic Hierarchy Process and Fuzzy Evaluation

Wellbore stability are influenced by many complex factors, and there is no commonly used prediction method on wellbore stability until now. Use of an efficient decision making technique which can take into account several criteria in such conditions is necessary. Referring to traditional wellbore stability analyzing methods, the fuzzy comprehensive evaluation method of predicting wellbore stability principle is developed, which is based on physical and chemical performances of clay mineral. In application, it is modified by using analytic hierarchy process to confirm weight that minimizes the effect by human factors, applying the maximum subjection principle to obtain evaluation results. In applications of Hailar area, using this method to predict wellbore stability is of high reliability and strong practicability.