ABSTRACT As a difficult problem, sidewall instability has been beset drilling workers all the time. Not only does it cause huge economic losses, but also it determines the success or failure of drilling engineering. Due to complex relationship between various factors which influence sidewall stability, it hasn’t been found a widely applied method to predicate sidewall stability so far. Therefore, in order to formulate corresponding measures to ensure successful drilling, searching for a kind of better method to forecast sidewall stability before drilling becomes an imperative and significant topic for drilling engineering. On the basis of traditional sidewall stability analytical method, we have put forward the Fuzzy Comprehensive Evaluation Method to forecast sidewall stability regulation using physico-chemical performance parameters of the clay mineral. This method has been improved by introducing the Analytic Hierarchy Process (AHP) and the Maximum Subjection Principle in the application process. After introducing Analytic Hierarchy Process to identify weight, and Maximum Subjection Principle to obtain evaluation results, it has reduced the influence of human factors and enhanced the accuracy of the fuzzy evaluation results. The application in Hailaer Area indicates that this method can predict sidewall stability of gas-oil well with high credibility and strong practicability.
Cite this paper
Liu, B. and Kong, F. (2012) Research and application of sidewall stability predic-tion method based on analytic hierarchy process and fuzzy integrative evaluation method. Natural Science, 4, 142-147. doi: 10.4236/ns.2012.42021.
 Hoang, S. and Abousleiman, Y. (2004) The analytical solution for wellbore stability in multilateral junctions in nonhydrostatic in-situ stress field. SPE No. 90245.
 Feng, Z.Q., Ren, Y.G., Zhang, X.D., et al. (2004) Law of oil and gas distribution in Hailaer Basin and orientation of exploration at next stage. Chinese Journal of China Petroleum Exploration, 9, 19-22.
 Guz', A.N. and Kuliev, G. (1983) Stability of drill wells. International Applied Mechanics, 19, 97-105.
 Tan, X.C., Ding, X., Chen, J.S., et al. (2008) Application of hierarchic analysis to quantitative evaluation of carbonate reservoir. Chinese Journal of Southwest Petroleum University (Science & Techno logy Edition), 30, 38-40.
 Lei, Z.X., Chen, Y.M. and Xu, Y.D. (2007) Integrated evaluation on reservoir profile modification suitability degree using fuzzy hierarchy determination. Petroleum Geology & Oilfield Development in Daqing, 26, 82-86.
 Liang, B.S., Cao, D.L. (Eds.) (2007) Fuzzy mathematics and its application. Science Publishing Company Press, Beijing, 56-60.
 Zeng, Z.J., Guo, J.C., Zhao, J.Z., et al. (2006) Refracturing Candidate Well Multilevel Fuzzy Decision Method. Petroleum Geology & Oilfield Development in Daqing, 25, 73-76.
 Peng, S.P., Pu, X.L., Lei, G., et al. (2004) Use Fuzzy Comprehensive Evaluation Method to Judge Well Sidewall Stability. Chinese Journal of Fault-block Oll & Gas Field, 11, 58-62.
 Jiang, Y.F., Liu, H., Liu, Z.H., et al. (2009) Study and Application of Formation Water Production and Borehole Wall Stability Prediction Technologies in Daqing Gas/ Foam Drilling. SPE No. 13499.
 Cuddy, S. (1997) The application of the mathematics of fuzzy logic to petrophysics. SPWLA No. 1997-S.
 Li, Z.D., Zhou, J.L., Wen, H., et al. (2008) Characteristics of reservoirs in northern Beixixiepo area of Hailar Basin and their influencing factors. Chinese Journal of Acta Petrologica et Mineralogica, 27, 45-51.
 Chen, Y.H. and Sun, C.Y. (2001) Effective degree of Maximum Subjection Principle in Fuzzy Comprehensive Evaluation Method. Chinese Journal of Chongqing Normal University (Natural Science Edition), 11, 45-47.