Research On The Fuzzy Reliability Of Side-abrasion Failure Of Rod String For Polymer Drive Pump Wells

Through investigating and analyzing failure modes of side-abrasion failure of rod string for polymer drive pump wells, I study failure modes of side-abrasion failure of rod string and their effect degree by the fuzzy general judgment method, and get the deadliness level of the main 5 failure modes. According to reliability and statistical theory, I get the database of side-abrasion failure of rod string for polymer drive pump wells after I collect, analyze and deal with the field failure data. Then I analyze its fuzzy reliability by Bayes method. At first I diagnose unusual data point and estimate life distributing parameter of each failure mode by Bayes method. Secondly confirm the life probability model of each failure mode by the fuzzy general judgment method. Base on subjection function rule, therewith polymer drive pump wells'field life situation I confirm the life data's subjection function of each failure mode. At last I calculate the life indexes and fuzzy reliability indexes of side-abrasion failure of rod string failure, and analyze them generally. Comparing with normal reliability method, I find fuzzy reliability method is more close to the field situation when the failure data belongs to small sample, so it should have more science foundation to direct production practice. Finally I simulate the fuzzy reliability of side-abrasion failure of rod string for polymer drive pump wells. First, establish the fuzzy reliability simulation logic by the fuzzy reliability theory; second, build mathematics model by fuzzy mathematics and probability and statistics; last, I simulate the fuzzy reliability of side-abrasion failure of rod string by Monte Carlo method, get the fuzzy reliability value and its believable scope when believable level is 95%.