Abstract: In order to solve the wellbore stability issues of Nenjiang, Yaojia, and Qingshankou formations in Yaoyingtai, Qianan, Changling regions, the anti-collapse drilling fluid made of organic silicate based potassium humate polymer is selected, and the BHA and rheological parameters of the drilling fluid are optimized, through analyzing the formation features and operations in the three regions. By the strong plugging and inhibition capabilities of the drilling fluid, the wellbore stabiliy issue is solved in Yaoyingtai, Qianan, and Changling regions. And the objective of increasing drilling speed, shortening drilling cycle, and reducing drilling cost is achived.