Abstract: There are a large number of complex formations in the western South China Sea which are easy to collapse and have poor drilling ability. The commercial rock mechanics analysis software is not specific and efficient.In order to ensure the safe and rapid drilling of complex formations in the western South China Sea, CNOOC has independently developed its first rock mechanics analysis system. The system has high degree of data visualization, simple operation, intelligent data screening, multi-well parameter analysis and comparison, and key parameters can be displayed along wellbore trajectory. The system has strong practicability and can be used for calculating rock mechanics parameters, wellbore stability analysis, drilling parameters evaluation, reservoir sand control prediction analysis, etc. The field application shows that the calculation accuracy of the system is high, which can provide reference for the design and construction of drilling and completion.This system can be extended to other oilfields.