Group 1 - The core achievement of China National Petroleum Corporation Bohai Drilling Company is the successful application of the "solubility product method" for hard water softening, which resolved the high hardness production water issue at well Jin 89-6X1, ensuring safe construction and compliance with wellbore and cementing quality standards [1][2] - The production water hardness at well Jin 89-6X1 exceeded industry standards by 5.2 times, leading to instability in polymer drilling fluid performance and potential safety risks [1] - The innovative technology reduced production water hardness to 4.8 millimoles per liter, fully meeting the requirements for drilling fluid preparation, and resulted in a cost saving of 40,000 yuan for drilling fluid expenses [1][2] Group 2 - The implementation of the "solubility product method" hard water softening avoided an additional transportation cost of 90,000 yuan for production water and reduced drilling fluid cost input by 40,000 yuan, achieving a cost reduction of 18% [2] - This technology breaks away from the traditional reliance on changing water sources and establishes a replicable standardized process of "detection-formulation-implementation-monitoring," providing a low-cost solution for drilling in high hardness water source areas in North China [2]