A study of new low-cost anti-scaling compound salt high-density solid-free killing fluid

A new low-cost anti-scaling compound salt high-density solid-free killing fluid system is developed by adopting the high-efficiency scale inhibition technology, using a newly-developed weighting agent, and taking cheap inorganic salts as the base fluid, to solve the problems that the common killing fluids for high temperature and high pressure oil and gas reservoirs include bromine, zinc, heavy calcium, etc. are poorly compatible with the formation water, pollutional to soil and highly corrosive to human body, and that the formate high density killing fluid has a high cost. The system contains neither solid-phase components nor divalent ions that are prone to scaling, such as calcium and magnesium ions. The salts used are all monovalent salts with a density of up to 1.70 g/cm³. Compared to the same grade of formate system, the cost is reduced by more than 50% while all the advantages of the formate system are remained. In addition, it is also consistent with the future development trend and the requirements of the national new safety and environmental protection for the low damage, low cost, high density, solid-free and non-toxic environment-friendly killing fluid system.