Chemical injection unit for drilling operations

A chemical injection unit consisting of one or more injection loops that uses a Venturi injector and motorized valve with a control system to isolate chemicals from water until operating conditions are suitable to carry the chemical and water mixture down the main flow pipe. The invention adjusts chemical injection rate to maintain desirable operational properties, including chemical injection rate, chemical concentration, or fluid viscosity. Accurate and real-time injection of chemicals is beneficial for safety as well as economics of the drilling operation in terms of reduced drilling time, efficient use of chemicals, and minimal variation in processing conditions.