Abstract: Improved techniques are provided for controlling the injection of a cellulose powder/water mixture input into a formation through an injection well for recovery of hydrocarbons. The initial dosing rate of powder added to the water is increased as a function of both the monitored pressure of the mixture in the wellbore in the vicinity of the formation, and the monitored flow rate of the injected mixture. The water flow rates and the flow dosing rates are optimised, and the mixture is controlled to obtain setting within the formation to enhance the recovery of hydrocarbons. A mixing tank is designed to prevent premature setting of the mixture. Portable equipment is provided for injecting the powder/water mixture into the formation, thereby increasing the versatility of the equipment reducing the overall costs of the recovery operation.