Loss circulation control
Specialists of PetroTool Drilling Fluids Division developed a method of loss circulation control while drilling using own developed certified reagent 'RTS'. Use of that method with 'RTS' reagent eliminated usage of expandable systems where historically it was the only option.
Method consists of few steps and is as follows:
• Run and set packer to the problem interval;
• Prepare high viscosity fluid (hi-visc pill) based on fresh water with LCM (grain size of 0.4-2" and concentration of 30-100kg/ m3);
• Add 'RTS' reagent with concentration of 6-20kg/m3 depending on intensiveness of drilling fluid loss;
• Pump prepared solution until receiving working pressure (WP) (depending on intensiveness of fluid loss may need extra amount of pumping).
Advantages of the method:
• Allows use of same bit size, without need of spud of extra casing to solve the circulation issue;
• Reduces time spend on resolving issue with loss of circulation;
• Cheaper than expandable systems;
• Not harmful for environment.