DUO-VIS * is a high molecular weight biopolymer used to increase the carrying capacity in water-based drilling fluid systems. DUO-VIS biopolymer has a unique ability to produce a solution with high rheological and thixotropic properties. Basic Physical Properties: Appearance is cream or light colored powder. Pour density is 800 kg / m3. Area and Method of Use. The main purpose of the DUO-VIS reagent is to ensure high rheological properties of the solution ( PV, CSN, SNS), holding and bearing capacity. The reagent has proven its effectiveness in all types of water-based drilling fluids, including weighted, saline, salt-saturated solutions, solutions based on seawater and completion fluid. DUO VIS is working on optimizing the rheological profile: a significant increase in the viscosity of the solution at low flow rates, low viscosity at high shear rates, solutions with “reverse” viscosity. Solutions with “reverse” viscosity is when the absolute value of the dynamic shear stress exceeds the plastic viscosity. As a result, such solutions have low effective viscosity at high flow rates (inside the drill string, downhole motor, through bit nozzles), which allows reducing pressure losses and increasing hydrodynamic power on the bit or ZD, increasing the penetration rate. At low flow rates (annular space, troughs, tanks), the effective viscosity of the solution increases significantly, which favorably affects the quality of the cleaning of the wellbore and the holding capacity of the solution. When processing the solution, it is recommended to slowly introduce DUO-VIS into the working tank through the mixing funnel to prevent the formation of lumps and clots (fish-eye effect). The recommended rate of introduction of the reagent into the solution is one bag per 10-15 minutes. The time of reagent dissolution in solution depends on the temperature, salinity of the solution and the speed of mixing. The recommended concentration of DUO-VIS in the solution depends on the required viscosity of the solution and ranges from 0.7 to 6 kg / m3 for most solutions. When preparing special liquids (milling, overhaul, etc.), it may be necessary to increase the concentration of the reagent to 11 kg / m3. In fresh clay-free solutions, the reagent remains effective up to 120 ° C. Thermal stability of DUO-VIS can be increased by adding salt, antioxidant, special stabilizers.
Xanthan gum for solution has the properties:
Appearance: white or cream powder.
Viscosity: 1.2-1.8 Pa4.