Well bore stability and borehole rules are the basic conditions for safe, high quality and fast drilling. Drilling fluids with good performances should be able to rely on the battlefield deactivation of liquid phase. Potassium formate drilling fluid has high ionic concentration, small free water, low water activity, and the introduction of porous Unstable Strata such as loose, crack development, easy to collapse, water expansion and spalling will greatly reduce the activity of its system, thus giving play to the anti-collapse effect.

1. Banding and Suspended Rock Ridge

The drilling fluid prepared by potassium formate is through circulation, bringing the cuttings broken by the bit to the surface, keeping the hole clean, and ensuring that the bit always contacts and breaks the new formation at the bottom of the well. Do not cause repeated cutting, keep safe and fast drilling. Potassium formate drilling fluid can suspend the drilling cuttings left in the well in annulus when it is connected to a single drill, tripped off or stopped circulating for some reason. The drilling cuttings will not sink quickly, and the occurrence of sand sinking and sticking will be prevented.

2. Balancing formation pressure and rock lateral pressure

In the process of drilling engineering design and drilling, it is necessary to adjust drilling fluid density continuously so that the fluid column pressure can balance formation pressure and formation lateral pressure, so as to prevent the occurrence of complex downhole quiet conditions such as blowout and well collapse. Potassium formate drilling fluid is used to form a thin and tough mud cake on the borehole wall to stabilize the drilled formation. It also prevents the liquid phase from invading the formation and weakens the degree of hydration expansion and dispersion of shale.

3. Cooling and lubrication Function

During drilling, the bit has been rotating under high depression to break rock strata. It generates large pots of heat, and the drilling tools are constantly scrambling with the well to generate heat. Through the circulation of potassium formate drilling fluid, these heat can be taken away in the most timely manner, thus cooling the drill bit and drilling tool. The function of prolonging its service life. Because of the existence of drilling fluid, the bit and the drill rotate in the liquid, which reduces the friction limit to a great extent and plays a very good lubrication role.

4. Transfer hydrodynamic power

Drilling fluid ejects at a very high flow rate at the bit nozzle, resulting in a high-speed jet that produces a strong impact on the bottom hole, thereby improving drilling speed and rock breaking efficiency. High pressure jet drilling is to use this principle to significantly improve the penetration rate. Potassium formate drilling fluid flows through the turbine blade at a higher flow rate from the drill pipe to make the turbine rotate and carry stones while drilling with a wetting wheel drilling tool.