Requirements for Using Water Well Drilling Tools

1. Drilling fluid requirements for water well drilling tools

Water well drilling tools can work effectively with all kinds of mud, including oil-based mud, emulsified mud and clay mud, and even clear water. Mud viscosity and specific gravity have little effect on the drilling tool, but have a direct impact on the pressure of the entire system. If the pressure at the recommended displacement is greater than the rated pump pressure value, it is necessary to reduce the mud displacement, or it is necessary to reduce the pressure drop through the drilling tool and bit.

Impurities such as sand particles in the mud will affect the performance of drilling tools and accelerate the wear of bearings and motor stators. Therefore, the sand content in the mud should be controlled below 1%. Only within the range can the drilling tool have high efficiency. Generally, the middle value of the input flow range should be taken as a suitable input flow value.

2. Mud pressure requirements for water well drilling tools

When the drilling tool is suspended and the displacement is unchanged, the pressure drop of the mud passing through the drilling tool is also unchanged. When the bit contacts the bottom hole and the WOB increases, the mud circulation pressure increases and the pump pressure also increases. When there is no bottom hole pressure, it is called circulating pump.

When the torque of the water well drilling tool is increased, the pump pressure will rise. At this time, the reading of the pressure gauge is called the drilling pump pressure. The off-bottom pump pressure is not a constant, it varies with the well depth and the characteristics of the mud. Generally, the off-bottom pump pressure after each connection is taken as an approximate value, which can fully meet the accuracy requirements.

When the drilling tool is working, when the pump pressure of the drilling tool reaches the recommended pressure, the drilling tool will generate a suitable torque. Continuing to increase the WOB will increase the pump pressure. When the design pressure is exceeded, the motor may brake. At this time, the WOB should be reduced immediately to prevent the internal damage of the drilling tool.