Mud pressure requirements
When the drilling tool is suspended, the displacement remains the same, and the mud pressure drop through the drilling tool remains the same. As the drill bit contacts the bottom of the well, the drilling pressure increases, the circulating pressure of the mud increases, and the pump pressure also increases. The driller can use the following formula to control the operation.：
Drilling pump pressure = circulating pump pressure + drilling tool load pressure drop (x MPa +1.5MPa)
Circulating pump pressure is the pump pressure when the drilling tool does not touch the bottom of the well, also known as the pump pressure from the bottom. When the drilling tool increases the torque, 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 depth of the well and the characteristics of the mud. However, in actual operation, it is not necessary to measure the accuracy value of the circulating pump pressure at any time. Generally, the off-bottom pump pressure after each contact is taken as an approximate value, so that it can fully meet the accuracy requirements of the formula.
During the work of the drilling tool, when the drilling pump pressure reaches the maximum recommended pressure, the drilling tool produces the best torque.Continue to increase the drilling pressure. When the maximum design pressure is exceeded, the motor may brake. At this time, the drilling pressure should be reduced immediately to prevent internal damage to the drilling tool.
