The working principle and operation method of Mud Motor

1. working principle

Mud motor is a positive displacement dynamic drilling tool that converts hydraulic energy into mechanical energy by using drilling fluid as power. When the pressure mud pumped by the mud pump flows into the motor, a certain pressure difference is formed at the entrance and exit of the motor, and the speed and torque are transmitted to the drill through the universal shaft and the drive shaft, so as to achieve drilling and workover operations.

2.Operation method

(1)Lower the drilling tool into the well:

① When drilling tool goes down the well, strictly control the lowering speed to prevent the motor from reversing when it is too fast, so that the internal connection wire trip.

② When entering the deep well section or encountering the high temperature well section, the mud should be regularly circulated to cool the drilling tool and protect the stator rubber.

③ When the drilling tool is near the bottom of the hole, it should slow down, circulation in advance and then continue to drill, and increase the displacement after the mud is returned from the wellhead.
Do not stop drilling or sit the drill tool at the bottom of the well.

(2)Drilling tool starting:

① If you are at the bottom of the hole, you must lift 0.3-0.6m and start the drilling pump.

② Clean the bottom of the well.

(3)Drilling of drilling tools:

① The bottom of the well should be fully cleaned before drilling, and the circulating pump pressure should be measured.

② The weight on bit should be increased slowly at the beginning of drilling. When drilling normally, the driller can control the operation with the following formula:

Drilling pump pressure = circulating pump pressure + tool load pressure drop

③ Start drilling, drilling speed should not be too fast, at this time easy to produce drill mud bag.

The torque generated by the drill is proportional to the pressure drop of the motor, so increasing the weight on bit can increase the torque.

(4)Pull the drill from the hole and check the drill tool:

When starting drilling, the bypass valve is in the open position to allow the drilling fluid in the drill string to flow into the annulus. A section of weighted drilling fluid is usually injected in the upper part of the drill string before lifting the drill, so that it can be discharged smoothly.

②Starting drilling should pay attention to the drilling speed, in order to prevent stuck drilling damage to the drilling tool.

③After the drilling tool mentions the position of the bypass valve, remove the components on the bypass valve port, clean it, screw on the lifting nipple, and put forward the drilling tool.

④Measure the bearing clearance of the drilling tool. If the bearing clearance exceeds the maximum tolerance, the drilling tool should be repaired and a new bearing replaced.

⑤Remove the drill tool, wash the drill bit from the drive shaft hole and wait for normal maintenance.