Mud Motor Drilling Innovations Are Lowering the Cost of Mud Motor Drilling

Mud motors are a common tool used in directional drilling applications. The HDD tool transfers the fluid that’s pumped downhole into mechanical power to help drive and steer the drill bit. While this equipment provides a variety of benefits, it can also reduce pressure by sending more fluid downhole than is necessary for optimum drilling operation. This results in an increased risk of inadvertent returns and higher overall jobsite costs.

To generate mechanical power, mud motors utilize the rotor/stator power section to convert hydraulic fluid energy into the mechanical horsepower of the multi-lobe rotor/stator. However, this power section is subject to inefficiencies that can cause the motor to stall out. The most significant causes of stall out include improper stator/rotor fit, thermal fatigue and improper mud temperature and bottom hole conditions.

In addition to Mud motor drilling generating mechanical power, the mud motor’s power section also converts the drilling fluid pressure into the rotor/stator torque. This torque is transmitted through the mud motor’s bearings and driveshaft to the drill bit. The more lubricated these components are, the less friction will be generated, which in turn leads to better performance.

Using mud motors, HDD operators must use a large amount of drilling fluid to achieve maximum performance. This can require a larger water tank on the drill site, which can exceed jobsite water limits. This may result in additional water tanks or pumps being required, which can increase the cost of the project.

Another concern with mud motors is that they send more fluid downhole than is needed to clean the borehole. When a mud motor is activated, it can take up to five times as much mud downhole as what is required to efficiently flush the borehole. This extra drilling fluid is caused by inefficiencies in the mud motor’s ability to create mechanical power.

The mud motor’s bent housing angle can also affect its performance. When a bent housing angle is too high, the mud motor experiences higher stress load, which can result in premature failure. The best solution is to plan the borehole and drill it to minimize sharp turning radii.

In addition to reducing energy loss, new innovations are helping to lower the cost of mud motor drilling. One example is the development of a new type of mud motor that allows operators to operate them in tight spaces. The small sized motors can fit in the space required for a single rotary table and provide more steering control than conventional mud motors. Additionally, a new hobbing process can be completed in half the time of traditional milling. This can reduce rotor profile deviations, which further improves the accuracy of a mud motor’s performance. Moreover, the smaller size of the motors also makes them easier to handle and maintain. Combined with improved design, these advancements are making mud motors more competitive for drilling in tight spaces and low-pressure formations. This can lead to better project efficiency and a greater return on investment.