120mm Mud Motor H5LZ120

120mm Mud Motor H5LZ120

 

The 120mm mud motor is a popular size in the Horizontal Directional Drilling (HDD) industry, known for its balance of power and maneuverability.

产品参数   Products Specification H5LZ120
钻头外径    Dia. of Bit	mm	149~200
	inch	5 7/8~7 /8
扣型(REG)            Thread（REG）		3 1/2 REG female  3 1/2 IF male
重量 毛/净(kg)        Weight  G/N（kg）		280/280
流速 (L/s)     Rate of Fow (L/s)		8~15
压差  (Mpa)      Diff. pressure (Mpa)		4
工作扭矩（N.m）Working torque (N.m)		1800
最大扭矩（N.m）Max.  torque (N.m)		3240
长度 （mm）            Length (mm)		4720
工作钻压 （KN）Working WOB (KN)		40
级数   Stage Number		3

Brief Introduction of Mud Motor

 

Mud motors are essential tools in trenchless construction, particularly in Horizontal Directional Drilling (HDD). They are used to rotate the drill bit at the end of the drill string, allowing us to bore underground without open excavation.

Rotating the Drill Bit (旋转钻头): The primary function of a mud motor is to power the drill bit rotation. Unlike rotary drilling where the entire drill string is rotated from the surface, in HDD with mud motors, only the drill bit rotates. This is crucial for directional control and efficiency.

Directional Drilling (定向钻进): Mud motors are key for steering the drill bit along a planned path. By combining the mud motor with a slightly bent housing and directional drilling tools, operators can precisely control the drilling direction to go around obstacles and reach target locations underground.

Powered by Mud (泥浆驱动): As the name suggests, mud motors are powered by hydraulic energy from the drilling mud. High-pressure mud is pumped down the drill string and through the motor, causing internal components to move and generate rotation.

In simple terms: Mud motors are like underground drills powered by mud, helping us steer and dig tunnels for pipes and cables without digging up the whole surface.

 

Mud Motor Operation User Guide

 

1. Back reaming with motor is prohibited. Slurry is recommended as drilling fluid.

After completing each steering (or pilot drilling) section, be sure to remove the mud motor before proceeding with pullback operations. Pulling back with the motor attached can cause stress concentration, leading to motor fracture or damage.

The drilling fluid of choice is mud. Select a mud pump with a corresponding displacement and model to drive it (see attached diagram 2.). Insufficient pump discharge flow can cause the motor to fail to start, or for the motor to lock up during drilling, resulting in no penetration (advance). Unstable pump discharge flow can cause the motor to operate intermittently, starting and stopping.

Another possible reason for poor mud pump discharge is partial blockage caused by large, hard rock particles forming within the drill pipe and motor, or between the probe housing and the drill pipe. This intermittent blockage causes the mud to flow intermittently, leading to unstable rotation speed. In such cases, it is best to disassemble and inspect the motor, drill pipe, and probe housing, and to clear any internal debris until the mud flows smoothly.

2. Flow rate of pump should not be lower than 800L/M, or the motor cannot be driven, or be locked in drilling process.

 

Mud Motor (mm)	95	120	165	172
Flow rate of Mud pump (L/M)	≥600	≥800	≥1300	≥1300

Diagram 2. selection of mud pump for mud motor

 

3. A new or idle motor should be rotated clockwise at least 2 rounds with a tong before working with a pump.

In on-site operations, first use a pipe wrench(or a hydraulic tong) to rotate the spindle head clockwise for more than 2 turns before starting pump circulation.

 

4. After use, user should clean it internally. Rotate the drive axle to remove the residual fluid.

After using the motor, be sure to clean out internal debris with clean water. After detaching the motor, use a pipe wrench to rotate the drive shaft clockwise to purge any residual fluid from inside the motor. Otherwise, the motor may fail to start when used again.

5. Drive axle of this motor is open for lubrication, hence fluid leak is not an issue.

Due to the open structure of the mud motor’s drive shaft section, the design allows for mud to leak from the gap between the drive shaft and the bearing housing. This leaked mud serves to lubricate and cool the TC bearings in the drive shaft area, preventing bearing seizure caused by excessive friction heat. Generally, this mud leakage is a normal phenomenon (leakage should not exceed 6% of the mud motor’s normal operating flow rate).

 

Performance Characteristics (性能特点 – Typical for 120mm Size):

While specific performance varies by manufacturer and model, 120mm mud motors generally offer a good balance of:

Moderate Torque: They provide sufficient torque for drilling in typical soil conditions and softer rock formations that are so common. Highest torque is not for their intended applications.
Reasonable Speed: Designed to operate at effective rotational speeds that optimize drilling efficiency in their target applications. Speed is often more important than extremely high torque in smaller diameter utility work.
Efficient Mud Flow: Engineered to operate efficiently within a manageable mud flow rate range, making them compatible with commonly used mud pumps in utility HDD rigs.
Versatility: 120mm motors are versatile enough to handle a variety of ground conditions encountered in urban utility work, from clay and soil to sand and some fractured rock.

Typical Applications (典型应用):

120mm mud motors are good in a range of utility and infrastructure projects, including:

• Fiber Optic and Telecommunication Installation:Ideal for installing conduits for fiber optic cables, telecommunication lines, and data cables, often in urban and suburban environments.
• Small Diameter Utility Pipelines: Suitable for installing smaller diameter pipelines for water, gas, and other utilities, especially for “last mile” connections to homes and businesses.
• Electrical Conduits: Used to create pathways for underground electrical lines and conduits.
• Shorter to Medium Length Bores: Best suited for shorter to medium length HDD bores, where the focus is on precision and navigating congested underground utilities.
• Residential and Urban Areas: Well-adapted for work in residential areas, urban environments, and areas with sensitive surface conditions, where minimizing surface disruption is crucial.