What should I do before HDD machine working?

Ⅰ. Construction preparation

1. Before construction, the center line of the planned pipeline should be laid out according to the design drawings, the entry point and exit point should be determined, and the position of crossing obstacles and crossing pipelines should be marked on the center line; according to the entry point, exit point and center line, the boundaries of the entry side, exit side, construction access road and pipeline prefabrication site should be determined.

2. The functional positions should be determined according to the construction plan layout in the construction organization design, and the enclosure, safety signs and traffic diversion should be done well.

3. The installation of horizontal directional HDD rigs should comply with the following regulations:

1) The HDD rig should be installed at the starting position of the design trajectory extension line;

2) The center axis of the HDD rig power head should coincide with the design trajectory extension line;

3) The HDD rig anchoring should meet the requirements of not failing under the maximum push and pull force of the HDD rig.

4. Before the guide construction, the guide instrument should be calibrated according to the following contents:

1) Check the power supply of the guide system (receiver, transmitter, remote synchronous monitor);

2) Check whether the receiver and remote synchronous monitor channels match;

3) Before each use of the guide system, the guide system should be calibrated according to the operating instructions;

4) Recalibration should be performed when replacing the transmitter, receiver, and drill body;

5) Before drilling, the interference signal in the construction area should be tested to determine the appropriate transmission and reception frequency.

5. Before construction, the following other contents should be checked:

1) Whether each instrument displays normally;

2) Whether the oil pipes and water pipes of the machinery are unobstructed and whether there is leakage;

3) Whether each circuit is working normally, whether there is leakage, and whether there are safety measures such as HDD rig grounding;

4) Whether the drill pipe thread is clean and intact, and whether it is deformed or damaged;

5) Whether the communication between the entry point and the exit point is unobstructed;

6) Whether the water source for construction is convenient for construction and whether the water quality is qualified.

 

II. HDD rig selection

1. The construction of pipeline crossing projects using horizontal directional drilling method should comprehensively consider factors such as construction site, formation conditions, pipeline diameter, burial depth and length, and reasonably select the type of HDD rig and performance parameters.

2. The rated pullback force of the horizontal directional HDD rig used in the construction can be selected according to 1.5 to 3.0 times the calculated value of the design pullback force.

3. The power of the horizontal directional HDD rig should match the project and can be determined based on the pipeline diameter, crossing length and pullback force.

III. Drilling mud preparation

1. Horizontal directional drilling should formulate a reasonable mud system and select appropriate slurry materials based on formation conditions, crossing pipeline diameter and length.

2. The design of drilling mud should include the following contents:

1) Determine the basic parameters of drilling mud such as specific gravity, viscosity, static shear force, dynamic shear force, filtration loss, mud cake thickness, allowable sand content, pH value, etc.;

2) The mix ratio of various slurry materials;

3) Calculation of drilling mud material dosage;

4) Mud preparation;

5) Formulate drilling mud circulation, purification and management measures.

3. Mud performance parameters should be determined according to geological conditions.

4. The calculation of drilling mud dosage should comprehensively consider factors such as the final expansion diameter, drilling length, expansion times, and leakage conditions in the hole.

5. The formulation and performance parameters of drilling mud should be monitored and adjusted in real time according to factors such as formation conditions, drilling technology, and conditions in the hole during construction.

6. The pumping volume of the mud pump during construction should be able to meet the construction requirements.

7. Stable mud circulation should be maintained during horizontal directional drilling construction.

8. The mud should be prepared in a special mixing container or mixing tank. The mud returned from the borehole should be treated and adjusted in a sedimentation tank or mud purification equipment before it can be reused.

9. When the drilling process needs to be interrupted for a long time, new mud should be added to the hole regularly and the drill tool should be moved to compensate for mud loss and prevent the occurrence of drill jamming accidents.

10. During the preparation of drilling mud, the drilling mud record form should be filled in according to the requirements of Appendix B.