Drilling with a PDC bit starts with a matched tool and drilling assembly. Use the operating guidance for the selected bit and equipment. A general article cannot turn one rotation range or a customer-case setting into a programme for every diameter, cutter layout and formation.
Prepare the tool and assembly information
Identify the bit model or drawing revision and the task: full-hole drilling, sampling or enlargement. Check the selected diameter, connection and mating component. For coring, include the barrel and core opening. Review tool condition and assembly requirements using the equipment and tool instructions before the run.
A three-wing spiral non-coring bit and a spiral PDC core bit need different assembly information. If the tool is not yet selected, start with the drilling-task selection guide.
Confirm operating parameters for this setup
| Item | Confirm before the run | Record during the run |
|---|---|---|
| Rotation | Permitted guidance for the selected bit, diameter and rig. | Actual setting and changes by depth interval. |
| Feed or load | How the rig measures and controls feed or weight on bit. | The recorded value, unit and measurement point. |
| Flushing | Selected medium, supply and return-path requirements. | Available measurements, returns and changes observed. |
| Sampling assembly | Barrel, core passage and required sample condition. | Recovered sample and interruptions where applicable. |
Do not treat rig hydraulic feed pressure as a direct measurement of weight on bit without the equipment’s conversion or measurement method. Keep units and measurement points with the record. A field case using a particular rotation setting is evidence about that setup, not a universal starting value.
Establish a baseline run record
Record the initial configuration, ground interval and approved settings. Note drilling progress together with returns, torque or load observations available from the rig, vibration and tool condition. Retain the depth at which a change occurs. A metres-per-hour figure alone does not explain why performance changed.
Review changes within the operating guidance
When the approved drilling programme calls for an adjustment, record what changed and the response. Keep other relevant conditions visible so the observation can be interpreted. Avoid changing several settings and then attributing the result to a single variable. Operation and adjustments should remain within the selected tool and equipment instructions.
Respond to abnormal observations
Loss of returns, abnormal torque, severe vibration or sudden penetration changes need assessment using the rig’s operating procedures and site practice. Increasing rotation or feed is not a universal remedy. Record the interval, ground change, settings and visible symptoms for the technical review.
| Observation | Useful evidence for review |
|---|---|
| Sudden penetration change | Depth, ground or returns change, settings and recent assembly changes. |
| Repeated blockage or poor cuttings returns | Flushing arrangement, passages, return observations and ground description. |
| Uneven or damaged cutters | Face and gauge photographs, run interval and recorded operating conditions. |
| Poor core recovery | Bit and barrel references, core dimensions, recovery observations and ground condition. |
Inspect and document the completed run
Identify the tool, drilled metres, drilling and handling time, observed wear, recovered sample where relevant and reason for removal. Photograph the face and gauge clearly. These records support a repeat order or a configuration change without assuming that every wear pattern has the same cause.
Use the technical-support checklist for an existing drilling issue, the design guide for configuration questions and the cost-input guide to evaluate documented run costs.
Existing drilling illustrations
