Planning an exploration drilling campaign for the first time can feel overwhelming. There are equipment choices, regulatory requirements, safety considerations, and technical decisions that all need to come together before a single drill rod goes in the ground. This guide breaks the process down into clear, manageable stages — from initial desktop study to final data delivery — so you can approach your first campaign with confidence.
Stage 1: Define Your Investigation Objectives
Before any equipment is specified or any contractor is engaged, you need to define exactly what the investigation is trying to achieve. Are you characterising a soil profile for a foundation design? Assessing contamination extent? Exploring for mineral resources? The objectives determine everything downstream: required depths, sampling frequency, testing requirements, and the type of rig best suited to the work.
Write a clear brief that captures the investigation objectives, the site area and expected formation types, required investigation depths, any known site constraints, and the data outputs needed. This brief becomes the basis for all subsequent decisions.
Stage 2: Desktop Study and Site Review
A desktop study is the foundation of good investigation planning. Review available geological maps, previous investigation data, geotechnical reports, and borehole records for the area. Understanding likely formation types and depths before mobilisation allows you to specify the right equipment and anticipate technical challenges.
Site access should also be assessed at desktop stage. Identify access routes, gate widths, overhead obstructions, and any weight restrictions. This information feeds directly into equipment selection — a site with restricted access may require a compact drill rig rather than a full-size exploration drill rig.
Review the regulatory environment too. Permits, planning approvals, environmental management requirements, and heritage or ecological constraints should all be understood before field work begins. Many exploration drilling campaigns are delayed because regulatory requirements were not identified early enough.
Stage 3: Select the Right Equipment
Equipment selection should be driven by your investigation objectives and site conditions. Exploration drill rigs come in a range of sizes and configurations. Full-size rigs offer greater depth capacity and torque for hard rock or deep investigations. Compact rigs are better suited to restricted access, lightweight transport, and shallow to medium-depth programs.
Consider whether to purchase, rent, or contract the drilling. For a one-off campaign, drill rig rental is often the most practical option, particularly if the rig type required is specialist. Drilling equipment rental providers typically supply the rig with an experienced operator, which reduces the technical burden on the project team.
When evaluating rigs, confirm the depth rating against your deepest required borehole, the torque specification against your anticipated formation hardness, and the availability of required sampling tools and testing attachments. Drilling rig tools and equipment should be matched to the investigation method specified — an SPT program requires a different tool set than a continuous core recovery program.
Stage 4: Plan the Borehole Layout
The spatial layout of your boreholes should be designed to meet the investigation objectives with the minimum number of holes required. For foundation investigations, boreholes are typically located at proposed structure corners and centre points. For contamination investigations, a grid layout may be more appropriate. For resource exploration, geological targets drive the layout.
Borehole spacing, depth, and sampling intervals should all be specified in the investigation plan before field mobilisation. This allows the contractor to price the work accurately and plan their resources. A well-defined borehole schedule also makes it easier to manage the work on-site and track progress against program.
Stage 5: Safety Planning
Exploration drilling carries genuine risks that must be managed systematically. Before mobilisation, a site-specific safety plan should be developed covering hazard identification, risk controls, emergency procedures, and equipment inspection requirements. Buried services must be located and marked before any drilling commences.
Drilling rig tools and the rig itself should be inspected and confirmed serviceable before deployment. A pre-start checklist should be completed on each shift. If the campaign involves exploration drilling in remote areas, communication protocols and emergency response plans need particular attention.
Stage 6: Mobilise and Execute
With planning complete, mobilisation should be straightforward. Confirm logistics, confirm site access, and ensure the drilling crew has all required documentation — safety plans, permits, investigation schedules, and borehole specification sheets. Brief the crew on site-specific hazards and investigation requirements at the start of the first shift.
During drilling, maintain daily logs of drilling progress, formation descriptions, sampling and testing data, and any site observations. Good field records are the foundation of a useful investigation report and protect the project in the event of later disputes about ground conditions.
Stage 7: Data Management and Reporting
Geotechnical data has no value if it cannot be accessed, interpreted, and communicated effectively. Establish a data management system before the campaign begins. Samples should be properly labelled, logged, and dispatched to the laboratory promptly. Field data should be entered into a project database daily, not left to be compiled at the end of the campaign.
The final investigation report should clearly present borehole logs, laboratory test results, in-situ test data, and a geotechnical interpretation that addresses the original investigation objectives. A well-structured report from a well-planned exploration drilling campaign is a significant asset for any engineering project.
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A complete step-by-step guide to planning your first exploration drilling campaign — from site assessment and rig selection to data delivery.