Branch hole programs


Branch hole programs

Branch holes (otherwise known as delineation drilling) is a form of drilling program where directional drilling techniques are used to branch out from an existing drillhole (the “parent hole” or “mother hole”) to reach a new target. They are also commonly referred to as “mother” and “daughter” holes. This application is predominantly used in resource definition.

In drilling programs where multiple holes are to be drilled with tight spacing, a branch hole program is a smart alternative to a standard drilling program. Particularly when the targets are at depth, as a standard drilling program will require significant amounts of drilling in rock formations of little interest before the target formation is reached.

In addition, natural deviation will make it challenging to achieve the required spacing pattern with standard drilling, potentially requiring adding additional holes to the program in order to properly define the resource.

A branch hole drilling program changes this by only requiring one or a few pilot holes to be drilled from surface. The remaining holes are started deep down in the pilot hole and deflected towards the target using directional drilling techniques, such as standard downhole motors, wedges, or our Directional Core Drilling technology. If managed effectively, multiple targets can be reached from each pilot hole in order to achieve the spacing requirements.

Branch hole programs


The challenge is with harnessing the various directional drilling techniques, and technology to achieve the desired results.

Unless utilizing our DeviDrill Directional Core Drilling technology or drilling contractors with proven navi-drilling expertise: planning, and executing a successful branch hole program with downhole motors or wedges are two different things. There is an ever-present risk that the downhole motor or wedge is not set or positioned correctly in the drill hole which can lead to periodically steering the hole in the wrong direction, wasted time, and re-work.

Downhole motors can be temperamental and additional water pumps and drill strings are required to utilize them.


The DeviDrill is an innovative directional core barrel which fits directly to the standard drill string and is fully compatible with the N-size wireline system. There is no need for additional water pumps, drill strings, or survey instruments. Devico’s survey tools are a fully integrated part of the tool, as they stay on board and measure while drilling (MWD).

Our proven Directional Core Drilling (DCD) technology is used to precisely steer and deflect the branch holes away from the pilot hole and onto the target.

The DCD service includes directional drilling tools, survey tools and experienced drilling engineers that follow the program closely.

The drilling engineers prepare drill plans and recommendations based on the client’s requirements in order to achieve the program in the most efficient and rewarding manner.


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