Machining downhole tools – Case study

A completed downhole tool which has been machined at GA Scotland, part of Pryme Group

Machining complex geometries

We were approached by a customer who specialises in downhole tools for the oil and gas industry. They needed a large batch of downhole parts machined with complex geometries. Our team at GA Scotland set about working on the best machining solution to keep the costs low for the customer whilst ensure that the exacting quality standards were maintained.

A downhole tool being machined

Overcoming machining challenges

The fins of the downhole tool needed to be considered when setting up tooling and toolpaths to prevent fouling. Our team needed to mill the complex profile with tooling at an extreme extension to avoid fouling against these protrusions during component machining.

From our wide range of machines, the team opted to carry out this order on our 4-axis, palletised horizontal machining centres. These machines are perfect for complex machining jobs of this size and the palletised system allowed our team to achieve near continuous running for a fast turnaround.

Accurate machining and trochoidal milling

To ensure accurate machining it was imperative to minimise any vibrations. After investigating the best method of work holding a suitable work holding jig was implemented. Tooling was carefully selected to minimise tool chatter which could lead to inaccurate machining and poor surface finish. Milling cycles used complex toolpaths with low cutter engagement to decrease load. Our team decided upon a trochoidal milling technique to reduce cycle times and reduce wear on tools. With these considerations made we were able to achieve the required surface finish and complex 3D geometry.

A downhole tool during cnc machining

The finished downhole tools passed all quality inspections and specifications, and were delivered to the customer on time. Excellent process reliability was maintained throughout the production run thanks to the planning and considerations made early in the process. This was one of the more challenging parts encountered by the talented team at GA Scotland, but they were delighted with the results that they attained.