An innovative engineering feat has been achieved in drilling large shafts on Auckland’s largest wastewater system– the 14.7-kilometre Central Interceptor project.

This document provides a framework for using long-chain PHPA polymer in foundation piling. It draws from articles and studies from the US and experience across New Zealand and Australia.

Following on from Clay and Luke’s previous blogs, Omer will look at clay samples out of the ground, and how to design a system to combat clays while optimising your drilling operations.

Drilling in clay formations can be challenging. Tooling choice and methodology are important contributors to the successful drilling of clays. Equally important and our focus here is looking into some of the drilling fluid chemicals that can help with this formation type.

Critical trenchless installations require a fluid system that is optimised to the ground conditions that will be encountered. At Blick, customers send us geotechnical reports, samples of formations or even photos to allow us to understand their conditions. Using this information we will design a fluid system to maximise their success.

Bentonite is a very reactive clay that shrinks or swells markedly in response to the removal or addition of water.

Bentonite consists mainly of smectite minerals (swelling or expandable clay), commonly formed by the decomposition of volcanic ash or sometimes from other igneous or sedimentary rocks.

Drilling in highly reactive, sticky clay can be a real challenge. Your reamer may ball up, making it difficult to cut and clean the hole - resulting in a thick cuttings bed that sticks to the drill pipe.