ClearBore

To accommodate the new legislation we have developed Clearbore™. ClearBore is an environmentally friendly, cost-effective, High Performance Water-Based Mud which is suitable for all tunnelling and drilling operations.

Patented in 2004, ClearBore is produced from dry, free flowing polymers, It provides exceptional borehole stability and cuttings removal in a wide range of ground conditions. It also provides a high enhanced gel strength as well as additional fluid loss control in comparison to other fluids.

ClearBore has been repeatedly successfully field-tested in the UK, Ireland and Middle East to the satisfaction of the drilling operators and managers. With a high carrying capacity, prevents bit balling and provides clay and shale inhibition making it a single component drilling fluid. ClearBore has a 10-fold volume-to-volume rheology comparison to high-yielding bentonite.

Reduce your disposal volumes and costs

ClearBores polymeric chains are designed to instantly break down and become chemically destroyed in the presence of small quantities of calcium hypochlorite. As the polymer breaks down, drilled cuttings will settle out of the fluid forming approximately 20% of the volume whilst the liquid phase will form about 80% of the volume. This can be done overnight in a pit or holding tank to leave a fluid phase of less than 400 ppm suspended solids. The water phase can then be decanted and disposed of to a wastewater treatment facility or in the sewerage infrastructure, with permission from the authorities. The sludge/solids can be disposed of as semi-dry waste to landfill at a reduced cost.

Testing

Composed of a propriety blend of natural and synthetic biopolymers, which are based on raw materials which will biodegrade within 4 to 52 weeks to break down into oxides of carbon and nitrogen. For EPA approval the product was subject to a 5-day technical scooping study to investigate the potential toxicity and environmental impact. This included X-Ray fluorescence spectroscopy (XRF), inductively coupled plasma atomic emission spectroscopy (ICP-AES), ion chromatography (IC), eco-toxicology assessment and biological oxygen demand tests on the product. The XRF, ICP-AES and IC results recorded very low concentrations for the elements and anionic analytes they were measuring i.e. fluoride, bromide, calcium, sodium, sulphates, heavy metals etc.

The eco-toxicology was assessed by the EA utilising the BSI method BS6068. This involved exposing juvenile daphnids to the Clearbore solution for 48 hours under controlled laboratory conditions to investigate the effect on the swimming capabilities of the organisms. The number of immobile daphnids out of a test population of 100 is counted by optical microscopy. The result at a 1:10000 concentration showed 10% mortality and the toxicity at this concentration was assumed to be negligible.

The BOD5 results at a 1:10000 concentration was below a level that would be considered an environmental threat and is similar to that of many unpolluted surface waters.