Substantial quantities of drill cuttings waste are generated during the drilling of offshore exploration and production wells. In the past this waste has been discharged in situ. However, in recent times, legislation has severely restricted this route of disposal and the majority of waste generated during drilling operations now tends to be shipped to shore for treatment and disposal.
Elvary Neftigas, an international consortium of oil companies, was responsible for drilling a number of exploration wells in the sea off Sakhalin Island. The waste from preliminary drilling activities was initially treated and then disposed of as landfill. The aim of this project was to assess whether the drilling waste would be a suitable raw material to be used in the manufacture of concrete building materials.
Aquatera, supported by a local partner company, REA Consulting, carried out a number of tasks ranging from the identification of the potential uses of the waste, reviewing the applicable legislation, assessing local processing and testing facilities, and organising sampling and testing of the drilling waste material.
Unfortunately, the quantities of hydrocarbon reserves discovered were lower than expected and the drilling programme was terminated early. As a result this study was not fully completed. The initial study indicated that there was significant engineering and demand potential for the re-use of the drilling waste in the manufacture of concrete products, however, the test results also indicated that some of the constituents present in the waste exceeded threshold values set out in the applicable legislation and that further studies would need to be undertaken to determine the significance of the findings.