Field test of herder and controlled burning of spilled oil in Kazakhstan

Abstract

Recent years have seen renewed interest in the viability of using herding chemicals in conjunction with in-situ burning. NCOC, an operator in the shallow north Caspian Sea, undertook herder research as an extension to studies performed under the Arctic Response Technology Joint Industry Programme (JIP). The purpose was to investigate the feasibility of using herders as part of their response toolkit. Laboratory tests were performed in Kazakhstan on weathered Kashagan export crude oil, using two herders listed on the US NCP Product Schedule. Results were positive and it was considered that a reasonable size test spill under realistic conditions was required to verify laboratory work. In November 2018 a field trial was undertaken in the boat basin at Damba in western Kazakhstan. A volume of 400 litres of artificially weathered Kashagan crude was pumped onto the water surface and allowed to spread. Air and water temperatures were just above freezing and a small amount of ice was present due to overnight low temperatures. The test was recorded by an unmanned aerial vehicle, using thermal IR and 4K video. After the oil had been allowed to spread out to be <1 mm, i.e. too thin to sustain combustion, a small boat was used to spray Siltech OP-40 herder around the periphery of the oil. After less than five minutes the effect of the herder became apparent. The oiled area was observed to begin contracting. A member of the boat crew successfully placed an igniter into the thick oil. A plume of black smoke was produced and the oil burned vigorously with flames of 2 to 3 metres high for approximately 8 minutes. After the burning had finished a visual inspection showed a relatively small quantity of oil residue. Pre- and post-environmental monitoring of the test site was undertaken. Based on the success of the test, the next steps are to develop a formal methodology for the inclusion of herders in the list of approved oil spill treatment products. It will then be possible to incorporate the technique into contingency plans using NEBA/SIMA justification. This will have the potential to improve the response options and speed of response to incidents in broken ice or open waters.