Studies in support of the regulation of dispersant use in the Kazakhstan Sector of the Caspian Sea (KSCS)

Abstract

The use of oil spill dispersants is often regulated by national authorities to ensure that products approved for use as dispersants on spilled oil in national waters are of reasonable effectiveness and of low inherent toxicity. KING (Kazakh Institute of Oil & Gas) undertook a study to assess the use of oil spill dispersants on spilled oils in the Kazakhstan sector of the Caspian Sea (KSCS) to support decision-making for such regulations in the RoK (Republic of Kazakhstan). The KSCS has some characteristics that are unlike open ocean conditions in other parts of the world; the salinity is much lower than in the open sea. The shallow waters of the northern Caspian Sea have very low salinity (9 psu (practical salinity units) or less) due to the inflow of freshwater from the River Volga, and are frozen in winter. The deeper water in the southern part of the KSCS has a salinity of up to 14 psu. The effectiveness of oil spill dispersants is known to be affected by water salinity. Different countries around the world have developed different test methods to assess dispersant effectiveness. The project examined the options and decided to modify the WSL (Warren Spring Laboratory) LR 448 dispersant effectiveness test method, as used in the UK. The method was adapted by KING and testing was conducted by Karaganda State University (KSU) to test a variety of dispersants under Caspian Sea conditions. Dispersant effectiveness testing should be conducted with a test oil that is representative of oils that might be spilled in the area being considered. Kashagan crude oil was distilled to 200°C to simulate the evaporative loss that would occur shortly after the oil was spilled at sea and the residue used as the test oil in the dispersant effectiveness testing. Several commercially-available dispersants were tested using the modified LR 448 method with the 200°C+ Kashagan test oil under a variety of conditions with salinities ranging from 0 psu to 35 psu and at temperatures of 5°C and 25°C. The results indicate that some internationally recognized dispersants could be suitable for use in the KSCS.

Using Herders for Oil Spill Response in the Sea

“…Previously, the capability of using dispersants for the oil spills response [1,2] was investigated for Kashagan oil and for the conditions of the northern Caspian [3,4]. Based on the results of these works, the Ministry of Energy of the Republic of Kazakhstan approved the Method for Determination of Dispersants for inclusion on the list of dispersants for the liquidation of oil spills in the sea and inland water bodies of the Republic of Kazakhstan [5].…”