TECHNOLOGICAL SOLUTION FOR COMBATING HYDROGEN SULFIDE AT THE FIELD

One of the urgent problems in the production of hydrogen sulfide-containing oils is the problem of increasing the efficiency of hydrogen sulfide removal. Optimization of costs associated with the production, transportation and preparation of oil is very important at the present time. In order to reduce the costs of oil preparation, the use of a differentiated approach to solving the problem of its purification from hydrogen sulfide at the Kashagan field depends on the volumes of oil preparation, the mass fraction of hydrogen sulfide in the oil, the presence of gas near the high-sulfur oil preparation unit (UPVSN) that does not contain hydrogen sulfide, the presence of a gas collection system and the possibility of transporting increased volumes of hydrogen sulfide-containing gas to the sulfur purification unit. Taking these factors into account, it is necessary to identify the maximum values ​​​​of the volume fractions of methane, ethane, nitrogen and carbon dioxide in the composition of the stripping gas, at which the mass of oil will be preserved, as well as the conditions under which it will be purified from hydrogen sulfide in the conditions of the Kashagan field. Studies have shown that with an increase in the oil heating temperature and a decrease in the pressure in the desorption column, the maximum total volume fraction of methane and nitrogen in the mixture in the composition of the stripping gas decreases. A decrease in the mass fraction of hydrogen sulfide in oil below 100 ppm and maintaining the mass yield of oil depending on the proportion of these components in the composition of the stripping gas is possible if the oil temperature and pressure in the column are optimized. An increase in the total volume fraction of methane and nitrogen in the composition of the stripping gas leads to a decrease in its required consumption to achieve a certain efficiency of oil purification from hydrogen sulfide at specified operating parameters of the column.