Results of a Field Test to Improve Hydraulic Blowout Control Calculations

Abstract In the offshore environment, options to regain control over a blownout oil or gas well directly from surface, e.g. by capping are limited, particularly in the case of subsea wells or underground blowouts. Hence injection of a kill fluid via a relief well will often be the only alternative. In view of offshore logistics and cost of such an operation, this requires reliable estimates for the kill rate, pump pressure, hydraulic horsepower, kill fluid density and volume, prior to spudding relief well(s) and arranging for the pump equipment, fluid make-up plants and storage capacity. Various methods to estimate these parameters have been proposed. Validation of the methods has been very limited however since an actual blowout situation, with all inherent uncertainties (e.g. with respect to blowout well performance) does usually not allow a thorough kill job evaluation. To close this gap between theory and practise, a dedicated full scale field test to study how a dynamic well kill proceeds in a high rate gas well, has been designed, executed and analysed. Through variation of the blowout and kill rates, conditions under which the well ceased flowing could be determined accurately. Valuable insights on the processes taking place in the well during the kill were obtained. Analysis of the test results shows the correct methodology to predict the parameters for a successful and efficient kill job. P. 103