Research of Drilling Gas Kick and Blowout Characteristic Based on The Volume of Fluid Model

Abstract

The accident of drilling blowout out of control is a serious drilling accident. One of the measures that prevent this accident is detecting gas kick early. Mud pool liquid level method is one of the most widely used methods. But, due to the drilling bell mouth is exposed to the atmosphere, drilling fluid in the return pipe flow is not a full pipe flow but a free flow. When the gas kick was tiny, the change of mud pool level is unobvious and Liquid level detection device could not measure the level changes effectually. Drilling fluid return flow can’t be measured, and the error was so great that can’t detect the gas kick early. Air and drilling fluid (non-Newtonian fluid) were taken as mediums, to simulate the drilling fluid liquid level when drilling fluid return flow changed based on the Volume of Fluid multiphase flow model, then the characteristic of liquid level change in the return pipeline was analyzed with different gas rate in drilling fluid. It concluded that the liquid level in the bell mouth was changing obviously, when the drilling fluid has been changed with none gas. Give a suggest that Liquid level detection should be installed on the bell mouth in drilling fluid return pipe in order to find gas kick more accurately and effectively earlier. The gas kick rate has a great impact on the stability of the drilling fluid liquid level in the return pipeline.