摘要 |
Apparatus, systems, and methods for continuously circulating drilling fluid through a tubular string are described. The methods include connecting a sub having a central bore and a side bore to the tubular string, connecting a top drive to the tubular string, connecting a manifold to the sub and top drive, wherein the manifold comprises a plurality of electrically controlled valves, and controlling the flow of drilling fluid through the sub and top drive by selectively opening and closing the electrically controlled valves. |