Patent attributes
A displacement assistance device can include at least two flow paths in fluid communication with a flow passage, and a blocking member that blocks flow through each flow path in response to the flow through that flow path. A method of assisting displacement of a tubular string can include installing the tubular string, then discharging a blocking member into the tubular string, and flowing a fluid through a flow passage extending longitudinally through a displacement assistance device connected in the tubular string, thereby causing the member to repeatedly block flow through at least two flow paths in succession. A system can include a displacement assistance device connected in a tubular string, the device including at least two flow paths in communication with a flow passage extending through the tubular string, and a blocking member that alternately blocks flow through the flow paths in response to flow through the flow passage.