Abstract: A wellbore tool includes a wellhead to be installed at an entrance to a wellbore formed through a subterranean zone. The wellhead includes an uphole wellhead end that can extend upward from the entrance, and a downhole wellhead end that can extend downhole into the wellhead. The wellhead defines an opening extending from the uphole wellhead end to the downhole wellhead end. A spacer tool is attached to the downhole wellhead end, and includes an uphole spacer tool end and a downhole spacer tool end. The spacer tool defines a tapered opening tapering from end to end. The tool includes a master valve attached to the downhole spacer tool end of the spacer tool. The master valve defines a flow pathway fluidically coupled to the opening defined by the wellhead and the tapered opening defined by the spacer tool.

Abstract: The system and method for maintaining communications in a cellular network provides for automatically generating a bundle of partially overlapping beams when the primary link between a base station (BS) and a mobile station (MS) degrades so that the signal-to-noise ratio (SNR) of a received transmission falls below a defined threshold. The overlapping beams are generated by a beamformer having a circular array of antennas, the array being divided into groups radiating the signal in adjacent but partially overlapping sectors at an amplitude determined by extended Hamming codes having zero cross correlation. The bundle is radiated over a 360° pattern so that it overlaps the blocked signal. The MS demodulates and retrieves received signals having the highest correlation. The recovery time is quicker than conventional systems and methods, e.g., 200 microseconds when the MS uses a narrow pencil beam (5° beamwidth).