Dual pipe for increased fluid flow

摘要

A dual pipe drill string system having increased fluid flow. The dual pipe system comprises a plurality of pipe sections, each pipe section having an inner rod and an outer pipe. The inner rod and the outer pipe of each pipe section may be coupled to the inner rod and outer pipe of an adjacent pipe section. An annulus between the inner rod and the outer pipe defines a fluid flow path through the dual pipe system. The outer pipe defines a shoulder at each end of an individual pipe section. The inner rod defines at least one stop for maintaining the inner rod within the outer pipe. A spacing assembly disposed around the circumference of the inner rod defines paths for fluid flow and maintains a minimum distance between the stop and the shoulder at one end of outer pipe of the pipe section.