Houston Downhole builds several different types of tools that are used to circulate into the Drill String, into Casing or into Tubing.
Circulating Subs are Integral tools that have a 2” or 3” Figure 1502 Union Thread up and a Drill Pipe Tool Joint Pin down that is the same as what’s on the Drill Pipe. This tool is used to Circulate into the Drill pipe. It can also be furnished with a Box Thread down. It is rated for 10M or 15M PSI W.P.
Side Entry Subs – Houston Downhole builds them in two styles – One where the Side Outlet is an integral part of the tool, and a type that has a replaceable Side Outlet that can be replaced if it is damaged. The Side Entry is made up between two joints of drill pipe above the BOP. It allows circulation thru the Side Outlet. If wireline equipment needs to be dropped down the string, it can be fed thru the side outlet. Either style can be rated for 10M or 15M PSI Working Pressure.
Dual Side Entry Sub is built integrally and with two sets of Union Outlet Ports. The major difference in this tool and the standard Side Entry Sub is the ID does not go completely thru the tool. The section of the body between the two outlets is solid. These tools are designed to be made up on the last stand of drill pipe. The Valves above it near the Top Drive, and the BOP just below it can actually be tested simultaneously. Using a Dual Side Entry can save at least 3 hours of rig time on every BOP test. These can be rated for 10M or 15M PSI Working Pressure.
Circulating Swedges are integral tools with a 2” or 3” Figure 1502 Union Thread up and a Casing or Tubing Pin Thread down. They are used to circulate into the Casing or Tubing. On these tools, the Casing or Tubing size, grade & weight per foot is what determines the Pressure Rating. We build these in all the tubing sizes and up thru 24-1/2” in Casing sizes.
Crossover Bushings are also used to circulate. Instead of a Union Thread up they have a Tool Joint Box thread up. It is the same thread as the Drill Pipe, the Kelly Valves and the Circulating Sub has. You could have a joint any one of these three tools made up to the top of the Crossover Bushing and the Tubing or Casing made up below. These tools do not have a rated pressure because they have threads on both ends. The strength factor on a Crossover Bushing is controlled by the upper Tool Joint thread.