Dual Circulation Sub

Product Details

The Access Downhole Dual Circulation Sub is a simple with multiple means of activation. It was designed in part as a means of emergency circulation when any of the BHA components below it in the string become plugged off. A secondary utilization being to alter the direction of flow when changing the fluid type (adding acid, N2, etc.)
Initially the sub can be functioned by utilizing the emergency bust disc if circulation is not possible. There are multiple pressure limit selections for the disc itself; the most common few being 5,000psi, 6,500psi, and 8,000psi.

The secondary means of activation involves the ball drop method. There are a few situations where this utility is the most beneficial option. Dual Circulation Subs shine when switching to a fluid (co- mingled or otherwise) that can be detrimental to the BHA below it, dropping a flow and diverting the fluid to the annulus.

The addition of a dual circulation sub can add both depth to the treatment, as well as a "easy-out" in the case of an operational setback involving debris inside the tool string.

Major Benefits

  • Selectable burst discs for differing wellbore conditions and pressure limitations
  • Method of utilizing multiple types of fluids and gasses to complete operations without damaging semi-sensitive BHA components
  • Short enough to not make a large difference in the total length of the BHA
  • Shear screws for ball activation also configurable to the operational scope and pressure limits


Tool OD (in.) ID (in.) Ball Size(s) (in.)**Length (in.) Maximum Tensile Strength (lbs) Maximum Torsional Strength (lbs) Burst Disc Options (psi)
1.6880.40630.43755.5068,100 765 5,000 6,500 8,000
2.125 0.5630.625 5.00 127,0001,7705,000 6,500 8,000
2.8750.750 0.8125 5.00201,9006,4905,000 6,500 8,000
3.1250.750 0.81257.95375,5008,0455,000 6,500 8,000

* Specific service connections available upon request.
** Pistons can be made for specifically requested ball size configurations.