At the heart of Ziebel’s proprietary technology is the 0.6 inch diameter Z-Rod® composite carbon rod which deploys the fiber optic strands or cables securely into the wellbore. The rod carries 2 multi-mode strands and 4 single mode strands enclosed in a stainless steel tube. The composite is made of longitudinal carbon fibers bound together in a polymer matrix. It is light and extremely strong (more than 10 tons in tension) while being chemically stable and compatible for service in all normally found well fluids.

Z-Rod® is manufactured in a tightly controlled continuous process to achieve consistent properties over the typical finished length of 23,000ft. The rod is semi-stiff and has no “memory”, which means it can be coiled on a 12’ drum, but when uncoiled it will straighten without trying to hold its previous bend like steel coil tubing.

Z-Rod® is stiff enough to be pushed out into the horizontal sections of wells until frictional forces cannot be overcome. The reach limits are determined by the internal diameter of the pipe, the condition and roughness of the internal surface and the amount of debris in the hole. Ziebel simulates the expected horizontal reach of the rod by running IDEX software model which predicts when the available push (compressive load) from the surface will be unable to overcome the frictional resistance and the rod lock-up in a similar manner to coil tubing. Unless there are obstructions in the well this typically produces accuracies of 95% in reach estimates.

The carbon rod has been tested for compatibility with 15% HCL acid wash and with scale inhibitor chemical cocktails, which offers the possibility of real-time stimulation monitoring while these treatments are bull-headed from the surface, to confirm the effectiveness of any diversion methods employed and that the fluids are being delivered to their target zones correctly. It is also immune to H2S.