Well intervention firm Ziebel has completed its 100th Z-Rod distributed fibre optic sensing job.
The milestone job was performed for ConocoPhillips in the United States to determine the flow profile of zones within a fracked unconventional well.
The Houston-headquartered company has operations bases in Aberdeen and Stavanger, with employees carrying out work using both land and offshore units in Norway, Denmark, Oman, Abu Dhabi, and the US.
The Z-Rod system consists of a 6.5m carbon fiber composite rod with embedded fiber optic lines that make it possible to deploy both distributed temperature and distributed acoustic sensing along the complete wellbore.
The 15mm diamater rod is injected into the well from coil tubing-like surface equipment and can travel up to 1,800m along the horizontal section of a well.
Applications ranged from the evaluation of flow in unconventional wells to well integrity diagnosis, monitoring water injection schemes, gas lift optimization, and understanding inter-well communication and interference.
The Z-Rod’s small diameter results in significantly reduced choking effects versus traditional coil tubing, enabling it to determine which perforated zones along the length of the wellbore are actually contributing to production. This information allows unconventional field operators to optimise their completion strategies.
Unlike traditional logging tools that can only survey a few inches of the well at a time, sensing provides a complete wellbore profile that is captured several times per second.
Chief executive Francis Neill, said: “As operators of unconventional wells strive to improve recovery factors and reduce well costs, the data to enable this is becoming more critical.”