The Well Leak Detector (WLD), a cased-hole logging tool developed by TecWel, detects and locates leakage in a wellbore with a depth accuracy of a few inches. Any oil, gas, water or multiphase fluid leak can be detected with rates from as small as 0.02 liter/min (or 0.004 GPM) and upwards. Also multiple leaks in a wellbore can be detected.
With the WLD TecWel is able to detect any leak in:
The production packer
The expansion joint, or any other subassembly
The tubing
The Downhole Safety Valve - DHSV
The control line to the DHSV
Any of the casings in the well
The wellhea
Specifications for using the tool:
The WLD is deployed inside the tubing, even when logging to identify a casing leak. While logging with the WLD, the only thing that the WLD needs is an active leak, and the subjection of the failing barrier to a ∆P (differential pressure) causing a flow of fluids through the leak point(s) (i.e. generating an active leak). While logging with a line speed from 3 to10 m/min (10 to 30 ft/min) to locate a leak, the well could be shut in, producing or injecting into the reservoir and still the WLD can find the leak point. The WLD can also been run inside a casing (i.e. no tubing installed in the well).
The standard WLD Tool String is configured like this: