The Production Logging stack consists of a single string of individual tools, each containing one or more sensors. It is run in a well on a monocable that supplies power and transmits data.
These tools are designed to provide a full set of measurements in any combination of oil, gas and water in producing wells.
Along with standard measurements of Pressure, Temperature, Density, Capacitance and Flow, the PL stack provides accurate depth correlation with Gamma-Ray and Collar Locator tools. Depth corrections due to irregular motion are made using an accelerometer tool. It is also possible to monitor Casing Corrosion without the need to pull tubing. Compatible tools are also available from other suppliers, such as centralyzers, weight bars, and cable heads, that use the industry-standard GO single-pin connection. Due to the rational combination of sensors in some tools, the overall stack length is less than 10 feet.
All sensors have been verified in a Flow-loop over a wide range of three-phase flow rates and borehole inclinations.
The tools are digital and modular, so they can be stacked in any order below the CPT-B COMBO tool which is the master controller. Data are transmitted up a monocable to the logging computer at a speed of 20 KB/sec.
The COMBO interrogates up to 11 compatible sensors stacked below it at a rate of 16 times per second. Some tools are also available in analog output versions.
Training in the planning and interpretation of Production Logging is available through a course offered by Robert E. Maute, PhD, of RSE Inc. Dr. Maute teaches his program entitled Practical Interpretation of Production Logs worldwide, and is very familiar with the CBG tools.
Interpretation of Production Logs may be enhanced by use of software that considers all the measurements as inputs to a global solution. An example of such commercial software is “PLATO”, available from Interpretive Software Products which can make best use of the superior accuracy and performance of the CBG tools.