The Dual Laterolog (DLL) measures formation resistivity over a wide range in boreholes with salty or moderately fresh drilling muds. The DLL has an array of electrodes that focus electrical current into the formation. The current returns either to the tool body (for the shallow “LLS” resistivity measurement), or to a surface reference (for the deep “LLD” resistivity measurement). The result is a reliable resistivity measurement in circumstances where an induction tool response may be adversely affected by the mud salinity or high formation resistivity.
The DLL is run with a rigid bridle. One section of the bridle has an electrode to measure the Spontaneous Potential (SP).
- Rugged construction: 302°F and 20 kpsi
- LLS and LLD vertical resolution of 24 inches
- Fully compatible with UltrawireTM tools
- Easy to transport: can be broken down into sections shorter than 10 feet
When the DLL is combined with our Micro Spherically Focused Log (MSFL), a resistivity profile with three depths of investigation is possible. The combination of the DLL and MSFL readings can be used to calculate Rt and Rxo.
The MSFL has a pad with electrodes that focus electrical current into the formation in order to measure the flushed zone resistivity (Rxo). When combined with DLL data, the MSFL provides a shallow resistivity measurement for invasion profiling.
The MSFL has two fully independent caliper arms that force the pad against the borehole wall while providing a borehole gauge measurement. The tool has a high vertical resolution.
- Fully compatible with Ultrawire tools
- Fully independent tool that can be placed anywhere in the string
- MSFL/MEL use a common sonde body allowing the pads to be interchangeable
- Easy to transport: under 10 feet in length