HQTek provides the following three types of open hole logging tools:
High Resolution Dual Laterolog
High Resolution Dual Laterolog (HRDLL) provides reliable means of measuring formation resistivity in conductive borehole fluids under harsh downhole conditions. The HRDLL tool provides the measurements of four resistivity curves (traditional LLD & LLS and high resolution HRLLD & HRLLS) in a single log run. The high resolution resistivity curves (HRLLD and HRLLS) have a vertical resolution equal to 8" in an 8" diameter hole.
A computed focusing scheme is used to implement the focusing conditions. The schema eliminates the monitoring loop found traditionally in laterologs and increases tool accuracy.
The HRDLL tool is combinable with a MSFL (Micro Spherically Focused Log) or a MLL (Micro Laterolog).
Micro Spherical Focused Log
The Micro-Spherically Focused Log (MSFL) is a pad-type miniature version of the SFL (Spherically Focused Log) that was developed to eliminate borehole effects and achieve superior shallow investigation. The MSFL measurement involves only the first few inches of the formation immediately adjacent to the borehole, the flushed zone (Rxo), in which drilling fluid has displaced all formation fluids. The MSFL log provides a measurement of the flushed zone resistivity with low mudcake correction. The electrodes for the MSFL are imbedded in an insulating pad mounted on a powered caliper arm. A caliper curve is usually provided with the resistivity measurement.
A computed focusing scheme is used to implement the focusing conditions. The schema eliminates the monitoring loop found traditionally in MSFL and increases tool accuracy.
The MSFL tool also provides Micro Electrode Log measurements (RMG - micro gradient log and RMN - micro potential log) in one log run. The RMG and RMN are computed based on a inversion model.
Static Spontaneous Logging Tool
Static Spontaneous Potential Tool (SSPT) is an electric logging tool that provides direct measurements of the Static Spontaneous Potential in conductive borehole fluids under harsh downhole conditions.
A computed focusing scheme is used to implement the focusing conditions.
SSPT has the following advantages: less affected by the formation thickness, formation resistivity, and borehole; better resolution to define the boundaries of the permeable formations; matched resolution with DLL log; and better estimation of Rw.
SSPT is our patented tool. We presented a technical paper for the SSPT in the 2009 SPWLA Annual Meeting.