FORMATION EVALUATION: RESISTIVITY

• 200Mhz Dielectric (DEL2)
  The Dielectric logging instrument is a shallow investigation water saturation device particularly valuable in fresh formation waters or where Rw is unknown or changing. The 200 MHz instrument investigates the flushed zone and is a pad-type device which is operated in contact with the formation.
• 3D Explorer Induction Logging Service (3DEX)
  
  The 3D Explorer Induction tool delivers a more accurate evaluation of laminated sand-shale sequences and was developed to provide improved identification and quantification of hydrocarbons.
• High Definition Induction Log (HDIL)
  The High-Definition Induction Log (HDIL) service, a full-spectrum array-type induction logging service, provides formation resistivities at multiple depths of investigation in freshwater- and oil-based drilling mud systems. The combination of the HDIL system?s high-vertical resolution and deep-investigating measurements with inversion Processingessing, provides a detailed analysis of formation resistivity (Rt ), flushed zone resistivity (Rxo ) and depth of invasion.
• FOCUS High Definition Induction Log (FOCUS HDIL)
  Baker Atlas has introduced FOCUS, the latest in high efficiency premium open hole logging systems. All downhole instruments have been redesigned, incorporating advanced downhole sensor technology into shorter, lighter, more reliable logging instruments that are capable of providing formation evaluation measurements with the same precision and accuracy as the industry's highest quality sensors at up to twice the speed of conventional triple-combo and quad combo logging tool strings. The logging system consists of the four standard major open hole measurements (resistivity, density, neutron, acoustic), plus auxiliary services.
• High-Definition Lateral Log (HDLL)
  The High-Definition Lateral Log (HDLL) service, a new-generation array-type galvanic measurement logging service, provides formation resistivities at multiple depths of investigation in conductive, water-based drilling mud systems. The combination of the HDLL system?s high-vertical resolution and deep-investigating measurements with inversion processing provides a detailed analysis of formation resistivity (Rt), flushed zone resistivity (Rxo), and depth of invasion. The HDLL subsurface instrument utilizes a single-current injection electrode and 18 measurement electrodes. The injection current and injection potential are acquired as well as a set of selected potentials (U), first differences (V), and second differences (W) of the measurement electrodes. These measurements provide more accurate formation resistivity data than conventional systems in thinly bedded hydrocarbon-bearing reservoirs and in the presence of deep drilling fluid invasion. Using HDLL data results in a better reservoir description, more accurate water saturation (Sw) determination, and a detailed evaluation of the drilling fluid invasion profile.
• Dual Laterolog (DLL)
  Dual Laterolog instruments are electrode tools designed to produce reliable formation resistivity measurements in boreholes containing saline drilling fluids. They operate by "focusing" a survey current into the formation. Dual Laterolog instruments are superior to induction instruments in high resistivity (>100 ohm-m) formations and/or well-bores with drilling fluids more conductive than the in-situ formation waters.
• Micro-Proximity Log (PROX)
  The Micro-Proximity Log is a focused pad device that measures the resistivity of the invaded zone near the borehole. It has a deeper depth of investigation and larger vertical resolution than the Microlaterolog, and is designed to work best in fresh drilling muds with thicker mudcakes, a situation where the Microlaterolog performs poorly. When used in conjunction with deeper reading resistivity measurements, the PROX can provide a good indication of movable hydrocarbons in these conditions.
• Minilog (ML)
  The Minilog is a pad device that measures resistivity at two shallow, but different, depths of investigation. This allows the identification of mudcake, and therefore permeable formations.
• Micro Laterolog (MLL)
  The Micro Laterolog is a focused pad device that measures the resistivity of the invaded zone near the borehole. It is designed to work best when the resistivity of the flushed zone is much greater than that of the mudcake, a situation where the Minilog performs poorly. When used in conjunction with deeper reading resistivity measurements, the MLL can provide a good indication of movable hydrocarbons.
• Thin Bed Resistivity Tool (TBRT)
  The Thin-Bed Resistivity (TBRT) instrument provides high vertical resolution previously associated only with micro-resistivity devices, yet it has a depth of investigation in the range of 13 to 21 in. (330 to 533 mm). As a result, under ideal shallow invasion conditions, the TBRT service can be used to measure formation resistivities in beds less than 2 in. (51 mm) in thickness. Even when invasion is deeper, TBRT provides an excellent indication of hydrocarbons in thin beds, and is the best choice for bed identification when thin bed processing is done to enhance the resolution of standard resistivity tools.