• The Borehole Logging Systems produced by Delta Epsilon Instruments have proved invaluable for quickly and accurately determining fresh water producing formations from borehole logs.
  • Borehole logging enables the driller or geologist/geophysicist to “see” the critical characteristics of a potential well that are unobtainable by other methods.
  • Borehole loggers from Delta Epsilon equipped with a basic combination gamma and electric logging probe positively identify fresh water formations, precisely delineate their thickness, and reveal the undesirable intrusion of clay lenses or brackish water.

Groundwater logging with a Delta Epsilon well logging system is intuitive and easy to learn, equipment costs are reasonable and the information gained almost always increases the efficiency and effectiveness of groundwater exploration. Logging also assures good well design and construction.

With a fundamental understanding of log interpretation, borehole geophysical methods will yield valuable information that will almost always be worth the cost and effort involved.

The Borehole Logging Systems produced by Delta Epsilon Instruments have proven to be invaluable for quickly identifying fresh water producing formations from well logs. Well logging for groundwater exploration enables the driller or geologist to “see” the critical characteristics of a well that are unobtainable by any other methods.

Borehole Logging Data

These characteristics can only be determined through borehole logging and cannot be predicted from one well to the next. A borehole logging system from Delta Epsilon obtained the data shown below from a site in Texas using a GE- 9409 combination gamma and electric logging tool. Borehole data permitted the geologist to determine the well on the right had significant potential to be a productive water well. In contrast, the log on the left from a nearby adjacent well revealed this well was less promising, and, as a result, this well was not completed.

Commonly Used Probes For Groundwater Exploration and Water Well Development

GE-0809 Combination probes for the simultaneous recording of Gamma, Single Point Resistance. S.P. , Short and Long Normal Resistivities.

Fundamental to almost all groundwater logging is a combination gamma and electrical properties tool. All groundwater related logging systems should be equipped with this device. For a majority of our customers, this combination of measurements are all that is required to locate fresh water bearing formations, evaluate them for likely porosity and permeability as well as estimating water quality. The stratigraphy and lithology represented by these logs are also instructive in terms of well completion and development as a guide to locating the boundaries of water producing formations and the appropriate placement of casing and well screens.

CA-0909 Three Arm Linear Caliper Tool.

This device is used to measure the diameter of a borehole. It can also be use to identify seams or breaks in casing. There are circumstances where knowing the condition of a well in terms of washouts and strictures prior to attempting to install casing and well screens is essential to the well completion procedure. A caliper measurement can also be helpful in correcting gamma and resistivity logs that have been influenced or distorted by the effects of washouts in the well.

FT-9504 Combination Fluid Temperature and Conductivity Tool.

These measurements can be instructive in terms of understanding fluid flow in or out of a well and can serve as a guide for well screen placement particularly in instances where there are multiple water bearing zones penetrated by drilling. These measurements are also helpful in estimating water quality as a function of fluid conductivity as a function of Total Dissolved Solids as well as reconciling differing resistivity values of that of the drilling fluid vs. the adjacent formations.

FM-1009 Impeller Flowmeter Tool.

This device is useful in understanding fluid flow in or out of a well. Knowledge of flow characteristics may also serve as a guide for the optimal placement of well screens at the point of maximum recharge of water into a well. The FM-1009 features a very low mass titanium impeller and precision low friction bearings.

DEBIC-01 Induction conductivity tool

This device is useful for groundwater and environmental surveys when working in a brackish water or other highly conductive environment. It permits the acquisition of conductivity or resistivity data that cannot be obtained by conventional normal devices under these circumstances. It also has the advantage of being able to function in plastic cased boreholes or monitoring wells.

FS 1505

The fluid sampler is deployed and controlled by the logging system and permits the acquisition of 1 liter samples of well fluid from a desired depth increment.

DEBCM01 High Resolution Borehole Video Camera

The BCM01 camera is unique in that it is the only affordable camera we know of that can reliably obtain borehole video through up to 500 meters of standard four copper conductor armored logging cable. Conventionally the choices for borehole video are the use of limited and fragile coaxial cable or more commonly a separate borehole video system. The ability to operate on four copper conductor conventional logging cable permits the BCM01 to be used on the same logger that is used for geophysical well logging. The BCM01camera may be run on the Delta Epsilon 1-4D- 250 or GVX-4 four conductor logging systems. In groundwater applications video surveys are often required for casing, well screen and pump inspection purposes.