BASE GEOPHYSICS

Most surface geophysical techniques provide vast information about subsurfaces. However when it comes to trace detailed information about subsurface in a certain cross section- area, it is highly recommended to deploy these techniques in a drilled hole. This is termed as Borehole geophysics .  What is Borehole Geophysics? Borehole geophysics involves the depth wise sequential record of physical parameters such as resistivity, density, temperature, porosity, etc. It may sometimes be known as Geophysical Logging . Borehole : Is the narrow hole drilled into ground for the purpose either of obtaining subsurface information or extracting fluids such as water, gas, oil, contaminants. It is the same as a well, but they may differ due to the fact that the borehole is drilled at great depth and has small diameter compared to traditional wells. The basic geophysical borehole system is made up of these parts,  Downhole probe : It consists of sensing instruments/equipment that are lower...

There are many different geophysical investigation techniques, However when it comes to exploring detailed information about the subsurface, we need to drill the hole and make a detailed collection of subsurface data related to physical properties of the subsurface materials, this is termed as Borehole or downhole geophysics . Borehole geophysics involves the depth wise sequential record of physical parameters such as resistivity, density, temperature. It may sometimes be known as Geophysical logging . There are many different geophysical logging techniques however this post is going to describe briefly about electrical borehole logging . Electrical Borehole logging What is electrical borehole logging? Electrical borehole logging measures the flow of electric current in and adjacent to a well, using the same principles as various surface electrical methods. Types of Electrical Borehole Logging 1. resistivity logging 1.1 Single-Point Resistance logging This measures the resistance in o...

Borehole geophysical logging employs different techniques in exploring detailed information of the subsurface. However when radiation technique is utilized this log is known as Radiation (nuclear) logging . Today I want to let you know in brief through this post about this type of borehole geophysical technique. What does Radiometric Logging involve? What is Radiometric Logging? radiometric logging radiometric logging , measures the total intensity of natural gamma radiation that presents in rocks and sediments. Radiometric Logging is primarily based on the principle of Radioactivity as the part of nuclear physics and this is why it also known as Radiation (Nuclear) Logging It is related to radioactivity of radionuclides such as Potassium ( 40 K), Thorium ( 232 Th) and Uranium ( 238 U). Basically radiation (radiometric) logging techniques are of two types, which are passive and active . Further more, these two (2) basic categories can be subdivided into various types. This pos...