borehole
magnetometer
measure magnetic intensities in boreholes by lower the fluxgate magnetometer or proton magnetometer .......... used in iron ore prospecting .......should know the place we want ( zone of ores ) by magnetic instruments and then drill hole for borehole magnetometer .....we cannot find ores by make core ( kknowned why )with out making magnetic measures.........used in correlation in boreholes (like borehole seismic )(i will talk in borehole seismic in another topic]
gamma ray logginng
radioactive rocks used in correlation sedimentary strata in petroleum prospecting .....put gamma ray detector in boreholes....shale ,shaly sand stone :high conductivity like we know from radiometric survey ....coal and salt and limestone ,Qtz weak conductivity
as we know used for uranium prospecting
neutron loggging
two borehole methods:neutron gamma_neutron neutronemploy neutron from from source like radium and breyllium
brellium (4-9)+hellium (2-4)--->carbon (6-12)+neutron (0-1)+energy
this formula was knowed in nuclear
brellium are bombered by alpha paryicles from radium and fast neutrons
thermal neutron
neutron (0-1)+hydrogen (1-1)--->hydrogen (1-2)+gamma rediation
what does this mean? easy
when neutron collisions with nucli are gradually slow down untill they reach thermal velocities
and hydrogen are present in oil .gas , water .....so, alpha detected by lower the neutron sourses and counter
intenisty neutrons scattered by hydrogen atoms and intenisty of alpha rediation is detected.....but know that neutron donot ionize so use special equipment geiger tube filled boron triflouride gas
neutron(0-1)+boron --->lithium +alpha particles
alpha and neutron can ionize trifloride gas < if this happen reveals presence of neutrons
number of neutrons inversely propotional to number of hydrogens and number of gamma......means that decrease in neutrons mean incrase in hydrogens and increase oil and gas and water
geothermal survey
heat flow through rocks ....radiometric properties of rocks ....tectonic activity (volcanoes )....we are measure the thermal conductivity through of rocks and heat flow for rocks.......study deformation structure on rocks like anticlines .domes ,cracks and fissures.......used in correlation of stratigraphic position in borholes continued
, please , tell me if the topics is good for u or not , i will talk the next time in geochemical surveys ,optimum point and line spacing, position location in airborne survey ,other some notes....thanks