Gamma Ray Log
Introduction of Gamma Ray Log
Introduction of Gamma Ray Log
 |
| مقدمه عن اشعه الجاما ودورها فى تسجيلات الابار |
Is the measurement of the natural radioactivity of formation in general shales tend to have high radioactivity while sandstone-limestone-salt-anhydrite have low radioactivity
Its tools used to determine shae content in a shaly sand and used for stratigraphic correlations
Gamma ray is a radioactivity log which measured natural radioactivity in the rock
******************************************************
Properties Of Gamma Ray
Gamma rays burst of high energy electromagnetic waves that are emitted by radioactive elements
All gamma-ray encountered in the earth is emitted by uranium
******************************************************
? The similarity between Gamma Ray and SP
The gamma ray is similar to sp and gamma ray is replace the sp in salt muds and in air-filled holes and when Rmf=Rw
because sp are used only in fresh mud and don't use in salt mud
******************************************************
Theory
Gamma-ray are high energy electromagnetic waves produced by the decay of radioactivity isotopes such as
k40-th-u
The rays pass from the formation and enter the borehole .the gamma ray detector registers incoming gamma rays as an electronic pulses
The pulse is sent to the uphole computer where they are counted and timed
******************************************************
Interpretation
The interpretation of gamma-ray curve is based on the assumption that
shale have abundant potassium 40 in their composition the open lattice structure and waves bonds in clays encourage incorporation of impurities the most common of these impurities are uranium-thorium
thus
shales have high radioactivity
sandstone, quartz, carbonates have strong bonds and generally don't allow impurities to occupy the composition
thus
sandstone and carbonates have low radioactivity
limestone undergo rearrangement of crystal structure and addition magnesium to become dolomite
******************************************************
Advantage of Gamma Ray
Good shale indicator
Good correlations
Gamma-ray can be run in open and cased hole
Used to determine the top and the bottom of a layer
Describe of radioactive and nonradioactive minerals
مقدمه عن اشعه الجاما ودورها فى تسجيلات الابار
The rays pass from the formation and enter the borehole .the gamma ray detector registers incoming gamma rays as an electronic pulses
The pulse is sent to the uphole computer where they are counted and timed
******************************************************
Interpretation
The interpretation of gamma-ray curve is based on the assumption that
shale have abundant potassium 40 in their composition the open lattice structure and waves bonds in clays encourage incorporation of impurities the most common of these impurities are uranium-thorium
thus
shales have high radioactivity
sandstone, quartz, carbonates have strong bonds and generally don't allow impurities to occupy the composition
thus
sandstone and carbonates have low radioactivity
limestone undergo rearrangement of crystal structure and addition magnesium to become dolomite
******************************************************
Advantage of Gamma Ray
Good shale indicator
Good correlations
Gamma-ray can be run in open and cased hole
Used to determine the top and the bottom of a layer
Describe of radioactive and nonradioactive minerals
مقدمه عن اشعه الجاما ودورها فى تسجيلات الابار