## Gamma ray shale index

where IGR is the gamma ray index, Vsh is the shale volume, GRlog is the gamma ray reading, GRmax is the maximum gamma ray reading, and GRmin is the minimum gamma ray reading. Calculating shale volume is an important thing to do because, it can be useful to calculate the water saturation, if the reservoir has shale within its body (shaly) such

4 Mar 2016 PDF | The relationship between gamma ray index, Igr and shale content, Vsh, in shaly sands is a quantitative indication for shale content. Shale Volume from Gamma Ray Log Models. Learn basics, borehole corrections, normalization, spectral gamma ray methods, non-linear Clavier corrections,  Background. • The Gamma Ray log is a continuous measurement of Principal isotopes emitting radiation are Potassium-40, Calculate shale index, IRA , by. 18 Nov 2015 Well-logging Lab No. 4 - Calculation of Gamma Ray Index IGR for Shale Volume Calculation - Free download as PDF File (.pdf), Text File (.txt)  7 Jan 2018 The volume of shale expressed as a decimal fraction or percentage is called Vshales. Calculation of the Gamma Ray Index (IGR ) is the first

## estimated from the gamma ray or gamma ray-derived shale log. This sort compare hydrogen index with gamma ray and with aluminum concentrations. As with.

In areas with low shale volume (i.e. areas with Gamma Ray less than. 50 API); minerals such as montmorillonite are widely observed. Consequently a direct  The volume of shale was calculated from gamma ray index and the values range from 11% to 17% indicating that the fraction of shale in the reservoirs is quite low. chosen for an investigation of the mineralogical sources for the gamma-ray activity, and with 2), and is overlain by the marine shales of the maturity index). 20 Jan 2017 saturation in the shaly formation. Different shale indicator methods are used in practice, which are based on the estimation of gamma ray index  Calculate the gamma ray index and shale volume if the rocks at depth 3,500 ft and 7,500 ft. Q.9. Sonic log reading. Calculate porosity. fts t fts t.

### SHALE Volume FROM Gamma Ray LOGS. The two most common shale indicating logs are the gamma ray (GR) and spontaneous potential (SP) logs. The units of measurement for GR are API units or counts per second, and for SP are millivolts.

Shale is usually more radioactive than sand or carbonate, gamma ray log can be used to calculate volume of shale in porous reservoirs. The volume of shale expressed as a decimal fraction or percentage is called V shale. Calculation of the gamma ray index is the first step needed to determine the volume of shale from gamma ray log. SHALE Volume FROM Gamma Ray LOGS. The two most common shale indicating logs are the gamma ray (GR) and spontaneous potential (SP) logs. The units of measurement for GR are API units or counts per second, and for SP are millivolts. The equation (1) shown below defines an IGR shaliness index as a function of the GR gamma ray log signal: It only needs to record the response of the gamma ray log for a nearby known shale body and a nearby known clean rock. Gamma Ray Index - IGR Shale Volume - GR Gamma ray index (IGR) is calculated from the well logging tool that has its same name. This index takes into account minimum gamma ray (GR) value (cleanest zone), the maximum GR value (most shaly zone), and the value of the study area or depth. The section is nearly a thousand feet in length and the gamma-ray scale has been expanded to 400 API units to accommodate the higher radioactive black shales. The limestones have low radioactivity, with a value of about 20 API units. A representative value for the gray shales is in the neighborhood of 120 API units. Even better, the difference does not depend upon Gamma Ray, so it provides a GR independent estimator: Clay minerals like kaolinite, chlorite, illite, and montmorillonite, have a high hydrogen index.

### Brittleness index prediction in shale gas reservoirs based on efficient network models. and the ratio of gamma rays to the photoelectric absorption cross section index showed a good correlation with mineralogical brittleness. little research has been done on shale brittleness index prediction using any artificial intelligence approaches.

In areas with low shale volume (i.e. areas with Gamma Ray less than. 50 API); minerals such as montmorillonite are widely observed. Consequently a direct  The volume of shale was calculated from gamma ray index and the values range from 11% to 17% indicating that the fraction of shale in the reservoirs is quite low.

## Gamma ray logging is a method of measuring naturally occurring gamma radiation to In particular, shales usually emit more gamma rays than other sedimentary rocks, such as sandstone, gypsum, salt, coal, dolomite, Retrieved from "https://en.wikipedia.org/w/index.php?title=Gamma_ray_logging&oldid= 932192032".

estimated from the gamma ray or gamma ray-derived shale log. This sort compare hydrogen index with gamma ray and with aluminum concentrations. As with. When shale composition is constant, the simple linear gamma ray shale index works well for typical shaly sands regardless of how the shale is distributed within   has a reading of 120 API units. The Gamma Ray Shale Index of a formation is 0.25. The. Gamma Ray reading across f this formation is? (2 marks). 25 API units. Gamma Ray, Sonic, and Thin to med. bedded sandy limestone and shale, Strong correlation between Fracture Index and gamma ray values – indicating a  hydrogen index (HI), is commonly expressed in spontaneous gamma ray, neutron, and density) using shale, matrix-hydrogen, and neutron lithology units .

25 Jul 2015 Igr = Gamma ray index. Bulk volume of water. This is the product of water saturation and porosity corrected for shale: BVW=Sw*Фe… Fig. 9 – Reported gamma-ray index to shale volume conversions (from Bigelow). Table 3 A more likely presumption is that the radiation level is dependent on the mixture densities and not volumes (Wahl [6] and Katahara [4] ). Shale is usually more radioactive than sand or carbonate, gamma ray log can be used to calculate volume of shale in porous reservoirs. The volume of shale expressed as a decimal fraction or percentage is called V shale. Calculation of the gamma ray index is the first step needed to determine the volume of shale from gamma ray log. SHALE Volume FROM Gamma Ray LOGS. The two most common shale indicating logs are the gamma ray (GR) and spontaneous potential (SP) logs. The units of measurement for GR are API units or counts per second, and for SP are millivolts. The equation (1) shown below defines an IGR shaliness index as a function of the GR gamma ray log signal: It only needs to record the response of the gamma ray log for a nearby known shale body and a nearby known clean rock. Gamma Ray Index - IGR Shale Volume - GR Gamma ray index (IGR) is calculated from the well logging tool that has its same name. This index takes into account minimum gamma ray (GR) value (cleanest zone), the maximum GR value (most shaly zone), and the value of the study area or depth.