Th/You proportion get across-plot is actually produced towards cored durations of each really in order to look at the to your depositional environment (Fig. 10).
The clay typing was later accomplished by a group of cross-plots (Fig. 11) with various combinations including thorium versus potassium, photoelectric (PEF) versus potassium, photoelectric versus Th/K ratio and thorium versus AldosO3/(Al2O3 + SiO2). For generating the last one , the XRF data were used. The presence of clay minerals like illite, montmorillonite and glauconite are evident from Fig. 11, however chlorite and kaolinte are not detected by this method.
The results of log-derived clay typing: a Th (vs) K, from Schlumberger ; b PEF (vs) K, from Schlumberger ; c PEF (vs) Th/K, from Schlumberger ; d Th (vs) Al2O3/(Al2O3 + SiO2) from . Black circle Gas producing well data points, and black up-pointing triangle non-producing well data points
Discussion
As a result of the insignificant sum of one’s potassium-free clay nutrients throughout the Shurijeh Development, the fresh sheer gamma beam, potassium and you can thorium signing study were utilized with certainty to find estimates off Shurijeh clay blogs. There is certainly a robust linear correlation between the pounds % clay additionally the natural gamma beam diary research according to the Pearson’s relationship coefficient. With regards to the XRD efficiency, brand new low-creating better was a whole lot more shaly that have a beneficial clay number of you to . 5 buy away from magnitude bigger than which had been inside the the newest gasoline generating really. The clay content determined from the altered natural gamma ray diary and its own spectral components investigation, surpassed the real core-mentioned for the factor, most likely by most other non-clay radioactive nutritional elements and you may/or perhaps the sized testing.
It’s clear the borehole logging means actions the newest natural radioactivity inside an enormous portion of material weigh of several kilograms, compared with this new core try hence is short for just a tiny percentage of a kg. This can be known as the size testing impact. On occurrence in place of gamma ray mix-patch (Fig. It was investigated regarding Fig. On the basis of the mediocre % relative mistake, certainly one of most of the before proposed modifications on the Shurijeh Development, men and women produced of the Dewan, Bhuyan–Passey, and you will Larinov encountered the very extensively overestimations. Dewan formula lead the greatest estimate problems, of the rapid property value 3 in its materials, that was a knowledgeable guess and there is actually zero counted research in the books to support it. Buhyan–Passey modification generated apparently incorrect estimations, as a result of the non-sensible presumption away from similar attributes for clay nutritional elements from the clastic reservoirs together with surrounding shales.
Larinov equation into the extremely consolidated rocks given overestimations too in addition to cause of that it inapplicability you are going to rest about general assumption used in the materials. It is are created according to the simple fact that this new elderly stones subjected to deep burial contain much more illitic nutrition as compared to most other stones because of the illitization regarding smectite as the a features out of burial depth. Since there are of numerous exclusions to that particular generalization, in the event that clay content was chose from Larinov older material contour, eg what is shown in Fig. The newest amendment advised by the Clavier is actually a sacrifice between your tertiary and you may old rock equations to possess quote of the clay content material in the reservoirs; however, they did actually some overestimate the fresh clay blogs of your Shurijeh tank Development (Fig.
Total, it looked your generalization element of empirical low-linear calibration relationships is actually much better than the last calibrations and you can brand new fitted error of your design are quicker
This new arrangement within XRD data in addition to Stieber rates is satisfactory; but the estimations given by the latest empirical calibration increased the precision of one’s estimations better than one to. On the clay articles http://www.datingranking.net/pl/blackplanet-recenzja quote objective, the use of the fresh new empirical relationships was receive significantly more reputable than just the before recommended variations of the sheer gamma ray record, because of its indicator thinking and you can lower estimation problems. The newest estimate problems of the many previously proposed variations was depended on the diary sorts of (the new gamma ray, potassium otherwise thorium logs), instead of brand new empirical non-linear calibration which had up to equivalent mistakes for all of your own different types of logs.