So it empirical relationship is actually one particular successful estimator for approximately 20% weight percent clay articles; the gaydar promo codes most famous situation about sandstone reservoirs
It’s also inferred using this study one to, the fresh new Shurijeh reservoir Development try transferred on aquatic ecosystem due to the fact Th/U proportion varied anywhere between step one.8 and 23.dos regarding the gas promoting well and you will anywhere between step 1.2 and you can 5.6 on non-promoting really. The studies situations in both wells discover Th/You ratios lower than 10 indicating one to, the new depositional ecosystem had an aquatic characteristics. The greater Th/You proportion from the energy creating better would be on account of more oxidizing standards or perhaps to a higher intensity of almost every other radioactive minerals for example K-feldspar otherwise heavier nutritional elements on the mud dimensions fraction. The new intermediate Th/You ratio throughout the dos–seven in the low-producing really showed a decreased values from weathering and you can leaching out of uranium, otherwise it could be inferred given that a sign of blends off materials off reduced and high ratio environments.
This new get across-plots of land testing made it clear that Shurijeh isn’t a great clean tank since line of group analysis things just weren’t close to the foundation in not one of the cross-plots found throughout the Fig. 11; these people were every clustered regarding down remaining-hand spot each and every mix spot. Faster differences within wells as opposed to between wells, ideal particular scientific changes particularly additional diagentic histories anywhere between wells. The details affairs of your energy generating well had been reduced well discriminated but the exhibited relatively modest potassium and you can thorium into the mix plot marked A through Fig. eleven. For both wells, the information and knowledge issues towards clay typing mix-plots of land dropped within the a particular area you to definitely showed all round types of one’s clay vitamins in the area. Yet not, specific data of one another wells had been managed to move on off the development. Even when, there can be zero contract to the clay models lead from the each cross-patch, however, in accordance with the overall performance considering of them, the brand new clay mineralogy throughout the formation around data would-be ended since simply off glauconite/smectite/muscovite/Illite sizes. These abilities were not in the contract with that of XRD lab education accomplished with the center examples of each other wells. The latest kaolinite, chlorite, plus the mixed level clay vitamins were including remained unrecognized because of the it petrophysical method.
Results
In this paper, all previously proposed modifications of natural gamma ray log and its spectral components data were reviewed and a new calibration equation for reliable assessment of the clay content in the Shurijeh reservoir Formation was presented. The quantitative XRD results showed a low average percentage of clay minerals for the gas producing well and moderate amounts for the non-producing well. The differences between the varying amounts of clay minerals in wells were attributed to the changes in the diagentic histories. In both wells, all the previously proposed modifications overestimated the weight percent clay indicating it is critical to calibrate petrophysically-derived weight percent clay to the laboratory data to find better estimations. The results also showed by using natural Steiber modified gamma ray values, more reliable clay contents could be obtained rather than all other previous modifications in this area. On the basis of minimum average percent relative error, the natural gamma ray and thorium curves were powerful tools to recognize the clay zones in a sandstone reservoir rather than potassium curve. In summary, the comparison of core clay contents from quantitative XRD data, estimated values using the previously proposed modifications and the empirical calibration, demonstrates that a simple nonlinear regression using the XRD data and natural gamma ray index (IGR) allows for the quantification of clay content with the least percent relative errors, i.e., lower than 12%, which is comparable to the values of the methodological errors associated with the XRD analysis. The excellent agreement between the locally calibrated natural gamma ray index and the clay quantitative XRD data showed it was well suited to provide reliable quantitative clay content estimates. The application of the proposed approach in this paper, will significantly improve the weight percent clay estimations from the gamma ray log in the Gonbadli field. The depositional environment can be correctly recognized from the spectral gamma ray logging ratio, however the safest method of reservoir clay typing is still based on the laboratory analysis of core samples. Overall, the natural gamma ray log and its spectral components data proved to be dependable qualitative and quantitative tools to diagnose clay minerals in sub-surface formation studies. In this paper, the broad scope of problem-solving capability of them was illustrated in the reservoir formation evaluation.