Recognition model of potassium-rich brines in the middle and deep layers of the Qaidam Basin
The central depression area in the western part of the Qaidam Basin is rich in potassium-bearing deep brines with high development value.The deep brines have complex lithology and diverse pore types,which makes it difficult to evaluate the potassium element in the brines.In order to explore industrial grade potassium rich brine layers and study the response law of potassium element logging,quantitative evaluation of potassium ion content in brine layers was carried out using formation water re-sistance spectra and volume models.The results show that:the formation water resistivity spectrum ob-tained based on the micro-resistivity imaging data can effectively identify the water layer by extracting the mean and geometric mean,and the formation water resistivity spectrum of the water layer has a nar-row distribution,with the peak of the spectrum at the front,and the mean and geometric mean are smal-ler;the porosity,skeleton and mud content of the reservoir is obtained by using the calculated volumet-ric model of elemental potassium,and the results can be quantitatively evaluated by using the Induc-tively Coupled Plasma Emission Spectrometry spectroscopy(ICP-OES)before and after the salt wash-ing,which can be used to quantify the brine content.OES can quantitatively evaluate the potassium ion content of the brine layer;ICP-OES and natural gamma energy spectrometry logging can calibrate the total potassium content of the brine layer,and the combination of multivariate linear regression can es-tablish an elemental evaluation method for the brine layer.The lithium content of brine calculated by volumetric model is in good agreement with the experimental results,and this study can quickly and ef-fectively identify the potassium content of brine,improve the identification ability of brine reservoir,and provide an important basis for the prediction of the spatial distribution of brine in the study area.
万方数据
维普
