For routine and special core analysis, first we plugged cores for removing oil, water, evaporates, drilling mud and other contaminants and then washed with solvents and dried out. The common washing for some cores is that, they do not wash part of evaporates, asphaltenes, surfactants or drilling materials in the rock samples. Without removing these contaminants, the porosity and permeability calculated from these rock samples are not precise at all. In case of washing samples, there is always a problem in conducting tests on cores in laboratories. In this research, we tried to minimize the possible damages in this process by detecting a sample with predominant clay minerals based on X-Ray Diffraction (XRD) test and Cation Exchange Capacity (CEC) test of the samples, then washing with 3 different solvents by Soxhlet extractor. Finally, we, measured the strength of the wettability changes of each sample. This can be evaluated with Zeta potential test. After providing SEM and microscopic images, we compared the damages to each other. Then with the EDS test, we investigated the removal of the elements in the sample by its solvent. In this study, different solvents were tested on clay minerals with the aim of identifying the effect of these solvents and comparing the different effects on these samples. Pre- and post- analyzes were performed at optimal conditions for washing and drying.

The purpose of this article was to generate and compare seismic modeling results with real vertical seismic profiling data (VSP data) based on Dipole Shear Imager (DSI) data in the reservoir zone (Kangan and upper Dalan Formations) of a well in South Pars gas field. Estimation of shear wave velocity (Vs) and density for layers above the reservoir zone, for which; DSI data did not exist, was also done by the applied modeling method to estimate elastic parameters of the layers. In this method, modeling for X-component of the VSP survey was run by utilizing the DSI data set of reservoir zone and the VSP survey report of the studied well with high precision. Computed results for the proposed modeling method led to achieving highly accurate, close to the reality of VSP model around the studied well. According to compression wave velocity (VP) attained from VSP survey reports of the well and Vp/Vs ratio obtained from Dipole Shear Imager (DSI), modeling was done. Afterward, shear wave velocity (Vs) for upper layers of reservoir zone estimated with high precision, then density and elastic moduli for the above layers and the reservoir zone were calculated.