An Analysis on the Coherency and Importance of the Physical and Chemical Parameters of the Soils in Tarim Region

With the exploitation of oil and gas fields in western China, more and more metallic facilities will be buried in desert and salinized soils, corrosion and corrosion control, therefore, have been placed on the agenda. So, a comprehensive investigation on soil corrosivity was made in five oil zones in northern Tarim a great deal of data obtained. The physical and chemical properties of soils are tested both at laboratory and field and the coherency and importance analysis for the 24 important parameters in the measured data is made using PCA method. The analysis result shows the following 5 parameters are the most important: ①Field pH value, being related to meny other parameters, having the comprehensive function similar to that of the resistivity of the inland wet soil, ranking second and first in the importance list of parameters from field and laboratory respectively; ②Soil heterogeneity, ranking third and second in the importance list repectively; ③Carbonate, being related to Cu equilibrium potential, having the formation similar to "inhibition of acid-base corrosion", and ranking second and third in the importance list; ④Soil mineralization, the same kind of index with the electric conductance of leachate, an important factor in soil corrosivity; ⑤The index of sulfide, a unique property having little relation with other soil parameters. These five parameters can reflect the basic soil properties, being the reference data for the corrosion control of metallic facilities.