Polymodality of Secondary Kaolinite Distribution in Open Sandy Reservoir Systems

Abstract

Numerous studies by various authors on the results of transformation of open systems have shown that the intensities and contents of the transformed elements have a polymodal form of statistical distribution in the case of external influence on the system. Apparently, the essence of the phenomenon of statistical polymodality of transformation of systems is universal. Therefore, the universal theory of polymodal distribution formation can be used to analyze samples of secondary mineral contents in permeable sand reservoirs, which are open systems. Obviously, each mode of the polymodal statistical distribution of the transformed elements will be the result of the manifestation of some attractor. The purpose of this paper is to present a universal kinematic theory of the formation of a polymodal statistical distribution of the number of transformed elements of an open system, where secondary clay minerals, kaolinites subjected to the process of superimposed epigenesis in a sandy reservoir, are considered as the formed elements. The objects of the study are samples of secondary kaolinitization intensity values in sand intervals of oil and gas fields of the Yamal Peninsula and the contents of secondary kaolinite (determined from the core) in the Upper Jurassic sand strata of the Stolbovoye oil-and-gas field. The process of secondary kaolinitization is due to the influence of deep fluids. The research method was determined on the basis of the obtained equation of unified modes of a polymodal distribution of the number of transforming elements (in the process of transformation of systems). The number (intensity) of transformed elements is proportional to the ratio of the system transformation time to the flow time of the external influence on the elements of this system. Seven basic constants (attractors) related to the “golden” proportion are theoretically calculated, bringing them into conformity with the universal principles of system transformation process states. Having compared the constants obtained theoretically with the calculated unified values of the modes of the empirical data, the states of the system-transformation processes with respect to each mode are determined. Analysis of the modes calculated in the polymodal distribution of the secondary kaolinite intensities and kaolinite content, as well as comparison of the mode values (with the corresponding transformation principle) with the empirical data on the transformation processes, give evidence for the validity of the universal kinematic theory. Thus, using universal principles of transformation, on the basis of the determined contents of secondary kaolinite in the studied intervals of the permeable strata, it is possible to identify zones with desired chemical and hydrodynamic properties and characteristics.