Multifactorial and multiscale causes of salinization of productive horizons in hydrocarbon deposits of the southern Siberian Platform

One of the fundamental problems of prospecting, exploration and exploitation of oil and gas fields is the co–occurrence, temporal and spatial relationships of oil and gas-bearing and salt-bearing strata of various scales: from productive oil and gas horizons of individual fields to oil and gas complexes. Almost all productive oil and gas horizons of hydrocarbon fields of the Siberian platform including the widespread Yaraktinsky horizon are subject to intensive salinization processes of various scales and for various reasons. Based on genetic features and the sequence of occurrence salinizations could be classified into primary salinization – syngenetic occurring simultaneously with sedimentation, and secondary one – postgenetic caused by a number of diverse natural and man-made factors. The paper considers the main factors of salinization, which with a certain degree of conventionality can be differentiated as follows: by scale – global (historical and geological) and regional (trap magmatism); by causes – tectonic and magmatic; by occurrence time – primary (syngenetic) and secondary (epigenetic); by nature – natural and man-made (occurring during operation). Downhole equipment is subject to intense man-made salinization in the near-wellbore zone of the productive formation in the interwellbore space, which ultimately complicates drilling processes, leads to accidents, and significantly increases the cost of equipment during operation.

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