Geological-geophysical characteristics of the salt-bearing fluid traps at Siberian Platform
Nowadays, due to the start of large-scale development of the big helium-containing gas fields in Eastern Siberia, an interest grows in Russia to the issues of recovery, and middle- and long-term storage of helium in a form of methane-helium concentrate. A productive Eastern Siberia complex of Vendian-Cambrian sediments being characterized with high concentration of this unique gas is somewhat like domestic helium Eldorado. It is important that unlike the American and European helium-bearing fields, which are rather exhausted now, development of the helium-bearing fields in Eastern Siberia is at an initial stage. Simultaneously it creates the additional scientific and engineering problems for gas producers. The huge helium reserves, a statutiry requirement for its obligatory recovery, and commercial tasks of its profitable sales in conditions of limited consumer market predetermine critical necessity for creation of reliable underground storages for helium concentrate. Realization of this task is greatly complicated by the high penetrability of this inertial gas, which could be compared only with the penetrability of hydrogen. The most covers of hydrocarbon deposits are able to hold helium only for few years or even months.The article reveals results of authors' practical scientific studies aimed at determination of geological and petrophysical reliability of sealing thicknesses in order to substantiate selection of local structures for arrangement of underground helium concentrate storages. In course of works the well logs and well test data, results of heliumsurveys and petrophysical core tests, as well as archive and published materials were used. Finally, some interesting peculiarities of natural helium-bearing hydrocarbon systems were discovered. Also new data were obtained. At the end of the article these results are suggested for discussion.