Classification of two-phase hydrocarbon deposits in connection with their industrial exploration on the example of Mangyshlak deposits

None of the existing classifications makes it possible to clearly divide two-phase deposits into different types, from oil-gas caps to oil-oil-related gas deposits, taking into account their fundamental differences that affect the exploration features. Thus, it is preferable to name all deposits in which the presence of oil and free gas is established by prospecting works as oil and gas oil. The meaning of these terms should be considered the same. About 40 years ago there were discussions on this issue too: some said that the main fluid in the reservoir is at the end, and if the reservoir is called gas-oil, the oil predominates there, while others argued that in the name of the reservoir in which oil predominates, it should be in front - oil and gas. This article discusses why the known classifications of two-phase hydrocarbon deposits conflict. The article considers variants of use of the proposed classifications for substantiation and rational carrying out of exploration works on deposits Tasbulat and Zhetybai. According to the results of the study, the most acceptable classification at the stage of industrial exploration in terms of the choice of location and number of exploration wells, as well as the tasks assigned to them, has been proposed.