POSSIBILITY STUDY OF HYDRATE FORMATION IN RESERVOIRS OF THE NORTH-EASTERN PART OF THE INDIGIRKA-ZYRYANKA TROUGH

The paper gives a brief description of geological section of the Indigirka-Zyryanka trough, promising for oil and gas, and the results of parametric drilling. Possibility study of hydrate formation in reservoir conditions of trough as one of the reasons for obtaining negative well test results was conducted. Performed calculations of the equilibrium conditions of hydrate formation have determined that the hydrate stability zone covers an insignificant interval of deposits 222 m thick below the bottom of permafrost rocks. It is concluded that the main reason for the insignificance of the hydrate formation zone is a relatively high geothermal gradient, which causes sufficiently high reservoir temperatures in the section. It is noted that favorable conditions for the formation of gas hydrates may arise in the presence of heavy differential pressure drawdown on the formation in the vicinity of borehole.