DETECTION OF BURIED GAS HYDRATES FROM INERT-GAS CONCENTRATIONS

Abstract

Use of the entire group of inert gases as an indicator of the presence of hydrates has many advantages. First, it avoids the above problem of inaccurate knowledge of the composition of the original gas. Second, the ability of inert gases to form individual hydrates increases in the order (He, Ne)-Ar-Kr-Xe. Third, by virtue of its chemical properties, the inert-gas system would be immune to various types of interference by chemical and biochemical processes that would alter the concentrations of any other, noninert components. Fourth, mass spectrometry can be used to determine the concentrations and isotopic compositions of the inert components with high accuracy. The above reasoning was partially tested by analyzing two gas samples from the Messoyakh field, where artificially-induced gas hydrate generation in zones adjoining the drillhole in the upper part of the productive sequence was suspected. The results indicate that the gases generated during operation of the Messoyakh field were residues of a hydration process. Thus, the overall composition of the inert component of natural gases is a promising indicator for use in detecting and prospecting for gas hydrates.