METHOD TO DETECT GAS HYDRATES IN LOW-TEMPERATURE ROCKS Russian patent published in 2013 - IPC E21B47/07 

FIELD: oil and gas industry.

SUBSTANCE: standard electric logging of a well is carried out in low-temperature rocks, the area of possible bedding of gas hydrates and hydrate formation is identified in them. In the identified area of low-temperature rocks, on the basis of data of standard electric logging, zones are registered, in which measured values of the apparent electric resistance of low-temperature rocks are equal to at least 15 Ohm.m. Coolant is pumped in the investigated rock interval, afterwards thermometry is realised using highly sensitive thermometers, providing for error of temperature measurements of not more than 0.01°C, and zones are sought for, rock temperature in which, relative to the lowest registered temperature in the identified zone is at least by 0.2-0.5°C lower than the temperature of rocks adjacent to the borders of the detected zones. At the same time the latter zones are considered as zones containing gas hydrates. The area of possible bedding and hydrate formation is the area of rock bedding characterised by availability of thermobaric conditions for gas hydrates existence in rocks.

EFFECT: its higher efficiency by detection of gas hydrate rocks bedded in low-temperature rocks below a foot of permafrost rocks.

3 cl, 1 dwg