About deformation changes of fractured reservoirs permeability

Authors: N.P. Lebedynets (VNIIneft OAO, RF, Moscow)

Key words: fractured reservoir, permeability, well productivity, pressure, strain, elastic capacity.

The increased interest in the possible anthropogenic changes in reservoir properties of productive deposits in the process of well operation and oil fields development is recently observed. At the same time the decrease of permeability of fractured reservoir rocks at formation pressure drop

is primarily implied. Some results of modern and earlier research with respect to Yurubcheno-Tokhomskoye and other fields with fractured reservoirs are considered. The conclusion on the feasibility of realization in many cases of elastic capacity of oil-and-water bearing systems with no concern about productive deposits permeability is made. It seems that a certain restraint at the interpretation of results of any research and development on their basis practical recommendations for real fields is necessary. In many cases, the elastic capacity of deposits with fractured reservoirs (of their oil-and-water bearing systems) can be used for oil recovery with little concern about the layers conductivity and wells productivity and at a big savings for reservoir pressure maintenance. At the same time it is impossible to exclude and some possible negative technological changes of reservoir properties by individual objects, primarily shallow lying, with increased bed shaliness. In each case a comprehensive analysis of available data and a possibly fuller account of the know-how are needed.