EXPERIMENTAL STUDY OF STORAGE-VARIABLE TRANSIENT PULSE METHOD FOR PERMEABILITY MEASUREMENT
WANG Ying，LI Xiaochun，WEI Ning
(State Key Laboratory of Geomechanics and Geotechnical Engineering，Institute of Rock and Soil Mechanics， Chinese Academy of Sciences，Wuhan，Hubei 430071，China)
Abstract：Based on the storage-variable transient pulse method and its experimental arrangement，the limitations of the old arrangement in measuring range have been discussed. As a result of the shortcomings，the old arrangement has been modified perfectly. The validity and repeatability of storage-variable transient pulse method have been improved greatly by using the new arrangement. The storage varied range of the new storage-variable apparatus has been testified over 10－2–102 mL/MPa，by making the repeatability experiments for one and the same sample at multi-order apparatus storages. The appropriate measuring range of the new experimental arrangement has been confirmed between 1 mD and 1 D，as well as the proper measuring time during 10 s–2.5 h，moreover，the new arrangement performs satisfactorily showing from high repeatability which is less than 5%. The test results show that the relations among specific storage of apparatus，decay time and permeability obtained from tests in accordance with those shown from theory. Small storage of apparatus can shorten measuring time，whereas large storage will prolong testing time. That is to say，small storage for impermeable sample and large storage for high-permeable one should be selected. Thus it is clear that many kinds of rocks with different permeabilities and also those permeabilities varied widely can be measured efficiently by using transient pulse method experimental arrangement，thereby a broad application prospect will be looked forward.
