Influence of hysteretic stress path behavior on seal integrity during gas storage operation in a depleted reservoir  

作　　者：Pierre Jeanne Yingqi Zhang Jonny Rutqvist 

机构地区：[1]Lawrence Berkeley National Laboratory,Energy Geosciences Division,Berkeley,CA,94720,USA

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2020年第4期886-899,共14页岩石力学与岩土工程学报（英文版）

基　　金：conducted with funding provided by the California Energy Commission under the contract PIR-16-027 for Research on Risk Management Framework for Underground Natural Gas infrastructure in California。

摘　　要：In this study,we numerically investigate the influence of hysteretic stress path behavior on the seal integrity during underground gas storage operations in a depleted reservoir.Our study area is the Honor Rancho Underground Storage Facility in Los Angeles County(California,USA),which was converted into an underground gas storage facility in 1975 after 20 years of oil and gas production.In our simulations,the geomechanical behavior of the sand reservoir is modeled using two models:(1)a linear elastic model(non-hysteretic stress path)that does not take into consideration irreversible deformation,and(2)a plastic cap mechanical model which considers changes in rock elastic properties due to irreversible deformations caused by plastic reservoir compaction(hysteretic stress path).It shows that the irreversible compaction of the geological layer over geologic time and during the reservoir depletion can have important consequences on stress tensor orientation and magnitude.Ignoring depletion-induced irreversible compaction can lead to an over-estimation of the calculation of the maximum working reservoir pressure.Moreover,this irreversible compaction may bring the nearby faults closer to reactivation.However,regardless of the two models applied,the geomechanical analysis shows that for the estimated stress conditions applied in this study,the Honor Rancho Underground Storage Facility is being safely operated at pressures much below what would be required to compromise the seal integrity.

关 键 词：Gas storage Stress path Geomechanical simulation Caprock integrity Fault stability Modified cam-clay model Honor rancho underground storage facility 

分 类 号：TE972[石油与天然气工程—石油机械设备]