INVESTIGATIONS ON STUDIED SITUATIONS ASSOCIATED WITH MECHANICAL ASPECTS AND DEVELOPMENT FOR UNDERGROUND STORAGE OF PETROLEUM AND NATURAL GAS IN ROCKSALT
Abstract:Rocksalt is often utilized as underground storage media in which petroleum and natural gas are stored regarding as strategical and commercial resources,which have been extensively utilized in European countries because of mechanical characteristics of rocksalt such as lower permeability and rheology. On the base of the studies and investigations associated with mechanical aspects of rocksalt such as petroleum and natural gas,underground caverns are firstly divided into four stages as follows:(1) the stage of simple application for underground storage combination mechanical knowledge and experiences of mining engineering during the beginning of 1960s;(2) the stage of models researches utilizing large rocksalt samples in which simulating the process of natural gas or petroleum storage dated from the middle of 1960s to the end of 1970s;(3) the stage of numerical simulation and calculation by means of FEM or FLAC,considering experimental results of rocksalt samples from 1970s to the middle of 1990s;(4) the stage of damage and healing constitutive of rocksalt from the middle of 1990s up to now,and situations of each stage are analyzed and discussed. Dominant researchers and their studies associated with mechanical properties of rocksalt are also given. Then,some typical constitutive equations for rocksalt are summarized and discussed. Furthermore,the characteristics of constitutive equations are introduced,particularly,Norton model and Hou/Lux constitutive model of damage and healing for rocksalt are induced. The advantages and disadvantages between the two constitutive models are indicated. Finally,the development trends of mechanical studies of rocksalt as petroleum and gas underground storage are listed.