The Fundamental Study On Building Gas-oil Storage Cavern In Rock Salt Deposit

Based on the safety of our country'energy sources and the project of west gas transporting to east, it is urgent to build gigantic storage cavern.We have done some fundamental experiments on feasibility, building methods and stability of analysis on the gas-oil storage cavern which built in the rock salt beds, to provide some references for building storage cavern in rock salt beds.If the storage caverns are built in the rock salt, it is priority to use the chemical dissolution for building the cavern.Through experiments, we have studied on solution characteristic of glauberite-one kind of rock salt-in water and chemical impregnant,the characteristic curves of solution are established in different solution condition.That can direct the fast slot in the rock salt beds.Osmosis is a decisive parameter which relate whether the storage cavern be built in the rock salt beds or not .Through the three-dimensional osmosis experiment , the osmosis characristic laws which change with time to high are built. In mechanics experiment ,we get the parameters of compression strength,tensile strength and shear strenght.Considering differnt temperature of the liquid in the storage cavern under differnt tension,we have done the mechanics experiments on rock salt in high temperature,get theconclusion that the rock salt parameters improved highly .At the same time, we studied on the solution mining method, included single-well convection and double-well solution connection. As the use of solution mining method-double-well solution connection ,we conclude that level circle storage cavern which built by directed connection solution method or level ellipse storage cavern which built by double-well hydraulic fracturing connection is fit for the geologic condition in our country in the storage cavern building . Using the FEM analysis soft we have analyzed the stability of the cavern in different inside-press, we found the plastic area and vertical displacement are diminished with the increasing inside press,at the same time,the vertical stress tend to the press of base rock ,and get the conclusion that underground 1000 meters, to build circular cavern with diameter of 50 meters or ellipse cavern with long axis of 25 meters and inside press above 10MP, no area show plasticity,the stability of cavern is well.