Experimental Study And Theoretical Analysis Of Water-sealed Mechanism Of Underground Water-sealed Oil Storage

As groundround water seal oil storage has the advantages of security, storagecapacity, economic, and environmental protection, in recent decades it achievesconsiderable development. Our country has been stepping up the construction ofUnderground Water-sealed Oil Storage project in eastern coastal areas, but at presentmechanism and conditions of Underground Water-sealed Oil Storage still stay in theexperience judge level. It is urgent to carry out systematic research work on themechanism of Underground Water-sealed Oil Storage. Through the research ofsingle-fracture model test, combining hydrological conditions, geological conditionsand the general characteristics of groundwater in crystallization cracks, this paperstudy water-sealed mechanisms and factors of influencing Underground Water-sealedOil Storage on the aspects of geological conditions and groundwater dynamics. It hasa certain theoretical significance and practical value for guiding choosing reasonablelocation of caverns and setting of water curtain system. Researches in this paperinclude:(1). Study of geological conditions, hydrological conditions and generalcharacteristics of fissure water of Underground Water-sealed Oil Storage, whichenlightens the design of the model and the research of mechanism.(2). Relations and laws among hydraulic jump, water column height, crack widthand the height of water level an be obtained through model tests, which has importantsignificance for guiding choosing location of caverns and cavern depth.(3). Through the results of displacement tests, displacement process betweenwater and oil can be quantified by water-jump change and two parameters of N1andN2is introduced to quantify water-jump value of units of the degree of oiling valueand drawdown of water. Two conditions are simulated, which provide a scientificbasis for the evaluation of water-sealed conditions and remedies of oil spilling.(4). On the basis of the analysis of experiments results, combining the geologicalconditions and hydrological conditions, from the perspective of geology, two macro mechanism are proposed: mechanism when water supply is adequate and mechanismwhen water supply is insufficient.(5). On the basis of the results of tests, from the hydrodynamic point of viewpropose, microscopic mechanism of water-sealed conditions is proposed.One-dimensional differential equations of the fracture seepage is established, whichbecomes the theoretical basis of microscopic mechanism of water-sealed conditionsand can gudience the research of water-sealed mechanism and the evaluation of oilspill risk.