Morphology Detection And Stability Evaluation Of Salt Cave Underground Energy Storage

Halite ground energy reserve has the advantages that is low building cost,a facile construction technique,excellent leak tightness and not vulnerable to be attacked.It has become the main measure of energy storage in every country.However,owing to the effect of construction techniques and geology agent,it is hard to the cavities of ground energy reserve to generate regular contour,which poses a major security menace to the long and steady operation of ground energy reserve.Therefore,it has very important realistic meaning to develop three-dimensional message locate and operation period stability assessment of energy storage caverns.This paper mainly finished as followings four fields of study work:（1）The influencing factors of the stability of ground energy gas storage cavern in salt layer are analyzed theoretically,and the responsive relationship between the cavity parameters,surrounding salt formations,running pressure,mechanical characteristics of lamination and interlayers,mechanical characteristics of salt rock and the stability of gas storage is emphatically elaborated.The stability standards and usability standards are concluded;The merits and demerits of disparate stability appraisal methods of salt cavity gas storages are compared and analyzed,and optimization hierarchy-entropy method is optimal selected as the stability evaluation method of gas storage cavern in operation period.（2）Based on a gas storage project in Jintan,the cavity shape field detection was carried out.The cavity is crescent-shaped as a whole,and the central position of the chamber is inside-notch in the northwest area and convex in the south eastern area.The3d configuration geometric description of the gas storage chamber is constructed by accessing the morphological data of the gas storage reservoir,and the rationality of the3d shape is verified.The regional malformation at top and basement of the gas storage cavern is severe,which influences the whole stability of the gas storage chamber.（3）The three-dimensional shape of the gas storage cavity as base,building the numerical computation model of the cavity by utilizing the numerical simulation software Flac^3D,and the long-term creep of the salty caver storage with three forms（ellipsoid,semi-major axis ellipsoid and real chamber）under different operating conditions is researched.It is found that the deformation of the regular cavity is uniform and the contraction displacement of the cavity is small,while the deformation-processed of the real cavity mainly takes place at the concave deformed body in the cavity.Under the same working conditions,the volumetric shrinkage and maximal position shift of the real cavity are larger than two types of regular cavities,and the real cavity gas storage is less stable than the regular cavity in operation.The conclusion obtains the necessity of simulation modeling research based on real cavity.It is suggested that the running pressure safety margin of the reservoir is 8～18 MPa.（4）The reason and impact factor of gas storage accidents at native and foreign are statistically analyzed,and the stability assessment system of ground salt cavern gas storage in operation period is constructed.The assessment system is used to comprehensively evaluate the stability of Jintan Gas Storage,and the score of stability evaluation is 72.52,which pertain a relatively stable state,but it needs to take control measures.Finally,the relevant efficient recommended measures are proposes corresponding for the issue during the build database and operating processes of the gas storage cavity.The research wroks of this paper can supply a beneficial reference for the create database and running administration of salty cavern gas storage.