简介：Webuiltathree-dimensionalmodeltosimulatethedisturbanceofthestressfieldnearthereversefaultinZhaziao,LeyiTownshipowingtohydraulicfracturing.Theporepressure,andshearandnormalstressesduringfracturingareanalyzedindetail.Inputrockmechanicsparametersaretakenfromlaboratorytestdataofshalesamplesfromthestudyarea.Thesimulationresultssuggestthatafter16hoursoffluidinjection,thepore-pressurevariationcanactivatethereversefault,i.e.,weobservereverseslip,andtheshearstressanddisplacementonthefaultplaneincreasewithtime.Thebiggeststress–strainchangeoccursafteronehouroffluidinjectionandtheyieldpointappearsabout0.5hafterinjection.Toobservethestressevolutionineachsection,thenormaldisplacementontheboundaryisconstrainedandthefaultplaneissetasnonpermeable.Thus,theslidingislimitedandthesheardisplacementisonlyinthescaleofmillimeters,andthecalculatedmagnitudeoftheinducedearthquakesisbetweenMw-3.5andMw-0.2.Thesimulationresultssuggestthatfluidwaterinjectionresultsininhomogeneousfracturing.Themainrupturedareasarearoundtheinjectionpositions,whereastheextentofrupturingandcracksinotherareasarerelativelysmall.Nevertheless,nonnegligiblefaultactivationisrecorded.Sensitivityanalysisofthekeyparameterssuggeststhattheporepressureismostsensitivetothemaximumunbalancedforceandtheinternalfrictionanglestronglyaffectsthefaultslip.Finally,thecomparisonbetweentheeffectivenormalstressandthemaximumandminimumprincipalstressesonthefaultplaneexplainsthefaultinstability,i.e.,theMohrcirclemovestowardstheleftwithdecreasingradiusreducesandintersectsthecriticalslipenvelope,andcausesthefaulttoslip.

简介：地震数据重构是地震数据处理的重要步骤之一,重构算法的精度、效率与抗噪性是地震数据重构技术的核心研究内容。研究针对傅里叶域凸集投影(POCS)算法,在定义的最优阈值评价标准基础上,提出了反比例阈值模型,该模型具有在大系数区间比指数模型更快下降速率、而在小系数区间比指数模型更慢下降速率,从而在保证弱反射信号重构精度的同时有效提高POCS地震数据重构算法计算效率。为提高反比例阈值对不同地震数据特点的适应性,在地震数据谱能量分布差异性特征分析基础上,研究提出了在反比例阈值模型分母上增加适应地震数据谱能量特征的因变参数,通过调节该因变参数获得适应不同地震数据特点的最佳阈值曲线,进一步提高算法的计算精度与计算效率。为了实现重构过程中随机噪音的自适应衰减,提高重构后地震数据信噪比,研究提出了数据驱动的加权回加系数计算策略,利用每次迭代对应数据驱动阈值占阈值区间的百分比获得加权回加系数。研究将新方法应用于模拟三维数据和实际三维地震数据,分析结果表明反比例阈值相对传统阈值在提高数据重构计算效率和精度方面具有明显的优越性,新提出的加权回加系数计算策略能有效提高重构数据的信噪比。