简介：地层品质因子Q的可用于地震资料高分辨率处理,而从VSP资料下行直达波更容易获取准确的地层品质因子。通过对零偏移距VSP资料的监控子波和下行初至波的频谱进行综合分析,仿照Ricker子波频谱的表达式,本文提出了震源子波频谱新的表达式。在震源子波频谱新的表达式基础上,我们介绍了改进的频谱拟合法和改进的谱比法的层Q值反演方法及相应的处理流程。基于本文提出的层Q值反演方法,利用实际的零偏移距VSP资料的下行直达波,反演稳定的层Q值,并用于零偏移距VSP资料及井旁地面地震资料的反Q滤波振幅补偿处理,提高了地震资料的分辨率。

简介：Inthispaper,wetheoreticallyandnumericallystudyacombinedmonopole–dipolemeasurementmodetoshowitscapabilitytoovercometheissuesencounteredinconventionalsingle-wellimaging,i.e.,thelowsignal-to-noiseratioofthereflectionsandazimuthambiguity.First,theazimuthambiguity,whichexistsextensivelyinconventionalsingle-wellimaging,issolvedwithanimprovedimagingprocedureusingcombinedmonopole–dipoleloggingdatainadditiontoconventionalloggingdata.Furthermore,wedemonstratethatthedirectwavespropagatingalongtheboreholeswithstrongenergy,canbeeffectivelyeliminatedwiththeproposedcombinedmonopole–dipolemeasurementmode.Thereflectionsarethereforepredominantinthecombinedmonopole–dipoledataevenbeforethesignalsarefiltered;thus,thereflections’arrivaltimesineachreceiverareidentified,whichmayhelpminimizethedifficultiesinfilteringconventionalloggingdata.Theoptimizedprocessingflowofthecombinedmeasurementmodeloggingimageisgiveninthispaper.Theproposedcombinedmonopole–dipolemeasurementmodemayimprovetheaccuracyofsingle-wellimaging.

简介：Anewmulti-moderesistivityimagingsonde,withtoroidalcoilsassource,canconductthreeresistivitymeasurements:azimuthalresistivity,lateralresistivity,andbitresistivitymeasurements.Thus,theloggingtimeandcostaregreatlysaved.Thetoroidalcoilsaresimplifiedasanextendedvoltagedipoleandtheresponseequationsarederivedforahomogenousformation.Basedon3DFEM,thedepthofinvestigation(DOI),verticalresolution,circumferentialazimuthalcapacity,boreholediameter,mudresistivity,thicknessoftargetformation,andtheresistivityofthesurroundingformationandmudinvasionaresimulated.TheresultssuggestthatthethreemeasurementmodesofthenewsondearedifferentinverticalresolutionsandDOIs.Thecircumferentialdetectionabilityoftheazimuthbuttondependsonthecontrastbetweentheanomalyandformationresistivityandtheopenangleoftheanomaly.Whethertheboreholeistruncatedatthebitornothasagreatinfluenceonthesimulationresults.Theboreholeandmudinvasionaffecttheapparentresistivityinallmodes,buttheeffectsofresistivityofsurroundingformationandthicknessofthetargetformationareonlycorrectedforlateralresistivitymeasurement.