PetroleumScienceinEnglishChapterThreeExploringforPetroleum（石油勘探）Developmentoftheexplorationandproductiontechniqueofpetroleumpeoplefoundpetroleumbychance（偶然）becauseitsseepedup（油苗）tothesurfaceandmainlyuseditforlightandheating.Laterpeoplefoundoilpoolsclosetothesurfaceandusetheequipmentasthosenowadaysweusetogetwaterfromwellstoobtainoil.After1859，thefirstpetroleumwellduginTitusville,Pennsylvania,USA，theoilindustryquicklydevelopedintoanextremelycomplextechnology,firsttofindoilbeneaththeearthandthentodrill（钻井）deeperanddeeperwellstobringittothesurface,asthereserves（储量）ofpetroleumgetlessandless.Offshore（海上）explorationandproductionhasbeengreatlypracticed.Moretechnique（技术）andtools（工具）andfields（领域）areinvolvedinfindingnewrecoverableresources（可开采的资源）ofpetroleumtomeetthedemandoftheworld.ExploringforPetroleum3.Aimpermeable（不渗透的）layermustoccuraboveareservoirbed,sinceoilislighterthanwater,ittendstomoveupwardsthroughopenings（孔洞）andcracks（裂隙）untilitencounters（遇到）imperviousbedsthatcannotpenetrate（穿透）.Theoilmaythenaccumulatebeneaththeimpervious（不渗透的）layers.4.Afavorable（有利的）structuremustexisttoconcentrate（积聚）theoilandgas；anticlines,faultsarecommonexamples.1.Geologicalsurvey（地质勘察）:petroleumgeologistsgotothesite（现场）observing（观察）theitsgeologicaloutlines（地质概貌）andsurroundings（地质环境）,examiningthelayersofrockscroppingout（露头）onthesurfaceoftheground,therockscouldbeprojectedinto（深入）thesubsurfaceandthelocation（位置）oftrapcouldbepredicted（预测）.3.Testdrilling（钻探）istheonlywaytoknowforsure（确定）ifthereiscommercial（商业的）gasoroilinasubsurfacetrapworthwhile（值得）toberecovered.Geologicalsurvey(frombeginningtotheend)geologicalreconnaissance地质普查detailedgeologicalsurvey详细地质勘察Geophysicalprospectingguarantees（确保）thesuccessofthepetroleumexplorationWhatisgeophysicalprospecting?GeophysicalinvestigationsoftheinterioroftheEarthinvolvetakingmeasurementsatorneartheEarth’ssurfacethatareinfluencedbytheinternaldistributionofphysicalproperties.（对地球内部的地球物理研究包括在地球表面或近地表做的种种测量，因为地表或近地表受地球内部物理特性分布的影响）(2)Analysisofthesemea