简介:TheNorthYellowSeaBasin(NYSB),whichwasdevelopedonthebasementofNorthChina(Huabei)continentalblock,isatypicalcontinentalMesozoic-Cenozoicsedimentarybasinintheseaarea.ItsMesozoicbasinisaresidualbasin,belowwhichthereisprobablyalargerPaleozoicsedimentarybasin.TheNorthYellowSeaBasincomprisesfoursagsandthreeuplifts.Ofthem,theeasternsagisaMesozoic-CenozoicsedimentarysaginNYSBandhasthebiggestsedimentthickness;thecurrentKoreandrillingwellsareconcentratedintheeasternsag.Thissagiscomparativelyrichinoilandgasresourcesandthushasarelativelygoodpetroleumprospectinthesea.ThecentralsaghasalsoaccommodatedthickMesozoic-Cenozoicsediments.ThelatestresearchresultsshowthattherearethreeseriesofhydrocarbonsourcerocksintheNorthYellowSeaBasin,namely,blackshalesofthePaleogene,JurassicandCretaceous.TheprincipalhydrocarbonsourcerocksinNYSBaretheMesozoicblackshale.AccordingtothedrillingdataofKorea,theblackshalesofthePaleogene,JurassicandCretaceoushaveallcomeuptothestandardsofgoodandmaturesourcerocks.TheNYSBownsanintactsystemofoilgeneration,reservoirandcappingrocksthatcanhelphydrocarbontoforminthebasinandthusithasthegreatpotentialofoilandgas.TheverticaldistributionofthehydrocarbonresourcesismainlyconsideredtobeintheCretaceousandthenintheJurassic.
简介:Decreasingtherisksandgeohazardsassociatedwithdrillingengineeringinhigh-temperaturehigh-pressure(HTHP)geologicsettingsbeginswiththeimplementationofpre-drillingpredictiontechniques(PPTs).ToimprovetheaccuracyofgeopressurepredictioninHTHPhydrocarbonreservoirsoffshoreHainanIsland,wemadeacomprehensivesummaryofcurrentPPTstoidentifyexistingproblemsandchallengesbyanalyzingtheglobaldistributionofHTHPhydrocarbonreservoirs,theresearchstatusofPPTs,andthegeologicsettinganditsHTHPformationmechanism.OurresearchresultsindicatethattheHTHPformationmechanisminthestudyareaiscausedbymultiplefactors,includingrapidloading,diapirintrusions,hydrocarbongeneration,andthethermalexpansionofporefluids.Duetothismulti-factorinteraction,acloudofHTHPhydrocarbonreservoirshasdevelopedintheYing-QiongBasin,butonlytraditionalPPTshavebeenimplemented,basedontheassumptionofconditionsthatdonotconformtotheactualgeologicenvironment,e.g.,Bellotti’slawandEaton’slaw.Inthispaper,wefocusontheseissues,identifysomechallengesandsolutions,andcallforfurtherPPTresearchtoaddressthedrawbacksofpreviousworksandmeetthechallengesassociatedwiththedeepwatertechnologygap.Inthisway,wehopetocontributetotheimprovedaccuracyofgeopressurepredictionpriortodrillingandprovidesupportforfutureHTHPdrillingoffshoreHainanIsland.