第43卷第1期(2024-01)油气田地面工程https://yqtd.cbpt.cnki.net综合研究低渗透CO2驱注入井注入困难原因分析与防治对策*马锋1,2范冬艳1,2高强1,2李永宽1,21吉林油田公司油气工艺研究院2CO2驱油与埋存试验基地摘要:CO2的平稳注入是低渗透油藏CO2驱扩大波及体积与提高采收率的保障,针对CO2驱注入井、水、气交替过程中陆续出现的油管缩径、油管堵塞、近井油层堵塞等引起的注入困难问题,依托注水管线冲洗、连续油管冲洗返吐等方式,对储层、井筒、井口、管线等重要节点,开展了岩心、水质、固体沉积物、堵塞物取样分析,结果表明:由于注入水水质不合格,含油、机杂以及FeCO3、FeS、CaCO3等腐蚀结垢产物的二次污染是引起注入困难的主要原因。根据不同堵塞位置,优选设计了连续油管热洗+钻磨、连续油管旋转喷射+解堵液等解堵治理技术与措施,有效解除了井筒及近井地带堵塞现象。同时,针对欠注原因,优选了防腐药剂体系,配套了接力加药工艺与井口过滤器,形成了日常防控技术措施,保障了地面管线内防腐效果与入井流体合格,减少了管线、井筒、地层二次污染。通过防治技术相结合,保障了CO2驱注入系统高效、平稳注入。关键词:CO2驱;注入困难;解堵;接力加药;井口过滤AnalysisontheCausesofInjectionDifficultiesinLow-permeabilityCO2FloodingInjec⁃tionWellsandCountermeasures*MAFeng1,2,FANDongyan1,2,GAOQiang1,2,LIYongkuan1,21OilandGasTechnologyResearchInstituteofJilinOilfieldCompany2CO2FloodingandBurialTestBaseAbstract:ThesmoothinjectionofCO2istheguaranteefortheexpansionofsweptvolumeanden-hancedoilrecoveryofCO2floodinginlow-permeabilityreservoirs.Inviewoftheinjectiondifficultiescausedbytubingshrinkage,tubingplugging,andnear-wellreservoirpluggingduringthewater-gasalternationsofCO2floodingwells,themethodsofwaterinjectionpipelineflushing,andcoiledtubingflushingandbackflowareadopted.Samplesofcore,waterquality,solidsediment,andblockageareanalyzedforimportantnodessuchasreservoir,wellbore,wellhead,andpipeline.Itisfoundthattheinjectionwaterqualityisnotqualified,thesecondarypollutioncausedbyoil,impurities,andcorro-sionandscaleproductssuchasFeCO3,FeS,andCaCO3arethemaincauseofinjectiondifficulties.Accordingtodifferentpluggingpositions,the...