In order to realize the reasonable exploration and development of tight sandstone reservoir in Changqing Oilfield,the reservoir characteristics of target block are analyzed,the reservoir sensitivity evaluation experiment is carried out,and corresponding reservoir protection measures are suggested.Reservoir characteristic analysis results show that the target reservoir is mainly fine sandstone and siltstone,clay mineral total reach 14.5％ with illitesmectite and kaolinite,Ⅰ oil group and Ⅱ oil group average porosity are 12.24％ and 10.11％,the average penetration rate are 0.465 mD and 0.135 mD,respectively,and the formation water and water type is NaHCO3.The reservoir sensitivity evaluation results show that the target reservoir speed sensitivity is medium to high speed sensitive strong velocity sensitivity;water sensitive damage is medium to strong,critical salinity is 5 609.7 mg/L,the reservoir has weak base sensitivity,the sensitivity of hydrochloric acid and soil acid is non-acid sensitive,which can be treated by acidification,and the stress sensitivity degree is medium to strong.According to the exploration and development of tight sandstone reservoir in the later stage,reasonable reservoir protection measures should be selected,including reservoir protection fluid research,auxiliary processing agent research and acidizing fracturing construction technology selection,combined with the reservoir characteristics and reservoir sensitivity evaluation results.The technical support is provided for efficient development of tight sandstone reservoirs in Changqing Oilfield.%为实现长庆油田致密砂岩油气藏的合理勘探开发,分析了目标区块的储层特征,并进行了储层敏感性评价试验,提出了相应的储层保护措施建议.储层特征分析结果表明:目标区块储层以细砂岩和粉砂岩为主,黏土矿物总量达到14.5％,以伊蒙混层和高岭石为主,Ⅰ油组和Ⅱ油组平均孔隙度分别为12.24％和10.11％,平均渗透率分别为0.465 mD和0.135 mD,地层水水型为NaHCO3型.储层敏感性评价结果表明:目标区块储层速敏损害程度为中等偏强速敏至强速敏;水敏损害程度为中等偏强,临界矿化度为5 609.7 mg/L;储层具有弱碱敏;盐酸和土酸敏感性评价结果为无酸敏,为可酸化处理地层;应力敏感性程度为中等偏强.针对致密砂岩储层后期的勘探开发,应结合储层特征及敏感性评价结果,选择合理的储层保护措施,包括储层保护型工作液的研究、配套处理剂的研究以及酸化压裂施工工艺的选择等,为确保长庆油田致密砂岩油气藏的高效开发提供技术保障.
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