摘要
莱州湾凹陷垦利某油田沙四段砂砾岩体地层厚度纵、横向差异大,受岩性、物性等因素影响,储层非均质性强。在测井响应特征相近的层段,测试结论却有油层、有干层,储层有效性评价面临极大挑战。针对这一难题,综合取心、铸体薄片、扫描电镜等资料发现,受母岩火山碎屑物质的影响,砂砾岩发生了蚀变,蚀变程度的差异,导致黏土含量的变化。全岩分析和测井曲线综合表明,中子孔隙度和密度相对值法计算的黏土含量可以定量判别地层蚀变程度,并构建了蚀变指数,将蚀变指数与全岩分析黏土含量建立联立关系,可以准确计算地层的总黏土含量。黏土含量小、纵波时差大,储层有效性好;反之较差。因此,基于黏土含量和纵波时差建立了储层品质因子,结合蚀变指数,建立了复杂砂砾岩储层有效性评价图版。经实际资料证实,该方法确定的有效储层准确可靠,这也对今后类似储层的测井评价具有重要指导意义。
The thickness of glutenite reservoir in Shahejie Formation 4 Member in Kenli oilfield,Laizhouwan sag varies greatly in vertical and horizontal directions.Affected by lithology,physical properties and other factors,the reservoir shows strong heterogeneity.In intervals with similar logging response characteristics,the test conclusions are different between oil layers and dry layers,which makes the evaluation of reservoir effectiveness facing great challenges.In view of this problem,combined with the data of coring,cast thin section and scanning electron microscope,it is found that the glutenite has been altered under the influence of parent rock pyroclastics,and the alteration degree results in clay content changes.The whole rock analysis and logging curves show that the clay content calculated by neutron porosity and density relative value method can quantitatively distinguish the formation alteration degree,thus the alteration index is constructed.The total clay content of the formation can be accurately calculated by establishing a simultaneous relationship between the alteration index and the clay content of whole rock analysis.If the clay content is small and the P-wave slowness is large,the reservoir effectiveness is good;On the contrary,it is poor.Therefore,based on the clay content and P-wave slowness,the reservoir quality factor is established,and combined with the alteration index,the evaluation chart of complex glutenite reservoir effectiveness is established.The actual data show that the effective reservoir determined by this method is accurate and reliable,which is of great guiding significance for the logging evaluation of similar reservoirs in the future.
作者
王培春
崔云江
WANG Peichun;CUI Yunjiang(CNOOC China Limited,Tianjin Branch,Tianjin 300459,China)
出处
《中国海上油气》
CAS
CSCD
北大核心
2022年第2期59-66,共8页
China Offshore Oil and Gas
基金
中海石油重大科技专项“渤海中深层复杂油气藏高效开发技术(CNOOC-KJ135ZDXM36TJ03TJ)”部分研究成果。
关键词
砂砾岩
有效性
蚀变
黏土
纵波时差
品质因子
glutenite
effectiveness
alteration
clay
P-wave slowness
quality factor
