摘要
针对TMCG盆地火山碎屑砂质复成分砾岩→过渡复成分砾岩→凝灰质(高伽马)的3类复成分砾岩的不同测井响应特征,以岩心实物观察和X衍射全岩分析和X衍射频谱分析结果为基础,对具有不同测井响应特征的砾岩的矿物成分、岩石结构、化学元素构成及其对测井响应特征的影响进行深入分析。3类砾岩的放射性逐渐增加与岩石中所含黏土类型及其含量相关性小,是其所含砾石母岩中基性火山碎屑岩减少、酸性火山碎屑岩含量增加导致U和Th含量增加所致,与具低放射性造矿氧化物含量减少有关;3类砾岩的中子响应值逐渐变小,与岩石中含有大量结晶水和结构水的矿物含量关系较小,主要原因是岩石中大中子俘获截面稀有元素和大中子俘获截面造矿氧化物的含量逐渐减少所致。分析结果明确了测井响应特征的主要影响因素,为储层评价岩石骨架参数、孔隙度模型、泥质含量模型等的确定奠定良好基础。
There are different logging response characteristics of polymictic pyroclast- conglomerate in TMCG basin. Based on core physical observation and Xray diffraction whole core analysis and X-ray diffraction spectrum analysis, the conglomerate mineral composition, rock structure, chemical element and their influences on log responses are thoroughly analyed. Radiation increasing of three types of conglomerate only has a little correlation with its clay types and contents; The reduction of basic pyroclast in the native conglomerate and increase of acidic pyroclast content results in U and Th content increments, and have relation with decrease of lower radiation oxidate content in the rock-forming mineral. The neutron log response of the 3 types of conglomerate gradually reduces, which does not have close relation with mineral contents in the rocks with much crystal water and conatitutional water, but mainly has relation with decrease of the rare elements and oxidate contents in thermal neutron capture cross sections. The above analyses obviously indicate the main influence factors on log responses, which provides a good foundation for further determining the rock matrix parameters, porosity model and shaly content model.
出处
《测井技术》
CAS
CSCD
北大核心
2012年第6期569-574,共6页
Well Logging Technology
关键词
测井解释
测井响应
复成分砾岩
自然伽马
中子
交会图
log interpretation, logging response, polygenetic conglomerate, natural gamma, neutron, cross-plot
