摘要
含油气盆地太古宇逐渐成为现实的油气勘探领域之一。针对油气勘探工作中盆地覆盖区基底——太古宇的岩石类型难以判识的问题,以济阳坳陷太古宇为例,借鉴其周边露头区太古宇的发育特征,综合利用坳陷内钻井取心观察、岩心镜下鉴定结果、录井资料及岩心的岩石地球化学分析等资料,明确了济阳坳陷太古宇的岩石类型包括岩浆岩和变质岩两大类8种,以岩浆岩为主,主要为二长花岗岩,其次为闪长岩。以岩心资料为基础,通过对比分析,筛选了自然伽马、声波时差、补偿中子、补偿密度和光电吸收截面指数等岩性敏感测井曲线,并进一步建立了基于常规敏感测井曲线交会图与曲线叠置法、基于地质统计的Fisher定量判识法等岩石类型判识方法。通过与已知结果对比,岩石类型判识准确率达80%以上,应用上述方法,可以很好地实现盆地覆盖区太古宇岩石类型的综合判识。
The Archaeozoic in a petroliferous basin is becoming a feasible target for oil and gas exploration. In practices, it is difficult to identify the rock types of Archaeozoic as the basement of a basin. This paper presents a synthetic method, which is verified through application in the Jiyang depression. Firstly, with reference to the characteristics of Archaeozoic in outcrops surrounding the Jiyang depression, and based on relevant data obtained through core observations, core slice identification with microscope, mud logging and geochemical analysis of cores, the Archaeozoic in the Jiyang depression is proved with 8 types of rocks in two categories （magmatic rocks and metamorphic rocks）. The magmatic rocks are predominant, mainly including monzonitic granite and diorite. Then, some lithology-sensitive well logging curves （incl. GR, AC, CNL, DEN and PE） are selected after comparative analysis with core data, and the synthetic method of crossplot and logging curve overlaying based on conventional sensitive logging curves and of Fisher quantitative identification based on geologic statistics is further established. Comparison with known results reveals that the accuracy rate of the synthetic method to identify rock types reaches more than 80%. The synthetic method can be applied to comprehensively identify the rock types of Archaeozoic under the covered region in a basin.
出处
《中国石油勘探》
CAS
北大核心
2016年第5期26-32,共7页
China Petroleum Exploration
基金
国家科技重大专项"渤海湾盆地精细勘探关键技术(二期)"(2011ZX05006)
中国石油化工股份有限公司科研项目"太古界潜山储层成因分布与成藏研究"(P08038)
关键词
太古宇
覆盖区
岩浆岩
岩石类型
量化判识
济阳坳陷
Archaeozoic
covered region
magmatic rock
rock type
quantitative identification
Jiyang depression
