元素录井技术在塔中奥陶系碳酸盐岩地层中的应用

Application of element logging technology in Ordovician formations of carbonate rock in Tazhong

为解决塔中油区桑塔木组、良里塔格组及鹰山组地层界面的精准卡取及地质精细划分问题,采用元素录井技术,通过应用图板法、分类表法、CaO/MgO比值法,准确落实了奥陶系碳酸盐岩岩性,并进行了较为精细的划分。依据拟合GR以及岩性组合剖面、Sr/Ba、Sr/Th比值等手段,在随钻地层划分及对比、沉积相判别方面应用效果突出;依据SiO_(2)、Al_(2)O_(3)、CaO、SO_(3)等特征化学成分,可区分生屑灰岩、生屑砂屑灰岩、砂(砾)屑灰岩,并对礁滩体储层、岩溶储层进行有效识别和评价。最终实现了对塔中油区奥陶系碳酸盐储层的现场准确识别与评价和对钻井工程安全的技术支持,提升了现场录井质量。

To solve problems in precise determination and fine geological division of Sangtam,Lianglitage and Yingshan Formations in Tazhong oildom,by applying element logging technology,charts,taxonomy,and CaO/MgO ratio,the lithology of Ordovician carbonate rocks is accurately determined and a relatively fine division is carried out.By fitting GR and lithology combination profile,Sr/Ba and Sr/Th ratio and other methods,outstanding application effect in the division and comparison of formation while drilling,and the discrimination of sedimentary facies is showed.According to the characteristic chemical composition of SiO_(2),Al_(2)O_(3),CaO,SO_(3),bioclastic limestone,bioclastic limestone,and gluten clastic limestone can be distinguished,and the reef shoal reservoirs and karst reservoirs can be effectively identified and evaluated.It finally realized the on-site accurate identification and evaluation of Ordovician carbonate reservoirs in Tazhong oildom and technical support for the safety of drilling engineering,which improved the quality of on-site logging.