CAJ | 학술논문

在石油勘探领域，细碎岩屑样品的岩性识别，特别是物性接近的火成岩的高精度识别是地质学的难题之一。针对这一问题，提出了一种基于激光诱导击穿光谱技术（LIBS）元素分析和全碱-硅（TAS）图版的新方法。利用自主搭建的 LIBS 系统，首先通过对比实验，系统的研究了脉冲能量、采集延时、采集方式、预燃对光谱信号的影响，确定了对火成岩样品元素分析的最佳条件：脉冲能量50 mJ，采集延时2μs，采集同一样品表面20个不同点的光谱积分平均，并通过实验证明了预燃的样品处理方式不适合火成岩样品，有效提高了样品检测光谱数据的重复性。随后确定了火成岩岩性识别常用7种元素（钠镁铝硅钾钙铁）的特征谱线，定性分析和比较了不同岩性的火成岩样品；利用已知元素含量的国标系列岩石样品信息，生成了钠、硅、钾的定标曲线，线性相关系数均大于0．9，并利用国标岩石样品考察了定量分析的准确性；利用定标曲线法定量分析了火成岩样品的元素含量，并采用 TAS 图版法识别火成岩的岩性，准确率达90．7％。研究表明，LIBS 技术能够有效实现火成岩岩性的高精度识别。
재석유감탐영역，세쇄암설양품적암성식별，특별시물성접근적화성암적고정도식별시지질학적난제지일。침대저일문제，제출료일충기우격광유도격천광보기술（LIBS）원소분석화전감-규（TAS）도판적신방법。이용자주탑건적 LIBS 계통，수선통과대비실험，계통적연구료맥충능량、채집연시、채집방식、예연대광보신호적영향，학정료대화성암양품원소분석적최가조건：맥충능량50 mJ，채집연시2μs，채집동일양품표면20개불동점적광보적분평균，병통과실험증명료예연적양품처리방식불괄합화성암양품，유효제고료양품검측광보수거적중복성。수후학정료화성암암성식별상용7충원소（납미려규갑개철）적특정보선，정성분석화비교료불동암성적화성암양품；이용이지원소함량적국표계렬암석양품신식，생성료납、규、갑적정표곡선，선성상관계수균대우0．9，병이용국표암석양품고찰료정량분석적준학성；이용정표곡선법정량분석료화성암양품적원소함량，병채용 TAS 도판법식별화성암적암성，준학솔체90．7％。연구표명，LIBS 기술능구유효실현화성암암성적고정도식별。
In the field of petroleum exploration,lithology identification of finely cuttings sample,especially high precision identi-fication of igneous rock with similar property,has become one of the geological problems.In order to solve this problem,a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS)and Total Alkali versus Silica (TAS)diagram.Using independent LIBS system,factors influencing spectral signal,such as pulse energy,acquisition time de-lay,spectrum acquisition method and pre-ablation are researched through contrast experiments systematically.The best analysis conditions of igneous rock are determined:pulse energy is 50 mJ,acquisition time delay is 2 μs,the analysis result is integral av-erage of 20 different points of sample’s surface,and pre-ablation has been proved not suitable for igneous rock sample by experi-ment.The repeatability of spectral data is improved effectively.Characteristic lines of 7 elements (Na,Mg,Al,Si,K,Ca,Fe) commonly used for lithology identification of igneous rock are determined,and igneous rock samples of different lithology are an-alyzed and compared.Calibration curves of Na,K,Si are generated by using national standard series of rock samples,and all the linearly dependent coefficients are greater than 0.9.The accuracy of quantitative analysis is investigated by national standard samples.Element content of igneous rock is analyzed quantitatively by calibration curve,and its lithology is identified accurately by the method of TAS diagram,whose accuracy rate is 90.7%.The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock.