CAJ | 학술논문

土库曼斯坦恰什古伊地区有效储集层为卡洛夫-牛津阶碳酸盐岩，该段GR变化小，旋回分析困难，导致有利储层预测难。利用该区Cha-21井所取岩芯中采集的41个样品测定的碳氧同位素，结合区域沉积演化分析资料，探讨了卡洛夫-牛津阶储层段沉积时的海平面变化。结果表明，氧同位素的原始信息已被成岩作用破坏，而碳同位素基本保持了原始特征，因此碳同位素可用于同位素地层研究和古环境分析；据此计算出盐度指数变化范围为128.25～136.63，明显大于海水和淡水的分界标准，反映成岩流体具有较高盐度海源水性质；由δ13C的变化所确定的研究区的海平面变化曲线与卡洛夫-牛津阶全球海平面变化曲线吻合，印证了该区储层地质年代定为卡洛夫-牛津期是准确的；依据海平面变化曲线，将卡洛夫-牛津阶主力储层段分为3个沉积旋回5个演化阶段。该成果填补了该区碳氧同位素地层研究的空白，对深化盆地沉积演化规律的认识及预测储层有利区块具有重要意义。
토고만사탄흡십고이지구유효저집층위잡락부-우진계탄산염암，해단GR변화소，선회분석곤난，도치유리저층예측난。이용해구Cha-21정소취암심중채집적41개양품측정적탄양동위소，결합구역침적연화분석자료，탐토료잡락부-우진계저층단침적시적해평면변화。결과표명，양동위소적원시신식이피성암작용파배，이탄동위소기본보지료원시특정，인차탄동위소가용우동위소지층연구화고배경분석；거차계산출염도지수변화범위위128.25～136.63，명현대우해수화담수적분계표준，반영성암류체구유교고염도해원수성질；유δ13C적변화소학정적연구구적해평면변화곡선여잡락부-우진계전구해평면변화곡선문합，인증료해구저층지질년대정위잡락부-우진기시준학적；의거해평면변화곡선，장잡락부-우진계주력저층단분위3개침적선회5개연화계단。해성과전보료해구탄양동위소지층연구적공백，대심화분지침적연화규률적인식급예측저층유리구괴구유중요의의。
The effective reservoir in Chashgui Area,Turkmenistan,is Callovian-Oxfordian carbonate rocks. Since the GR curve does not varies much,it is difficult to predict the favorable reservoir distribution. Using the carbon and oxygen isotope from the 41 samples out of the core of the Well Cha-21 in Chashgui Area,combining with the data of the sedimentary evolution, this paper discusses the sea-level changes during the sedimentation of the Callovian-Oxfordian reservoirs. It is shown that the information in the oxygen isotope has been damaged,and the information in the carbon isotope has been preserved. So the carbon isotope can be used to study the isotope stratigraphy and analyze the Palaeo-environment. The calculated salinity index is 128.25～136.63,which is higher than the division standard between brine and freshwater,so the diagenetic fluid is high salinity brine. The carbon-isotope stratigraphic curve is almost consistent with the global sea-level curve,which proved that the reservoir geologic period is really Callovian-Oxfordian. According to the sea-level change curve,the main reservoirs in Callovian-Oxfordian are divided into 3 sedimentary cycles and 5 evolutionary phases. Those results fill up the blank in the isotopic stratigraphy studies,which are important significance for the in-deep understanding of the law of sedimentary evolution,and predicting the favorable blocks.