塔河油田奥陶系油田水同位素特征及地质意义  

ISOTOPIC CHARACTERISTICS OF OIL FILED WATERS FROM ORDOVICIAN OIL ACCUMULATIONS IN TAHE OILFIELD AND ITS GEOLOGICAL SIGNIFICANCES

作　　者：贾存善[1] 马旭杰[2] 饶丹[3] 高仁祥[3] 

机构地区：[1]中国矿业大学资源与安全工程学院,北京100083 [2]中国石化西北分公司勘探开发研究院,乌鲁木齐830011 [3]中国石油化工股份有限公司石油勘探开发研究院无锡石油地质研究所,江苏无锡214151

出　　处：《石油实验地质》2007年第3期292-297,共6页Petroleum Geology & Experiment

摘　　要：塔河油田奥陶系地层水的δD(SMOW)分布于-44.7‰^-61.0‰,表明为古大气降水和原生沉积水的混合水,并以古大气水为主。根据油田水的高压物性参数、HCO3-离子碳同位素、锶同位素87Sr/86Sr比值等的横向变化规律,大致判断出塔里木盆地阿克库勒凸起古大气水的优势流动方向为从阿克库勒凸起的东北构造高地向鼻凸倾伏的西南方向流动,并且在此流动过程中由构造轴部向两翼分流,通过对断裂、裂隙等薄弱带的不断溶蚀扩大,最终形成塔河油田奥陶系复杂的碳酸盐岩岩溶缝洞系统,为油气聚集成藏提供了有效的储集空间。因此,古大气水流动的方向对岩溶缝洞系统的分布以及缝洞单元的连通性具有重要的控制作用。Hydrogen isotope values（δD） of oil field waters from the Ordovician oil accumulations in Tahe oilfield cover -44. 7‰～- 61.0‰ （SMOW）, from which one can conclude that the oilfield waters are mostly paleo-atmospheric waters mixed with original sediment seawater. Based on the transverse change trends of the parameters in these oilfield waters, such as high pressure physical parameter, carbon isotope of HCO3^- electronegative ion and ^87Sr/^86Sr ratio of strontium isotope, one can roughly deduce that the predominant flow direction of paleo-atmospheric water is from the northeastern tectonic high position to the southwestern plunge end of the Arkekule nose salient. In this process, the current flowed from axis to two wings of the tectonic, which would cut through weakness belt of faults or cracks and enlarge the space by carbonates corrosion, finally formed complicated karst fracture-cavity system of the Ordovician carbonates in Tahe Oilfield. Therefore, the flow direction of paleo-atmospheric water controled the distribution of fracture-cavity system and connectivity of fracture-cavity cells.

关 键 词：岩溶缝洞系统 同位素 油田水 奥陶系 塔河油田 塔里木盆地 

分 类 号：TE133[石油与天然气工程—油气勘探]