Radium Isotopes as Indicators of Pump Test Induced Changes in Fluid Composition; Fluid Age Dating by Means of 81Kr, 39Ar, 37Ar and 85Kr During the Long-Term Pumping Test 2002/2003 at the KTB Pilot Hole

本研究将在大陆深井先导孔(KTB-VB)抽水试验期间，通过测量~(226)Ra、~(228)Ra、~(224)Ra、~(223)Ra和~(39)Ar、~(37)Ar、~(85)Kr、~(81)Kr等放射性稀有气体同位素，研究流体动力学及其水力学变化。这项研究的目的是根据镭同位素比率得出有关所开采流体的来源和流动路径的信息。此外，通过Re同位素比值的测定，可以推断出围岩中流体-岩石相互作用的变化。对Ar同位素39Ar和37Ar的测量提供了有关地下产生的放射性核素(如36Cl、129L、14C、4He、3He)从岩石释放和转移到孔隙水中的速率和过程的信息。开发的流体的年龄将通过长寿命的氪同位素81Kr进行。我们的调查是对计划在KTB-VB进行的其他地球化学和水力调查的最佳补充。从这些结果的综合中可以预料到关于流体力学的深远结论。

In this study the fluid dynamics and their hydraulically induced changes will be investigated by measurement of the radium isotopes 226Ra, 228Ra, 224Ra, 223Ra and the radioactive noble gas isotopes 39Ar, 37Ar, 85Kr and 81Kr during the pumping test at the continental deep drilling pilot hole (KTB-VB). The objective of the study is to derive information on the provenance and flow paths of the exploited fluids from radium isotope ratios. In addition changes in fluid rock interaction in the host rock can be concluded from the radium isotope ratio determinations. The measurement of the argon isotopes 39Ar and 37Ar provide information on the production rates and on the release and transfer processes of subsurface produced radionuclides (like 36Cl, 129l, 14C, 4He, 3He) from the rock into the pore water. An age dating of the exploited fluids will be performed by means of the long-lived krypton isotope 81Kr. Our investigations form an optimal supplement to other geochemical and hydraulic investigations planned at the KTB-VB. Far-reaching conclusions about fluid dynamics can be expected from the synthesis of the results.