Identifying and Dating the Destruction of Hydrocarbon Reservoirs Using Secondary Chemical Remanent Magnetization

Destructive processes are thought to be common in pre‐Cenozoic oil‐gas reservoirs. The timing, mechanism, and even identification of these processes, however, are difficult to clearly characterize, which obscures the evolution of such systems and the assessment of oil and gas reserves. Here, we reveal a new link between secondary chemical remanent magnetization acquisition and tectonically driven destruction of hydrocarbon reservoirs, which can be used to date the destructive processes and identify their tectonic controls. We performed a detailed paleomagnetic analysis of rocks from a typical destroyed reservoir (Majiang reservoir, China) and combined these data with scanning electronic microscope imaging and strontium isotope, total organic carbon, and clay analysis. We found that the Late Triassic syntilting secondary chemical remanent magnetizations of source and reservoir rocks resulted from the destructive processes driven by the Indosinian orogeny. We therefore argue that palaeomagnetic methods can be used to constrain destructive events within hydrocarbon reservoirs worldwide.

破坏性过程被认为在前新生代油气藏中较为常见。然而，这些过程的时间、机制甚至识别都难以清晰描述，这模糊了此类系统的演化以及油气储量的评估。在此，我们揭示了次生化学剩磁获得与构造驱动的油气藏破坏之间的一种新联系，这种联系可用于确定破坏过程的年代并识别其构造控制因素。我们对来自一个典型的已破坏油藏（中国麻江油藏）的岩石进行了详细的古地磁分析，并将这些数据与扫描电子显微镜成像以及锶同位素、总有机碳和黏土分析相结合。我们发现，源岩和储层岩石的晚三叠世同斜次生化学剩磁是由印支造山运动驱动的破坏过程所导致的。因此，我们认为古地磁方法可用于确定全球油气藏内的破坏事件。