Organic-rich shale reservoirs are rich in reductive minerals, such as pyrite and other organic matters. The working fluid for the development of shale gas reservoirs contains large amount of dissolved oxygen. Once the working fluid enters the organic shale reservoir, it will oxidize the reducing components, cause mineral transformation, release solid phase particles, change the pore structures, and damage the seepage capacity of organic-rich shale reservoirs. The understanding and evaluation of the oxidation sensitivity is of great significance for improving the productivity of shale reservoirs. Therefore, organic shale of the Longmaxi Formation in the Pengshui area of the southeastern Sichuan Basin (China) was taken as the research object in the current work. In order to evaluate the reservoir fluid sensitivity, experiments were conducted to evaluate the oxidation sensitivity of the organic-rich shale reservoir. The experimental results showed that oxic fluids had the highest degree of damage on the permeability of shale than the reductive and degassed fluids. The oxidation sensitivity indices, Sox, of the shale samples were found to be 65.62% and 54.88%, respectively, which are moderately strong. The mechanism for the damage of the oxidation sensitivity of shale involves the production of Fe₂O₃, Fe(OH)₃, FeCO₃ (siderite), CaSO₄·2H₂O (dihydrate gypsum), MgSO₄, other precipitated solid particles (chemicals), and the shale debris. Therefore, the pores and fractures were blocked by solid particles, resulting in the decrease in fracture width as well as the number of solid particles, which could be expelled. An appropriate concentration of oxidants has a positive effect on the permeability of organic-rich shale. The oxidation will produce macroscopic cracks and a large number of dissolution pores that significantly improved the transport capacity of the pore fracture system, and increased the permeability of the organic-rich shale.

富含有机物的页岩储层富含还原性矿物，例如黄铁矿和其他有机物。用于开发页岩气藏的工作流体包含大量的溶解氧。一旦工作流体进入有机页岩储层，它将氧化还原组分，引起矿物转化，释放固相颗粒，改变孔隙结构，并破坏富含有机物的页岩储层的渗透能力。对氧化敏感性的理解和评价对提高页岩储层的生产效率具有重要意义。因此，当前工作以四川盆地东南部彭水地区龙马溪组有机页岩为研究对象。为了评估储层流体的敏感性，进行实验以评估富含有机物的页岩储层的氧化敏感性。实验结果表明，与还原性和脱气性流体相比，含氧流体对页岩渗透性的破坏程度最高。页岩样品的氧化敏感性指数Sox分别为65.62％和54.88％，中等强度。页岩氧化敏感性受损的机理涉及铁的产生₂ O ₃，Fe（OH）₃，FeCO ₃（菱铁矿），CaSO ₄ ·2H ₂ O（二水合石膏），MgSO ₄，其他沉淀的固体颗粒（化学物质）和页岩碎屑。因此，孔隙和裂缝被固体颗粒堵塞，导致裂缝宽度的减小以及可被排出的固体颗粒数量的减少。适当浓度的氧化剂会对富含有机物的页岩的渗透性产生积极影响。氧化将产生宏观裂缝和大量溶蚀孔隙，这将显着提高孔隙破裂系统的输送能力，并增加富含有机物的页岩的渗透性。