_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper URTeC 3722736, “The Impact of Hydraulic Fracturing Fluid on the Near-Wellbore Shale Region Involving Interactions With Steel, Cement, and Shale,” by Wei Xiong, Brandon McAdams, and Mengling Stuckman, National Energy Technology Laboratory, et al. The paper has not been peer reviewed. _ Numerous studies have been conducted on rock/fluid interactions of deep shale reservoirs exposed to hydraulic fracturing fluid (HFF). However, the effect of fluid/steel/cement components on the chemistry of the near-wellbore shale region has been overlooked. In the study described in the complete paper, steel, cement, and shale samples were exposed to HFF sequentially in the same batch for 3 days at 66°C. Unlike the reaction of fresh HFF to direct exposure to shale, the fluid chemistry and exposed surfaces of steel and cement were altered significantly after exposure. Methods Sequential Exposure Experiment. For the sequential exposure batch, three steel coupons were placed at the bottom of a borosilicate bottle with 300 mL of HFF. After 3 days of exposure, all three steel coupons were removed. 100 mL of the reacted fluid was collected and filtered for fluid-chemistry analysis. Then, two cement coupons were placed in the bottle to react with the remaining 200 mL of fluid at the same temperature. After 3 days of reaction, the two cement coupons were removed with 100 mL of fluid as a liquid sample. Finally, one shale sample was placed in the bottle, exposed to the remaining 100 mL of fluid for 3 days. A controlled group using individual coupons was the subject of experiments using the same setup. One steel, cement, or shale coupon was placed in each bottle with 100 mL of HFF individually. A blank group with 100 mL of HFF without any coupons also was set up at the same conditions. These control groups reacted for 3 days. Analytical Methods. A three-electrode voltametric system was composed of a mercury/gold (Hg/Au) amalgam 100-µm-disc working electrode (WE), a solid-state silver/silver-chloride (Ag/AgCl) reference electrode (RE), and a platinum wire counter, or auxiliary, electrode (CE). The species undergoes oxidation or reduction at the WE interface at a potential measured against the potential of the RE wherein any exchange of electrons at the WE interface is compensated by the CE to complete the circuit within the potentiostat. Peaks observed in complex solutions like those in this study can be compared with known responses in previous studies to arrive at a qualitative assessment of what is happening, and when, in these solutions with respect to redox chemistry. For the purposes of continuity, all potentials reported in the complete paper are in relation to the Ag/AgCl reference electrode and require a positive adjustment of approximately 0.21 V.