produced fluids

Samples were periodically collected at wellheads using sterile sampling bags (quarterly sampling with a 3-month temporal resolution), transported to the laboratory via cold-chain transportation, and subjected to standardized environmental microbial DNA extraction, amplification, and sequencing protocols.16S rRNA gene sequencing (V4-V5 regions, sequencing depth: 50,000 reads/sample) was performed on the Illumina NovaSeq 6000 platform, followed by taxonomic annotation using the Qiime2 pipeline (v2022.8) and the SILVA 138 database.The primary data matrix is structured as:Columns (x-axis): Well identifiers formatted as "sampling time-well name" (e.g., 2023Q1-W-001 for the first quarter of 2023).Rows (y-axis): 50 microbial taxa at the genus level, with relative abundances reported as percentages (precision: 0.000001%).The dataset captures temporal microbial composition variations across all monitored wells.

No missing data are present, and no uncontrolled measurement errors were identified during data generation or processing.