Sampling through perforation guns with flushing

A system, comprising:

• a casing configured to mount within an open hole of a wellsite;
• a sample collecting system configured to analyze one or more properties of a first fluid;
• and
• a monitoring system configured to mount outside of the casing and monitor a geological formation, wherein the monitoring system comprises:
• a perforating device outside of the casing, wherein the perforating device is configured to produce one or more perforations into the geological formation outside of the casing in a perforating operation of the monitoring system, and wherein the one or more perforations are configured to enable fluid flow between the geological formation and the monitoring system;
• and
• a fluid circuit outside of the casing, wherein the fluid circuit comprises:
• a U-tube coupled to a fluid supply:
• a sampling conduit coupled to the U-tube and the perforating device;
• a filter, wherein the filter is disposed along the sampling conduit;
• and
• a flush conduit coupled to the U-tube and the sampling conduit, wherein the flush conduit comprises a check valve, wherein the fluid circuit is coupled to the perforating device, and wherein the fluid circuit is configured to route the first fluid from the geological formation to the sample collecting system during a sampling operation of the monitoring system.