C182 pilot reported receiving low oil pressure indications and diverting to a nearby airport.

Narrative

The event occurred during a training flight from ZZZ1 Airport towards the vicinity of ZZZ airspace; with an intended landing back at ZZZ1 airport. While beginning my transit on my planned route of flight towards the practice area; the oil pressure indicator began small fluctuations. Approaching the practice area after coordinating with ZZZ1 Approach (no flight following was requested; but I informed them that i would be monitoring their frequency); the fluctuations started becoming more significant; but still within the green operating range and centered on where the oil pressure steady state had been for the preceding portion of the flight. Approximately 1 minute into the flight in the Northeastern portion of the practice area; the pressure fluctuations began dropping below the green arc intermittently and increasing in disparity (greater changes in oil pressure fluctuation). I observed that oil temperature was steady and that there was no visible oil leaks on the cowling or on the left main landing gear boot; and as a result elected to terminate my route and proceed towards my home airport; ZZZ1. Upon reaching the Northern boundary of the practice area and clearing ZZZ1 airport's runway XX centerline; I began a climb to 3;500 feet to provide myself a maximum amount of airborne time to glide in the case of an engine failure. I proactively opened the aircraft checklist to determine if there were appropriate emergency procedures in the case that an engine oil pressure low posted. Approaching ZZZ2 airport and clear vertically of its airspace at 3200 MSL (still in the climb to 3500) I switched from ZZZ1 approach to ZZZ approach in the case that assistance was needed approaching ZZZ3 airport. Approximately 2 minutes later and at approximately 3300' MSL; the oil pressure indication continued fluctuate but were observed as trending lower than previously and intermittantly touching the red arc. Due to the unknown nature of the Oil pressure fluctuations; and as the result of the fluctuations continually trending lower over the course of a 10 minute period from entry into the practice area to flight over ZZZ2 airport; I elected to [request priority handling] with ZZZ approach. I informed ZZZ approach my callsign; range and bearing off of ZZZ VOR; and VFR squawk of 1200. I was given a vector towards ZZZ3 airport and informed by ZZZ Approach that they would coordinate with tower for my arrival. Approaching the airfield I was switched from approach to ZZZ3 tower. I checked in with tower providing my location and intention to land; and was given the option for runway XY or XZ with winds out of the Northeast and optional pattern direction. I elected to proceed for a downwind for runway XY knowing that I was priority to land with no heard traffic cleared to land before me; and due to the length of the runway at 7;100'. The landing was uneventful and I taxied to the FBO and shut down.During the course of the flight and after verifying with my ADS-B data; no unintentional violation of airspace boundaries occurred. ZZZ approach was extremely helpful and quickly reacted to my declaration in a professional manner; as did ZZZ3 Tower. This report is submitted; from my perspective; as a positive experience in support from the controlling agencies and procedures being executed correctly.