Pressure variance systems for subsea fluid injection

The present disclosure generally relates to a system for injecting a fluid into a subsea hydrocarbon extraction component. The system comprises a pressure variance device including an ambient chamber and a variance chamber, the ambient chamber exposed to an external subsea environment and configured to transfer the pressure to the variance chamber via a pressure variance device piston. The system further comprises an accumulator including a fluid delivery chamber and a pressure chamber, the pressure chamber configured to receive the pressure from the variance chamber and transfer the pressure to the fluid delivery chamber via an accumulator piston. The system also comprises a control system configured to regulate injection of the fluid from the fluid delivery chamber into the hydrocarbon extraction component. In this way, the system can intensify or deintensify a hydrostatic pressure in the subsea environment to inject chemicals in the hydrocarbon extraction component at a desired pressure.