DOWN-HOLE PRESSURE MONITORING SYSTEM

A non-electric down-hole formation pressure monitoring system utilizing a typical down-hole chemical injection system for pressure data acquisition used with surface computer integration to produce an accurate picture of formation pressure variations utilizing pressure differentials across a pressure balanced valve located adjacent the chemical injection orifice. Computer controlled manipulation of the injection pump pressure maintains a constant differential pressure across the pressure balance valve thus tracking the well formation pressure deviations. The surface computer monitors pump noise, plumbing noise due to vibration, etc., temperature, and fluid and/or gas coefficients, and compensates for any adverse effects that may affect the accuracy of the formation pressures. Down-hole pressure monitoring is achieved in chemical injection or dedicated pressure-monitoring mode with only minor surface adaptations to the well chemical injection pump skid.