Hydraulic Pulse Interference Test Brochure

Type Curve Analysis of Confined Aquifer 35’ to 110’ bgsSource Well and Receiver Well both at 100’-105’PR-d178a.cdrHydraulic Pulse Interference TestTypical Hydraulic Pulse Interference Test SetupDuring the pulse interference test, the source well’s flowrate and pressure are monitored along with all of thereceiver pressure transducers. It is essential that thepressure transducers are of high precision and that theflow rates and pressures are all continuously monitoredand recorded at high data acquisition rates. To ensure thetests are repeatable, the pulse switching mechanism needsto be automatically controlled and recorded on the dataacquisition system. To optimize the resolution of the test,the injection/shut in time interval and/or injection flowrate will need to be varied depending on site conditionsand the distances between source and receiver wells.The hydraulic pulse interference test is an ideal test for thequantification of a site’s hydrogeological properties. Thepulse interference test is highly sensitive tohydrogeological properties between the pulse source andreceiver wells. The transient nature of the test, involvingthe time delay and attenuation of the hydraulic pulse,enables the formation’s complete hydraulic properties tobe computed. The method is equally applicable to porousmedia and fractured bedrock systems. The advantages ofthe pulse interference test are the short duration of the test,the high resolution and directional characterization dataobtained, and the lack of any generated contaminatedgroundwater during the test.GeoSierra has developed specialized equipment andanalytical interpretation procedures for sitehydrogeologic characterization by the hydraulic pulseinterference test. The equipment consists of highprecision pressure transducers, constant flow rate pumpand solenoid adjustable valves, packers and a high speeddata acquistion system. Analytic and type curve analysesare available for the interpretation of the hydraulic pulseinterference test in a variety of formations consisting ofeither porous media or fractured bedrock systems.Hydraulic pulse interference tests involve a cyclicinjection of fluid into the source well, and by highprecision measurement of the pressure pulse in aneighboring well, detailed hydraulic characterizationbetween wells can be made. The pulse interference test ishighly sensitive to hydrogeological properties betweenthe pulse source and receiver wells. To maximize thepulse test’s resolution, a small section of the injector wellis isolated by packers, the flow rate into the sourceinjector well is rate controlled and set at a constant flowrate depending on the site hydraulic conditions. Highprecision pressure transducers are located in receiverwells. The injector well is pulsed for a set time, shut in forthe same time period, and the cycle repeated. The pulsesource and receivers can be located at differing depthlocations in their respective wells and a detailed image ofthe site’s hydraulic conditions can be determined.FluidPumpSolenoid FlowSwitching ValveObservation WellsHighPrecisionPressureTransducerPackersGroundSurfaceTime (minutes)ReceiverPressure(psi)SourceFlowRate(gals/min)0 1 2 3 4 500.010.020.030.040.050.060.070.080.090.10102030405060708090100PW-2 MatchedPW-2 MeasuredPW-3Pulse Well PW-3 at 100'-105'Confined Aquifer 35' to 110' bgsHydraulic Conductivity = 105 ft/daySpecific Storage = 5.2x10-6 /ftDimensionless TimeDimensionlessPressure10410510610710810-610-510-410-310-21e33.5e31e43.5e41e53.5e51e63.5e61e73.5e7Time (mins)Pressure(psi)10-110010110210-410-310-210-1Type Curve Analysis of Confined Aquifer 35' to 110' bgsSource Well and Receiver Well both at 100'-105'HydroGeologic CharacterizationHydraulic Pulse Interference TestReceiver Well Pressure Responsewith Matched Analytical ModelGeoSierra, LLC3730 Chamblee Tucker Rd.Atlanta, GA 30341Tel: (678) 406-0094Fax: (770) 934-9476Web: www.geosierra.com