valve having ball 83 cavity 84 flow path 86 fluid injector tubing 88 fluid accelerator 90 with fluid exhaust port 92 chamber 94 and outlet 96 as shown in fig3 chamber 94 has a conical shape to facilitate movement of fluid out from fluid exhaust port 92 and through outlet 96 once assembled longitudinal bore 76 is formed between screen 50 lower coupler 60 ported member 62 isolation device 66 and upper coupler 72 by placing bores 51 61 63 67 73 in fluid communication with each other longitudinal bore 76 is in fluid communication with outlet 96 of jet pump 80 through valve 82 cavity 84 flow path 86 fluid exhaust port 92 and chamber 94 in one particular operation of downhole tool 40 a tubing string not shown is used to dispose downhole tool 40 into wellbore 20 after disposition within wellbore 20 isolation device 66 is activated so that annulus 21 of wellbore 20 is divided into upper zone 22 above isolation device 66 and lower zone 23 below isolation device 66 activation of isolation device 66 can be accomplished using known methods with particular reference to the arrows shown in fig3 that illustrate fluid flow through downhole tool 40 after setting isolation device 66 within wellbore 20 fluid such as water is pumped down fluid injector tubing 88 through fluid accelerator 90 and out of fluid exhaust port 92 into chamber 94 fluid accelerator 90 and fluid exhaust port 92 increase the pressure at which the fluid is expelled from fluid injector tubing 88 thereby creating a venturi effect due to the increased pressure expulsion of fluid through fluid exhaust port 92 negative pressure is created within jet pump 80 and thus in upper zone 22 so.