| 摘要 |
A method is provided for determining the actual inflow rates of gas and liquid into a wellbore from a reservoir. The wellhead is first closed and the wellhead pressure is measured over time. For a briefly period, gas is flowed from the wellhead and the wellhead pressure is measured again. Using the two conditions, the original wellbore gas volume and an original fluid inflow rate is determined. Gas is again flowed from the wellhead, both the flow and the pressure being measured, but this time for a prolonged duration, sufficient to affect the reservoir. Assuming the original gas inflow rate and original gas volume remain unchanged during the prolonged flow, a total rate of fluid inflow from the reservoir is determined, and finally an incremental inflow rate of fluid from the reservoir is calculated as being the difference between the total rate of fluid inflow less the original rate of gas flow. If the well is a gas well, the incremental fluid inflow is the actual gas inflow rate. If the fluid inflow is known to be liquid, then an incremental change in volume is equivalent to the liquid inflow rate. Using an exponential relationship for the pressure change during wellhead flow, a theoretical curve pressure response curve can be created, displayed and compared against the actual pressure response, any deviation therebetween being indicative of fluid inflow from the reservoir.
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