Method of determining fluid inflow rates

Abstract

Actual inflow rates of gas and liquid into a wellbore from a reservoir are determined by flowing fluid from a wellhead for a prolonged duration so as to affect the reservoir. The flow and the wellhead pressure are measured. Knowing or determining an gas volume, a total rate of fluid inflow from the reservoir can be determined. If the well was previously flowing, then an original fluid flow rate is known. 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. 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.

Dependencies are inferred from the claim text.