The method of determining a production well flow profile, including determination of hydrodynamic characteristics of reservoir pay zone

Abstract

The invention relates to oil and gas production industry and can be used in production well logging operations. The method of determining a production well flow (production) profile in terms of hydrodynamic characteristics of individual reservoir units (their productivities and far-field reservoir pressures) in a multilayer reservoir includes temperature Tf(1) and bottomhole pressure pb(1) measurements along the wellbore after the well has been producing for a long time at a known constant rate in a quasi-stationary regime, after which the rate is changed by a predetermined value for a period sufficient for a new quasi-stationary flow regime to set in, and then temperature Tf(2) and bottomhole pressure pb(2) measurements along the wellbore are repeated. Whenever necessary and practicable, additional temperature and bottomhole pressure measurements along the wellbore are performed in different well-operation regimes, at different total flow rates. Then the reservoir pressure plex and productivity Kl are estimated and flow rates Vl are determined for each l-th unit (l=1, 2, . . . L, where L is the top layer number) in each well-operation (production) regime on the basis of bottomhole pressure and temperature measurement data, with the total production rates of the well in all logging regimes being known, by solving the system algebraic equations, starting from the topmost layer L (l=L, . . . , 2, 1). ClQl(T∧fl−T∨fl)=Kl(plex−pbl)(Tlex−T∨fl+εfl(plex−pbl)), Vl=Kl(plex−pbl), where εfl is effective (non-stationary) Joule-Thomson coefficient; Tlex—the average geothermal temperature across the l-th layer; T∨fl—the flowing temperature at the lower boundary of the l-th layer; T∧fl—the resulting flowing temperature at the top of the l-th layer; Cl—the ratio of the volumetric heat capacity of flow above the top of the l-th layer and that of the flow entering the well from the l-th layer; Tcl—the mean mixing temperature of the fluid flow from the l-th layer; Ql—the total cumulative flow rate of the l-th layer and all the underlying layers. pbl—the measured bottomhole pressure at the depth of the layer l. Application of this invention increases the accuracy and reliability of estimation of the wellbore flow (production) profile through determination of hydrodynamic characteristics of individual reservoir units (their productivities and far-field pressures) in a multilayer reservoir.

Dependencies are inferred from the claim text.