A stationary oil inflow to the wellbore taking into account the initial pressure gradient
- PDF / 868,130 Bytes
- 5 Pages / 595.276 x 790.866 pts Page_size
- 103 Downloads / 222 Views
ORIGINAL PAPER
A stationary oil inflow to the wellbore taking into account the initial pressure gradient Ilyas Ravan Hasanov 1 & Mahammad Asaf Jamalbayov 1 Received: 22 May 2018 / Accepted: 13 August 2020 # Saudi Society for Geosciences 2020
Abstract In the development of deposits with abnormal properties of hydrocarbons, a number of complex and specific problems arise related to the study of the physical and hydrodynamic foundations of the manifestation of the non-Newtonian nature of filtration in a porous medium. Unlike conventional oil reservoirs, in deposits with anomalous oils, some minimum shear stress is required dependent on the properties of the fluid and the collector, to initiate filtration. In this paper, it is shown that for a steady flow of hydrocarbons to a well, taking into account the static (i.e., initial) pressure gradient, in contrast to the existing formula for production rate, the value of the initial pressure depression Δp0 depends on the radius of the power contour in a nonlinear manner. A more accurate formula for the pressure distribution was obtained, and a plot of the dependence of the drainage radius on depression for different values of Δp0 was constructed, and it was found that the effect of the initial pressure gradient on the well drainage radius is more significant than was found in earlier studies. Keywords Initial gradient . Flow rate . Pressure distribution . Stationary inflow
Introduction According to the data of GF Trebin (Trebin et al. 1974), about 25% of all the country’s deposits can be attributed to deposits with anomalous oil properties. Analysis of field data on deposits of Azerbaijan (Mirzadjanzadeh et al. 1971) showed that, in the case of waterflooding for deposits with nonNewtonian oil, oil recovery (0.35) is less than oil recovery from deposits with Newtonian oil (0.49). In work (Mirzadjanzadeh et al. 1971, 2003), according to the results of laboratory studies and according to well tests, it was found that flow of tarry and paraffin-rich oils in porous reservoirs does not follow the Darcy law. The presence of an initial pressure gradient changes sharply the flow pattern giving rise to stagnant zones in homogeneous fluid flow and to dead areas of motionless oil during waterflooding. Calculations show that when the real values of initial pressure Responsible Editor: Santanu Banerjee * Ilyas Ravan Hasanov [email protected] 1
SOCAR “OilGasScientificResearchProject” Institute, Hasan bey Zardabi, 88А, AZ1122 Baku, Azerbaijan
gradient are equal to some hundredths of atm/m, the stagnant zones and dead areas may occupy a considerable part of the reservoir. Disregard of the peculiarities of flow with initial pressure, gradient results in a considerable decrease of oil recovery. The existence of an initial pressure gradient in gas flow may reduce the completeness of gas recovery. Other studies also showed that the presence of an initial gradient takes place not only on oil, but also in gas fields. This effect is observed, for example, when the gas moves in a porous med
Data Loading...
