Model of non-steady and non-linear effects influencing on hydraulic fractures productivity for oil, gas and gas-condensate fields

Abstract

   Introduction. The existing approach to assessing the conductivity of a hydraulic fracture does not always clearly describe the actual operating data, especially for gas condensate fields. Possible reasons for this discrepancy are the lack of consideration of non-stationary effects arising during flow in the reservoir and insufficiently strict consideration of non-linear effects arising during flow in the fracture.

   Aim. Development of a methodology that allows assessing the conductivity of hydraulic fractures taking into account non-stationary and non-linear effects.

   Materials and methods. The work uses an analytical dimensionless model of flow in a hydraulic fracture developed by the author. The control parameters of the model are dimensionless conductivity and dimensionless D-factor.

   Results. The paper shows that the classical approach to describing the conductivity of a hydraulic fracture through the ratio of the conductivities of the formation and the fracture requires adjustment. It is proposed to take into account non-stationary effects arising during flow in the formation in the calculation of dimensionless conductivity, as well as to take into account the value of the dimensionless D-factor, the need for such adjustments is demonstrated. In addition, the paper shows that gas wells with hydraulic fractures can have a significant value of the D-factor associated with non-linear flow in the proppant package.

   Conclusion. The results of the work can be used in the design of the hydraulic fracturing process, in the design of field development using wells with hydraulic fracturing fractures, as well as in the selection of suitable methods for modeling hydraulic fracturing both in analytical models and in hydrodynamic simulators.