A Numerical Study of the Influence of Nonlinear Fluid Flow Mechanism on Dynamic Production in Tight Oil Reservoirs

EasyChair Preprint 3449

Abstract

The Fluid flow mechanism in unconventional reservoirs is much more complicated than that in conventional reservoirs mainly because of the co-existing of various sized micro-nano pores and natural / artificial fractures in the same reservoir. Due to the various flow patterns and seepage mechanism among different-sized medium, and also among different production periods in the same medium, the dynamic production is influenced by both the spatial variable and time variable. The capacity of the tight oil reservoirs is also thus greatly influenced. In this paper, numerical simulation is used to automatically identify the flow pattern according to the critical criteria of flow in different medium, and to simulate the dynamic production process with kinetic equations. The simulation is mainly focused on the following characteristics shown in the production process of tight oil reservoirs: I) high-velocity nonlinear, quasi-linear and low-velocity nonlinear flow regimes; II) flow patterns and seepage mechanism among different-sized medium in the same production periods; and III) flow patterns and seepage mechanism among different production periods in the same medium. The simulation results reveal that: a) as the start-up pressure gradient increases, the production gradually decreases; b) the higher the high-velocity non-Darcy coefficient, the lower the production; c) the higher the nonlinear seepage coefficient n value, the higher the production; d)in the same production stage, the flow regime in different locations and porous-fractured media have great differences. Also, at the same location, it changes drastically at different production stages. Based on the above analysis, a better understanding about the influence of the flow state and seepage mechanism on dynamic production and productivity is obtained, which will help optimizing the development method and improving the accuracy of oil well productivity forecasting.

Keyphrases: Flow regime identification, Nonlinear Fluid Flow Mechanism, numerical simulation, tight oil reservoirs

@booklet{EasyChair:3449,
  author    = {Jiaxin Dong and Qiquan Ran and Hui Peng and Zhiping Wang},
  title     = {A Numerical Study of the Influence of Nonlinear Fluid Flow Mechanism on Dynamic Production in Tight Oil Reservoirs},
  howpublished = {EasyChair Preprint 3449},
  year      = {EasyChair, 2020}}