西南石油大学学报(自然科学版)

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A Flow Model Reflecting Dynamic Kick-off Pressure Gradient for Low#br# Permeability Reservoirs

Su Haibo*   

  1. Research Institute of Exploration and Development,Shengli Oilfield Company,SINOPEC,Dongying,Shandong 257015,China
  • Online:2015-12-01 Published:2015-12-01

Abstract:

Based on the fluid boundary layer theory,this paper presents a new flow model that can be used to describe the
non-linear seepage feature in low permeability reservoir to obtain continuous function of the dynamic kick-off pressure gradient.
And the nonlinear seepage flow model of dynamic kick-off pressure gradient is considered to establish the mathematical model
of one-dimensional single-phase fluid flow,and the discrete equations are linearized with fully implicit method. Besides,the
distribution feature of formation pressure and influence of nonlinear seepage flow coefficient on moving boundary expansion
are studied comparatively from linear seepage model,quasi linear formation pressure and nonlinear seepage model reflecting
dynamic kick-off pressure gradient. Numerical results indicate that with the influence of the dynamic kick-off pressure gradient,
the formation pressure of near well region declines more greatly,while formation pressure in the far zone is higher,and
formation pressure decline range is narrower. In addition,when nonlinear coefficient numerical value is smaller,the degree of
fluid flow nonlinearity is stronger,and expansion velocity of dynamic boundary is lower.

Key words: low permeability reservoir, boundary layer, nonlinear seepage, dynamic change of starting pressure gradient,
moving boundary

CLC Number: