Numerical Well Test Interpretation of Massive Multistage Fractured HorizontalWells in Tight Oil Reservoirs and Effect of Permeability ofExterior Region on Well Test Curves
Li Daolun
Yang Jinghai
Yan Shu
Zha Wenshu
Lu Detang
Zeng Yishan
Abstract：Numerical well test interpretation of massive multistage fractured horizontal wells can be used for the fracturing effect evaluation, which is very important for productivity evaluation.However, few field case studies have been conducted.Numerical solution of oil-water two-phase flow based on PEBI grid and description of stimulated reservoir volume (SRV) by main fractures with infinite conductivity and improved permeability of the region with minor fractures are used in combination to interpret the transient pressure of massive multistage fractured horizontal wells in tight oil reservoirs in Daqing oilfield.The interpretation and sensitivity analysis of permeability of exterior region show that the value of pressure derivative becomes smaller at early time and becomes larger at late time when the permeability of exterior region decreases, compared with pressure derivative without permeability modification, which indicates a turning point on the curves of pressure derivative.Prior to the turning point, the pressure derivative with smaller permeability in exterior region is relatively smaller, while after the point, the pressure derivative is larger.The time of appearance of the turning point is related to the magnitude of permeability between those of exterior and interior regions.Therefore, when good fitting of pressure derivative curves achieves at early time and bad fitting of pressure derivative curves at late time, adjustment of permeability of exterior region cannot wholly improve the fitting effect, and other parameters need to be adjusted to improve the fitting.This study can facilitate future transient pressure analysis for massive multistage fractured horizontal wells in tight oil reservoirs.
Keywords：multistage fractured horizontal wellstimulated reservoir volumefracture half lengthperpendicular bisector gridnumerical solutionoil-water two-phasepetroleum geology
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 1324-1332 )