Numerical Investigation of the Time-Dependent and the Proppant Dominated Stress Shadow Effects in a Transverse Multiple Fracture System and Optimization

In this paper, a numerical study is conducted to investigate the stress shadow effects (stress reorientation and change) during hydraulic fracturing in a transverse multiple fracture system. A numerical model is used for the numerical study. It is a 3D model and can simulate the fracture operation from injection begin to full closure (fracture contact). Therefore, there is no need to assume the fracture geometry for the investigation of the stress shadow effects (unlike previous studies). In the numerical study, the first and second operations in a fictive transverse multiple fracture system are simulated, meanwhile the stress shadow effects and their influences on the propagation and proppant placement of the second fracture are investigated. According to the results, the following conclusions are discerned: (1) most proppants are located in the lower part of the reservoir, even below the perforation; (2) the stress shadow effects are time-dependent and proppant dominated; (3) the stress shadow effects affect the fracture propagation and the proppant placement of the second fracture, and also the fracture conductivity of the first fracture; (4) the time-dependent stress shadow effects can be divided into four phases, fracture enlargement, closure without proppant contact, closure with proppant contact and full closure; and (5) the superposition effect of the stress shadow in a transverse multiple fracture system exists. According to the conclusions, some optimizations are recommended.

[1]  I. N. Sneddon,et al.  The distribution of stress in the neighbourhood of a flat elliptical crack in an elastic solid , 1950, Mathematical Proceedings of the Cambridge Philosophical Society.

[2]  Michael P. Cleary.  Comprehensive Design Formulae For Hydraulic Fracturing , 1980 .

[3]  I. N. Sneddon,et al.  The opening of a Griffith crack under internal pressure , 1946 .

[4]  N. Nagel,et al.  Stress Shadowing and Microseismic Events: A Numerical Evaluation , 2011 .

[5]  Jon E. Olson,et al.  Multi-fracture propagation modeling: Applications to hydraulic fracturing in shales and tight gas sands , 2008 .

[6]  Xiaowei Weng,et al.  Numerical Modeling of Hydraulic Fracturing In Naturally Fractured Formations , 2011 .

[7]  Kamy Sepehrnoori,et al.  Simulation of gas desorption and geomechanics effects for unconventional gas reservoirs , 2014 .

[8]  Lucas W. Bazan,et al.  Optimization of Multiple Transverse Hydraulic Fractures in Horizontal Wellbores , 2010 .

[9]  K. Sepehrnoori,et al.  Simulation of gas desorption and geomechanics effects for unconventional gas reservoirs , 2013 .

[10]  Anthony Peirce,et al.  An efficient multi‐layer planar 3D fracture growth algorithm using a fixed mesh approach , 2002 .

[11]  Yang Gou,et al.  Numerical investigation of a low-efficient hydraulic fracturing operation in a tight gas reservoir in the North German Basin , 2014 .

[12]  Xiaowei Weng,et al.  Numerical Modeling of Hydraulic Fractures Interaction in Complex Naturally Fractured Formations , 2013, Rock Mechanics and Rock Engineering.

[13]  Mukul M. Sharma,et al.  Optimizing Fracture Spacing and Sequencing in Horizontal-Well Fracturing , 2011 .

[14]  Eduard Siebrits,et al.  Uniform asymptotic approximations for accurate modeling of cracks in layered elastic media* , 2001 .

[15]  B. R. Meyer.  Three-Dimensional Hydraulic Fracturing Simulation on Personal Computers: Theory and Comparison Studies , 1989 .

[16]  Kamy Sepehrnoori,et al.  Optimization of Multiple Hydraulically Fractured Horizontal Wells in Unconventional Gas Reservoirs , 2013 .

[17]  Mohamed Y. Soliman,et al.  Hydraulic Fracturing Design and Optimization: A Modification to Zipper Frac , 2012 .

[18]  Lei Zhou,et al.  A new numerical 3D-model for simulation of hydraulic fracturing in consideration of hydro-mechanical coupling effects , 2013 .

[19]  Yueming Cheng.  Boundary Element Analysis of the Stress Distribution Around Multiple Fractures: Implications for the Spacing of Perforation Clusters of Hydraulically Fractured Horizontal Wells , 2009 .

[20]  Yang Gou,et al.  Numerical modeling and investigation of fracture propagation with arbitrary orientation through fluid injection in tight gas reservoirs with combined XFEM and FVM , 2015, Environmental Earth Sciences.