Dynamic Interaction within Multiple Limited Entry Fractures in Horizontal Wells: Theory, Implications and Field Verification

Abstract

Abstract Interaction between adjacent fractures in horizontal wells has been recognized and discussed for some time. However, the scope of these discussions has been narrow and covers a limited number of actual field situations. In this paper, effects of dynamic interactions between multiple fractures are analyzed for different operational scenarios. These include effects of passive (previously fractured), active (being fractured) and multiple active fractures. A new aspect of this study, not previously covered in the literature, is examination of fracture inclination with respect to the wellbore. Paper will show that; The effect of dynamic interaction between adjacent fractures is largest when there is small difference between magnitudes of the two horizontal principal stresses, high net fracturing pressure, and short spacing between fractures.Dynamic fracture interaction is most significant when multiple fractures are created simultaneously (e. g., in Plug & Perf completions with limited entry design).There are important basic differences between dynamic interactions caused by transverse and inclined fractures. The influence is larger with inclined fractures.In multiple fracturing treatments based on limited entry, if the created fractures are transverse, dynamic interaction may cause shorter fractures to deflect and coalesce with longer adjacent fractures, thus further accelerating their growth.Compared to a single fracture, multiple limited entry fractures in horizontal wells require higher extension pressure. However, interaction between fractures is not likely to cause a significantly higher pressure in successive pumping stages in the same well.Dynamic interaction between multiple simultaneous fractures has little impact on ISIP values between successive pumping stages.In cases of small difference between the two horizontal principal stresses and high net fracturing pressure dynamic interaction can cause fracture deviations of more than 45°. This will increase the possibility of linkage between shorter fractures with longer adjacent fractures and accelerating their growth.The results presented here are in line with actual field data. The analysis presented here differs from some existing solutions in certain critical assumptions regarding the effect of a passive fracture on the propagation of an active fracture. However, the present results are in line with actual field data trends.