Numerical Investigation of Hydraulic Fractures in Multiple Horizontal Wells: Analysis of Zipper & Modified Zipper Fracking

Abstract

New fracturing designs and techniques have been developed in recent years to increase the production of trapped hydrocarbons. The new techniques are designed to reduce stress contrast during fracture propagation while increasing complexity and maximising stimulated reservoir volume. One of these techniques is zipper fracture, which involves simultaneously stimulating two parallel horizontal wells from toe to heel. Throughout this procedure, generated fractures in each cluster propagate toward each other, forcing fracture propagation in a direction perpendicular to the main fracture due to induced stresses near the tips. The industry has approved zipper fracture’s effectiveness; however, the treatment’s optimization is still being debated.

A thorough comparison of zipper fracturing and modified zipper fracturing has been conducted in this paper. The results show that the modified zipper frac slightly improves fracturing treatment performance when compared to the original zipper frac by increasing contact area and, as a result, fluid production. The MFZ design enhances the stress interference between the fractures, resulting in an effective stimulated reservoir volume (SRV) that boosts hydrocarbon production. Instead of having the fractures of two neighbouring wells point toward each other, they are staggered so that the fractures overlap.