How to Engineer Transverse Hydraulic Fractures from Horizontal Wells in Reverse-Faulting Stressed Environments

ABSTRACT: Hydraulic fracture (HF) orientation impacts the well deliverability from hydrocarbon reservoirs. Completions efficiency and stimulated-well productivity from such low-permeability ("tight") formations like shales is significantly improved having multiple HFs oriented transversely rather than longitudinally in relation to a horizontal well's lateral. Nevertheless, transverse-HF initiation from horizontal wells drilled in reverse-faulting stressed environments is challenging, as the in-situ stress field naturally promotes unfavorable longitudinal ("pancake-like") HFs. This paper explores a method for inducing transverse-HF initiation from these reverse-faulting stress states by smart use of stress shadows from previously-initiated HFs. The proposed method involves initiating two longitudinal HFs whose growth will stop at a level sufficient for the stress shadowing triggered by their widths to alter the stress state in their surrounding vicinities, such that when a third HF initiation is attempted in the region in-between them, it will result to a transverse-HF initiation. Laboratory-scale experiments on transparent gelatin blocks are used for validation purposes with a specially-designed manifold enabling non-simultaneous injection at different regions ("frac stages") from the same fluid source, mimicking a multistage-HF treatment on a horizontal well. Variations of this method are possible, including alternative forms where two transverse HFs are promoted from a single longitudinal HF initiated a-priori.