Shale hydraulic fracture morphology and inter-well interference rule under multi-wellbore test

• Published in: Applied rheology (Lappersdorf, Germany) Vol. 34; no. 1; pp. 108002 - 55
• Main Authors: Ma, Yulin, Du, Yupeng, Lu, Dandan
• Format: Journal Article
• Language: English
• Published: De Gruyter 25.04.2024
• Subjects: hydraulic fracturing; in situ stress state; inter-well interference; stress state; true triaxial; well pattern
• ISSN: 1617-8106; 1617-8106
• DOI: 10.1515/arh-2024-0005

This study conducted a series of true triaxial hydraulic fracturing experiments on Longmaxi Formation shale. We investigated the interaction between internal factors and external factors on the inter-well interference of 400 mm cubic porous specimens. During dual wellbore fracturing at different formations, forming inter-well interference through secondary hydraulic fractures lead to a lower interference intensity and larger stimulated rock area. When adopting a three-layer well layout during three-wellbore fracturing, the vertical distance between the wells is shortened, activating more bedding planes. Regardless of a horizontal well placement with two wellbores or a three-dimensional two-layer well placement with three wellbores, increasing the vertical stress leads to more potent inter-well interference. There is no absolute positive correlation between the stimulated rock area and inter-well interference. It can be influenced by the presence of natural fractures within the formation that can even lead to a reduction in the stimulated area. When the well placement changes from two horizontal wellbores to three-dimensional two-layer sites with three wellbores and the vertical stress increases, the inter-well interference becomes stronger, but the stimulated rock area only increases by 22.6%. These findings provide crucial guidance for the hydraulic fracturing design of shale reservoirs.