Laboratory study on casing deformation during multistage horizontal well fracturing in shale gas development and strain based casing design.

Shale gas development in the Sichuan-Chongqing region in China has experienced a high level of casing deformation or failure during hydraulic fracturing treatment, which has resulted in significant productivity decline and economic losses. This problem has motivated many studies in the literature but focusing on the shearing deformation using the finite element method. This paper categorizes the casing failure modes and mechanisms in the region and presents casing collapse laboratory results. The designed laboratory tests rendered us critical data points in casing deformation under different loading scenarios. For multiple stage hydraulic wells in the region, we propose to use a strain-based protocol for casing design instead of the current design based on maximum stress. • Present laboratory experiments on casing deformation due to shearing stress. • Propose a model to predict the maximum allowable stress for a casing tubular. • Update statistics on casing deformations and failures in the Changning-Weiyuan region. • Introduce one of a kind laboratory experiment setup for full size tubular testing. [ABSTRACT FROM AUTHOR]