STUDY ON MECHANISM OF CASING FAILURE INDUCED BY THE RESERVOIR COMPACTION

Casing failure is a worldwide problem in oil industry and severely impacts the economic benefits. The typical forms of the casing failure includes casing corrosion, radial deformation and shear etc., and the causes include corrosion of the formation water, non-uniform load on the casing initiated by the formation deformation or the hydration of the shale, shear initiated by formation sliding. As to the casing failure induced by the reservoir compaction, the reasons and the mechanisms of the reservoir compaction were studied; furthermore, the mechanisms of the casing failure in the compaction reservoir were analyzed and presented in detail. Measures for controlling casing failure in the compaction reservoir are put forward, which include increase the level of the casing design and determine suitable casing program; inject water to maintain the formation pressure, use the non-API thick wall casing, etc.