INHIBITING LONGITUDINAL PROPAGATION OF CRACKS IN WELLBORE CEMENT

摘要

Procedures include designing parameters for cementation jobs based upon the wellbore geometries and loading conditions. The cementation parameters such as Young's modulus are selected such that longitudinal crack propagation is inhibited. Procedures also include determining critical loading conditions for an already-cemented casing annulus based upon the specified cement properties and wellbore conditions. The critical loading conditions are determined such that longitudinal crack propagation in the cement is inhibited. Techniques are used to improve the friction coefficients between the casing and cement to inhibit longitudinal crack propagation. The treatments can include forming surface patterns that enhance friction and/or making the casing surface oleophopic and/or hydrophilic.

主权项

1. A method of cementing an annular volume within a wellbore, the volume partially defined by an outer surface of a casing, the method comprising:
determining one or more properties for performing the cementing resulting in a cement within the annular volume that is resistant to crack propagation in directions parallel to a main longitudinal axis of the wellbore, wherein the determining is based in part on an amount of friction between the outer surface of the casing and the cement; and cementing the annular volume according to the one or more determined properties.