Determining differential stress based on formation curvature and mechanical units using borehole logs

摘要

A method for performing wellbore operations of a field having a subterranean formation. The method includes determining, based on an image log of a wellbore penetrating the subterranean formation, a plurality of interpreted geological surfaces, identifying a plurality of estimated slickensides from the plurality of interpreted geological surfaces based on at least one pre-determined criterion, calculating, using a processor, a differential stress using a curvature model representing at least one mechanical unit defined by the plurality of estimated slickensides, generating a stress model using the differential stress, identifying a modeled wellbore stress-induced failure in response to a total stress value in the stress model exceeding a strength property of the subterranean formation, determining a difference between the modeled wellbore stress-induced failure and an observed stress-induced failure in the subterranean formation, and updating the stress model by adjusting the plurality of estimated slickensides to, in turn, adjust the difference.

主权项

1. A method for performing wellbore operations of a field having a subterranean formation, the method comprising:
determining, based on an image log of a wellbore penetrating the subterranean formation, a plurality of interpreted geological surfaces; identifying a plurality of estimated slickensides from the plurality of interpreted geological surfaces based on at least one pre-determined criterion; calculating, using a processor, a differential stress using a curvature model representing a formation curvature in at least one mechanical unit defined by the plurality of estimated slickensides; generating a stress model using the differential stress; identifying a modeled wellbore stress-induced failure in response to a total stress value in the stress model exceeding a strength property of the subterranean formation; determining a difference between the modeled wellbore stress-induced failure and an observed stress-induced failure in the subterranean formation; and updating the stress model by adjusting the plurality of estimated slickensides to, in turn, adjust the difference wherein generating the stress model comprises revising an initial stress model of the subterranean formation using the differential stress, wherein the initial stress model represents at least far-field stresses of a wellbore in the subterranean formation, wherein the plurality of interpreted geological surfaces comprises a curvature determined from the image log, wherein the plurality of interpreted geological surfaces correspond to actual geological surfaces disposed about the wellbore in the subterranean formation, and wherein the curvature model represents the at least one mechanical unit as a bent layer based on a curvature of the plurality of interpreted geological surfaces.