Using Surface Deformation To Estimate Reservoir Dilation: Strategies To Improve Accuracy

摘要

Reservoir dilat(at)ions, which are induced by a variety of sub-surface injection operations, propagate to the surrounding formations and extend up to the ground surface, resulting in surface deformations. The surface deformations can be mea-sured using various technologies and can be inverted to infer reservoir dilations (volume change distribution). This paper discusses the mathematical aspects of the inverse process in detail and investigates factors affecting the accuracy of the inverse solution through a parametric study. Based on results of the parametric study, the volume change distribution in the lateral direction can be estimated with both high accuracy and high resolution by applying the Tikhonov regularization technique. The volume change distribution in the vertical di-rection can also be resolved to a certain extent by providing further information regarding the desired solution in terms of an initial estimate. Strategies to improve accuracy of the in-verse solution in the lateral as well as in the vertical directions are also discussed.