How far does surface heave propagate? A discussion on analytical and numerical modeling of the surface heave induced by subsurface fluid injection

Abstract

Reservoir dilations occur due to variety of subsurface injection operations including waste disposal, waterflooding, steam injection, CO2 sequestration and aquifer storage recovery. These reservoir dilations propagate to the surrounding formations and extend up to the ground surface resulting in surface heaves. This paper discusses modeling of the surface heave by applying both analytical and numerical methods. Results of the study demonstrate that the lateral extent of a finite element model has a direct impact on the surface heave profile and if the lateral boundaries are too close to the line of symmetry, there will be significant errors in the finite element results. This paper proposes a rapid way of estimating a sufficient lateral extent for the finite element model by using a new chart. The chart contains a family of curves, which can be used to estimate the surface heave propagation distance under various injection depths, injection periods and soil properties.