Ensuring Geomechanics Engineers Have You on the Right Stress Path to Success

While geomechanics plays a critical role in areas such as wellbore stability and hydraulic fracturing, it also provides important insights on how the “mechanical” behaviour of formations influences and interacts with fluid flow – the domain of reservoir engineers. Changes in fluid pressure and temperature during production or injection alter the stresses within the rock (within the reservoir and caprock), leading to deformation that can change a formations pore structure (with a common reference to “dilation” as a pore altering process), fracture characteristics and permeability (both absolute and relative permeability), directly affecting how fluids move. And in general, numerical modelling techniques, typically referred to as coupled (or uncoupled) reservoir geomechanical modeling is used to explore the impacts of these processes. But all these models, ranging over multiple degrees of complexity, all require fundamental input data to characterize the stress strain behaviour (constitutive behavior) and its relationship to permeability change. And many (and one could argue, most) cases, the properties required for these simulations come from correlations and log-based interpretations but when core is available for lab testing programs, experimental work is conducted that provides data for the development of the constitutive models. 
 
And for the purposes of this talk, this is where things become “stressful” for the reservoir engineer. The reason for this is that for whatever process is under consideration by the reservoir engineer, production or injection, the reservoir-geomechanical behavior (determined from the lab tests) should ideally be determined for the same “stress path” followed in the reservoir (or caprock, for that matter). And all geomechanical (geotechnical) engineers know that stress path impacts the stress-strain behavior and consequently, any permeability relationship that is developed using data from tests conducted along the wrong stress path can provide meaningless results or worse, misleading results.
 
This talk will review what a stress path entails, examine lab data from different stress paths, and present modeling data to illustrate typical stress paths in various scenarios. We will discuss how these stress paths relate to changes in reservoir flow properties and emphasize why it is crucial for reservoir engineers to ensure that geomechanical engineers are not leading them down the wrong “stress path”….
 
Registration closes on Wednesday, May 21 at 8AM MDT.