Abstract: Systems and methods to inhibit packoff during drilling assembly removal from a wellbore, utilizing a drilling assembly that includes a transition region between a first section having a first cross-sectional area and a second section having a second cross-sectional area, wherein the second cross-sectional area is greater than the first cross-sectional area. The transition region includes a fluidizing assembly configured to partially fluidize a portion of the cuttings bed that is proximal to the transition region, and/or be in fluid communication with a flow control assembly configured to control flow rate of a fluidizing stream from the fluidizing assembly and to the portion of cuttings bed.

Abstract: Methods for creating and using space-time surrogate models of subsurface regions, such as subsurface regions containing at least one hydrocarbon formation. The created surrogate models are explicit models that may be created from implicit models, such as computationally intensive full-physics models. The space-time surrogate models are parametric with respect to preselected variables, such as space, state, and/or design variables, while also indicating responsiveness of the preselected variables with respect to time. In some embodiments, the space-time surrogate model may be parametric with respect to preselected variables as well as to time. Methods for updating and evolving models of subsurface regions are also disclosed.

Abstract: Methods for creating and using discretized physics-based models of subsurface regions, which may contain a hydrocarbon reservoir or other subsurface feature(s). The methods may include selecting a pre-solved model, applying a mesh to the pre-solved model, defining the shape of the subsurface region to be modeled, and transforming the pre-solved model, to which the mesh has been applied, to the shape of the subsurface region. In some methods, the pre-solved model is an idealized model. In some methods, the mesh is applied to a solution of potential field lines associated with the pre-solved model, and in some methods, the solution of potential field lines is a composite solution of a plurality of solutions of potential field lines. In some methods, one or more supershapes are used to define the shape of the subsurface region. In some methods, a hyperelastic strain deformation calculation is utilized for the transforming.

Abstract: Methods for creating and using space-time surrogate models of subsurface regions, such as subsurface regions containing at least one hydrocarbon formation. The created surrogate models are explicit models that may be created from implicit models, such as computationally intensive full-physics models. The space-time surrogate models are parametric with respect to preselected variables, such as space, state, and/or design variables, while also indicating responsiveness of the preselected variables with respect to time. In some embodiments, the space-time surrogate model may be parametric with respect to preselected variables as well as to time. Methods for updating and evolving models of subsurface regions are also disclosed.

Abstract: Systems and methods to inhibit packoff during drilling assembly removal from a wellbore, utilizing a drilling assembly that includes a transition region between a first section having a first cross-sectional area and a second section having a second cross-sectional area, wherein the second cross-sectional area is greater than the first cross-sectional area. The transition region includes a fluidizing assembly configured to partially fluidize a portion of the cuttings bed that is proximal to the transition region, and/or be in fluid communication with a flow control assembly configured to control flow rate of a fluidizing stream from the fluidizing assembly and to the portion of cuttings bed.

Abstract: Methods for creating and using discretized physics-based models of subsurface regions, which may contain a hydrocarbon reservoir or other subsurface feature(s). The methods may include selecting a pre-solved model, applying a mesh to the pre-solved model, defining the shape of the subsurface region to be modeled, and transforming the pre-solved model, to which the mesh has been applied, to the shape of the subsurface region. In some methods, the pre-solved model is an idealized model. In some methods, the mesh is applied to a solution of potential field lines associated with the pre-solved model, and in some methods, the solution of potential field lines is a composite solution of a plurality of solutions of potential field lines. In some methods, one or more supershapes are used to define the shape of the subsurface region. In some methods, a hyperelastic strain deformation calculation is utilized for the transforming.

Abstract: Methods of predicting earth stresses in response to pore pressure changes in a hydrocarbon-bearing reservoir within a geomechanical system, include establishing physical boundaries for the geomechanical system and acquiring reservoir characteristics. Geomechanical simulations simulate the effects of changes in reservoir characteristics on stress in rock formations within the physical boundaries to determine the rock formation strength at selected nodes in the reservoir. The strength of the rock formations at the nodes is represented by an effective strain (?eff), which includes a compaction strain (?c) and out-of-plane shear strains (?1-3, Y2-3) at a nodal point. The methods further include determining an effective strain criteria (?effcr) from a history of well failures in the physical boundaries. The effective strain (?effcr) at a selected nodal point is compared with the effective strain criteria (?effcr) to determine if the effective strain (?eff) exceeds the effective strain criteria (?effcr).

Abstract: Methods for creating and using space-time surrogate models of subsurface regions, such as subsurface regions containing at least one hydrocarbon formation. The created surrogate models are explicit models that may be created from implicit models, such as computationally intensive full-physics models. The space-time surrogate models are parametric with respect to preselected variables, such as space, state, and/or design variables, while also indicating responsiveness of the preselected variables with respect to time. In some embodiments, the space-time surrogate model may be parametric with respect to preselected variables as well as to time. Methods for updating and evolving models of subsurface regions are also disclosed.

Abstract: Methods of predicting earth stresses in response to pore pressure changes in a hydrocarbon-bearing reservoir within a geomechanical system, include establishing physical boundaries for the geomechanical system and acquiring reservoir characteristics. Geomechanical simulations simulate the effects of changes in reservoir characteristics on stress in rock formations within the physical boundaries to determine the rock formation strength at selected nodes in the reservoir. The strength of the rock formations at the nodes is represented by an effective strain (?eff), which includes a compaction strain (?c) and out-of-plane shear strains (?1-3, Y2-3) at a nodal point. The methods further include determining an effective strain criteria (?effcr) from a history of well failures in the physical boundaries. The effective strain (?effcr) at a selected nodal point is compared with the effective strain criteria (?effcr) to determine if the effective strain (?eff) exceeds the effective strain criteria (?effcr).