Randy Hazlett | Nazarbayev University (original) (raw)

Papers by Randy Hazlett

International journal of coal geology, Jun 1, 2024

Results in engineering, Mar 1, 2024

Geothermics, Feb 29, 2024

Springer eBooks, 1995

Displacement simulation in realistic pore networks, such as those derived from X-ray microtomogra... more Displacement simulation in realistic pore networks, such as those derived from X-ray microtomography, is presented for the regime where capillarity controls fluid motions and spatial distributions. Complex displacement sequences involving both imbibition and drainage are constructed to extract wettability indices. The percolation properties of predicted equilibrium phase distributions are analyzed. Equilibrium fluid distributions are used to model transport properties for each phase.

Springer eBooks, Dec 14, 2018

This chapter aims to encourage negotiators to not only pursue their desire to create value throug... more This chapter aims to encourage negotiators to not only pursue their desire to create value through their short-term deals but also to strive to achieve more elusive evolutionary solutions that will impact future generations. Future generations include future interactions between the parties, general developments in society, and, literally, interactions between negotiators’ descendants. We introduce the moral pillars that can support such transcendental negotiations and encourage readers to practice these pillars in their next negotiations. A brief review of negotiation theory is presented, laying the groundwork for introducing a type of negotiation, as an alternative to the commonly-discussed distributive and integrative categories. In this alternative framing of interaction, negotiators transcend the transaction and break away from the paradigm of individualism, which dictates that the only possible way to achieve success is by manipulating others, emphasizing personal gain and selfishness.

All Days, Oct 5, 2003

The need for accurate well productivity models with arbitrary well trajectories spurred a revival... more The need for accurate well productivity models with arbitrary well trajectories spurred a revival in analytic solution methodology for fluid transport problems. Analytic formulations often depict single phase flow throughout the reservoir. The Babu-Odeh horizontal well solution for a box-shaped reservoir with spatially invariant properties is generalized here to allow closed-form solutions for heterogeneous media. A reservoir is decomposed into interacting regions, each with its own reservoir properties and associated analytic potential flow solution. Using well-established boundary element techniques, pressure and flux continuity are imposed at selected interface points to solve for the steady material exchange between regions. Constant pressure and zero flux features (fractures and barriers) are easily entertained at region boundaries. The 2-D, pseudo-steady state solution for heterogeneous media is embedded within a reservoir performance feedback loop of a powerful gradient search method to produce a robust optimal in-fill well placement algorithm. Utilizing this approach, new criteria are developed concerning optimal placement of vertical wells for primary production with respect to heterogeneity, asymmetry, and anisotropy. The semi-analytic method has been extended to 3-dimensional flows to serve as a compute engine for a new generation of reservoir management and optimization tools. Introduction Well placement strategy in in-fill programs is strongly dependent upon the reservoir development plan and the present stage in that overall plan. Often well patterns are deployed based upon uniform permeability models; however, the role of reservoir heterogeneity can be formidable. Most wells are placed as production wells and selectively converted to injectors as fields mature and interwell communication patterns become increasingly important. While reservoir engineers have numerical simulation methods capable of reservoir performance feedback with regard to candidate well placement, many of these models have inherent restrictions on the ability to accurately model well performance. Few reservoir engineers have the luxury to discretize on the level of the wellbore radius, but rather rely on block-centered, wellbore coupling correlations. Well production engineers utilize models with fine-scale discretization; however, their inflow performance predictions can be limited in reservoir scope. While analytical models provided the foundation for much of modern reservoir engineering1, the need to consider more realistic reservoir architecture and the advent of computers and advanced numerical simulation capabilities have greatly deemphasized the role of closed form solutions to fluid flow problems. One exception has been in the depiction of well equations to relate wellbore pressure to a cell block pressure in numerical simulation2–4, which avoids the need for grid refinement around wells. The interest in accurate productivity portrayal for advanced well designs generated a new interest in analytic solution methodology5–8. While analytic solutions to horizontal well scenarios furnished a much needed connection between simulation block averages and observables on the scale of the wellbore radius, the issue of reservoir heterogeneity is largely unaddressed. A method is described herein which utilizes easily computable analytic formulations for potential flow within a boundary element method (BEM) in order to derive closed form solutions in two and three dimensions for single phase, pseudo-steady state fluid flow in heterogeneous systems. The reservoir performance model is furthermore embedded within an optimization feedback loop to indicate optimal in-fill well locations. The method is then used to study optimal well positioning in relation to spatial porosity variation, permeability heterogeneity, and well interference.

Social Science Research Network, 2022

Advances in geo-energy research, Oct 20, 2022

Journal of Petroleum Science and Engineering, Dec 1, 1999

Computational Geosciences, Oct 22, 2021

Spe Journal, Apr 1, 2021

Summary Decline curve analysis (DCA) has been the mainstay in unconventional reservoir evaluation... more Summary Decline curve analysis (DCA) has been the mainstay in unconventional reservoir evaluation. Because of the extremely low matrix permeability, each well is evaluated economically for ultimate recovery as if it were its own reservoir. Classification and normalization of well potential is difficult because of ever-changing stimulation total contact area and a hyperbolic curve fit parameter that is disconnected from any traditional reservoir characterization descriptor. A new discrete fracture model approach allows direct modeling of inflow performance in terms of fracture geometry, drainage volume shape, and matrix permeability. Running such a model with variable geometrical input to match the data in lieu of standard regression techniques allows extraction of a meaningful parameter set for reservoir characterization, an expected outcome from all conventional well testing. Because the entirety of unconventional well operation is in transient mode, the discrete fractured well solution to the diffusivity equation is used to model temporal well performance. The analytical solution to the diffusivity equation for a line source or a 2D fracture operating under constrained bottomhole pressure consists of a sum of terms, each with exponential damping with time. Each of these terms has a relationship with the constant rate, semisteady-state solution for inflow, although the well is not operated with constant rate, nor will this flow regime ever be realized. The new model is compared with known literature models, and sensitivity analyses are presented for variable geometry to illustrate the depiction of different time regimes naturally falling out of the unified diffusivity equation solution for discrete fractures. We demonstrate that apparent hyperbolic character transitioning to exponential decline can be modeled directly with this new methodology without the need to define any crossover point. The mathematical solution to the physical problem captures the rate transient functionality and any and all transitions. Each exponential term in the model is related to the various possible interferences that may develop, each occurring at a different time, thus yielding geometrical information about the drainage pattern or development of fracture interference within the context of ultralow matrix permeability. Previous results analyzed by traditional DCA can be reinterpreted with this model to yield an alternate set of descriptors. The approach can be used to characterize the efficacy of evolving stimulation practices in terms of geometry within the same field and thus contribute to the current type curve analyses subject to binning. It enables the possibility of intermixing of vertical and horizontal well performance information as simply gathering systems of different geometry operating in the same reservoir. The new method will assist in reservoir characterization and evaluation of evolving stimulation technologies in the same field and allow classification of new type curves.

Social Science Research Network, 2023

Transport in Porous Media, Aug 1, 1995

Displacement simulation in realistic pore networks, such as those derived from X-ray microtomogra... more Displacement simulation in realistic pore networks, such as those derived from X-ray microtomography, is presented for the regime where capillarity controls fluid motions and spatial distributions. Complex displacement sequences involving both imbibition and drainage are constructed to extract wettability indices. The percolation properties of predicted equilibrium phase distributions are analyzed. Equilibrium fluid distributions are used to model transport properties for each phase.

International journal of coal geology, Jun 1, 2024

Results in engineering, Mar 1, 2024

Geothermics, Feb 29, 2024

Springer eBooks, 1995

Displacement simulation in realistic pore networks, such as those derived from X-ray microtomogra... more Displacement simulation in realistic pore networks, such as those derived from X-ray microtomography, is presented for the regime where capillarity controls fluid motions and spatial distributions. Complex displacement sequences involving both imbibition and drainage are constructed to extract wettability indices. The percolation properties of predicted equilibrium phase distributions are analyzed. Equilibrium fluid distributions are used to model transport properties for each phase.

Springer eBooks, Dec 14, 2018

This chapter aims to encourage negotiators to not only pursue their desire to create value throug... more This chapter aims to encourage negotiators to not only pursue their desire to create value through their short-term deals but also to strive to achieve more elusive evolutionary solutions that will impact future generations. Future generations include future interactions between the parties, general developments in society, and, literally, interactions between negotiators’ descendants. We introduce the moral pillars that can support such transcendental negotiations and encourage readers to practice these pillars in their next negotiations. A brief review of negotiation theory is presented, laying the groundwork for introducing a type of negotiation, as an alternative to the commonly-discussed distributive and integrative categories. In this alternative framing of interaction, negotiators transcend the transaction and break away from the paradigm of individualism, which dictates that the only possible way to achieve success is by manipulating others, emphasizing personal gain and selfishness.

All Days, Oct 5, 2003

The need for accurate well productivity models with arbitrary well trajectories spurred a revival... more The need for accurate well productivity models with arbitrary well trajectories spurred a revival in analytic solution methodology for fluid transport problems. Analytic formulations often depict single phase flow throughout the reservoir. The Babu-Odeh horizontal well solution for a box-shaped reservoir with spatially invariant properties is generalized here to allow closed-form solutions for heterogeneous media. A reservoir is decomposed into interacting regions, each with its own reservoir properties and associated analytic potential flow solution. Using well-established boundary element techniques, pressure and flux continuity are imposed at selected interface points to solve for the steady material exchange between regions. Constant pressure and zero flux features (fractures and barriers) are easily entertained at region boundaries. The 2-D, pseudo-steady state solution for heterogeneous media is embedded within a reservoir performance feedback loop of a powerful gradient search method to produce a robust optimal in-fill well placement algorithm. Utilizing this approach, new criteria are developed concerning optimal placement of vertical wells for primary production with respect to heterogeneity, asymmetry, and anisotropy. The semi-analytic method has been extended to 3-dimensional flows to serve as a compute engine for a new generation of reservoir management and optimization tools. Introduction Well placement strategy in in-fill programs is strongly dependent upon the reservoir development plan and the present stage in that overall plan. Often well patterns are deployed based upon uniform permeability models; however, the role of reservoir heterogeneity can be formidable. Most wells are placed as production wells and selectively converted to injectors as fields mature and interwell communication patterns become increasingly important. While reservoir engineers have numerical simulation methods capable of reservoir performance feedback with regard to candidate well placement, many of these models have inherent restrictions on the ability to accurately model well performance. Few reservoir engineers have the luxury to discretize on the level of the wellbore radius, but rather rely on block-centered, wellbore coupling correlations. Well production engineers utilize models with fine-scale discretization; however, their inflow performance predictions can be limited in reservoir scope. While analytical models provided the foundation for much of modern reservoir engineering1, the need to consider more realistic reservoir architecture and the advent of computers and advanced numerical simulation capabilities have greatly deemphasized the role of closed form solutions to fluid flow problems. One exception has been in the depiction of well equations to relate wellbore pressure to a cell block pressure in numerical simulation2–4, which avoids the need for grid refinement around wells. The interest in accurate productivity portrayal for advanced well designs generated a new interest in analytic solution methodology5–8. While analytic solutions to horizontal well scenarios furnished a much needed connection between simulation block averages and observables on the scale of the wellbore radius, the issue of reservoir heterogeneity is largely unaddressed. A method is described herein which utilizes easily computable analytic formulations for potential flow within a boundary element method (BEM) in order to derive closed form solutions in two and three dimensions for single phase, pseudo-steady state fluid flow in heterogeneous systems. The reservoir performance model is furthermore embedded within an optimization feedback loop to indicate optimal in-fill well locations. The method is then used to study optimal well positioning in relation to spatial porosity variation, permeability heterogeneity, and well interference.

Social Science Research Network, 2022

Advances in geo-energy research, Oct 20, 2022

Journal of Petroleum Science and Engineering, Dec 1, 1999

Computational Geosciences, Oct 22, 2021

Spe Journal, Apr 1, 2021

Summary Decline curve analysis (DCA) has been the mainstay in unconventional reservoir evaluation... more Summary Decline curve analysis (DCA) has been the mainstay in unconventional reservoir evaluation. Because of the extremely low matrix permeability, each well is evaluated economically for ultimate recovery as if it were its own reservoir. Classification and normalization of well potential is difficult because of ever-changing stimulation total contact area and a hyperbolic curve fit parameter that is disconnected from any traditional reservoir characterization descriptor. A new discrete fracture model approach allows direct modeling of inflow performance in terms of fracture geometry, drainage volume shape, and matrix permeability. Running such a model with variable geometrical input to match the data in lieu of standard regression techniques allows extraction of a meaningful parameter set for reservoir characterization, an expected outcome from all conventional well testing. Because the entirety of unconventional well operation is in transient mode, the discrete fractured well solution to the diffusivity equation is used to model temporal well performance. The analytical solution to the diffusivity equation for a line source or a 2D fracture operating under constrained bottomhole pressure consists of a sum of terms, each with exponential damping with time. Each of these terms has a relationship with the constant rate, semisteady-state solution for inflow, although the well is not operated with constant rate, nor will this flow regime ever be realized. The new model is compared with known literature models, and sensitivity analyses are presented for variable geometry to illustrate the depiction of different time regimes naturally falling out of the unified diffusivity equation solution for discrete fractures. We demonstrate that apparent hyperbolic character transitioning to exponential decline can be modeled directly with this new methodology without the need to define any crossover point. The mathematical solution to the physical problem captures the rate transient functionality and any and all transitions. Each exponential term in the model is related to the various possible interferences that may develop, each occurring at a different time, thus yielding geometrical information about the drainage pattern or development of fracture interference within the context of ultralow matrix permeability. Previous results analyzed by traditional DCA can be reinterpreted with this model to yield an alternate set of descriptors. The approach can be used to characterize the efficacy of evolving stimulation practices in terms of geometry within the same field and thus contribute to the current type curve analyses subject to binning. It enables the possibility of intermixing of vertical and horizontal well performance information as simply gathering systems of different geometry operating in the same reservoir. The new method will assist in reservoir characterization and evaluation of evolving stimulation technologies in the same field and allow classification of new type curves.

Social Science Research Network, 2023

Transport in Porous Media, Aug 1, 1995

Displacement simulation in realistic pore networks, such as those derived from X-ray microtomogra... more Displacement simulation in realistic pore networks, such as those derived from X-ray microtomography, is presented for the regime where capillarity controls fluid motions and spatial distributions. Complex displacement sequences involving both imbibition and drainage are constructed to extract wettability indices. The percolation properties of predicted equilibrium phase distributions are analyzed. Equilibrium fluid distributions are used to model transport properties for each phase.