24 results on '"Hector D. Perez"'
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2. DisjunctiveProgramming.jl: Generalized Disjunctive Programming Models and Algorithms for JuMP.
- Author
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Hector D. Perez, Shivank Joshi, and Ignacio E. Grossmann
- Published
- 2023
- Full Text
- View/download PDF
Catalog
3. Integrating information, financial, and material flows in a chemical supply chain.
- Author
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Hector D. Perez, Kyle C. Harshbarger, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2023
- Full Text
- View/download PDF
4. A digital twin framework for online optimization of supply chain business processes.
- Author
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Hector D. Perez, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2022
- Full Text
- View/download PDF
5. OR-Gym: A Reinforcement Learning Library for Operations Research Problem.
- Author
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Christian D. Hubbs, Hector D. Perez, Owais Sarwar, Nikolaos V. Sahinidis, Ignacio E. Grossmann, and John M. Wassick
- Published
- 2020
6. Batch scheduling with quality-based changeovers.
- Author
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Braulio Brunaud, Hector D. Perez, Satyajith Amaran, Scott J. Bury, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2020
- Full Text
- View/download PDF
7. Optimization of extended business processes in digital supply chains using mathematical programming.
- Author
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Hector D. Perez, Satyajith Amaran, Esra Erisen, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2021
- Full Text
- View/download PDF
8. Scheduling of Material and Information Flows in the Manufacturing of Chemicals for the Order-to-Cash Process of a Digital Supply Chain
- Author
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Hector D. Perez, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2022
- Full Text
- View/download PDF
9. Contributors
- Author
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Heiner Ackermann, Simen Akkermans, Satyajith Amaran, Michael Amrhein, Norbert Asprion, Tilman Barz, Satyajeet Bhonsale, Lorenz T. Biegler, Filippo Bisotti, Dominique Bonvin, Michael Bortz, Mariano Nicolas Cruz Bournazou, Luisa C. Brée, Andreas Bulan, Jorge Diaz, Sebastian Engell, Gregor Foltin, Grégory François, Andrea Galeazzi, Francesco Gallo, Federico Galvanin, Jochen Gattermayer, Thomas Gerlach, Joachim Gross, Ignacio E. Grossmann, David Hajnal, Raoul Heese, Melanie Heidgen, Michael Helmling, Jesús D. Hernández, Christoph Herwig, Stefan Hoeser, Shachit S. Iyer, Julian Kager, Thomas Kochenburger, Stefan Lehner, Neele Leithäuser, Filip Logist, Jonas Mairhofer, Flavio Manenti, David C. Miller, Alexander Mitsos, Jan Mohring, Peter Neubauer, Philippe Nimmegeers, Chinedu O. Okoli, Luca Onofri, Hector D. Perez, Karen Perrey, Jürgen Rarey, Gianluca Rizzi, Kosan Roh, Miguel A. Romero-Valle, Jochen Schmid, Jan C. Schöneberger, Hergen Schultze, Daniel Staak, Ioanna Stamati, Philipp Süss, Dries Telen, Carlos Tellaeche, Jan F.M. Van Impe, John M. Wassick, Christian Weiß, and Jarosław Wlazło more...
- Published
- 2022
- Full Text
- View/download PDF
10. Applications of the RTN scheduling model in the chemical industry
- Author
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Hector D. Perez, Satyajith Amaran, Shachit S. Iyer, John M. Wassick, and Ignacio E. Grossmann
- Published
- 2022
- Full Text
- View/download PDF
11. Recent Advances in Computational Models for the Discrete and Continuous Optimization of Industrial Process Systems
- Author
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Hector D. Perez and Ignacio E. Grossmann
- Subjects
Continuous optimization ,Mathematical optimization ,Computational model ,Optimization problem ,Linear programming ,Computer science ,Robust optimization ,Integer programming ,Stochastic programming ,Nonlinear programming - Abstract
An overview of the mathematical formulations used for discrete and continuous optimization are presented. These include Linear Programming, Nonlinear Programming, Integer Programming, Mixed-Integer Linear Programming, Mixed-Integer Nonlinear Programming, Logic-based Optimization, Stochastic Programming, Robust Optimization, and Flexibility Analysis. Successful applications of optimization models in industry are presented in the following fields: upstream oil & gas, materials blending, natural gas, biofuels, water treatment, electricity market integration, plant reliability, and supply chain design. Ongoing projects applying computational models to optimize industrial process systems are also mentioned. Implementations of customized optimization techniques that improve computational performance and enable finding solutions to otherwise unsolvable optimization problems are highlighted. These include strengthening cuts, decomposition strategies, model reformulation, and linearization, among others. more...
- Published
- 2021
- Full Text
- View/download PDF
12. A Digital Twin Framework for Business Transactional Processes in Supply Chains
- Author
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Esra Erisen, Satyajith Amaran, John M. Wassick, Ignacio E. Grossmann, and Hector D. Perez
- Subjects
Business process management ,business.industry ,Business process ,Process (engineering) ,Computer science ,Replica ,Supply chain ,Scheduling (production processes) ,State (computer science) ,Greedy algorithm ,business ,Industrial engineering - Abstract
An integrated framework for building a virtual replica of business transactional processes in supply chains is presented. The framework consists of two main components: a simulation module and an optimization module. Business processes are modeled as networks of queues through which requests (internal or external to the enterprise) can flow. The digital replica of the business processes creates value by providing a simulation platform upon which to: 1) test optimization strategies, 2) forecast potential delays in requests based on the current state of the real process and the historical data, 3) identify and mitigate bottlenecks, and 4) provide more accurate fulfillment dates to customers. The optimization can be performed offline or in real-time in a feed-back loop as the simulation is being executed. As an integrated simulation and optimization environment, the framework bridges and extends the literature in business process simulation and business process optimization, building upon previous work by the authors that was restricted to only business process scheduling in static deterministic environments. A case study is presented in which three mathematical programming models and a greedy heuristic are compared. A sensitivity study shows the value in using simulation to mitigate operational bottlenecks. more...
- Published
- 2021
- Full Text
- View/download PDF
13. Optimization of Business Transactional Processes in a Digital Supply Chain
- Author
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Esra Erisen, Hector D. Perez, Ignacio E. Grossmann, John M. Wassick, and Satyajith Amaran
- Subjects
Customer experience ,Transactional leadership ,Linear programming ,Transaction processing ,Computer science ,Supply chain ,Scheduling (production processes) ,Novelty ,Supply chain optimization ,Industrial engineering - Abstract
A new continuous time multistage scheduling Mixed-Integer Linear Programming (MILP) model is proposed to optimize the business transactional processes in supply chains. The novelty of this approach is in using techniques from the Process Systems Engineering (PSE) and Operations Research (OR) communities to address a side of supply chain optimization (information flow) that has not been targeted previously. This model accounts for the allocation of resources in processing orders at each of the stages of a business transactional process. The objective of the model is to improve customer experience, using on-time-delivery (OTD) as a surrogate metric for this target. An illustrative example, featuring a subset of the business transactional steps in the Order-to-Cash (OTC) process is presented, showing the potential of using mathematical programming to improve supply chain performance. The model enables identifying bottlenecks in the processes and determining where additional resources should be allocated. The model can also be used as a valuable tool to assist customer service representatives in establishing realistic promise-to-delivery dates for their clients. more...
- Published
- 2020
- Full Text
- View/download PDF
14. Multivariate Control for Managed-Pressure-Drilling Systems by Use of High-Speed Telemetry
- Author
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Hector D. Perez, John D. Hedengren, Anthony Paul Pink, David S. Pixton, Reza Asgharzadeh Shishavan, and Casey Hubbell
- Subjects
Multivariate statistics ,Engineering ,business.industry ,020209 energy ,Control (management) ,Energy Engineering and Power Technology ,Drilling ,Control engineering ,02 engineering and technology ,Geotechnical Engineering and Engineering Geology ,020401 chemical engineering ,Telemetry ,0202 electrical engineering, electronic engineering, information engineering ,0204 chemical engineering ,business - Abstract
Summary With the recent advance in high-speed data communication offered by wired-drillpipe (WDP) telemetry, it is now possible to design automated control systems that directly use downhole data (e.g., pressure) to optimize drilling procedures. This research couples drilling hydraulics, rate of penetration (ROP), and rotational-speed (rev/min) control into a single controller for managed-pressure-drilling (MPD) systems. This novel multivariate controller improves drilling performance during normal drilling operations and enhances safety during abnormal drilling conditions such as unwanted gas-influx situations. New advances in drilling automation have made the closed-loop control of downhole weight on bit (WOB) and drillstring rotational speed (rev/min) possible. This study uses two feedback controllers that control the downhole WOB and rev/min by use of surface data. A multivariate nonlinear model-predictive controller (NMPC) uses downhole and surface measurements to simultaneously regulate the bottomhole-assembly (BHA) pressure and maximize the ROP. For this purpose, NMPC provides the necessary set points for the WOB and rev/min feedback controllers and manipulates the choke-valve opening and pump-flow rates. Controller performance is enhanced by means of a nonlinear estimator that works continuously online with the NMPC and provides the necessary estimated parameter values (such as annulus density, friction factor, and gas influx) for precise and efficient drilling control. The designed NMPC controller has a multipriority approach that is described in the following three scenarios: during unexpected gas influx, the NMPC gives priority to BHA pressure control and attenuates the influx effectively by means of a novel kick-attenuation method that switches the control objective from BHA pressure to choke-valve pressure; during connection procedures when adding a new stand, ROP is stopped and the NMPC focuses on maintaining the BHA pressure constant; and during normal drilling operation, which involves changes in the rock formation and differential pressures, NMPC gives priority to ROP maximization while maintaining rev/min, WOB, and BHA pressure within specified bounds. Preliminary results suggest that this multivariate controller for ROP and BHA-pressure control decreases drilling costs, reduces operator workload, and minimizes risk significantly. Specific improvements in drilling performance include higher ROP, effective kick attenuation, and more-uniform cuttings. The use of a multivariate NMPC allows for better ROP optimization and BHA-pressure control than is possible with the use of two independent controllers. These benefits are demonstrated across the three scenarios mentioned previously. In simulation, this technology delivers significant performance improvements during MPD and furthers the development of automated-driller systems. more...
- Published
- 2016
- Full Text
- View/download PDF
15. Algorithmic Approaches to Inventory Management Optimization
- Author
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Hector D. Perez, Christian D. Hubbs, Ignacio E. Grossmann, and Can Li
- Subjects
reinforcement learning ,multi-echelon ,Linear programming ,Operations research ,Computer science ,Supply chain ,inventory management ,0211 other engineering and technologies ,Bioengineering ,02 engineering and technology ,lcsh:Chemical technology ,lcsh:Chemistry ,stochastic programming ,Stochastic simulation ,0202 electrical engineering, electronic engineering, information engineering ,Chemical Engineering (miscellaneous) ,Reinforcement learning ,lcsh:TP1-1185 ,supply chain ,021103 operations research ,Process Chemistry and Technology ,Node (networking) ,Stochastic programming ,lcsh:QD1-999 ,Service level ,020201 artificial intelligence & image processing ,Profitability index - Abstract
An inventory management problem is addressed for a make-to-order supply chain that has inventory holding and/or manufacturing locations at each node. The lead times between nodes and production capacity limits are heterogeneous across the network. This study focuses on a single product, a multi-period centralized system in which a retailer is subject to an uncertain stationary consumer demand at each time period. Two sales scenarios are considered for any unfulfilled demand: backlogging or lost sales. The daily inventory replenishment requests from immediate suppliers throughout the network are modeled and optimized using three different approaches: (1) deterministic linear programming, (2) multi-stage stochastic linear programming, and (3) reinforcement learning. The performance of the three methods is compared and contrasted in terms of profit (reward), service level, and inventory profiles throughout the supply chain. The proposed optimization strategies are tested in a stochastic simulation environment that was built upon the open-source OR-Gym Python package. The results indicate that, of the three approaches, stochastic modeling yields the largest increase in profit, whereas reinforcement learning creates more balanced inventory policies that would potentially respond well to network disruptions. Furthermore, deterministic models perform well in determining dynamic reorder policies that are comparable to reinforcement learning in terms of their profitability. more...
- Published
- 2021
- Full Text
- View/download PDF
16. Effects of Particle Size and Shape on the Performance of a Trickle Fixed-Bed Recycle Reactor for Fischer–Tropsch Synthesis
- Author
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Robson P. S. Peguin, Kyle M. Brunner, Joshua C. Duncan, Calvin H. Bartholomew, Hector D. Perez, Luke D. Harrison, and William C. Hecker
- Subjects
Pressure drop ,Materials science ,Chemical engineering ,General Chemical Engineering ,Fischer–Tropsch process ,SPHERES ,General Chemistry ,Particle size ,Heat transfer coefficient ,Porosity ,Industrial and Manufacturing Engineering ,Catalysis ,Syngas - Abstract
A previously developed one-dimensional reactor model was employed to understand the effects of pellet size and geometry on the performance of a wall-cooled multitubular fixed-bed Fischer–Tropsch reactor for producing hydrocarbons from synthesis gas. The effects of pellet size/shape on catalyst effectiveness, bed void fraction, and overall heat transfer coefficient were studied through a comprehensive parametric study of a reactor with cobalt catalyst. The relative impact of each of these parameters on the overall required amount of catalyst was also determined. The simulations show that the amount of catalyst required to achieve a specified conversion increases with pellet size and shape in the order: trilobes < hollow cylinders < cylinders < spheres. The pressure drop per unit length can be significantly reduced and the catalyst effectiveness increased by using advanced extrudates, i.e., trilobes or hollow cylinders. more...
- Published
- 2015
- Full Text
- View/download PDF
17. Effect of promoter deposition order on platinum-, ruthenium-, or rhenium-promoted cobalt Fischer–Tropsch catalysts
- Author
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Calvin H. Bartholomew, Kari M. Cook, Hector D. Perez, and William C. Hecker
- Subjects
Process Chemistry and Technology ,Inorganic chemistry ,chemistry.chemical_element ,Fischer–Tropsch process ,Rhenium ,engineering.material ,Catalysis ,Ruthenium ,chemistry ,engineering ,Noble metal ,Platinum ,Cobalt ,Deposition (chemistry) - Abstract
The effect of noble metal (NM) promoter (Pt, Re, or Ru) deposition order was investigated for commercially-representative Co Fischer–Tropsch catalysts (nominally 25 wt% Co on a La stabilized alumina support). The effects of deposition sequence (co-deposition vs. sequential deposition) were studied in terms of NM retention and distribution, Co crystallite size, Co reducibility, and catalyst activity and selectivity. Ru retention was more...
- Published
- 2014
- Full Text
- View/download PDF
18. Intelligent Control Techniques Applied to Improve the Performance of Water Treatment Facilities Bring Great Financial Benefits to the Colombian Oil Industry
- Author
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H. R. Pérez-Rodríguez, Hector D. Perez, and G. Grandas Grandas
- Subjects
Engineering ,Risk analysis (engineering) ,Waste management ,Petroleum industry ,business.industry ,Water treatment ,business ,Intelligent control ,Fuzzy logic control - Abstract
This paper reports on the benefits of applying Fuzzy Logic Control (FLC) over the traditional Proportional-Integral-Derivative (PID) approach to improve the operation reliability of plant of produced water treatment. Reservoir rocks normally contain both petroleum hydrocarbons and water. This water is frequently referred to as “connate water” or “formation water” and becomes produced water when the reservoir is produced and the fluids are brought to the surface Produced water is the largest volume waste stream in the oil and gas exploration and production processes. Fluid produced in the Colombian Rubiales and Quifa oil field is composed by approximately 95% of water and 5% of oil. Separation of water from production fluid and its treatment and disposal are critical for the continuous of oil production. Applying Fuzzy logic as automatic control approach for the facilities that separates the water and treats it has represented a 10% increase in the amount of water treated using the same installed infrastructure. This improvement represents savings in CAPEX of US $ 5.76 per barrel of water that is treated with the previously installed infrastructure. OPEX savings are significant and are related to operating costs that are avoided because (1) by not having to build additional plants to treat water that is processed with the current infrastructure no costs associated with its operation (2) due to the better functioning of treatment plants chemical consumption is reduced and (3) the automation improvement allows much better use of staff assigned to the facilities. The benefits in operation of the plants associated with fuzzy logic control were achieved (1) on having maintained producing(operating) in more continuous form the water treatment plants, (2) Decreasing the shutdown of the facilities by reducing the variability of the process variables, and (3) by increasing the level of automation of the plants and the reliability in operation. Application of intelligent control approach is a novelty in the industry of oil fields. The main control approach applied has been Proportional, Integral and Derivative (PID) approach. more...
- Published
- 2015
- Full Text
- View/download PDF
19. Applied Advanced Control Systems for Electrostatic Dehydrators in the Upstream Oil Industry
- Author
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Hector D. Perez, G. Grandas Grandas, and H. R. Pérez-Rodríguez
- Subjects
Upstream (petroleum industry) ,Model predictive control ,Engineering ,Petroleum industry ,business.industry ,Control system ,Dual frequency ,business ,Process engineering - Abstract
A linear unconstrained model predictive control (MPC) scheme has been designed to optimize the operation of dual frequency electrostatic dehydrators in the Colombian Rubiales and Quifa oil fields. This multi-objective controller optimizes operation by maximizing the amount of daily oil production, while maintaining the base sediment and water (BS&W) specification at the exit of the electrostatic dehydrator at or below 1.0%. The designed controller uses models that describe the dynamics of the dehydrator system to meet the objectives described above. The model of the entire system consists of two empirical sub-models: one for the crude-steam heat exchangers upstream of the electrotreater and one for the treater. Each of these models is used to design an MPC controller for the corresponding subsystem. The electrotreater MPC works as the master controller, dictating crude temperature setpoints to the exchanger MPC. The exchanger MPC then adjusts the vapor flow valve opening to obtain the optimum temperature for the outlet BS&W specification. The electrotreater controller also adjusts the treater inlet/outlet flows and the transformer voltage setpoints to meet the desired objectives. This control scheme allows for 1) less variability in the output BS&W, 2) maximized daily crude oil production, and 3) tighter control. The decrease in BS&W variability helps ensure that the product quality control and increases the rate of oil production by minimizing the need for further oil dehydration steps. In terms of OPEX, financial benefits are obtained by optimizing the dehydrator operation due to the reduction in the amount of costly emulsion breaking chemicals used in this and other stages of the dehydration process to ensure an effluent BS&W specification of 1.0%. In terms of CAPEX, this control scheme minimizes the need for additional infrastructure necessary to further dehydrate the oil produced to pipeline specifications. This is the first time such a control scheme is known to have been developed for oil dehydration facilities. The approach proposed in this paper makes further implementation of advanced control systems an intriguing and promising venture that includes benefits such as increased oil production and decreased operating and capital costs. more...
- Published
- 2015
- Full Text
- View/download PDF
20. Multivariate Control for Managed Pressure Drilling Systems Using High Speed Telemetry
- Author
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Hector D. Perez, Anthony Paul Pink, John D. Hedengren, David S. Pixton, Casey Hubbell, and Reza Asgharzadeh Shishavan
- Subjects
Engineering ,Multivariate statistics ,business.industry ,Telemetry ,Control (management) ,Drilling ,Control engineering ,Nonlinear control ,business ,Rate of penetration - Abstract
With the recent advance in high speed data communication offered by wired drill pipe (WDP) telemetry, it is now possible to design automated control systems that directly utilize downhole data (e.g. pressure) to optimize drilling procedures. This research couples drilling hydraulics, rate of penetration (ROP), and rotational speed (RPM) control into a single controller for managed pressure drilling systems. This novel multivariate controller improves drilling performance during normal drilling operations and enhances safety during abnormal drilling conditions such as unwanted gas influx situations. New advances in drilling automation have made the closed loop control of downhole weight on bit (WOB) and drill string rotational speed (RPM) possible. This study uses two feedback controllers that control the downhole WOB and RPM using surface data. A multivariate nonlinear model predictive controller (NMPC) uses downhole and surface measurements to simultaneously regulate the bottom hole assembly (BHA) pressure and maximize the ROP. For this purpose, NMPC provides the necessary set points for the WOB and RPM feedback controllers as well as manipulates the choke valve opening and pump flow rates. Controller performance is enhanced via a nonlinear estimator that works continuously online with the NMPC and provides the necessary estimated parameter values (i.e. annulus density, friction factor, and gas influx) for precise and efficient drilling control. The designed NMPC controller has a multi-priority approach which is described in the following three scenarios: (1) during unexpected gas influx, the NMPC gives priority to BHA pressure control and attenuates the influx effectively via a novel kick attenuation method that switches the control objective from BHA pressure to choke valve pressure; (2) during connection procedures when adding a new stand, ROP is stopped and the NMPC focuses on maintaining the BHA pressure constant; (3) during normal drilling operation, which involves changes in the rock formation and differential pressures, NMPC gives priority to ROP maximization while maintaining RPM, WOB, and BHA pressure within specified bounds. Preliminary results suggest that this multivariate controller for ROP and BHA pressure control will decrease drilling costs, reduce operator workload, and minimize risk significantly. Specific improvements in drilling performance include higher ROP, effective kick attenuation, and more uniform cuttings. The use of a multivariate NMPC allows for better ROP optimization and BHA pressure control than would be possible with the use of two independent controllers. These benefits are demonstrated across the three scenarios mentioned above. This technology has potential to deliver significant performance improvements during managed pressure drilling and further the development of auto driller systems. more...
- Published
- 2014
- Full Text
- View/download PDF
21. Combined Rate of Penetration and Pressure Regulation for Drilling Optimization Using High Speed Telemetry
- Author
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David S. Pixton, Hector D. Perez, Reza Asgharzadeh Shishavan, John D. Hedengren, and Casey Hubbell
- Subjects
Engineering ,business.industry ,Telemetry ,Drilling ,business ,Rate of penetration ,Marine engineering - Abstract
Low latency feedback, high bandwidth, and improved sensor placement are key benefits provided by wired drill pipe (WDP) technology. Improved WDP reliability, based on over 100 wells of field experience, enables more aggressive application of the technology, including closed-loop control of drilling processes. Often, there is a requirement to consider multiple variables when attempting to control complex processes such as drilling in deepwater wells. Such is the case when dynamically optimizing rate of penetration in a pressure-critical wellbore environment. Formerly, rate of penetration (ROP) and borehole pressure (BHP) have been considered separate optimization and automation tasks, respectively. This study combines ROP and BHP into a single comprehensive controller for a managed pressure drilling (MPD) application. The controller adjusts mud pump flow rate, choke valve position, drill string rotation rate, and weight-on-bit (WOB) simultaneously and with coordinated actions. The automated operations are guided by an objective function that includes factors relevant to both BHP stabilization and ROP maximization. A preliminary MPD case study is used to assess the performance during different drilling events, including transition into varying formations causing an unexpected gas influx. For the unwanted gas influx case, the controller better stabilizes the pressure when there are low latency communications by simultaneously adjusting ROP. With WDP and the optimizing controller, there is substantial decrease in time required to control influx events as compared to earlier controllers or manual methods. The high speed data availability affects both the pressure control reaction time and the resulting severity of the kick. When encountering different formations, there is also noticeable benefit by allowing pressure to fluctuate within an acceptable range to optimize ROP. Combining ROP and BHP control minimizes risk, decreases drilling costs, and reduces operator workload. Improvements in drilling performance include higher ROP, lower risk of uncontrolled kick events, and more uniform cuttings loading. Another benefit of this combined ROP / BHP controller is that the reaction to gas influx is made more consistent and predictable relative to manual operations, reducing the demand for time-consuming remedial efforts. more...
- Published
- 2014
- Full Text
- View/download PDF
22. Addressing UBO and MPD Challenges with Wired Drill Pipe Telemetry
- Author
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Hector D. Perez, John D. Hedengren, David S. Pixton, Andrew David Craig, and Reza Asgharzadeh Shishavan
- Subjects
Engineering ,business.industry ,Pressure control ,Telemetry ,Mechanical engineering ,Control engineering ,Drill pipe ,business - Abstract
Wired drill pipe (WDP) telemetry has been used in over 100 wells worldwide to create a drillstring network that provides high bandwidth communications between tools deployed in the wellbore and the surface. When applied to managed pressure drilling (MPD) and underbalanced operations (UBO), wired drill pipe offers substantial benefits. Because of its independence from fluid flow, it gives visibility to downhole conditions where never before possible, including environments where traditional telemetry methods are not supported, and time intervals where pumps are not operating. Similarly, memory-quality data can be provided real-time from measurement tools located in the bottom hole assembly (BHA) as well as at points along the drillstring. Specific case studies and lessons learned from using wired drill pipe in the underbalanced and managed pressure drilling environments are summarized, as are recent enhancements to the wired drill pipe system, and their impact on extending the operating envelope and reliability of wired drill pipe. Methods for leveraging the increased quantity and quality of real-time data to improve the drilling process are important if the highest value is to be obtained from high-speed telemetry technology. To this end a novel automated borehole pressure (BHP) control system with predictive technology has been designed. A preliminary UBO case study is used to assess the performance of this controller during different drilling events, including a drill pipe connection procedure and an unexpected gas influx. While making a connection, the controller maintains tight pressure control and may enable efficiency improvements by allowing faster trip speeds, when offered as part of an automation system. For the gas influx case, the ability of the controller to properly control the influx is shown to be dependent on low latency communications, such as that provided by WDP. This controller offers a substantial decrease in time required to control influx events as compared to manual methods and earlier controllers. A nonlinear model predictive controller and a nonlinear estimator are used in the automation study. Information available from multiple sensors arrayed in a WDP system was found to be very useful in model parameter estimation, including friction factor and annular fluid density. Proper application of WDP technology to challenges experienced in the UBO/MPD environment can yield more cost effective and successful deployment of these methods, further improving the value UBO/MPD technology can provide. Future work will included continued development of the control system to more fully capture the value of wired pipe technology. more...
- Published
- 2014
- Full Text
- View/download PDF
23. An aspirin-triggered lipoxin A4 stable analog displays a unique topical anti-inflammatory profile
- Author
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Claudia Giesen, William J. Guilford, Iolanda M. Fierro, Sean P. Colgan, John G. Bauman, Hector D. Perez, Khusru Asadullah, John Parkinson, and Arndt Schottelius
- Subjects
medicine.drug_class ,Croton Oil ,Immunology ,Guinea Pigs ,Inflammation ,Pharmacology ,Administration, Cutaneous ,Leukotriene B4 ,Mice ,In vivo ,Cell Movement ,Hydroxyeicosatetraenoic Acids ,Immunology and Allergy ,Medicine ,Animals ,Humans ,Croton oil ,Hypersensitivity, Delayed ,Iloprost ,Allergic contact dermatitis ,Calcimycin ,Skin ,Aspirin ,business.industry ,Terpenes ,Anti-Inflammatory Agents, Non-Steroidal ,Chemotaxis ,Eosinophil ,medicine.disease ,Receptor antagonist ,Lipoxins ,Chemotaxis, Leukocyte ,Disease Models, Animal ,medicine.anatomical_structure ,Phthalic Anhydrides ,Female ,medicine.symptom ,Methylprednisolone aceponate ,Diterpenes ,business ,medicine.drug - Abstract
Lipoxins and 15-epi-lipoxins are counter-regulatory lipid mediators that modulate leukocyte trafficking and promote the resolution of inflammation. To assess the potential of lipoxins as novel anti-inflammatory agents, a stable 15-epi-lipoxin A4 analog, 15-epi-16-p-fluorophenoxy-lipoxin A4 methyl ester (ATLa), was synthesized by total organic synthesis and examined for efficacy relative to a potent leukotriene B4 (LTB4) receptor antagonist (LTB4R-Ant) and the clinically used topical glucocorticoid methylprednisolone aceponate. In vitro, ATLa was 100-fold more potent than LTB4R-Ant for inhibiting neutrophil chemotaxis and trans-epithelial cell migration induced by fMLP, but was ∼10-fold less potent than the LTB4R-Ant in blocking responses to LTB4. A broad panel of cutaneous inflammation models that display pathological aspects of psoriasis, atopic dermatitis, and allergic contact dermatitis was used to directly compare the topical efficacy of ATLa with that of LTB4R-Ant and methylprednisolone aceponate. ATLa was efficacious in all models tested: LTB4/Iloprost-, calcium ionophore-, croton oil-, and mezerein-induced inflammation and trimellitic anhydride-induced allergic delayed-type hypersensitivity. ATLa was efficacious in mouse and guinea pig skin inflammation models, exhibiting dose-dependent effects on edema, neutrophil or eosinophil infiltration, and epidermal hyperproliferation. We conclude that the LXA4 and aspirin-triggered LXA4 pathways play key anti-inflammatory roles in vivo. Moreover, these results suggest that ATLa and related LXA4 analogs may have broad therapeutic potential in inflammatory disorders and could provide an alternative to corticosteroids in certain clinical settings. more...
- Published
- 2002
24. Combined rate of penetration and pressure regulation for drilling optimization by use of high-speed telemetry
- Author
-
Hector D. Perez, Reza Ashgarzadeh Shishavan, David S. Pixton, John D. Hedengren, and Casey Hubbell
- Subjects
Engineering ,Petroleum engineering ,business.industry ,Mechanical Engineering ,Telemetry ,Pressure management ,Energy Engineering and Power Technology ,Drilling ,Well control ,business ,Rate of penetration - Abstract
Summary Low-latency feedback, high bandwidth, and improved sensor placement are key benefits provided by wired-drillpipe (WDP) technology. Improved WDP reliability, based on more than 100 wells of field experience, enables more-aggressive application of the technology, including closed-loop control of drilling processes. Often, there is a requirement to consider multiple variables when attempting to control complex processes, such as drilling in deepwater wells. Such is the case when dynamically optimizing rate of penetration (ROP) in a pressure-critical wellbore environment. Formerly, ROP and bottomhole pressure (BHP) have been considered separate optimization and automation tasks, respectively. This study combines ROP and BHP into a single comprehensive controller for a managed-pressure-drilling (MPD) application. The controller adjusts mud-pump flow rate, choke-valve position, drillstring-rotation rate, and weight on bit simultaneously and with coordinated actions. The automated operations are guided by an objective function that includes factors relevant to both BHP stabilization and ROP maximization. A preliminary MPD case study is used to assess the performance during different drilling events, including transition into varying formations, causing an unexpected gas influx. For the unwanted-gas-influx case, the controller better stabilizes the pressure when there are low-latency communications by simultaneously adjusting ROP. With WDP and the optimizing controller, there is substantial decrease in time required to control influx events compared with earlier controllers or manual methods. The high-speed data availability affects both the pressure-control reaction time and the resulting severity of the kick. When encountering different formations, there is also noticeable benefit by allowing pressure to fluctuate within an acceptable range to optimize ROP. Combining ROP control and BHP control minimizes risk, decreases drilling costs, and reduces operator workload. Improvements in drilling performance include higher ROP, lower risk of uncontrolled kick events, and more-uniform cuttings loading. Another benefit of this combined ROP/BHP controller is that the reaction to gas influx is made more consistent and predictable relative to manual operations, reducing the demand for time-consuming remedial efforts. more...
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