A high rate of penetration (ROP) is considered one of the most sought-after targets when drilling a well. While physics-based models determine the importance of drilling parameters, they fail to capture the extent or degree of influence of the interplay of the different dynamic drilling features. Parameters such as WOB, RPM, and flowrate, (Mechanical Specific Energy) MSE, bit run distance, gamma ray for each rock formation in West Texas were examined. Ensuring an adequate ROP while controlling the tool face orientation is quite challenging. Nevertheless, its helps follow the planned well trajectory and eliminates excessive doglegs that lead to wellbore deviations. Five different Machine Learning algorithms were implemented to optimize ROP and create a less tortuous borehole. The collected data was cleaned and preprocessed and used to structure and train Random Forest, Artificial Neural Networks, Support Vector Regression, Ridge Regression, and Gradient Boosting Machine and the appropriate hyperparameters were selected. A successful model was chosen based a minimized deviation from planned trajectory, minimized tortuosity, and maximized ROP. A MAE of 10% was achieved using Random Forest. The algorithms have demonstrated competence in the historical dataset, accordingly it will be further tested on blind data to serve as a real-time system for directional drilling optimization to enable a fully automated system.
{"title":"Application of Data Science and Machine Learning Algorithms for ROP Optimization in West Texas: Turning Data into Knowledge","authors":"C. Noshi","doi":"10.4043/29288-MS","DOIUrl":"https://doi.org/10.4043/29288-MS","url":null,"abstract":"\u0000 A high rate of penetration (ROP) is considered one of the most sought-after targets when drilling a well. While physics-based models determine the importance of drilling parameters, they fail to capture the extent or degree of influence of the interplay of the different dynamic drilling features. Parameters such as WOB, RPM, and flowrate, (Mechanical Specific Energy) MSE, bit run distance, gamma ray for each rock formation in West Texas were examined. Ensuring an adequate ROP while controlling the tool face orientation is quite challenging. Nevertheless, its helps follow the planned well trajectory and eliminates excessive doglegs that lead to wellbore deviations.\u0000 Five different Machine Learning algorithms were implemented to optimize ROP and create a less tortuous borehole. The collected data was cleaned and preprocessed and used to structure and train Random Forest, Artificial Neural Networks, Support Vector Regression, Ridge Regression, and Gradient Boosting Machine and the appropriate hyperparameters were selected.\u0000 A successful model was chosen based a minimized deviation from planned trajectory, minimized tortuosity, and maximized ROP. A MAE of 10% was achieved using Random Forest.\u0000 The algorithms have demonstrated competence in the historical dataset, accordingly it will be further tested on blind data to serve as a real-time system for directional drilling optimization to enable a fully automated system.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75291424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The growing global energy demand and the ecological advantages of low ozone depleting substance resulting from combustion of the natural gas products leads to consideration of economic, practical innovations of transporting the gas. The alternatives of marketing the unused gas include regional or local markets, projects of combined commodity and the export markets. Natural gas has been transported securely, dependably, and financially utilizing pipeline. This paper addresses the issue of Offshore LNG and Monetization with special attention to Supply Chain. In this particular project, the writer will be examining Stranded Offshore gas and Supply Chain, to demonstrate Monetization. Legislations and policies will be juxtaposed them against the upstream sector and downstream sector, with the aim of revealing the formerly misunderstood connections between supply chain and monetization. The question of Offshore LNG and Monetization have been greatly debated in the Gas and Energy field, with organizationsarguing Monetization and Supply Chain. However, these works have not adequately addressed the issue of Offshore LNG and Monetization with the supply chain philosophies. Various solutions for mismanaged stranded gas holds are presently being created and contemplated for commercialization. In the meantime, for the past decades, only the LNG industry (Liquefied Natural Gas) has efficiently conveyed many remote natural gas reserves to the various gas markets which are not reachable through pipelines, such as South Korea and Japan. In conclusion, by closely analyzing monetization and Offshore LNG, this project brings a new understanding of the rarely acknowledged/little recognized/neglected issue of Supply Chain Management. In spite of being a standout amongst the most copious sources of energy on earth, more than thirty-three percent of international natural gas fields stay unused and cannot be conveyed to the market monetarily. As far back as decades, it is evident that large amounts of fresh gas saves are certainly not the only things that are placed strategically. Consideration has been directed to more segregated vast gas reservoir that was earlier thought of as being excessively remote and impossible to develop. Once a typical industry works on, flaring is currently broadly debilitated, and numerous nations including Norway and Nigeria, that are coming up with emission or anti-flaring taxes and policies to discourage gas wastage.
{"title":"Offshore Liquefied Natural Gas LNG and Monetization","authors":"F. Alabi, Timothy Oluwarotimi Awotunde, J. David","doi":"10.4043/29509-MS","DOIUrl":"https://doi.org/10.4043/29509-MS","url":null,"abstract":"\u0000 The growing global energy demand and the ecological advantages of low ozone depleting substance resulting from combustion of the natural gas products leads to consideration of economic, practical innovations of transporting the gas. The alternatives of marketing the unused gas include regional or local markets, projects of combined commodity and the export markets. Natural gas has been transported securely, dependably, and financially utilizing pipeline. This paper addresses the issue of Offshore LNG and Monetization with special attention to Supply Chain.\u0000 In this particular project, the writer will be examining Stranded Offshore gas and Supply Chain, to demonstrate Monetization. Legislations and policies will be juxtaposed them against the upstream sector and downstream sector, with the aim of revealing the formerly misunderstood connections between supply chain and monetization. The question of Offshore LNG and Monetization have been greatly debated in the Gas and Energy field, with organizationsarguing Monetization and Supply Chain. However, these works have not adequately addressed the issue of Offshore LNG and Monetization with the supply chain philosophies.\u0000 Various solutions for mismanaged stranded gas holds are presently being created and contemplated for commercialization. In the meantime, for the past decades, only the LNG industry (Liquefied Natural Gas) has efficiently conveyed many remote natural gas reserves to the various gas markets which are not reachable through pipelines, such as South Korea and Japan. In conclusion, by closely analyzing monetization and Offshore LNG, this project brings a new understanding of the rarely acknowledged/little recognized/neglected issue of Supply Chain Management. In spite of being a standout amongst the most copious sources of energy on earth, more than thirty-three percent of international natural gas fields stay unused and cannot be conveyed to the market monetarily.\u0000 As far back as decades, it is evident that large amounts of fresh gas saves are certainly not the only things that are placed strategically. Consideration has been directed to more segregated vast gas reservoir that was earlier thought of as being excessively remote and impossible to develop. Once a typical industry works on, flaring is currently broadly debilitated, and numerous nations including Norway and Nigeria, that are coming up with emission or anti-flaring taxes and policies to discourage gas wastage.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73255306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The proposed concept relates to modifying the construction/assembly method to reduce the cost and schedule of a floating Spar wind platform. Detailed analysis was performed and execution plan developed to quantify the benefits of integrating the tower and the substructure at the construction yard in a horizontal position compared to installing the tower by lifting while the wind platform is floating vertically. Current offshore wind turbines are typically assembled by lifting and bolting standard onshore towers and wind turbine generators (WGT) onto a purpose designed floater. The concept presented here proposes to integrate the tower section and the floater at the fabrication yard while in horizontal position. During an internal Research and Development study of a floater with a long cylindrical design, like a Classic/Cell Spar, the Construction method was developed following which each phase of marine operations was carefully analyzed and compared with the conventional execution plan used to construct and assemble a floating Spar Wind platform. The equipment normally included in the Tower were investigated with the vendors for feasibility to be transported in a horizontal position. The Construction and Assembly method can be used for more efficient execution of future Spar and other floating structure type Wind Platforms. It was proven that: The integrated structure can withstand the loads during loadout/launching from the yard and float off, The integrated structure can handle the loads during a horizontal tow for transport from the fabrication yard to the inshore assembly site. Bending moments and shear forces were confirmed within acceptable limits. The integrated structure can withstand loads during upending, from the horizontal to vertical position, The integrated structure can handle the hydrostatic pressure should partial submergence be required for lift height during mating of the WTG. Overview of Tower integrated Wind floater Positions of openings in the hull, for handling water ballast for upending, solid ballast and water deballast following upending, need to be considered. Overall construction and assembly schedule was found to be efficient and added benefit to the concept. This integrated method creates the following two main advantages: It removes the challenges of the mating interface flange between the floater and the tower. This flange can prove costly. It also has limitations in term of size and load capacity that could potentially impact future development. The welding solution can accommodate a wider range of diameters, hence wider range of rotor dimensions. It simplifies mating operations and makes the mating schedule more efficient. It allows the use of smaller floating cranes for mating, as systems can be partially submerged to limit the lift height during mating. It reduces and simplifies the infrastructure spread required for mating operations. This proposed solution offers an opportunity to simplify pr
{"title":"Design of a Floating Spar Wind Platform with an Integrated Substructure and Tower","authors":"Mailys Sherman, A. Sablok, I. Kopsov, Liyong Chen","doi":"10.4043/29375-MS","DOIUrl":"https://doi.org/10.4043/29375-MS","url":null,"abstract":"\u0000 The proposed concept relates to modifying the construction/assembly method to reduce the cost and schedule of a floating Spar wind platform. Detailed analysis was performed and execution plan developed to quantify the benefits of integrating the tower and the substructure at the construction yard in a horizontal position compared to installing the tower by lifting while the wind platform is floating vertically.\u0000 Current offshore wind turbines are typically assembled by lifting and bolting standard onshore towers and wind turbine generators (WGT) onto a purpose designed floater. The concept presented here proposes to integrate the tower section and the floater at the fabrication yard while in horizontal position.\u0000 During an internal Research and Development study of a floater with a long cylindrical design, like a Classic/Cell Spar, the Construction method was developed following which each phase of marine operations was carefully analyzed and compared with the conventional execution plan used to construct and assemble a floating Spar Wind platform. The equipment normally included in the Tower were investigated with the vendors for feasibility to be transported in a horizontal position.\u0000 The Construction and Assembly method can be used for more efficient execution of future Spar and other floating structure type Wind Platforms.\u0000 It was proven that:\u0000 The integrated structure can withstand the loads during loadout/launching from the yard and float off,\u0000 The integrated structure can handle the loads during a horizontal tow for transport from the fabrication yard to the inshore assembly site. Bending moments and shear forces were confirmed within acceptable limits.\u0000 The integrated structure can withstand loads during upending, from the horizontal to vertical position,\u0000 The integrated structure can handle the hydrostatic pressure should partial submergence be required for lift height during mating of the WTG.\u0000 Overview of Tower integrated Wind floater\u0000 Positions of openings in the hull, for handling water ballast for upending, solid ballast and water deballast following upending, need to be considered.\u0000 Overall construction and assembly schedule was found to be efficient and added benefit to the concept.\u0000 This integrated method creates the following two main advantages:\u0000 It removes the challenges of the mating interface flange between the floater and the tower. This flange can prove costly. It also has limitations in term of size and load capacity that could potentially impact future development. The welding solution can accommodate a wider range of diameters, hence wider range of rotor dimensions.\u0000 It simplifies mating operations and makes the mating schedule more efficient. It allows the use of smaller floating cranes for mating, as systems can be partially submerged to limit the lift height during mating. It reduces and simplifies the infrastructure spread required for mating operations.\u0000 This proposed solution offers an opportunity to simplify pr","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75550568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hydrocarbon fields discovered in ever deeper waters and uncertainties regarding oil prices are driving the need for cost efficient riser concepts tailored for ultra-deep waters. The Single Independent Riser (SIR) is an innovative hybrid riser configuration optimized for Ultra-Deep water field development. This paper will provide a general overview of the SIR with a specific focus on its installation method and the associated tools that were developed. The SIR is based on a hybrid solution composed, from bottom-up, of a rigid part vertically tensioned by means of distributed or continuous buoyancy and a flexible jumper. This configuration features improved dynamic behavior for the rigid riser section under fatigue and extreme environmental conditions thanks to its compliant shape. The configuration of the flexible jumper ensures displacements of the rigid riser section are significantly decreased compared to that of an SHR. In addition, its design makes it adapted to any water depth beyond 1000 m. The SIR is also inherently safer as it is less sensitive to buoyancy loss than a riser tensioned by mean of a buoyancy tank. This design is highly versatile and can easily be staggered to comply with design constraints, congested lay out and installation scheme. The relevancy of the SIR has been assessed on the basis of several case studies derived from actual projects as well as on-coming prospects. The considered cases include a wide range of environments such as West of Africa, East of Africa, Brazil and riser types, both for pipe in pipe and single pipe arrangements, in order to confirm the suitability of the design. Extreme, wave fatigue, VIV fatigue, interference analyses were conducted through these assessments. In parallel, a dedicated installation method was developed to address the specificities of the design and to cover both dry and wet flexible jumper connections. In the frame of this study, specific installation tools were designed to reduce the need for offshore assets during installation. This paper will first provide a general overview of the SIR, illustrating the arrangement of the various components and providing outcomes of engineering studies confirming the relevancy of the design. A second part will focus on its installation method and the associated tools that were developed.
{"title":"Single Independent Riser: A Cost Efficient Ultra-Deep Water Riser","authors":"F. Lirola, Eric Revault, J. Lunven","doi":"10.4043/29389-MS","DOIUrl":"https://doi.org/10.4043/29389-MS","url":null,"abstract":"\u0000 Hydrocarbon fields discovered in ever deeper waters and uncertainties regarding oil prices are driving the need for cost efficient riser concepts tailored for ultra-deep waters. The Single Independent Riser (SIR) is an innovative hybrid riser configuration optimized for Ultra-Deep water field development. This paper will provide a general overview of the SIR with a specific focus on its installation method and the associated tools that were developed.\u0000 The SIR is based on a hybrid solution composed, from bottom-up, of a rigid part vertically tensioned by means of distributed or continuous buoyancy and a flexible jumper. This configuration features improved dynamic behavior for the rigid riser section under fatigue and extreme environmental conditions thanks to its compliant shape. The configuration of the flexible jumper ensures displacements of the rigid riser section are significantly decreased compared to that of an SHR. In addition, its design makes it adapted to any water depth beyond 1000 m. The SIR is also inherently safer as it is less sensitive to buoyancy loss than a riser tensioned by mean of a buoyancy tank. This design is highly versatile and can easily be staggered to comply with design constraints, congested lay out and installation scheme.\u0000 The relevancy of the SIR has been assessed on the basis of several case studies derived from actual projects as well as on-coming prospects. The considered cases include a wide range of environments such as West of Africa, East of Africa, Brazil and riser types, both for pipe in pipe and single pipe arrangements, in order to confirm the suitability of the design. Extreme, wave fatigue, VIV fatigue, interference analyses were conducted through these assessments. In parallel, a dedicated installation method was developed to address the specificities of the design and to cover both dry and wet flexible jumper connections. In the frame of this study, specific installation tools were designed to reduce the need for offshore assets during installation.\u0000 This paper will first provide a general overview of the SIR, illustrating the arrangement of the various components and providing outcomes of engineering studies confirming the relevancy of the design. A second part will focus on its installation method and the associated tools that were developed.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85235964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Data acquired from major gas hydrate field programs over the past 20 years has led to much better understanding of the distribution of gas hydrate on the continental margins and how to detect them. Gas hydrate systems are extensions of the conventional hydrocarbon system but are much more closely related to biogenic gas systems. The temperatures at which most biogenic gas is generated is mostly below the base of gas hydrate stability which means that most biogenic gas has to migrate into the gas hydrate stability zone and has to be at levels in excess of solubility for gas hydrates to form. Gas hydrates had been considered ‘self-sealing’ but evidence from pressure cores and laboratory experiments indicate that gas hydrate deposits may need local seals. Detection of gas hydrates though seismic and other remote sensing methods has been demonstrated through drilling and coring programs. The GC955 site in the Gulf of Mexico is used as an example to demonstrate exploration concepts, through basin models, seismic detection, and drilling and coring results. Data from other locations are also discussed. A review of remote sensing data that could be used to delineate and quantify gas hydrate deposits is presented with an emphasis on low frequency exploration 3D seismic for imaging gas hydrate deposits at the base of gas hydrate stability.
{"title":"Gas Hydrate Prospecting and Characterization","authors":"D. McConnell","doi":"10.4043/29604-MS","DOIUrl":"https://doi.org/10.4043/29604-MS","url":null,"abstract":"\u0000 Data acquired from major gas hydrate field programs over the past 20 years has led to much better understanding of the distribution of gas hydrate on the continental margins and how to detect them. Gas hydrate systems are extensions of the conventional hydrocarbon system but are much more closely related to biogenic gas systems. The temperatures at which most biogenic gas is generated is mostly below the base of gas hydrate stability which means that most biogenic gas has to migrate into the gas hydrate stability zone and has to be at levels in excess of solubility for gas hydrates to form. Gas hydrates had been considered ‘self-sealing’ but evidence from pressure cores and laboratory experiments indicate that gas hydrate deposits may need local seals. Detection of gas hydrates though seismic and other remote sensing methods has been demonstrated through drilling and coring programs. The GC955 site in the Gulf of Mexico is used as an example to demonstrate exploration concepts, through basin models, seismic detection, and drilling and coring results. Data from other locations are also discussed. A review of remote sensing data that could be used to delineate and quantify gas hydrate deposits is presented with an emphasis on low frequency exploration 3D seismic for imaging gas hydrate deposits at the base of gas hydrate stability.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79862024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoming Ye, Chunliang Huo, Xinlei Shi, Rongtao Chen, Dongdong Yang, Y. Mao
In the process of point bar internal architecture modeling, it is common to use local grid refinement method to model lateral accretion interlayers, which are often less than 1 meter thick but have a considerable impact on fluid flow. Due to huge grid amount and grid size difference, it often causes non-converging or converging too slowly of reservoir dynamic numerical simulation algorithm, which is not beneficial to practical application. In this study, we proposed a new method to model lateral accretion interlayers based on reservoir numerical simulation dynamic response. Firstly, modeling target area of lateral accretion interlayers is defined by history matching results analysis based on the point bar level geological model. Then, the lateral accretion interlayers of the selected target area are modeled and equivalently characterized through transmissibility multiplier data instead of geometric parameters in numerical simulation model. Lastly, the multiplier value of transmissibility multiplier data is determined based on reservoir numerical simulation dynamic response. The method of this paper only models the lateral accretion interlayers which have influence on fluid flow, which greatly reduced research workload than modeling the lateral accretion interlayers of the entire oilfield. The fluid seepage effect impacted by lateral accretion interlayers is characterized through transmissibility multiplier data; it has overcome the shortcomings of traditional local grid refinement method, and operation efficiency is greatly improved. The method has been successfully applied to model the lateral accretion interlayers for fine remaining oil distribution prediction in Q oilfield. Compared with traditional local grid refinement method, the computation time of numerical simulation is greatly reduced. The historical fitting rate of water content of a single well is grastly improved. Based on the new method, the water flooding degree coincidence rate between model prediction results and post-drilling logging interpretation is above 90%. In this study, we proposed a new lateral accretion interlayers modeling method to improve the numerical simulation accuracy and efficiency. It can also be used in other sedimentary facies types such as deltas for internal architecture modeling.
{"title":"Modeling Method of Point Bar Internal Lateral Accretion Interlayers of Meandering River Reservoir Based on Reservoir Numerical Simulation Dynamic Response","authors":"Xiaoming Ye, Chunliang Huo, Xinlei Shi, Rongtao Chen, Dongdong Yang, Y. Mao","doi":"10.4043/29439-MS","DOIUrl":"https://doi.org/10.4043/29439-MS","url":null,"abstract":"\u0000 In the process of point bar internal architecture modeling, it is common to use local grid refinement method to model lateral accretion interlayers, which are often less than 1 meter thick but have a considerable impact on fluid flow. Due to huge grid amount and grid size difference, it often causes non-converging or converging too slowly of reservoir dynamic numerical simulation algorithm, which is not beneficial to practical application.\u0000 In this study, we proposed a new method to model lateral accretion interlayers based on reservoir numerical simulation dynamic response. Firstly, modeling target area of lateral accretion interlayers is defined by history matching results analysis based on the point bar level geological model. Then, the lateral accretion interlayers of the selected target area are modeled and equivalently characterized through transmissibility multiplier data instead of geometric parameters in numerical simulation model. Lastly, the multiplier value of transmissibility multiplier data is determined based on reservoir numerical simulation dynamic response.\u0000 The method of this paper only models the lateral accretion interlayers which have influence on fluid flow, which greatly reduced research workload than modeling the lateral accretion interlayers of the entire oilfield. The fluid seepage effect impacted by lateral accretion interlayers is characterized through transmissibility multiplier data; it has overcome the shortcomings of traditional local grid refinement method, and operation efficiency is greatly improved. The method has been successfully applied to model the lateral accretion interlayers for fine remaining oil distribution prediction in Q oilfield. Compared with traditional local grid refinement method, the computation time of numerical simulation is greatly reduced. The historical fitting rate of water content of a single well is grastly improved. Based on the new method, the water flooding degree coincidence rate between model prediction results and post-drilling logging interpretation is above 90%.\u0000 In this study, we proposed a new lateral accretion interlayers modeling method to improve the numerical simulation accuracy and efficiency. It can also be used in other sedimentary facies types such as deltas for internal architecture modeling.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86547206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Methane hydrates (MHs) have been considered as the future clean energy resource because of the vast resource volume and the capability to store methane effectively. To synthesize MH-bearing samples in laboratory for analysis of the thermophysical/geomechanical properties and the formation/dissociation behavior is important because of the scarcity of obtaining naturally-occurring MH cores. With the aim to achieve maximum uniformity in the MH-bearing samples, we designed experiment involving a three- stage cooling process to induce MH formation in the sandy medium under an excess-water condition. The experimental measured P and T were used to estimate the phase saturations of all phases (aqueous, gas and hydrate) over time based on a pore-volume balance method. In the absence of direct visualization capability, we further analyzed the experimental results through numerical simulation to derive the spatial distributions of all phases in the sample. Heterogeneity was identified because of the heat inflow from the surrounding resulting from the imperfect insulation of the reactor. We reached the conclusion that creating homogeneous MH-bearing samples in laboratory is extremely challenging and may not be possible. Our results offer explanations for MH formation at preferential locations and shed light on alternative innovative designs of experimental apparatus or cooling processes (with increased number of cooling steps and longer duration) to create uniform MH-bearing core samples.
{"title":"Kinetic Behavior of CH-Hydrate Formation in a Sandy Medium Induced by a Multi-Stage Cooling Process","authors":"Zhenyuan Yin, G. Moridis, Z. Chong, Praveen Linga","doi":"10.4043/29393-MS","DOIUrl":"https://doi.org/10.4043/29393-MS","url":null,"abstract":"\u0000 Methane hydrates (MHs) have been considered as the future clean energy resource because of the vast resource volume and the capability to store methane effectively. To synthesize MH-bearing samples in laboratory for analysis of the thermophysical/geomechanical properties and the formation/dissociation behavior is important because of the scarcity of obtaining naturally-occurring MH cores. With the aim to achieve maximum uniformity in the MH-bearing samples, we designed experiment involving a three- stage cooling process to induce MH formation in the sandy medium under an excess-water condition. The experimental measured P and T were used to estimate the phase saturations of all phases (aqueous, gas and hydrate) over time based on a pore-volume balance method. In the absence of direct visualization capability, we further analyzed the experimental results through numerical simulation to derive the spatial distributions of all phases in the sample. Heterogeneity was identified because of the heat inflow from the surrounding resulting from the imperfect insulation of the reactor. We reached the conclusion that creating homogeneous MH-bearing samples in laboratory is extremely challenging and may not be possible. Our results offer explanations for MH formation at preferential locations and shed light on alternative innovative designs of experimental apparatus or cooling processes (with increased number of cooling steps and longer duration) to create uniform MH-bearing core samples.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89531409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Oliveira, Diogo Ferreira Alves Pereira, Gustavo Echenique Silveira, P. A. L. S. D. Melo
Reservoir management in offshore fields is a challenging task, particularly for mature fields because of a typical excessive production of water and/or gas. Due to several constraints on facilities capacity, assisted reservoir management process can deliver solutions to operate properly offshore fields, seeking for increasing oil production with better assessment of water and gas production and injection. Optimal Reservoir Management (ORM) can be applied aiming to maximize reservoir performance and to deliver well controls applicable to field operations. In this work, we implemented an assisted optimization procedure to maximize overall oil production for a field offshore Brazil in Campos Basin. We applied our ORM technique in an important field offshore Brazil, where cumulative oil production is maximized by optimally controlling water rates through injecting wells. Injection rates can vary in time, honoring operational requirements of smoothness. Geomechanical limits on injection pressures are considered to avoid loss of rock integrity and platform constraints on overall production and injection are imposed all times. Our approach deals with reservoir uncertainties described within a large set of calibrated simulation models to decide on optimal injection rates, taking into account possible risks. The model-based ORM under uncertainty that we developed has shown gains in total oil production over 20 years of operation up to 7.2% with respect to the base strategy currently applied. On average, results show an increase around 4% in oil production, with concomitant reduction in total water production and in the overall water injection. A pilot test in the actual field has been implemented to verify the consistency between modeling and reality (data observation), in order to guarantee that the gains forecasted by our study are feasible. We have chosen an area in the field to proceed an optimal injection control pilot, aiming to check the quality of the uncertain models in comparison with the observed data in practice. The pilot area has been selected based on aspects related with geological description, connectivity expected in the reservoir and operational constraints. The results of 8 months of pilot show clear coherence between models and reality within the uncertainty range expected to the reservoir of interest. To the best of our knowledge, it is the first time that an offshore field is actually operated based on a set of controls obtained by an assisted optimal reservoir management procedure, although it was performed still in a pilot scale. Results suggest robust benefits under reservoir uncertainties consideration and large-scale application shall take place soon, but it is out of the scope of this work. The pilot provided more confidence on field applications, leading to broader perspective for full-field implementations.
{"title":"Applied Optimal Reservoir Management: A Field Case Experience in Campos Basin","authors":"D. Oliveira, Diogo Ferreira Alves Pereira, Gustavo Echenique Silveira, P. A. L. S. D. Melo","doi":"10.4043/29564-MS","DOIUrl":"https://doi.org/10.4043/29564-MS","url":null,"abstract":"\u0000 Reservoir management in offshore fields is a challenging task, particularly for mature fields because of a typical excessive production of water and/or gas. Due to several constraints on facilities capacity, assisted reservoir management process can deliver solutions to operate properly offshore fields, seeking for increasing oil production with better assessment of water and gas production and injection. Optimal Reservoir Management (ORM) can be applied aiming to maximize reservoir performance and to deliver well controls applicable to field operations. In this work, we implemented an assisted optimization procedure to maximize overall oil production for a field offshore Brazil in Campos Basin.\u0000 We applied our ORM technique in an important field offshore Brazil, where cumulative oil production is maximized by optimally controlling water rates through injecting wells. Injection rates can vary in time, honoring operational requirements of smoothness. Geomechanical limits on injection pressures are considered to avoid loss of rock integrity and platform constraints on overall production and injection are imposed all times. Our approach deals with reservoir uncertainties described within a large set of calibrated simulation models to decide on optimal injection rates, taking into account possible risks.\u0000 The model-based ORM under uncertainty that we developed has shown gains in total oil production over 20 years of operation up to 7.2% with respect to the base strategy currently applied. On average, results show an increase around 4% in oil production, with concomitant reduction in total water production and in the overall water injection.\u0000 A pilot test in the actual field has been implemented to verify the consistency between modeling and reality (data observation), in order to guarantee that the gains forecasted by our study are feasible. We have chosen an area in the field to proceed an optimal injection control pilot, aiming to check the quality of the uncertain models in comparison with the observed data in practice. The pilot area has been selected based on aspects related with geological description, connectivity expected in the reservoir and operational constraints. The results of 8 months of pilot show clear coherence between models and reality within the uncertainty range expected to the reservoir of interest.\u0000 To the best of our knowledge, it is the first time that an offshore field is actually operated based on a set of controls obtained by an assisted optimal reservoir management procedure, although it was performed still in a pilot scale. Results suggest robust benefits under reservoir uncertainties consideration and large-scale application shall take place soon, but it is out of the scope of this work. The pilot provided more confidence on field applications, leading to broader perspective for full-field implementations.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74727926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The objective of this paper is to present the design and performance of an offshore floating wind turbine support structure and associated station keeping system, for a commercial 6 MW turbine. The results reported in this paper are based on a joint desk study performed by SBM and IFPEN for the development of this new floating support structure concept. The proposed system has been extensively analyzed thanks to time domain simulation software. Time domain models incorporate the wind turbine, the station keeping system, as well as structural components of the floating foundation. The system’s behavior has been assessed for a variety of environment conditions and turbine conditions (operating, idling, fault), resulting in an extensive design load case table. In addition to the nominal system, a number of sensitivities have been investigated to test the system response to various effects: marine growth accumulation on the floating support structure, anchor position tolerance, variations of water level. Results produced during this study show the good performance of the proposed floating wind turbine support structure and components. The proposed arrangement is capable of sustaining 20 years of operation with environment conditions up to the 50-year return period. The motions of the floating support structure are beneficial for the turbine performance, with low inclinations and low nacelle accelerations. As a consequence of these floating support structure’s low motions, the floating offshore wind turbine production is only marginally lower than the production of the same turbine on a fixed offshore foundation in the same environment. Production can occur up to the 50-year joint environment conditions. The work presented in this paper formed part of a design dossier independently reviewed by a certification body to obtain an ‘Approval in Principle‘ for the development of the floating support structure. The study has shown that the floater motion characteristics allow similar turbine production levels to be achieved by a turbine on a fixed offshore foundation, providing support to move of floating offshore energy production.
{"title":"Design and Performance of a TLP Type Floating Support Structure for a 6MW Offshore Wind Turbine","authors":"Bonnaffoux Guillaume, Bauduin Christian, Bertolotti Christine, Melis Cecile, Perdrizet Timothee, Poirette Yann","doi":"10.4043/29371-MS","DOIUrl":"https://doi.org/10.4043/29371-MS","url":null,"abstract":"\u0000 The objective of this paper is to present the design and performance of an offshore floating wind turbine support structure and associated station keeping system, for a commercial 6 MW turbine. The results reported in this paper are based on a joint desk study performed by SBM and IFPEN for the development of this new floating support structure concept.\u0000 The proposed system has been extensively analyzed thanks to time domain simulation software. Time domain models incorporate the wind turbine, the station keeping system, as well as structural components of the floating foundation. The system’s behavior has been assessed for a variety of environment conditions and turbine conditions (operating, idling, fault), resulting in an extensive design load case table. In addition to the nominal system, a number of sensitivities have been investigated to test the system response to various effects: marine growth accumulation on the floating support structure, anchor position tolerance, variations of water level.\u0000 Results produced during this study show the good performance of the proposed floating wind turbine support structure and components. The proposed arrangement is capable of sustaining 20 years of operation with environment conditions up to the 50-year return period. The motions of the floating support structure are beneficial for the turbine performance, with low inclinations and low nacelle accelerations. As a consequence of these floating support structure’s low motions, the floating offshore wind turbine production is only marginally lower than the production of the same turbine on a fixed offshore foundation in the same environment. Production can occur up to the 50-year joint environment conditions.\u0000 The work presented in this paper formed part of a design dossier independently reviewed by a certification body to obtain an ‘Approval in Principle‘ for the development of the floating support structure. The study has shown that the floater motion characteristics allow similar turbine production levels to be achieved by a turbine on a fixed offshore foundation, providing support to move of floating offshore energy production.","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80408233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Temperature effects on closure bolting play an important role when assessing high-pressure, high-temperature (HPHT) subsea equipment. This paper discusses the evaluation of uninsulated bolted connections, which are internally exposed to high pressure and temperature and externally exposed to cold seawater, via finite element analysis (FEA). These thermal gradients cause nonuniform thermal expansions, contractions, or both. The paper then compares this to identical insulated connections, which have a uniform temperature distribution across the bolted connection. Two pressure-containing bodies featuring nonstandard API four-bolt connections of different sizes were analyzed using FEA at 20,000-psi bore pressure. The larger body featured an API BX-169 gasket housing a 5-1/8-in internal bore at 300 degF, and the smaller body featured an API BX-151 gasket housing a ½-in internal bore at 150 degF. Both bodies were analyzed at high and low seawater convection rates with a temperature heat sink of 35 degF. This was then compared to identical insulated connections assuming a uniform temperature distribution. All verification was performed per API Technical Report 17TR8 utilizing American Society of Mechanical Enginers (ASME) Boiler and Pressure Vessel Code (BPVC), Section VIII, Div. 3 elastic-plastic analysis methods focused only on the serviceability check. The results of this design verification showed an increase in bolt tensile stress in the un-insulated cases when compared with the same internal pressure for insulated cases. This stress increase exceeded the allowable tensile stress as specified by API Spec 17D even at an internal temperature of 150 degF, which is below the design threshold where thermal effects must be accounted for as required by API Spec 6A. This required either a reduction in the installation preload, an increase in bolt size, a reduction in the design load-carrying capacity, or a combination thereof. For this study, a reduction in the installation preload to reduce the tensile stress below the API Spec 17D allowable limit was selected as the corrective measure due to preexisting bolt size constraints and operational requirements. Gasket contact pressure was reevaluated at the reduced preload and was found to be sufficient to maintain proper joint sealability. FEA provides a more comprehensive understanding of thermal gradient effects on subsea bolted connections and identifies loading effects not normally observed using standard analysis methods. It is also a recommendation to evaluate both insulated and un-insulated cases to ensure that the bolted connection will perform its intended function. This study showed bolt stress differences between thermally insulated and un-insulated connections that can result in bolt stresses beyond acceptance criteria for one while the other is satisfied. This highlights the importance of evaluating bolted connections to ensure acceptability for all operational cases. This study also shows th
{"title":"Influence of Thermal Gradients in Design Verification of Uninsulated HPHT Bolted Connections","authors":"T. Luce, J. Stevens, P. D. Pathak","doi":"10.4043/29308-MS","DOIUrl":"https://doi.org/10.4043/29308-MS","url":null,"abstract":"\u0000 Temperature effects on closure bolting play an important role when assessing high-pressure, high-temperature (HPHT) subsea equipment. This paper discusses the evaluation of uninsulated bolted connections, which are internally exposed to high pressure and temperature and externally exposed to cold seawater, via finite element analysis (FEA). These thermal gradients cause nonuniform thermal expansions, contractions, or both. The paper then compares this to identical insulated connections, which have a uniform temperature distribution across the bolted connection.\u0000 Two pressure-containing bodies featuring nonstandard API four-bolt connections of different sizes were analyzed using FEA at 20,000-psi bore pressure. The larger body featured an API BX-169 gasket housing a 5-1/8-in internal bore at 300 degF, and the smaller body featured an API BX-151 gasket housing a ½-in internal bore at 150 degF. Both bodies were analyzed at high and low seawater convection rates with a temperature heat sink of 35 degF. This was then compared to identical insulated connections assuming a uniform temperature distribution. All verification was performed per API Technical Report 17TR8 utilizing American Society of Mechanical Enginers (ASME) Boiler and Pressure Vessel Code (BPVC), Section VIII, Div. 3 elastic-plastic analysis methods focused only on the serviceability check.\u0000 The results of this design verification showed an increase in bolt tensile stress in the un-insulated cases when compared with the same internal pressure for insulated cases. This stress increase exceeded the allowable tensile stress as specified by API Spec 17D even at an internal temperature of 150 degF, which is below the design threshold where thermal effects must be accounted for as required by API Spec 6A. This required either a reduction in the installation preload, an increase in bolt size, a reduction in the design load-carrying capacity, or a combination thereof. For this study, a reduction in the installation preload to reduce the tensile stress below the API Spec 17D allowable limit was selected as the corrective measure due to preexisting bolt size constraints and operational requirements. Gasket contact pressure was reevaluated at the reduced preload and was found to be sufficient to maintain proper joint sealability. FEA provides a more comprehensive understanding of thermal gradient effects on subsea bolted connections and identifies loading effects not normally observed using standard analysis methods. It is also a recommendation to evaluate both insulated and un-insulated cases to ensure that the bolted connection will perform its intended function.\u0000 This study showed bolt stress differences between thermally insulated and un-insulated connections that can result in bolt stresses beyond acceptance criteria for one while the other is satisfied. This highlights the importance of evaluating bolted connections to ensure acceptability for all operational cases. This study also shows th","PeriodicalId":10968,"journal":{"name":"Day 3 Wed, May 08, 2019","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83019032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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