Boulders are known to be present within foundation zone depths at some Atlantic East Coast wind energy development areas, which can make it difficult to level a piled jacket or template and can lead to the progressive collapse of the pile toe, causing premature refusal during pile driving. Although detection and avoidance are preferred over mitigation, numerical analysis methods are available to assess the risk of pile refusal, which allows for informed decisions on whether avoidance is required and what types of mitigation to consider during construction. Detailed numerical evaluation (using one-dimensional wave equation analyses and two- and three-dimensional finite difference and finite element modeling) was performed to develop a better understanding of stresses in the pile during driving. The numerical modeling evaluated the effect of strength, thickness, inclination, shoe length, wall thickness, and lateral continuity on pile stresses. A three-dimensional model of the pile and driving shoe subjected to stress-time histories was used to evaluate the stresses at the pile toe and at the transition from the pile to the driving shoe. Example results are presented to illustrate failure mechanisms of hard layers that include boulders, and high-level guidance is provided on operational sequences and potential contingency measures.
{"title":"Assessing the Pile Driving Risk Due to the Presence of Boulders","authors":"R. Stevens, Z. Westgate, J. Kocijan","doi":"10.4043/29668-MS","DOIUrl":"https://doi.org/10.4043/29668-MS","url":null,"abstract":"\u0000 Boulders are known to be present within foundation zone depths at some Atlantic East Coast wind energy development areas, which can make it difficult to level a piled jacket or template and can lead to the progressive collapse of the pile toe, causing premature refusal during pile driving. Although detection and avoidance are preferred over mitigation, numerical analysis methods are available to assess the risk of pile refusal, which allows for informed decisions on whether avoidance is required and what types of mitigation to consider during construction. Detailed numerical evaluation (using one-dimensional wave equation analyses and two- and three-dimensional finite difference and finite element modeling) was performed to develop a better understanding of stresses in the pile during driving. The numerical modeling evaluated the effect of strength, thickness, inclination, shoe length, wall thickness, and lateral continuity on pile stresses. A three-dimensional model of the pile and driving shoe subjected to stress-time histories was used to evaluate the stresses at the pile toe and at the transition from the pile to the driving shoe. Example results are presented to illustrate failure mechanisms of hard layers that include boulders, and high-level guidance is provided on operational sequences and potential contingency measures.","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":"89529471","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 generalized use of multi-physics software may lead to significant errors when engineering judgement has not been exercised to its full extent. For that purpose ASME has developed Verification and Validation documents for Solid and Fluid Mechanics and is developing one for Energy Systems. Verification (solving the equation right) benefits from a large body of numerical analysis and theoretical handbooks but validation (solving the right equation) does not always appear to have the same foundation. This is particularly the case when it is necessary to build the confidence in extension to more complex scenarios and where testing is not feasible such as in the offshore industry. The selection of the applicable software or the development of a new one rests on the shoulders of the designer. Similitude laws state that identical results must be obtained when the dimensionless parameters are the same (n-theorem). In the pre-computer era dimensionless numbers have been extensively used in particular to design relevant experiments. Dimensionless Numbers are usually the ratio of two values representing two physical phenomena (such as momentum and viscous forces for the Reynolds number). Above a critical value, the numerator phenomenon is dominant whereas it is the denominator phenomenon which is dominant below the critical value. Different sets of equations for either ranges are packaged in a software. The boundaries of their domains of validity may then become blurred to the casual user. Another example for flow assurance is the case of compressibility effects which may become locally important, although under regular design rules (under the "erosional velocity" limit) they are not. Water-hammer is also an example for pressure fluctuations which are usually ignored unless in specific cases. It is proposed to define the domain of validity of a software by reference to the use of the Dimensionless Numbers relevant to the phenomena anticipated by the designer, and then to control that the value of the computer derived Dimensionless Numbers remain within the expected range. In essence Dimensionless Numbers must remain essential parameters to contribute to an educated engineering judgment in the computer era. The following process is proposed when dealing with a new design: -identify the relevant physical phenomena-assess, from Dimensionless Numbers, the applicable model-screen the software for its capacity to solve the computer model under the prescribed conditions-solve the computer model (with appropriate verification)-verify that the results are consistent with the assumptions by generating global and local Dimensionless Numbers. As the capacity of software increases to cover different engineering disciplines, there could be a sense that the computer dictates the results without the necessary control of engineering judgment, either because it is simply not available or not voiced at an effective level. Dimensionless Numbers hav
{"title":"Dimensionless Numbers as an Effective Tool for Validation & Verification","authors":"J. Saint-Marcoux","doi":"10.4043/29598-MS","DOIUrl":"https://doi.org/10.4043/29598-MS","url":null,"abstract":"\u0000 \u0000 \u0000 The generalized use of multi-physics software may lead to significant errors when engineering judgement has not been exercised to its full extent. For that purpose ASME has developed Verification and Validation documents for Solid and Fluid Mechanics and is developing one for Energy Systems.\u0000 Verification (solving the equation right) benefits from a large body of numerical analysis and theoretical handbooks but validation (solving the right equation) does not always appear to have the same foundation. This is particularly the case when it is necessary to build the confidence in extension to more complex scenarios and where testing is not feasible such as in the offshore industry. The selection of the applicable software or the development of a new one rests on the shoulders of the designer.\u0000 Similitude laws state that identical results must be obtained when the dimensionless parameters are the same (n-theorem). In the pre-computer era dimensionless numbers have been extensively used in particular to design relevant experiments.\u0000 Dimensionless Numbers are usually the ratio of two values representing two physical phenomena (such as momentum and viscous forces for the Reynolds number). Above a critical value, the numerator phenomenon is dominant whereas it is the denominator phenomenon which is dominant below the critical value. Different sets of equations for either ranges are packaged in a software. The boundaries of their domains of validity may then become blurred to the casual user.\u0000 Another example for flow assurance is the case of compressibility effects which may become locally important, although under regular design rules (under the \"erosional velocity\" limit) they are not. Water-hammer is also an example for pressure fluctuations which are usually ignored unless in specific cases.\u0000 It is proposed to define the domain of validity of a software by reference to the use of the Dimensionless Numbers relevant to the phenomena anticipated by the designer, and then to control that the value of the computer derived Dimensionless Numbers remain within the expected range. In essence Dimensionless Numbers must remain essential parameters to contribute to an educated engineering judgment in the computer era.\u0000 \u0000 \u0000 \u0000 The following process is proposed when dealing with a new design: -identify the relevant physical phenomena-assess, from Dimensionless Numbers, the applicable model-screen the software for its capacity to solve the computer model under the prescribed conditions-solve the computer model (with appropriate verification)-verify that the results are consistent with the assumptions by generating global and local Dimensionless Numbers.\u0000 \u0000 \u0000 \u0000 As the capacity of software increases to cover different engineering disciplines, there could be a sense that the computer dictates the results without the necessary control of engineering judgment, either because it is simply not available or not voiced at an effective level.\u0000 Dimensionless Numbers hav","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":"78634288","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}
As operators in the oil and gas industry continue to search for larger oil deposits in areas that are considered High Pressure and High Temperature (HPHT) environments, manufacturers of liner hanger/packer systems must conceive and validate designs that can support these projects. The XPak™ liner hanger/packer system is an expandable product that offers metal-to-metal and elastomer sealing capabilities at the liner top in host casing, capable of superior hanging capacity and seal integrity for installing casing strings of various lengths. The expansion process is achieved using a multi-piston hydraulic running tool with pressure application to displace an Expander inside the XPak hanger body. The displacement of the Expander inside the XPak hanger body relies on interference between the components to radially grow the hanger body to contact and interfere with the host casing. This interaction provides the sealing and anchoring capability of the XPak system. The Expander provides tieback capability via a polished bore receptacle and remains installed inside the hanger body for the lifetime of the installation. Operators are implementing robust host casing designs with less variance in wall thickness to utilize tubulars with higher burst and collapse ratings than those manufactured to API standard variances. The combination of higher burst pressure ratings for the host casing and limited variance on the inner diameters provides an ideal partner for the XPak system. Expandable products rely on a narrower host casing inner diameter range to create the interference needed for optimum performance, as opposed to conventional liner hanger systems which work over a broader diameter range. An ISO 14310 V0 qualification of a 7-5/8 × 12-1/4 HPHT XPak liner hanger/packer system for a major operator in the Gulf of Mexico successfully achieved testing milestones of 15 ksi internal pressure with a combined loading of 1,000 kips in tension at 375°F. The system was also qualified at a low temperature of 60°F reaching a successful test pressure of 21.75 ksi internally with a combined tension load of 1,000 kips. These testing requirements were provided in the customer's statement of requirements to handle extreme well loading conditions. FEA modeling is the primary tool for XPak design and focuses primarily on identifying and predicting material strain to help determine the system capabilities under simulated pressure and loading conditions. The distinct geometry and controlled deformation of the hanger body during expansion are simulated using FEA software to provide guidance to meet design parameters to reach high levels of performance. The initial conceptual design is taken through a complete range of potential well scenarios including: casing inner diameter ranges, maximum and minimum setting forces, geometric tolerancing, friction factors, and transient thermal loading. The results are compiled and reviewed to determine the optimal design model to satisfy t
{"title":"HPHT Expandable Liner Hanger Technology with Superior Pressure Integrity","authors":"E. Royer, R. Turney","doi":"10.4043/29494-MS","DOIUrl":"https://doi.org/10.4043/29494-MS","url":null,"abstract":"\u0000 As operators in the oil and gas industry continue to search for larger oil deposits in areas that are considered High Pressure and High Temperature (HPHT) environments, manufacturers of liner hanger/packer systems must conceive and validate designs that can support these projects. The XPak™ liner hanger/packer system is an expandable product that offers metal-to-metal and elastomer sealing capabilities at the liner top in host casing, capable of superior hanging capacity and seal integrity for installing casing strings of various lengths. The expansion process is achieved using a multi-piston hydraulic running tool with pressure application to displace an Expander inside the XPak hanger body. The displacement of the Expander inside the XPak hanger body relies on interference between the components to radially grow the hanger body to contact and interfere with the host casing. This interaction provides the sealing and anchoring capability of the XPak system. The Expander provides tieback capability via a polished bore receptacle and remains installed inside the hanger body for the lifetime of the installation.\u0000 Operators are implementing robust host casing designs with less variance in wall thickness to utilize tubulars with higher burst and collapse ratings than those manufactured to API standard variances. The combination of higher burst pressure ratings for the host casing and limited variance on the inner diameters provides an ideal partner for the XPak system. Expandable products rely on a narrower host casing inner diameter range to create the interference needed for optimum performance, as opposed to conventional liner hanger systems which work over a broader diameter range.\u0000 An ISO 14310 V0 qualification of a 7-5/8 × 12-1/4 HPHT XPak liner hanger/packer system for a major operator in the Gulf of Mexico successfully achieved testing milestones of 15 ksi internal pressure with a combined loading of 1,000 kips in tension at 375°F. The system was also qualified at a low temperature of 60°F reaching a successful test pressure of 21.75 ksi internally with a combined tension load of 1,000 kips. These testing requirements were provided in the customer's statement of requirements to handle extreme well loading conditions. FEA modeling is the primary tool for XPak design and focuses primarily on identifying and predicting material strain to help determine the system capabilities under simulated pressure and loading conditions. The distinct geometry and controlled deformation of the hanger body during expansion are simulated using FEA software to provide guidance to meet design parameters to reach high levels of performance. The initial conceptual design is taken through a complete range of potential well scenarios including: casing inner diameter ranges, maximum and minimum setting forces, geometric tolerancing, friction factors, and transient thermal loading. The results are compiled and reviewed to determine the optimal design model to satisfy t","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":"76582572","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 study is to analyze in detail a process for designing by means of numerical simulation a field test of gas production from hydrate deposits, and to discuss modeling results associated with several such planned tests. The paper discusses comprehensively the data required for a reliable estimate of gas production, and provides insights into production conditions and test well operating parameters that can adversely affect a planned test. The design process begins with the development of a reliable geologic model. It is followed by an analysis of the system stratigraphy, the identification of the hydrate-bearing zones and the associated interlayers, the definition of the initial conditions (pressure, temperature, phase distributions, and geomechanical stresses), the identification of all key media properties (flow, thermal, geomechanical), and the definition of success criteria for hydrate production tests. The geologic model is of paramount importance because it can define the system boundaries. We explore the relative importance of lateral vs. top and bottom flow boundaries within the context of the limited time frame of a field test. Initial pressures P in hydrate accumulations are relatively predictable as they are almost invariably hydrostatic. The initial temperature T distribution is important because T is the dominant parameter controlling the hydrate behavior. Knowledge of the P and T distributions are important in determining true time-invariant P- and T-boundaries. Other important initial conditions are (a) the spatial distribution of the possible phases and (b) the geomechanical stresses in the system and its surroundings. We discuss possible sources of the necessary data through analogs even when direct measurements are unavailable. We investigate the effect of heterogeneity in various parameters, and in the choice of the coordinate system. We explore the impact of spatial discretization, an important subject that has yet to be fully investigated. Finally, we provide modeling results covering a wide range of designs for production tests in oceanic and permafrost-associated hydrate deposits that describe fluid production and the flow and geomechanical system response, as well as implications for the well design and construction. To the authors' knowledge, this is the first paper discussing in detail the recommended process for the design of field tests of gas production from hydrates, and of the key issues that can affect not only production but also the flow and geomechanical behavior of the system during the test and the definition of the well construction requirements.
{"title":"Gas Hydrate Production Testing: Design Process and Modeling Results","authors":"G. Moridis, M. Reagan, A. Queiruga","doi":"10.4043/29432-MS","DOIUrl":"https://doi.org/10.4043/29432-MS","url":null,"abstract":"\u0000 The objective of this study is to analyze in detail a process for designing by means of numerical simulation a field test of gas production from hydrate deposits, and to discuss modeling results associated with several such planned tests. The paper discusses comprehensively the data required for a reliable estimate of gas production, and provides insights into production conditions and test well operating parameters that can adversely affect a planned test. The design process begins with the development of a reliable geologic model. It is followed by an analysis of the system stratigraphy, the identification of the hydrate-bearing zones and the associated interlayers, the definition of the initial conditions (pressure, temperature, phase distributions, and geomechanical stresses), the identification of all key media properties (flow, thermal, geomechanical), and the definition of success criteria for hydrate production tests.\u0000 The geologic model is of paramount importance because it can define the system boundaries. We explore the relative importance of lateral vs. top and bottom flow boundaries within the context of the limited time frame of a field test. Initial pressures P in hydrate accumulations are relatively predictable as they are almost invariably hydrostatic. The initial temperature T distribution is important because T is the dominant parameter controlling the hydrate behavior. Knowledge of the P and T distributions are important in determining true time-invariant P- and T-boundaries. Other important initial conditions are (a) the spatial distribution of the possible phases and (b) the geomechanical stresses in the system and its surroundings. We discuss possible sources of the necessary data through analogs even when direct measurements are unavailable. We investigate the effect of heterogeneity in various parameters, and in the choice of the coordinate system. We explore the impact of spatial discretization, an important subject that has yet to be fully investigated. Finally, we provide modeling results covering a wide range of designs for production tests in oceanic and permafrost-associated hydrate deposits that describe fluid production and the flow and geomechanical system response, as well as implications for the well design and construction.\u0000 To the authors' knowledge, this is the first paper discussing in detail the recommended process for the design of field tests of gas production from hydrates, and of the key issues that can affect not only production but also the flow and geomechanical behavior of the system during the test and the definition of the well construction requirements.","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":"82311617","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}
Giorgio Arcangeletti, F. Bacati, A. Radicioni, Bruno Breuskin, Sylvie Jacquet, A. D'Amico, Enrico La Sorda
The overall complexity of future subsea transportation systems is expected to increase due to new challenges posed by the novel field development schemes mainly dictated by the combination of tie-back distance and water depth with the target to make the field exploitation profitable, safe and reliable in the current Oil & Gas price scenario. It is becoming more frequent to face field development projects with long step-out distances associated with considerable water depth and/or low wellhead product temperature. During normal or transient conditions, these factors lead to flow assurance issues that can be avoided by deploying new cost effective technologies such as insulated and heated pipeline systems combined with subsea processing elements like Subsea Boosting. A dedicated team has performed different studies and internal development activities on this subject based on expected needs of Operators considering their real future subsea fields under investigation. New development schemes and operating philosophies have been identified together with the relevant technologies that, in some cases are under development, jointly with major suppliers. The most efficient production schemes have been selected and the conceptual design of its relevant technological building blocks has been performed. These building blocks have been further investigated in terms of market ownership & readiness with technology suppliers and O&G operators. The main enabling technologies involved for the oil fields are Subsea Active Heating/Insulation such as proprietary Electrically Trace-Heated Pipe In Pipe (ETH PIP), Subsea Boosting, Subsea Power Distribution and the All Electric Control System. ETH PiP, combined with Subsea Power Distribution (Subsea Switchgear, Subsea Transformers, Subsea VSD, etc.) and the All Electric Control System, can significantly support overall investment cost reduction and facilitate the tie-back development to an existing facility by ensuring the flexibility of operations and suitability with a wide range of project design basis. This paper outlines the selected development schemes for the long tieback oil fields and describes the main technological building blocks. It also outlines the actions initiated to provide a global solution for these types of fields and mainly to industrialize the second generation of the ETH PIP solution for longer tie-backs. It discusses the main components of the ETH PIP solution and the relevant Subsea Power Feeding System that provide and distribute power also to the other subsea utilities like boosting pumps and All Electric Control.
由于新的油田开发方案所带来的新挑战，未来海底运输系统的整体复杂性预计会增加，这些新方案主要是由回接距离和水深的结合决定的，目的是在当前的石油和天然气价格情况下使油田开采有利可图、安全和可靠。越来越多的油田开发项目面临着长台阶距离、大水深和/或低井口产品温度的问题。在正常或瞬态条件下，这些因素会导致流动保障问题，而这些问题可以通过部署新的经济高效的技术来避免，例如将隔热和加热管道系统与海底增压等海底处理元件相结合。一个专门的团队根据运营商的预期需求，考虑到他们正在调查的未来海底油田的实际情况，对该主题进行了不同的研究和内部开发活动。已经确定了新的发展计划和业务理念，以及在某些情况下正在与主要供应商共同开发的有关技术。选择了最有效的生产方案，并对其相关技术构件进行了概念设计。在技术供应商和油气运营商的市场所有权和准备情况方面，这些构建模块已经得到了进一步的研究。油田所涉及的主要支持技术是海底主动加热/绝缘，例如专有的电踪加热管中管(ETH PIP)、海底增压、海底配电和全电气控制系统。ETH PiP与海底配电(海底开关设备、海底变压器、海底VSD等)和全电气控制系统相结合，可以显著降低总体投资成本，并通过确保操作的灵活性和广泛的项目设计基础的适用性，促进与现有设施的回接开发。本文概述了长回拔油田的开发方案，并介绍了主要的技术组成部分。它还概述了为这些类型的油田提供全球解决方案所采取的行动，主要是将第二代ETH PIP解决方案工业化，用于更长的回接。讨论了ETH PIP解决方案的主要组成部分和相关的海底供电系统，该系统还为其他海底公用设施(如增压泵和All Electric Control)提供和分配电力。
{"title":"Innovative Field Development Scheme Based on Saipem's ETH PiP and Relevant Subsea Power Feeding System","authors":"Giorgio Arcangeletti, F. Bacati, A. Radicioni, Bruno Breuskin, Sylvie Jacquet, A. D'Amico, Enrico La Sorda","doi":"10.4043/29462-MS","DOIUrl":"https://doi.org/10.4043/29462-MS","url":null,"abstract":"\u0000 The overall complexity of future subsea transportation systems is expected to increase due to new challenges posed by the novel field development schemes mainly dictated by the combination of tie-back distance and water depth with the target to make the field exploitation profitable, safe and reliable in the current Oil & Gas price scenario.\u0000 It is becoming more frequent to face field development projects with long step-out distances associated with considerable water depth and/or low wellhead product temperature. During normal or transient conditions, these factors lead to flow assurance issues that can be avoided by deploying new cost effective technologies such as insulated and heated pipeline systems combined with subsea processing elements like Subsea Boosting.\u0000 A dedicated team has performed different studies and internal development activities on this subject based on expected needs of Operators considering their real future subsea fields under investigation.\u0000 New development schemes and operating philosophies have been identified together with the relevant technologies that, in some cases are under development, jointly with major suppliers.\u0000 The most efficient production schemes have been selected and the conceptual design of its relevant technological building blocks has been performed. These building blocks have been further investigated in terms of market ownership & readiness with technology suppliers and O&G operators. The main enabling technologies involved for the oil fields are Subsea Active Heating/Insulation such as proprietary Electrically Trace-Heated Pipe In Pipe (ETH PIP), Subsea Boosting, Subsea Power Distribution and the All Electric Control System.\u0000 ETH PiP, combined with Subsea Power Distribution (Subsea Switchgear, Subsea Transformers, Subsea VSD, etc.) and the All Electric Control System, can significantly support overall investment cost reduction and facilitate the tie-back development to an existing facility by ensuring the flexibility of operations and suitability with a wide range of project design basis.\u0000 This paper outlines the selected development schemes for the long tieback oil fields and describes the main technological building blocks. It also outlines the actions initiated to provide a global solution for these types of fields and mainly to industrialize the second generation of the ETH PIP solution for longer tie-backs.\u0000 It discusses the main components of the ETH PIP solution and the relevant Subsea Power Feeding System that provide and distribute power also to the other subsea utilities like boosting pumps and All Electric Control.","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":"77053325","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}
It is instructive to think about the current state of subsea well system design in its historical context. That is especially true if you look first at the earliest years, then at the years following the 1969 Santa Barbara blowout and spill, and then at the years following the Macondo blowout and spill. These last two periods illustrate both important similarities and important differences in equipment design, standardization, and regulation. This paper examines the advances in design, standardization, and regulation of subsea well control and well containment equipment. This progress has continued the conservative, step-wise advances that have characterized the history of the subsea drilling and well control industry. This paper uses as an example the recent project developing a new 20,000 psi/350F capping stack.
{"title":"Providing Well Containment Equipment for HPHT Service","authors":"Billy Cowan, Jim T. Kaculi, G. Frazer","doi":"10.4043/29620-MS","DOIUrl":"https://doi.org/10.4043/29620-MS","url":null,"abstract":"\u0000 It is instructive to think about the current state of subsea well system design in its historical context. That is especially true if you look first at the earliest years, then at the years following the 1969 Santa Barbara blowout and spill, and then at the years following the Macondo blowout and spill. These last two periods illustrate both important similarities and important differences in equipment design, standardization, and regulation.\u0000 This paper examines the advances in design, standardization, and regulation of subsea well control and well containment equipment. This progress has continued the conservative, step-wise advances that have characterized the history of the subsea drilling and well control industry. This paper uses as an example the recent project developing a new 20,000 psi/350F capping stack.","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":"90915374","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}
This study investigates how the variation in sediment layer geometry of hydrate-bearing sediments (HBS) affects geomechanical behaviors of HBS under depressurization. Two reservoir models with different layering structures but with the same hydrate quantity were constructed and the reservoir responses were numerically investigated during gradual depressurization process. To simulate thermo-hydro-mechanically coupled multiphysics processes occurring in HBS, a series of governing equations were discretized based on a finite volume concept, and coded into an explicit finite difference numerical simulator. An explicitly coupled, time-marching algorithm was used to couple thermo-hydro-mechanical responses associated with depressurization-driven hydrate dissociation. We herein modelded a hydrate deposit in Ulleung Basin, Korea for the sediment properties and geological setting. The simulation results clearly demonstrate that the "densely" layered HBS structure, composed of thin and interbedded clay-sand layers, is more prone to geomechanical instability though it led to more gas production. It is attributed to various mechanisms, including (i) the rapid water drainage from neighboring thin clay layers, (ii) the unique hydrate dissociation pattern in interbedded HBS, and (iii) the transfer of shear stress from hydrate-bearing, "stiff" sandy layers into adjacent thin "soft" clay layers. The layer geometry substantially affects not only the gas production but also the geomechanical stability of a hydrate reservoir. High-resolution sediment profiling appears to play an important role in numerical HBS simulations to reliably predict the feasibility of safe exploitation from layered HBS systems.
{"title":"Impact of Interbedded Structure of Sand and Clay Layers on Geomechanical Responses of Hydrate-Bearing Sediments During Depressurization","authors":"Y. Sohn, J. Lee, K. Song, T. Kwon","doi":"10.4043/29315-MS","DOIUrl":"https://doi.org/10.4043/29315-MS","url":null,"abstract":"\u0000 This study investigates how the variation in sediment layer geometry of hydrate-bearing sediments (HBS) affects geomechanical behaviors of HBS under depressurization. Two reservoir models with different layering structures but with the same hydrate quantity were constructed and the reservoir responses were numerically investigated during gradual depressurization process. To simulate thermo-hydro-mechanically coupled multiphysics processes occurring in HBS, a series of governing equations were discretized based on a finite volume concept, and coded into an explicit finite difference numerical simulator. An explicitly coupled, time-marching algorithm was used to couple thermo-hydro-mechanical responses associated with depressurization-driven hydrate dissociation. We herein modelded a hydrate deposit in Ulleung Basin, Korea for the sediment properties and geological setting. The simulation results clearly demonstrate that the \"densely\" layered HBS structure, composed of thin and interbedded clay-sand layers, is more prone to geomechanical instability though it led to more gas production. It is attributed to various mechanisms, including (i) the rapid water drainage from neighboring thin clay layers, (ii) the unique hydrate dissociation pattern in interbedded HBS, and (iii) the transfer of shear stress from hydrate-bearing, \"stiff\" sandy layers into adjacent thin \"soft\" clay layers. The layer geometry substantially affects not only the gas production but also the geomechanical stability of a hydrate reservoir. High-resolution sediment profiling appears to play an important role in numerical HBS simulations to reliably predict the feasibility of safe exploitation from layered HBS systems.","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":"86714249","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 high costs and high potential risks associated with drilling deepwater wells have prompted the development of an advanced computerized mud logging system. This paper highlights select technologies within the system and its application to three core areas of operation—circulating, making connections, and tripping—to provide early identification of fluid influxes and losses, thus helping ensure safe and efficient well delivery. The advanced mud logging system includes a kick-detection system, flowback monitoring, trip monitoring software, and mud accounting software based on a new methodology. The kick-detection system uses advanced flowmeters to enable stricter control of the drilling process; fluid influxes or losses are detected by integrating the variance for predicted and measured flow and alarming, with as little as a barrel gained or lost. Flowback monitoring uses sophisticated algorithms in conjunction with the same high-accuracy flowmeters to monitor influxes while making connections. These algorithms drive a complex alarm system tuned to trigger on minimal flow variance, pit volumes, and the rate of modification of each compared to a historical baseline. Additionally, trip-monitoring software automates the tracking of pipe displacements in real time to warn of a well control event, instead of relying on spreadsheets or handwritten calculations. Mud accounting software tracks drilling fluid balance across the entire pit system for redundant influx and loss detection and accounts for volume changes based on circulating rates. Application of the advanced mud logging system in the deepwater Gulf of Mexico (GOM) provided earlier detection of well control events—up to 10 minutes earlier than conventional well monitoring techniques. Flowback monitoring demonstrated the ability to identify minimal flow when making connections, which would be difficult to detect by visual inspection. The ability to trend flowback profiles consistently has allowed operators to reduce the pump's off time while making connections in less than 5 minutes, without jeopardizing the ability to confirm a static well. Additionally, the advanced system enables drilling operations to proceed without increasing mud weight and exacerbating wellbore damage during a ballooning event. This paper presents a case study in which the history of well control events documented in the literature was reviewed to help identify areas of improvement.
{"title":"Advanced Mud Logging: Key to Safe and Efficient Well Delivery","authors":"D. Blue, T. Blakey, M. Rowe","doi":"10.4043/29469-MS","DOIUrl":"https://doi.org/10.4043/29469-MS","url":null,"abstract":"\u0000 The high costs and high potential risks associated with drilling deepwater wells have prompted the development of an advanced computerized mud logging system. This paper highlights select technologies within the system and its application to three core areas of operation—circulating, making connections, and tripping—to provide early identification of fluid influxes and losses, thus helping ensure safe and efficient well delivery.\u0000 The advanced mud logging system includes a kick-detection system, flowback monitoring, trip monitoring software, and mud accounting software based on a new methodology. The kick-detection system uses advanced flowmeters to enable stricter control of the drilling process; fluid influxes or losses are detected by integrating the variance for predicted and measured flow and alarming, with as little as a barrel gained or lost. Flowback monitoring uses sophisticated algorithms in conjunction with the same high-accuracy flowmeters to monitor influxes while making connections. These algorithms drive a complex alarm system tuned to trigger on minimal flow variance, pit volumes, and the rate of modification of each compared to a historical baseline. Additionally, trip-monitoring software automates the tracking of pipe displacements in real time to warn of a well control event, instead of relying on spreadsheets or handwritten calculations. Mud accounting software tracks drilling fluid balance across the entire pit system for redundant influx and loss detection and accounts for volume changes based on circulating rates.\u0000 Application of the advanced mud logging system in the deepwater Gulf of Mexico (GOM) provided earlier detection of well control events—up to 10 minutes earlier than conventional well monitoring techniques. Flowback monitoring demonstrated the ability to identify minimal flow when making connections, which would be difficult to detect by visual inspection. The ability to trend flowback profiles consistently has allowed operators to reduce the pump's off time while making connections in less than 5 minutes, without jeopardizing the ability to confirm a static well.\u0000 Additionally, the advanced system enables drilling operations to proceed without increasing mud weight and exacerbating wellbore damage during a ballooning event.\u0000 This paper presents a case study in which the history of well control events documented in the literature was reviewed to help identify areas of improvement.","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":"86775098","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}
This paper is based on an ongoing multi-participant study which focuses on the development of concepts for unmanned or "Normally Unattended Installations" (NUIs) that can be used for the economic recovery of stranded oil and gas reserves considered too small for traditional floating production storage and offloading (FPSO) vessels, and too far away from existing facilities for tie-backs. The primary objective of the study is to apply existing technologies in novel ways and to utilize recent advances in digitalization to develop low manning concepts by facilitating remote control, remote monitoring, and reducing maintenance requirements. The study engaged key technology vendors and operators, who provided operational expertise and defined future operation philosophies. Concepts are being validated by classification societies, yards and installation contractors. The specific NUI concept explored in this paper is an unmanned production buoy that proved to be technically and economically feasible for the recovery of small hydrocarbon pools in deeper water. The case study is a realistic approximation of a small deepwater offshore development in the North Sea, however, it is not based on any specific prospect. The case study Basis of Design (BoD) has been defined to cover a range of API gravities, ensuring that the resultant topsides design concept is robust and applicable to a range of real field developments in the future without significant re-configuration. The study into the technical and economic feasibility of the unmanned production buoy considered alternatives for gas compression, treatment, separation; heating and cooling, power generation, automation systems, and digitalization. This paper presents the outcomes with respect to production buoy design, operating philosophy, automation and digitalization.
{"title":"New Concepts for a Normally Unattended Installation NUI – Design, Operation, Automation, and Digitalization","authors":"Elgonda LaGrange, J. Maisey","doi":"10.4043/29367-MS","DOIUrl":"https://doi.org/10.4043/29367-MS","url":null,"abstract":"\u0000 This paper is based on an ongoing multi-participant study which focuses on the development of concepts for unmanned or \"Normally Unattended Installations\" (NUIs) that can be used for the economic recovery of stranded oil and gas reserves considered too small for traditional floating production storage and offloading (FPSO) vessels, and too far away from existing facilities for tie-backs.\u0000 The primary objective of the study is to apply existing technologies in novel ways and to utilize recent advances in digitalization to develop low manning concepts by facilitating remote control, remote monitoring, and reducing maintenance requirements. The study engaged key technology vendors and operators, who provided operational expertise and defined future operation philosophies. Concepts are being validated by classification societies, yards and installation contractors.\u0000 The specific NUI concept explored in this paper is an unmanned production buoy that proved to be technically and economically feasible for the recovery of small hydrocarbon pools in deeper water. The case study is a realistic approximation of a small deepwater offshore development in the North Sea, however, it is not based on any specific prospect. The case study Basis of Design (BoD) has been defined to cover a range of API gravities, ensuring that the resultant topsides design concept is robust and applicable to a range of real field developments in the future without significant re-configuration.\u0000 The study into the technical and economic feasibility of the unmanned production buoy considered alternatives for gas compression, treatment, separation; heating and cooling, power generation, automation systems, and digitalization. This paper presents the outcomes with respect to production buoy design, operating philosophy, automation and digitalization.","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":"85778808","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}
This paper presents a unique gas-liquid experimental dataset acquired at large-diameter laboratory multiphase loop under elevated pressures. The dataset and corresponding model validations are useful to upscale available multiphase flow knowledge into large-diameter-high-pressure conditions commonly encountered in offshore facilities. Intermittent (slug and pseudo-slug) and segregated (stratified and annular) flow patterns were observed in the experiments. For given superficial liquid Froude number (FrSL), all flow pattern transitions scale with superficial gas Froude number (FrSG) within the experimental range, capturing the effects of pressure (gas density). The change in pressure gradient and liquid holdup across the intermittent to segregated transition is more pronounced at low vSL. In segregated flow, the pressure gradient (-dp/dL) increases with pressure and vSL. However, these effects are less noticeable in intermittent flow. In intermittent flow, -dp/dL is generally gravity dominated but may become friction dominated as vSL increases, owing to absence of film reversal. For given vSL, -dp/dL scales with FrSG. The relationship between dimensionless -dp/dL (P*) and Lockhart-Martinelli parameter (X*) scales the effects of pressure and vSL for segregated flow. Liquid holdup was observed to decrease with pressure and increase with vSL. As pressure increases, density difference between phases decreases and interfacial friction increases, thereby reducing slippage and holdup (HL). Two state-of-the-art models exhibit similar bias tendency. In the intermittent region the inaccuracy of -dp/dL and HL predictions increase with vSG, i.e.: deeper into pseudo-slug region. This error is larger at low vSL. For segregated flow, the models tend to underpredict -dp/dL as vSG increases. The magnitude of this error is larger at high vSL. This paper addresses the limitation of large-diameter-high-pressure data in multiphase flow literature. The presented data, scaling approaches, and model validation results are critical for model improvement. For practicing engineers, they can be used as an upscaled benchmark/practical guidance to design multiphase flow pipelines.
{"title":"Gas-Liquid Flow in an Upward Inclined Large Diameter Pipe Under Elevated Pressures","authors":"Auzan Soedarmo, E. Pereyra, C. Sarica","doi":"10.4043/29353-MS","DOIUrl":"https://doi.org/10.4043/29353-MS","url":null,"abstract":"\u0000 This paper presents a unique gas-liquid experimental dataset acquired at large-diameter laboratory multiphase loop under elevated pressures. The dataset and corresponding model validations are useful to upscale available multiphase flow knowledge into large-diameter-high-pressure conditions commonly encountered in offshore facilities.\u0000 Intermittent (slug and pseudo-slug) and segregated (stratified and annular) flow patterns were observed in the experiments. For given superficial liquid Froude number (FrSL), all flow pattern transitions scale with superficial gas Froude number (FrSG) within the experimental range, capturing the effects of pressure (gas density). The change in pressure gradient and liquid holdup across the intermittent to segregated transition is more pronounced at low vSL.\u0000 In segregated flow, the pressure gradient (-dp/dL) increases with pressure and vSL. However, these effects are less noticeable in intermittent flow. In intermittent flow, -dp/dL is generally gravity dominated but may become friction dominated as vSL increases, owing to absence of film reversal. For given vSL, -dp/dL scales with FrSG. The relationship between dimensionless -dp/dL (P*) and Lockhart-Martinelli parameter (X*) scales the effects of pressure and vSL for segregated flow. Liquid holdup was observed to decrease with pressure and increase with vSL. As pressure increases, density difference between phases decreases and interfacial friction increases, thereby reducing slippage and holdup (HL).\u0000 Two state-of-the-art models exhibit similar bias tendency. In the intermittent region the inaccuracy of -dp/dL and HL predictions increase with vSG, i.e.: deeper into pseudo-slug region. This error is larger at low vSL. For segregated flow, the models tend to underpredict -dp/dL as vSG increases. The magnitude of this error is larger at high vSL.\u0000 This paper addresses the limitation of large-diameter-high-pressure data in multiphase flow literature. The presented data, scaling approaches, and model validation results are critical for model improvement. For practicing engineers, they can be used as an upscaled benchmark/practical guidance to design multiphase flow pipelines.","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":"79273364","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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