Existing pressure drilling technologies are based on different principles and display distinct characteristics in terms of control pressure and degree of formation adaptability.In the present study,the constant-bottom...Existing pressure drilling technologies are based on different principles and display distinct characteristics in terms of control pressure and degree of formation adaptability.In the present study,the constant-bottomhole-pressure(CBHP)and controlled-mud-level(CML)dual gradient drilling methods are considered.Models for the equivalent circulating density(ECD)are introduced for both drilling methods,taking into account the control pressure parameters(wellhead back pressure,displacement,mud level,etc.)and the relationship between the equivalent circulating density curve in the wellbore and two different types of pressure profiles in deep-water areas.The findings suggest that the main pressure control parameter for CBHP drilling is the wellhead back pressure,while for CML dual gradient drilling,it is the mud level.Two examples are considered(wells S1 and B2).For S1,CML dual gradient drilling only needs to adjust the ECD curve once to drill down to the target layer without risk.By comparison,CBHP drilling requires multiple adjustments to reach the target well depth avoiding a kick risk.In well B2,the CBHP method can drill down to the desired zone or even deeper after a single adjustment of the ECD curve.In contrast,CML dual-gradient drilling requires multiple adjustments to reach the target well depth(otherwise there is a risk of lost circulation).Therefore,CML dual-gradient drilling should be considered as a better choice for well S1,while CBHP drilling is more suitable for well B2.展开更多
This paper investigates a human-in-the-loop(HiTL)adaptive predefined-time formation control design with selftriggered communication for multiple quadrotor unmanned aerial vehicles subject to asymmetric full-state cons...This paper investigates a human-in-the-loop(HiTL)adaptive predefined-time formation control design with selftriggered communication for multiple quadrotor unmanned aerial vehicles subject to asymmetric full-state constraints and actuator faults.First,the constrained vehicle dynamics are converted to unconstrained ones by constructing a universal nonlinear transformation function,where the feasibility condition restrictions inherent in traditional barrier/integral barrier Lyapunov functions are eliminated.Then,the HiTL control strategy is integrated into the formation design framework,which ensures that human decision-making can be directly applied to the non-autonomous leader,thereby enhancing the flexibility and adaptability of the controlled vehicles.Moreover,a self-triggered predefined-time formation control protocol is designed to allow non-periodic and on-demand updates of control signals without monitoring behaviour.Rigorous theoretical analysis indicates that the closed-loop attitude and position subsystems are practically predefined-time stable,and the formation tracking errors converge to the neighborhood around the origin within a pre-specified time while strictly adhering to asymmetric state constraints.Finally,comprehensive illustrative results validate the effectiveness of the proposed control scheme.展开更多
文摘Existing pressure drilling technologies are based on different principles and display distinct characteristics in terms of control pressure and degree of formation adaptability.In the present study,the constant-bottomhole-pressure(CBHP)and controlled-mud-level(CML)dual gradient drilling methods are considered.Models for the equivalent circulating density(ECD)are introduced for both drilling methods,taking into account the control pressure parameters(wellhead back pressure,displacement,mud level,etc.)and the relationship between the equivalent circulating density curve in the wellbore and two different types of pressure profiles in deep-water areas.The findings suggest that the main pressure control parameter for CBHP drilling is the wellhead back pressure,while for CML dual gradient drilling,it is the mud level.Two examples are considered(wells S1 and B2).For S1,CML dual gradient drilling only needs to adjust the ECD curve once to drill down to the target layer without risk.By comparison,CBHP drilling requires multiple adjustments to reach the target well depth avoiding a kick risk.In well B2,the CBHP method can drill down to the desired zone or even deeper after a single adjustment of the ECD curve.In contrast,CML dual-gradient drilling requires multiple adjustments to reach the target well depth(otherwise there is a risk of lost circulation).Therefore,CML dual-gradient drilling should be considered as a better choice for well S1,while CBHP drilling is more suitable for well B2.
基金supported by the National Natural Science Foundation of China(Grant Nos.62473130,62203153)the Outstanding Youth Innovation Research Group Project of Natural Science Foundation of Henan Province(Grant No.252300421004)+3 种基金the Central Plains Talent Program—Leading Talents in Basic Research of Henan Province,the Central Plains Talent Program—Science and Technology Innovation Outstanding Young Talents of Henan Provincethe Joint Fund of Science and Technology R&D Plan of Henan Province for Young Scientists(Grant No.235200810105)the Application Research Project of the Joint Fund of Science and Technology R&D Plan of Henan Province(Grant No.242103810052)the Technology Innovative Teams in University of Henan Province(Grant No.23IRTSTHN012)。
文摘This paper investigates a human-in-the-loop(HiTL)adaptive predefined-time formation control design with selftriggered communication for multiple quadrotor unmanned aerial vehicles subject to asymmetric full-state constraints and actuator faults.First,the constrained vehicle dynamics are converted to unconstrained ones by constructing a universal nonlinear transformation function,where the feasibility condition restrictions inherent in traditional barrier/integral barrier Lyapunov functions are eliminated.Then,the HiTL control strategy is integrated into the formation design framework,which ensures that human decision-making can be directly applied to the non-autonomous leader,thereby enhancing the flexibility and adaptability of the controlled vehicles.Moreover,a self-triggered predefined-time formation control protocol is designed to allow non-periodic and on-demand updates of control signals without monitoring behaviour.Rigorous theoretical analysis indicates that the closed-loop attitude and position subsystems are practically predefined-time stable,and the formation tracking errors converge to the neighborhood around the origin within a pre-specified time while strictly adhering to asymmetric state constraints.Finally,comprehensive illustrative results validate the effectiveness of the proposed control scheme.
