Automated Well Control Decision-Making during Managed Pressure Drilling Operations

Author(s):  
Ali Karimi Vajargah ◽  
Besmir Buranaj Hoxha ◽  
Eric van Oort
2014 ◽  
Vol 54 (1) ◽  
pp. 23
Author(s):  
Julmar Shaun Sadicon Toralde ◽  
Chad Henry Wuest ◽  
Robert DeGasperis

The threat of riser gas in deepwater drilling operations is real. Studies show that gas kicks unintentionally entrained in oil-based mud in deepwater are unlikely to break out of solution until they are above the subsea blowout preventers (BOPs). The rig diverter is conventionally used to vent riser gas with minimal control and considerable risk and environmental impact involved. Reactive riser gas systems provide a riser gas handling (RGH) joint that is composed of a retrofitted annular BOP and a flow spool with hoses installed on top of the rig marine riser. A proactive, alternative approach to riser gas handling, called riser gas risk mitigation, is proposed by using managed pressure drilling (MPD) equipment. MPD involves the use of a rotating control device (RCD) to create a closed and pressurisable drilling system where flow out of the well is diverted to an automated MPD choke manifold with a high-resolution mass flow meter that increases the sensitivity and reaction time of the system to kicks, losses and other unwanted drilling events. Experiments and field deployments have shown that the deepwater MPD system can detect a gas influx before it dissolves in oil-based mud, allowing for management of the same using conventional well control methods. Since the MPD system has already closed the well in, automatic diversion and control of gas in the riser is also possible, if required. This paper presents experience gained from deepwater MPD operations in the Asia-Pacific to illustrate this, and possible deployment options in Australia are discussed.


2011 ◽  
Vol 51 (1) ◽  
pp. 109 ◽  
Author(s):  
Steve Nas

Closing the wellbore at the top with a rotating control device (RCD) for some kinds of managed pressure drilling (MPD) operations raises a number of issues with regards to well control and kick detection. The wellbore is closed and the standard flow check of looking into the well is no longer possible. The use of a RCD provides drillers with an additional level of comfort because it is a pressure management device, but it doesn’t eliminate the need to have well control as a primary objective. In recent MPD operations, it has already been observed that well control procedures are relaxed as a result of managed pressure drilling. Is managed pressure drilling the same as primary well control, and how do we deal with kicks in managed pressure drilling operations? At what point in a well control process do we hand over from MPD to drillers’ well control, and who is responsible? This paper will present some of the issues that need to be considered when planning and conducting MPD operations. Early kick detection and annular pressure control are promoted as an essential part of MPD operations, but there can be confusion as to where the responsibility for well control lies. Does the responsibility remain with the drilling contractor and operator or with the provider of the MPD services. The paper provides some case studies where MPD and well control conflicted, causing a number of issues that in some cases led to the loss of wells.


2016 ◽  
Author(s):  
Z. Ma ◽  
A. Karimi Vajargah ◽  
A. Ambrus ◽  
P. Ashok ◽  
D. Chen ◽  
...  

2012 ◽  
Author(s):  
William Bacon ◽  
Albert Y. Tong ◽  
Oscar Roberto Gabaldon ◽  
Cathy Sugden ◽  
P.V. Suryanarayana

Author(s):  
Justin Parkhurst ◽  
Ludovica Ghilardi ◽  
Jayne Webster ◽  
Robert W Snow ◽  
Caroline A Lynch

Abstract This article explores how malaria control in sub-Saharan Africa is shaped in important ways by political and economic considerations within the contexts of aid-recipient nations and the global health community. Malaria control is often assumed to be a technically driven exercise: the remit of public health experts and epidemiologists who utilize available data to select the most effective package of activities given available resources. Yet research conducted with national and international stakeholders shows how the realities of malaria control decision-making are often more nuanced. Hegemonic ideas and interests of global actors, as well as the national and global institutional arrangements through which malaria control is funded and implemented, can all influence how national actors respond to malaria. Results from qualitative interviews in seven malaria-endemic countries indicate that malaria decision-making is constrained or directed by multiple competing objectives, including a need to balance overarching global goals with local realities, as well as a need for National Malaria Control Programmes to manage and coordinate a range of non-state stakeholders who may divide up regions and tasks within countries. Finally, beyond the influence that political and economic concerns have over programmatic decisions and action, our analysis further finds that malaria control efforts have institutionalized systems, structures and processes that may have implications for local capacity development.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 969
Author(s):  
Eric Cayeux ◽  
Benoît Daireaux ◽  
Adrian Ambrus ◽  
Rodica Mihai ◽  
Liv Carlsen

The drilling process is complex because unexpected situations may occur at any time. Furthermore, the drilling system is extremely long and slender, therefore prone to vibrations and often being dominated by long transient periods. Adding the fact that measurements are not well distributed along the drilling system, with the majority of real-time measurements only available at the top side and having only access to very sparse data from downhole, the drilling process is poorly observed therefore making it difficult to use standard control methods. Therefore, to achieve completely autonomous drilling operations, it is necessary to utilize a method that is capable of estimating the internal state of the drilling system from parsimonious information while being able to make decisions that will keep the operation safe but effective. A solution enabling autonomous decision-making while drilling has been developed. It relies on an optimization of the time to reach the section total depth (TD). The estimated time to reach the section TD is decomposed into the effective time spent in conducting the drilling operation and the likely time lost to solve unexpected drilling events. This optimization problem is solved by using a Markov decision process method. Several example scenarios have been run in a virtual rig environment to test the validity of the concept. It is found that the system is capable to adapt itself to various drilling conditions, as for example being aggressive when the operation runs smoothly and the estimated uncertainty of the internal states is low, but also more cautious when the downhole drilling conditions deteriorate or when observations tend to indicate more erratic behavior, which is often observed prior to a drilling event.


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