Riser Deployment and Hang-Off Analysis for a Harsh Environment, Deepwater Site

2004 ◽  
Author(s):  
Enda O’Sullivan ◽  
James N. Brekke ◽  
Michel Dib
Keyword(s):  
Decision Making ◽  
Deep Water ◽  
Drill String ◽  
Harsh Environment ◽  
Careful Attention ◽  
High Current ◽  
Retrieval Process ◽  
Heave Motion

In planning for a deepwater well, running/retrieval of a drilling riser in advance of rapidly developing seas was identified as a critical operation. The harsh seastates required careful attention to the well-specific operating criteria, (WSOC), or the metocean conditions that limit specific operations. Certain conditions would warrant the operation being shut down so that the riser could be pulled or run before conditions became excessive. In deep water, a running/retrieval operation can take several days and the consequences of being shut down part way can be severe. Moderately high current profiles can cause the riser to bind in the diverter housing, preventing further running or retrieval. If binding occurs, a dynamically-positioned vessel can carry out “drift running” operations to increase its operability. However, if conditions prohibit further running/retrieval, the riser may need to be hung off “hard” (with no compensation) at the drill floor or “soft” on the tensioners and/or drill string compensator. In such a case, in addition to large top riser angles, vessel heave motion can cause tension variation, depending on the hang-off conditions and the length of the deployed riser. This paper discusses how riser analysis was used to support the operational understanding of the riser running/retrieval process for this deepwater well. The results were used to assist in the planning and decision-making involved in drilling this well.

scholarly journals Feasibility Study of Selected Riser Concepts in Deep Water and Harsh Environment

2017 ◽  
Author(s):  
Gilang Muhammad Gemilang ◽  
Daniel Karunakaran
Keyword(s):  
Deep Water ◽  
Time History ◽  
Bending Moment ◽  
Harsh Environment ◽  
Steel Catenary Riser ◽  
Main Challenge ◽  
Large Motion ◽  
Touchdown Point ◽  
Heave Motion ◽  
Vessel Motion

One of the well-known riser systems, the Steel Catenary Riser (SCR), has been an attractive choice for the riser system in deep water. However, the main challenge of the SCR is large motions from the host platforms due to the harsh environment. The large motion of host platforms may induce excessive buckling and fatigue at the touchdown point. By screening the downward velocities at the hang-off point in the time history graph, the time at which the critical responses (i.e. buckling utilization, bending moment and compression) peak is identified. This study investigates the feasibility of the SCR configuration in terms of the capability to cope with the vessel motion. Several types of the SCR configurations are proposed in this study. The selected configurations of SCR in this study are conventional SCR, Weight Distributed SCR (WDSCR), and Steel Lazy Wave Riser (SLWR). The feasibility of the three riser configurations was analyzed in terms of strength and fatigue performance to understand the limitation of one over the other. The “lazy wave” configuration efficiently absorbs the vessel heave motions. Thereby the SLWR configuration is proven to be the most robust configuration to cope with large motion of the host platform. This study proves that although the SCR feasibility is limited due to vessel heave motion, innovative solutions can be established to extend its feasibility in order to cope with the vessel heave motion in harsh environment.

“ABCD” Implant Classification: A Comprehensive Philosophy for Treatment Planning in Completely Edentulous Arches

2020 ◽  
Vol 46 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Ali Tunkiwala ◽  
Udatta Kher ◽  
Nupur H. Vaidya
Keyword(s):  
Decision Making ◽  
Treatment Planning ◽  
Present Article ◽  
Treatment Plan ◽  
Bone Volume ◽  
Classification Systems ◽  
Decision Making Process ◽  
Careful Attention ◽  
Treatment Needs ◽  
Vital Parameters

A thorough and precise treatment plan that considers various factors such as age, availability of bone, interarch space for prosthesis design, smile line, lip support, patient desires, and economics is a necessity before implant surgery. Many previous classification systems for treatment planning in edentulous situations tend to focus on only a certain parameter such as esthetics, or available bone volume, or are specifically designed for the maxilla or mandible. The authors have proposed a simplified and universal ABCD classification that uses the 4 vital parameters of age, bone volume, cosmetic display, and degree of resorption to create an algorithm that satisfies the treatment needs of every patient. Various permutations of the 4 parameters can be used to arrive at a solution that streamlines the further phases of the rehabilitative process. The aim of the present article is to provide a science-driven approach to understand a patient's individual needs with careful attention to the interplay of all the aforementioned factors in the decision-making process.

Hydraulic Sytem for Wave Compensation of Deep-Water Exploration Ship

2012 ◽  
Vol 192 ◽  
pp. 201-206
Author(s):  
Zhi Xin Chen ◽  
Shuai Liu
Keyword(s):  
Deep Water ◽  
Structural Parameters ◽  
Dynamic Performance ◽  
Wire Rope ◽  
Transmission System ◽  
Compensation System ◽  
Work Condition ◽  
Extraction Equipment ◽  
The Stability ◽  
Heave Motion

In order to reduce the influence of the bench extraction equipment from the working deep-water exploration ship when it has swing or heave movement by wind and waves, according to the work condition and the structural parameters of 3000m deep-water exploration ship, Pump-controlled type and valve-controlled type hydraulic transmission system for waves compensation of deep-water exploration ship bench extraction equipment was researched through analysing and calculating. Wire rope which drags the bench is maintained appropriate tensioning status using this wave compensation system, when bench downs to the bottom of the sea. This system can bind and release wire rope to compensate for heave motion automatically, in order to keep the stability and security of the deep-water exploration ship before bench loading the bottom. Dynamic performance of wave compensation system is improved through controlling supplementation pressure and the accumulator parameters precisely.

A Consensus on the State of the Knowledge and Research Recommendations on the Fate and Effects of Deep Water Releases of Oil, Dispersants and Dispersed Oil

2014 ◽  
Vol 2014 (1) ◽  
pp. 225-237 ◽  
Author(s):  
Victoria Broje ◽  
Will Gala ◽  
Tim Nedwed ◽  
Joe Twomey
Keyword(s):  
Decision Making ◽  
Deep Water ◽  
Scientific Literature ◽  
American Petroleum Institute ◽  
The State ◽  
Oil Dispersants ◽  
Dispersed Oil ◽  
Application Decision ◽  
International Experts ◽  
Research Recommendations

ABSTRACT American Petroleum Institute (API) and its member companies have initiated a multi-year research program to generate information that can be used in subsea dispersant application decision-making. An important part of this program is the evaluation of biodegradation and toxicity of oil, dispersants and dispersed oil in a deepwater environment. The available scientific literature was reviewed by a panel of international experts in deepwater ecology, toxicology, microbiology, and petroleum chemistry, who summarized the state of the knowledge on these topics and recommended additional studies that would inform subsea dispersants decision-making. The recommended research projects have been funded by API. This paper summarizes findings to-date on toxicity and biodegradation of oil, dispersants and dispersed oil in deep water environments.

Development of a New On-Board Tool for Planning Drilling Riser Operations in High Current Environments

2007 ◽  
Author(s):  
Donogh W. Lang ◽  
Kieran Murphy ◽  
Michael Lane
Keyword(s):  
Accurate Determination ◽  
Fe Model ◽  
Simulation Tool ◽  
High Current ◽  
Retrieval Process ◽  
Drilling Rig ◽  
Drilling Rigs ◽  
Current Loading ◽  
Fully Coupled

With drilling and exploration occurring in ever deeper waters and harsh environmental conditions, the ability to properly plan critical operations such as deployment and retrieval of the drilling riser becomes increasingly important. Particularly in deepwater high current environments, deployment and retrieval operations can be limited by the length of time it takes to deploy or retrieve the riser and the danger of the riser joints binding in the diverter housing. These limitations can have significant impact on both operations and riser integrity. Drilling contractors have devised a number of means of conducting operations in high current environments in order to increase operational up-time and mitigate the risks involved. One approach is drift-running, where the drilling rig is positioned upstream of the well at the start of the deployment operation and the rig is allowed to drift in a controlled manner to the well as the riser is deployed. This procedure effectively reduces the current loading on the riser, thereby allowing the riser to be deployed without risk of binding in the diverter housing. This paper describes an on-board simulation tool designed for use on dynamically-positioned (DP) drilling rigs that can be used to plan deployment/retrieval and drift-running operations. The tool is a development of an on-board drift-off simulator that has been in operation on-board the latest generation of DP drillships for some time. The simulator uses a fully-coupled 3D finite element (FE) model of the riser system, thereby allowing accurate determination of the riser response to current loading. The simulator computes the angle of the riser in the diverter housing throughout the deployment/retrieval process. Additionally, the simulator can compute the optimum drift speed of the vessel to minimise the riser angle. Based on the results of these simulations, the on-board tool can determine the feasibility of deploying or retrieving the riser and can compute the required vessel track for carrying out drift-running operations. The tool allows on-board personnel to plan these operations using either prevailing or forecast metocean conditions. The key features of the on-board simulator are discussed, with particular emphasis on the procedure used to compute the drift-running track for the drilling rig during riser deployment. The benefits of the system in planning deployment/retrieval operations are illustrated by means of a number of case-studies.

scholarly journals Application of Sustainability Principles for Harsh Environment Exploration by Autonomous Robot

2019 ◽  
Vol 11 (9) ◽  
pp. 2518 ◽  
Author(s):  
Bausys ◽  
Cavallaro ◽  
Semenas
Keyword(s):  
Decision Making ◽  
Large Scale ◽  
Dynamic Decision Making ◽  
Autonomous Agent ◽  
Harsh Environment ◽  
Map Building ◽  
The European Union ◽  
Neutrosophic Sets ◽  
Environment Exploration ◽  
Sustainability Principles

Currently, the European Union (EU) is focusing on a large-scale campaign dedicated to developing a competitive circular economy and expanding the single digital market. One of the main goals of this campaign is the implementation of the sustainability principles in the development and deployment cycle of the new generation technologies. This paper focuses on the fast-growing field of autonomous mobile robots and the harsh environment exploration problem. Currently, most state-of-the-art navigation methods are utilising the idea of evaluating candidate observation locations by combining different task-related criteria. However, these map building solutions are often designed for operating in near-perfect environments, neglecting such factors as the danger to the robot. In this paper, a new strategy that aims to address the safety and re-usability of the autonomous mobile agent by implementing the economic sustainability principles is proposed. A novel multi-criteria decision-making method of Weighted Aggregated Sum Product Assessment—Single-Valued Neutrosophic Sets, namely WASPAS-SVNS, and the weight selection method of Step-Wise Weights Assessment Ratio Analysis (SWARA) are applied to model a dynamic decision-making system. The experimental evaluation of the proposed strategy shows that increased survivability of the autonomous agent can be observed. Compared to the greedy baseline strategy, the proposed method forms the movement path which orients the autonomous agent away from dangerous obstacles.

Aasta Hansteen Subsea Production System for Deep Water and Harsh Environment

2019 ◽  
Author(s):  
Severin Lindseth ◽  
Elling Røsby ◽  
Brynjar Vist ◽  
Knut Axel Aarnes
Keyword(s):  
Deep Water ◽  
Production System ◽  
Harsh Environment ◽  
Subsea Production System

New Approaches for Drilling Highly Depleted Reservoir in Deep Water Wells

2021 ◽  
Author(s):  
Ola Mohamed Balbaa ◽  
Hesham Mohamed ◽  
Sherif Mohamed Elkholy ◽  
Mohamed ElRashidy ◽  
Robert Munger ◽  
...  
Keyword(s):  
Deep Water ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Cost Effective ◽  
Drill String ◽  
Drilling Fluids ◽  
Prevention Measures ◽  
Enabling Factors ◽  
Design Changes ◽  
The Mediterranean

Abstract While drilling highly depleted gas reservoirs with a very narrow drilling window, Common drilling methods like utilizing loss of circulation pills, wellbore strengthening materials and managed pressure drilling (MPD) are being used in several reservoirs, yet it cannot be successful or cost effective if applied in a traditional manner. Innovative approaches to enable drilling wells in highly depleted reservoir in the Mediterranean deep water were adopted. The approaches incorporated design changes to the well and Bottom hole assembly (BHA), optimized drilling practices, and unconventional use of MPD while drilling and cementing production liner. Well design change in comparison to offset wells to allow drilling the reservoir in one hole section. Several design changes were considered in the BHA and drilling fluids to prevent as well as mitigate losses and differential sticking risks. From the BHA viewpoint, one of the key successful prevention measures was maximizing the standoff to reduce the contact area with the formation, this was achieved through utilizing spiral heavy wall drill pipe (HWDP) instead of drill collars in addition to a modeled placement of stabilizers and roller reamers. While on the drilling fluid side, Calcium carbonate material was added to strengthen wellbore, prevent losses and avoid formation damage. Particle size up to 1000 micron and concentration up to 40ppb was used to strengthen the depleted sands dynamically while drilling. Furthermore, as mitigation to stuck pipe, Jar and accelerator placement was simulated to achieve optimum impulse and impact force while maintaining the Jar above potential sticking zone. Whereas to address the consequence of a stuck pipe event, disconnect subs were placed in BHA to allow for recovering the drill string efficiently. MPD was first introduced in the Mediterranean in 2007 and continued to develop this well-known technique to mitigate various drilling challenges. For this well, MPD was one of the key enabling factors to safely drill, run and cement the production liner. Surface back pressure MPD allowed using the lowest possible mud weight in the hole and maintaining downhole pressure constant in order to manage the narrow drilling window between the formation pressure and fracture pressure (less than 0.4 ppg). MPD was also applied for the first time for running and cementing the production liner to prevent losses and achieve good cement quality which is a key to successful well production.

A Success Story of Critical Data Gathering During the Development Phase of Extreme ERD Well Drilling

2021 ◽  
Author(s):  
Atul Kumar Anurag ◽  
Adel Alkatheeri ◽  
Alvaro Sainz ◽  
Khalid Javid ◽  
Yaxin Liu ◽  
...  
Keyword(s):  
Decision Making ◽  
Real Time ◽  
Drill String ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Development Phase ◽  
Formation Pressure ◽  
Pressure Testing ◽  
Critical Data ◽  
Well Trajectory

Abstract This paper discusses a holistic combination of advanced formation evaluation techniques with pressure testing and reservoir navigation services to mitigate uncertainty related challenges in real time and successfully drill & place ERD laterals targeting Jurassic carbonate reservoirs. A meticulously planned approach to navigate the well trajectory by tracking the desired properties, informed decision-making while drilling and accurate data acquisition for aiding appropriate selection and placement in-flow control device (ICD) in lower completion design and future reservoir management contributed to the success of these complex wells in carbonate reservoirs. The first well in this study, involved drilling and evaluating a long lateral section as single oil producer targeting a carbonate reservoir. While no tar presence was expected, a combination of density, neutron porosity and nuclear magnetic resonance (NMR) logs while drilling resulted in identifying a deficit NMR porosity when compared to density porosity. Deployment of a formation pressure testing while drilling (FPWD) tool enabled measurement of the formation mobility and validate the presence of a tar. Using the same combination of measurements in the subsequent wells for delineating the tar enabled accurate planning of injection wells on the periphery of the field. Approximately 3 days were saved compared to the first well where the drill string had to be POOH to run-in with FPWD service. Hence, having FPWD tool in the same string helped in confirming the formation mobility in real time to call for critical decision making like changing the well trajectory or calling an early TD. Across all the wells drilled in this field, the formation pressure, mobility and porosity measurements provided valuable input for optimum ICD placement and design. Successful identification of unexpected tar resulted in substantial rig time savings, accurate planning of asset utilization and added confidence in design and placement of lower completions by utilizing LWD data. Benefits of integrated data and services combination became clear for applications involving advanced reservoir characterization and enhanced well placement in complex carbonate reservoirs. From the offset wells, a tar was seen in deeper formations but the integration of LWD NMR and mobility data from this well confirmed the presence of a tar within the zone of interest. The study established a cost-effective workflow for mitigating uncertainties related to tar encountered while drilling extreme ERD laterals in an offshore environment where any lost time results in significant increase in expenditures during the development phase. A systematic approach to tackle these uncertainties along with acquisition of critical data for the design & placement of completion results in optimum production from the reserves.

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