RAM analysis of dynamic positioning system: An approach taking into account uncertainties and criticality equipment ratings

Author(s):  
Maria V Clavijo ◽  
Adriana M Schleder ◽  
Enrique Lopez Droguett ◽  
Marcelo R Martins

Currently, a Dynamic Position (DP) System is commonly used for offshore operations. However, DP failures may generate environmental and economic losses; thus, this paper presents the Reliability, Availability and Maintainability (RAM) analysis for two different generations of DP system (DP2 and DP3) used in drilling operations. In addition to the RAM analysis, the approach proposed herein considers the uncertainties present in the equipment failure data and provides more information about criticality equipment ratings and probability density functions (pdf) of the repair times. The reliability analysis shows that, for 3 months of operation, the total failure probability of the DP2 system is 1.52% whereas this probability for the DP3 system is only 0.16%. The results reveal that the bus-bar is the most critical equipment of the DP2 system, whereas the wind sensor represents the priority equipment in the DP3 system. Using 90% confidence level, each DP configuration was evaluated for a 1-year operation, finding a reliability mean equal to 70.39% and 86.77% for the DP2 system and the DP3 system, respectively. The DP2 system asymptotic availability tends to present a constant value of 99.98% whereas for the DP3 system, it tends to be 99.99%. Finally, the maintainability analysis allows concluding that the mean time for system repair is expected to be 3.6 h. This paper presents a logical pathway for analysts, operators, and reliability engineers of the oil and gas industry.

Author(s):  
Grethe O. Ose ◽  
Trygve J. Steiro

Abstract Integrated operations (IO) is an ongoing change process in the oil and gas industry. New technological opportunities enable working in new ways that involve an integration of onshore and offshore personnel. This paper analyzes the results of two rounds of data gathering in an onshore drilling support center, in terms of the development of resilience. The first round took place in 2004/2005 and the second in 2012. This study presents a framework for the analysis of resilience and has used the case company as a mean of testing the framework. Our findings indicate that the support center has taken a huge step in the direction of becoming more resilient. The drilling company has tested a number of designs and sizes of support centers, each of which has different pros and cons. For the drilling discipline to develop resilience, it is essential that the number of rigs supported by a center is not too large, as they must not become involved in too many rigs and drilling operations. Our findings also indicate that the suggested framework provides a good overall picture of the development of resilience in the case company.


Author(s):  
Ricardo de Lepeleire ◽  
Nicolas Rogozinski ◽  
Hank Rogers ◽  
Daniel Ferrari

Within the oil and gas industry, significant costs are often incurred by the operating company during the well-construction phase of drilling operations. Specifically, the operators cost to drill a well can cost tens or hundreds of millions of USD. One specific area where significant changes in drilling operations have occurred is in the offshore environment, specifically operations from mobile offshore drilling units (MODUs). With the ever-increasing demand for oil and gas, operators globally have increased drilling budgets in an effort to meet forecasted demand. However, the increased budgets are often eroded or offset by increasing drilling costs. Therefore, operators are continually in search of new technology, processes, or procedures to help improve drilling operations and overall operational efficiencies. One Latin America operator identified a common operation as a possible area where operational cost could be easily reduced through the implementation of systems that allow the manipulation of valve manifolds remotely. Additionally, operating such valve manifolds remotely enhanced operational safety for personnel, which was an equally important consideration. This paper details the evaluation of existing equipment and procedures and a process used to develop a new remote-control system using a machine logic control (MLC) that has been designed, built, tested, and deployed successfully on MODUs operating in Latin America.


Author(s):  
Zhenqiu Fu ◽  
Wei Li ◽  
Hao Sun ◽  
Meng Yuan ◽  
Xin Li ◽  
...  

Abstract In general, the lifetime of the offshore oil and gas platform is about 20–30 years, and a large number of oil and gas platforms is approaching the end of their service. So, how to decommission these oil and gas platforms safely and cleanly becomes an urgent problem for the oil and gas industry and related organizations. And the costs for decommissioning equipment and services are expected to be as low as possible. It is important to develop the innovative removal techniques to reduce the overall cost of decommissioning. In this paper, we propose a new concept to remove large and heavy structures with a single lift, utilizing three semi-submerged vessels. The main process of the twin-lift solution for decommissioning includes two semi-submerged vessels lifting the topside together, and then carrying the topside to the third semi-submerged vessel. This method is simple in principle and does not require the manufacture of new special vessels, only needs to make simple modifications to existing semi-submerged vessels. It requires high positioning accuracy especially under environmental disturbances to ensure the safety of transportation. To ensure efficiency and safety, we develop a dynamic positioning (DP) system and perform a wave tank test for such a twin-lift decommissioning solution. Some aspects of an experimental facility set-up for scaled model test with dynamic positioning system are described. It includes the topology of the experiment and details of the deck mating, DP and monitoring system.


2019 ◽  
Vol 11 (1) ◽  
pp. 200 ◽  
Author(s):  
Ali Al-Hemoud ◽  
Ali Al-Dousari ◽  
Raafat Misak ◽  
Mane Al-Sudairawi ◽  
Adil Naseeb ◽  
...  

There is a lack of published research on the economic effect and the risk associated with sand and dust storms (SDS) worldwide. The objectives of this study are to estimate the economic impact of SDS on the oil and gas industry in Kuwait, to estimate a risk index for each loss, and to recommend a sustainable system for the mitigation of the damaging effects and economic losses of infrastructures. Hot spots of wind erosion, wind corridors, and dust frequency and severity formed the basis to locate the most susceptible oil and gas fields and operations. Ten sectors with potential loss vulnerabilities were evaluated: exploration, drilling, production, gas, marine, soil remediation, project management, water handling, maintenance, and research and development. Sand encroachment, although not a sector per se, was also considered. The results indicate that sand, and to lesser extent dust, are damaging and costly to the oil and gas infrastructure of Kuwait, with an economic cost estimation of US$9.36 million, a total of 5159 nonproductive lost hours, and 347,310 m3 of annual sand removal. A risk assessment identified three sectors with the highest risk indices (RI): drilling (RI = 25), project management (RI = 20), and maintenance (RI = 16). Sand encroachment also constituted a high risk (RI = 25). Mitigation of sand storms using a hybrid biological–mechanical system was shown to be cost-effective with an equivalent saving of 4.6 years of sand encroachment. The hazard implications of sand storm events continue to be a major concern for policy-makers given their detrimental economic impacts, and require that government officials wisely allocate investment budgets to effectively control and mitigate their damaging effects.


2021 ◽  
Vol 11 (5) ◽  
pp. 2157-2178
Author(s):  
David Oluwasegun Afolayan ◽  
Adelana Rasak Adetunji ◽  
Azikiwe Peter Onwualu ◽  
Oghenerume Ogolo ◽  
Richard Kwasi Amankwah

AbstractSuccessful drilling operations are dependent on the properties of the drilling fluid used to drill wells. Barite is used as a weighting agent during the preparation of drilling fluid. Over the years, oil and gas industry in Nigeria has been depending mainly on imported barite for drilling operations, whereas the country has huge deposits of barite. There is the need to assess the properties of the locally sourced barite for their suitability in drilling fluid formulation. This study presents the local processing methods of barite and examines the crude and on-the-site processed barite’s physio-chemical properties. These parameters were compared with American Petroleum Institute and Department of Petroleum Resources standards. XRD results show that on-the-site beneficiated barite has 87.79% BaSO4, 6.66% silica, 0.03% total soluble salt, 1.39% Fe2O3, and 1.603% heavy metals. Chemical analysis indicated that the pH, moisture content, metallic content such as Ca, Pb, Zn, Mg, Cu, and Cd minerals, and extractable carbonates were within the standard specified for usage as a drilling fluid weighting agent. The analysed crude barite samples were basic, within the pH of 8.3 and 8.6. Locally processed barite has lower Fe, Pb, Cd, and Cu content compared to industrially accepted barite. The specific gravity increased from 4.02 ± 0.07 to 4.15 ± 0.13, and the hardness reduced potentially from 5 Mohr to 3.5 Mohr on the hardness scale. The amount of impurities was sufficiently low, and the specific gravity of the samples improved to meet the needs of any drilling operation and compare favourably with industrially accepted barite.


2021 ◽  
Author(s):  
Mario A. Rivas ◽  
Andres A. Ramirez ◽  
Bader S. Al-Zahrani ◽  
Khaled K. Abouelnaaj

Abstract One of the major challenges the Oil and Gas Industry faces nowadays during drilling operations is the twist-offs on Bottom Hole Assembly (BHA) components such as Drilling Jars, Shock Tools, Mud Motors, Roller Reamers, Stabilizers, Drill Collars, PBLs, Heavy Weight Drill Pipe (HWDP), Drill Pipe (DP), etc. To overcome this challenge, an initiative was proposed by performing a study based on twist-offs experienced on BHA components while drilling operations and recommendations are provided to reduce and eliminate twist-offs related to drilling with suboptimal drilling parameters. The statistical data for the twist-off events was collected coming from Daily Drilling Reports, and the analysis was limited to all wells which presented twist-offs on the drillstring and BHA components. Three examples of twist-offs due to drilling with erratic torque are discussed as well as a successful example of drilling parameters optimization. The three examples which presented drillstring and BHA twist-offs were analyzed using available BHA Dynamics and vibrations software and it was discovered that the parameters utilized (operational RPM) fell within the critical zone shearing force peaks (resonance vibrations). The components with the most twist-offs were identified. The hole size where we have the most twist-offs were also identified, which will help in focusing on these areas for the recommendations provided. This analysis will help Drilling Engineers and Foremen to foresee vibration dysfunctions and act accordingly by the use of available BHA Dynamics software in order to optimize drilling parameters before and during drilling. By drilling within a safe operating RPM window (away from resonant RPM), there will be reduction in the number of twist-offs and associated lost time.


2011 ◽  
Vol 488-489 ◽  
pp. 670-673 ◽  
Author(s):  
Marin Petrović ◽  
Alojz Ivanković ◽  
Neal Murphy

Polycrystalline diamond (PCD) materials have a variety of applications, mainly as cutting tools for machining non-ferrous metals and non-metallic materials. A significant application of PCD is in oil and gas industry for rock drilling operations. Other important areas, such as mining, have yet to reach their full potential. These cutters/tools are subjected to high operating temperatures, impact loads and abrasive wear during these operations, which may lead to their sudden failure. An advantage of these materials is that their structure and composition can be engineered to return properties required for specific applications and operations.


Author(s):  
Svein Herman Nilsen ◽  
Massimiliano Russo ◽  
Guttorm Grytøyr

Over the last decades, the complexity and duration of offshore drilling operations have steadily increased. The size and weight of the risers and BOP stack has grown significantly. These factors have led to an increase in fatigue loads imposed on the wellhead structures during drilling and completion operations. Wellhead fatigue might ultimately lead to loss of well structural integrity and pressure containment and therefore safe and reliable drilling of subsea wellheads has gained high priority in the global oil and gas industry. This paper presents two of the most complex real time instrumentation campaigns for drilling operations. Analyses of a connected drilling riser system including the well structure are complex and involve several engineering disciplines. In addition, there are many unknowns going into the equations when accumulated fatigue damage of the wellhead is estimated. Therefore, assumptions need to be made, very often on the conservative side. A typical example are the global drilling riser analyses where the environmental conditions, actual rig motion and riser / BOP behavior are uncertain. With the duplex scope of accurately documenting the wellhead fatigue status during drilling operations and of achieving a better understanding of the actual risk level of wellhead fatigue, Statoil decided to start a very comprehensive monitoring campaign. Two MODU representing very different generations of rigs in terms of weights and types of equipment were instrumented from topside to BOP connector. Strain gauges were installed around the BOP connector as close as possible to the wellhead in order to capture wellhead response as accurately as possible. Due to the large number of sensors, high accuracy requirement and high sampling frequency of data to be shown live, a cabled solution was selected vs remote battery operated sensors transmitting via acoustic. Double set of cables, sensors and topside equipment were installed in order to make the instrumentation system fully redundant and suited for permanent installation. All data were additionally made available real time onshore to allow the full overview of the operation. To author’s knowledge, these two instrumentation systems are the most comprehensive and complex of this type installed on a drilling riser as of today. The first of the two system was installed approximately three years ago and it is still in operation. This paper describes the instrumentation systems installed and gives an extract of the quality data extracted and already used in already published studies [1, 2, 3].


Author(s):  
Hamidreza Ahmadimoghaddamseighalani ◽  
Pierre Mertiny

Kelly valves, also known as full opening safety valves, are widely used in the oil and gas industry for the purpose of blowout prevention. Crack propagation in the stem hole feature of Kelly valves is of concern during service in drilling operations as fatigue may lead to catastrophic failure. A computational tool to predict the fatigue life of these valves when a crack is present was therefore created. The present paper describes the numerical modeling approach in which an elliptical crack in the stem hole feature was introduced. To predict the fatigue life of the valve based on the J-integral method, ANSYS Workbench was used for a FEA analysis in conjunction with Microsoft EXCEL and Iron Python programming.


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