Lazy-Wave Buoyancy Length Reduction Based on Fatigue Reliability Analysis

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Vinícius Ribeiro Machado da Silva ◽  
Luis V. S. Sagrilo ◽  
Mario Alfredo Vignoles
Keyword(s):  
Reliability Analysis ◽  
Cost Reduction ◽  
Structural Reliability ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Fatigue Reliability ◽  
Gas Industry ◽  
Deep Waters ◽  
Sea Bed ◽  
Length Reduction

The current downturn of the oil and gas industry force managers to take hard decisions about the continuity of projects, resulting in delays, postponements, or even their cancellation. In order to keep with them, the rush for cost reduction is a reality and the industry is pushing the involved parties to be aligned with this objective. The Brazilian presalt region, characterized by ultra-deep waters, faces this scenario where flexible risers in lazy-wave configurations are usually adopted as a solution to safe transfer fluids from sea bed until the floating unit. The smaller the buoyancy length, the cheaper the project becomes, reducing the necessary amount of buoys and the time spent for its installation. This paper investigates the possibility of buoyancy length reduction of lazy-wave configurations by using structural reliability methods on fatigue failure mode. The application of the fatigue reliability approach considers four 6 in flexible riser configurations: an original lazy-wave, a lazy-wave with less 30% of buoyancy length, another one with less 50% of buoyancy length and a free-hanging. Failure probabilities and safety factor calibration curves are shown for each configuration and compared among themselves. The results indicate the possibility of defining a lazy-wave configuration with smaller buoyancy lengths, reaching 75% of reduction without changing the preconized high safety class. Structural reliability analysis is available to help engineers understand the driving random variables of the problem, supporting the actual scenario of cost reduction for better decision-making based on quantified risk.

Lazy-Wave Buoyancy Length Reduction Based on Fatigue Reliability Analysis

2017 ◽  
Author(s):  
Vinícius Ribeiro Machado da Silva ◽  
Luis V. S. Sagrilo ◽  
Mario Alfredo Vignoles
Keyword(s):  
Reliability Analysis ◽  
Safety Factor ◽  
Cost Reduction ◽  
Structural Reliability ◽  
Oil And Gas ◽  
Random Variables ◽  
Oil And Gas Industry ◽  
Potential Method ◽  
Fatigue Reliability ◽  
Length Reduction

When the profit scenario of an industry changes, the continuity of some projects can be at risk. The current downturn of the oil and gas industry force managers to take hard decisions about the continuity of projects, resulting in delays, postponements or even the cancellation of forecasted projects. In order to keep with these projects, the rush for cost reduction is a reality and the industry is pushing the involved parties to be aligned with this objective. The Brazilian Pre-Salt region, characterized by ultra-deep waters, is an example of this scenario. Subsea structures represented by flexible risers, which are responsible for the flow assurance of oil, gas and water, are forecasted to have a demand about 4.000 km in the next years. Usually, in these type of applications, lazy-wave configurations are adopted, increasing the costs of the solution with the necessity of the buoyancy modules acquisition. The smaller the buoyancy length is the cheaper the project become, reducing the necessary amount of buoys and the time spent for its installation. These type of solutions can probably carry with it a high level of conservatism, imposed by the use of standardized safety factors, and can potentially be optimized with the adoption of probabilistic approaches within the chain of analysis. The objective of this paper is to assess the possibility of buoyancy length reduction of lazy-wave configurations by using structural reliability methods of analysis. The focus stays on the evaluation of the fatigue of the armour wires located at the bend stiffener region, one of the most critical failure mode for the design of flexible pipes in offshore Brazilian installations. As already discussed in Ref. [1], many variables can influence on such kind of analysis. Based on this previous study, the first six random variables, identified to be the most important ones, are taken to carry out the analysis. The fatigue reliability approach considers four 6” flexible riser configurations: an original lazy-wave, a lazy-wave with less 30% of buoyance length, another one with less 50% of buoyance length and a free-hanging configuration. Failure probabilities and safety factor calibration curves are shown for each presented configuration and compared among themselves. The results indicate the possibility of defining a lazy-wave configuration with smaller buoyancy lengths, reaching 75% of reduction without changing the preconized high safety class at last year of its operational time. Safety factor curves shows to have similar behavior no matter the configuration considered. Structural reliability analysis comes as a potential method to help engineers to have a better understanding on the driving random variables of the problem, giving a support for the actual cost reduction scenario and for better decision-makings based on quantified risk.

Pipeline Material Reliability Analysis Regarding to Probability of Failure Using Corrosion Degradation Model

2011 ◽  
Vol 422 ◽  
pp. 705-715 ◽  
Author(s):  
Patuan Alfon ◽  
Johny W. Soedarsono ◽  
Dedi Priadi ◽  
S Sulistijono
Keyword(s):  
Reliability Analysis ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Probability Of Failure ◽  
Distribution Method ◽  
Gas Industry ◽  
Internal Corrosion ◽  
Corrosion Failure ◽  
Calculation Results ◽  
External Corrosion

Reliability of equipment of the oil and gas industry is vital, whereas on pipeline transmission system, decreasing the integrity of the pipeline is generally caused by corrosion. Failure that occurs due to corrosion deterioration influenced by the environment within a certain time, and has exceeded the nominal thickness of the pipe so there is a failure. This study used the reliability analysis approach based on modeling corrosion degradation ratio that is determined by the amount of the corrosion rate externally and internally. Using the Weibull probabilistic distribution method, results that the reliability of pipeline will decrease with increasing lifetime. It was identified that internal corrosion has a major contribution to the remaining life of pipeline. From the calculation results obtained by external corrosion has the greatest reliability over 60 years, followed by internal corrosion less than 30 years and the least is by cumulative corrosion which is less than 20 years. From the value of reliability, it can be known probability of failure (POF) which is the anti reliability.

International Geomechanics Symposium a success

2021 ◽  
Vol 40 (2) ◽  
pp. 152-153
Author(s):  
Gang Han ◽  
Abdulaziz Mansour ◽  
Mohammed Badri ◽  
Tariq Mahmood
Keyword(s):  
Rock Mechanics ◽  
Value Chain ◽  
Cost Reduction ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Modeling Simulation ◽  
Efficiency Cost ◽  
Improved Performance

As the oil and gas industry is striving for efficiency, cost reduction, and improved performance across the value chain, integrated workflows that combine various disciplines into subsurface drilling, characterization, and production have become increasingly important. Geomechanics is gaining stronger ground as a vital tool in modeling, simulation, and operations. Given its importance, the American Rock Mechanics Association, Dhahran Geoscience Society, and Society of Exploration Geophysicists cohosted the International Geomechanics Symposium. The event was conducted virtually 3–5 November 2020.

Collapse Propagation of Deep Water Pipelines

2017 ◽  
Author(s):  
Ana Paula França de Souza ◽  
Rafael F. Solano ◽  
Fabio B. de Azevedo ◽  
Erwan Karjadi ◽  
Caroline Ferraz
Keyword(s):  
Wall Thickness ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
External Pressure ◽  
External Diameter ◽  
Gas Industry ◽  
Deep Waters ◽  
Water Pipelines ◽  
Offshore Oil And Gas ◽  
Pipeline Design

Nowadays, the global trend is an increasing need for oil and gas. As the easily recoverable fields have been already developed, the trend in the offshore oil and gas industry is going deeper into the more challenging outlook, such as outside West Africa, the Brazilian Pre-Salt developments and in the Gulf of Mexico. For ultra-deep waters the main design challenge is related to the high external pressure that may cause collapse of pipelines. This potential failure mode is normally dealt with by increasing the pipe wall thickness, but at ultra-deep waters this may require very thick pipe that becomes very costly, difficult to manufacture and hard to install due to its weight. Facing the challenges of the pipeline design for ultra-deep waters, the Collapse Joint Industry Project (JIP) was started to develop a guideline for wall thickness design optimization for offshore pipelines with external diameter to wall thickness ratio less than 20 (D/t < 20). As part of the JIP, nine buckle propagation tests were conducted on full scale seamless pipes. This paper describes these experiments and new conclusions that were raised in light of the test results.

Cost Optimization in Mega Oil & Gas Projects

2021 ◽  
Author(s):  
Mohamed Ali Awwad ◽  
Ahmed Marei Al Radhi ◽  
Manoj Kumar Panigrahy ◽  
Suraj Kumar Gopal
Keyword(s):  
Life Cycle ◽  
Project Management ◽  
Cost Reduction ◽  
Oil And Gas ◽  
Life Experience ◽  
Continuous Process ◽  
Cost Optimization ◽  
Real Life ◽  
Oil And Gas Industry ◽  
Gas Industry

Abstract Cost optimization is a continuous process in any business to drive cost reduction, while maximizing business value. Currently, cost reduction is being adopted by Oil & Gas firms as a core strategy, in order to maximize the profit margin. With global economies facing recession and wide fluctuations in energy demands, it seems low costs is becoming the safety valve for Oil & Gas companies. The oil and gas industry is under tremendous revenue and costs pressures. The indication is that globally, the oil and gas industry has experienced a huge drop in revenue in recent past. Some exploration and production oil firms have either halted or slowed down their production operations. Companies that manage their costs effectively will gain a competitive advantage. The oil market has less maneuverability with oil cartels determining the international price of oil. Project Costs are the major cost drivers of the Life Cycle costing & so Cost optimization of all mega Oil & Gas Projects became necessitated. Mega Oil & Gas projects, especially at ADNOC Offshore locations, are complex, labor-intensive and located inside Arabian Sea. These workforces are mainly from south Asian countries and so offshore sites are often subjected to the constraints of insufficient labor. These projects face multiple challenges in project management like severe weather, geographical conditions, insufficient work spaces etc. in addition to labor forces. Cost reductions are accomplished through optimization of its strong and robust project management organization, management of uncertainties, high quality engineering, and implementation of value engineering during engineering, procurement, construction and commissioning (EPCC) phases and effective management of changes along with key Stakeholders expectations throughout the project life cycle. This paper is based on the authors’ real life experience in implementation of many complex and mega upstream Oil & Gas projects with ADNOC Offshore who is currently leading multiple projects at DAS & Zirku islands. The most workable methods in this regard are listed here below.

scholarly journals Effect of Frequency on Hydrocarbon (HC) Detection Using 3D Finite Integral Modeling

2012 ◽  
Vol 326-328 ◽  
pp. 654-661 ◽  
Author(s):  
Hanita Daud ◽  
Majid Niaz Akhtar ◽  
Noorhana Yahya ◽  
Nadeem Nasir ◽  
Hasan Soleimani
Keyword(s):  
Magnetic Fields ◽  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Hydrocarbon Reservoirs ◽  
Constant Current ◽  
Gas Industry ◽  
Sea Bed ◽  
Electric And Magnetic Fields ◽  
Deep Target ◽  
Target Depth

Detection of hydrocarbon in sea bed logging (SBL) is still a very challenging task for deep target reservoirs. The response of electromagnetic (EM) field from marine environment is very low and it is very difficult to predict deep target reservoirs below 2500 m from the sea floor. Straight antennas at 0.125 Hz and 0.0625 Hz are used for the detection of deep target hydrocarbon reservoirs below the seafloor. The finite integration method (FIM) is applied on 3D geological seabed models. The proposed area of the seabed model (16 km ×16 km) was simulated by using CST (computer simulation technology) EM studio. The comparison of different frequencies for different target depths was done in our proposed model. Total electric and magnetic fields were applied instead of scattered electric and magnetic fields, due to its accurate and precise measurements of resistivity contrast at the target depth up to 3000 m. From the results, it was observed that straight antenna at 0.0625 Hz shows 50.11% resistivity contrast at target depth of 1000 m whereas straight antenna at 0.125 Hz showed 42.30% resistivity contrast at the same target depth for the E-field. It was found that the E-field response decreased as the target depth increased gradually by 500 m from 1000 m to 3000 m at different values of frequencies with constant current (1250 A). It was also investigated that at frequency of 0.0625 Hz, straight antenna gave 7.10% better delineation of hydrocarbon at 3000 m target depth. It was speculated that an antenna at 0.0625 Hz may be able to detect hydrocarbon reservoirs at 4000 m target depth below the seafloor. This EM antenna may open a new frontier for oil and gas industry for the detection of deep target hydrocarbon reservoirs below the seafloor.

Deployment of Digital NDT Solutions in the Oil and Gas Industry

2020 ◽  
Vol 78 (7) ◽  
pp. 861-868
Author(s):  
Casper Wassink ◽  
Marc Grenier ◽  
Oliver Roy ◽  
Neil Pearson
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Gas Industry

What Does Rent Give to Federal Budget (on the Russia's Budget Dependence upon "Oil Dollars")

2004 ◽  
pp. 51-69 ◽  
Author(s):  
E. Sharipova ◽  
I. Tcherkashin
Keyword(s):  
Oil And Gas ◽  
Strong Dependence ◽  
Oil Prices ◽  
Federal Budget ◽  
Oil And Gas Industry ◽  
Gas Industry ◽  
Resource Rent ◽  
Tax Legislation ◽  
Russian Economy ◽  
The Government

Federal tax revenues from the main sectors of the Russian economy after the 1998 crisis are examined in the article. Authors present the structure of revenues from these sectors by main taxes for 1999-2003 and prospects for 2004. Emphasis is given to an increasing dependence of budget on revenues from oil and gas industries. The share of proceeds from these sectors has reached 1/3 of total federal revenues. To explain this fact world oil prices dynamics and changes in tax legislation in Russia are considered. Empirical results show strong dependence of budget revenues on oil prices. The analysis of changes in tax legislation in oil and gas industry shows that the government has managed to redistribute resource rent in favor of the state.

Sign in / Sign up

Export Citation Format

Share Document