Fitness-for-Service Assessment Approach for Ageing Pipeline Section Based on Sparse Historical Data

2021 ◽  
Vol 12 (01) ◽  
pp. 2150001
Author(s):  
Tahereh Naraghi ◽  
Mehdi F. Najib ◽  
Ali S. Nobari ◽  
Kamran Nikbin
Keyword(s):  
Oil And Gas ◽  
Historical Data ◽  
Mean Value ◽  
Evaluation Methodology ◽  
Metal Loss ◽  
Material Degradation ◽  
Failure Data ◽  
Metallurgical Analysis ◽  
Oil Pipelines ◽  
Assessment Approach

Fitness-for-service (FFS) assessment is a common evaluation methodology in oil and gas industries to assess the integrity of in-service structures that may contain flaws, metal thinning and pitting damage. However, given the level of unknowns or missing information in the industry deterministic predictions are unacceptable and invariably the lower bound values could also be substantially conservative. The aim of this work is to develop a generic process to ensure, within a level of confidence, the operational safety and integrity of aging gas or oil pipelines sections based on available data. Fitness for service procedure according to “API 579-1/ASME FFS-1” is performed using local metal loss and micro-cracking to predict a range of safe life for the ageing pipeline operated for around 40 years. The mean value predictions of the present assessment indicate that the flaws away from the weld are within an acceptable boundary which implies the pipes would be fit to continue in operation and at least have 10 years remaining life, whilst the flaws near the weld need to be repaired as soon as possible. This is based on the best average values for the NDE and material property results available. However, adopting extreme caution in the analysis will render the pipes obsolete and ready for replacement. Understanding the risks to be taken in such situations becomes an expert system decision based not just on the FFS analysis but on both quantitative historical data, loading history, material degradation due to environment, corrosion rates and metallurgical analysis in addition to qualitative experience collected from other databases and pipes failure data. Beyond such a procedure the safe option would be a full burst pressure testing of the length of pipeline in question to identify possible leaks of old pipes.

Fitness for Service Assessment of Cross Country Oil Pipelines Based on API 579 (Application of API 579 on ASME B 31.4)

2019 ◽  
Author(s):  
Pradeep Purnana ◽  
Shiyas Ibrahim
Keyword(s):  
Oil And Gas ◽  
Internal Surface ◽  
Life Assessment ◽  
Metal Loss ◽  
Complex Method ◽  
General Corrosion ◽  
Loss Assessment ◽  
Oil Pipelines ◽  
Corrosion Defects ◽  
Cross Country

Pipelines are one of the safest forms of transportation for oil and gas. However, Pipelines may experience defects, such as corrosion, cracks during service period. Therefore, evaluation of these defects is very important in terms of assessment and for continued safe operation. Corrosion defects at the external surface of pipelines are often the result of fabrication faults, coating or cathodic protection issues, residual stress, cyclic loading, temperature or local environment (soil chemistry). In general, corrosion may occur in most pipes due to coating failure, and a pipe without any protective coating will experience external corrosion after some years. However, corrosion can occur on the internal surface of the pipeline due to contaminants in the products such as small sand particles. At present, there are different assessment methods for different types of defects in pipelines. The most popular codes for defect assessment in oil and gas pipelines are RSTRENG, Modified B31G, BS 7910 and API 579. Besides these codes and methods, there are numerical programs, such as CorLAS, which have been used successfully for assessing crack flaws in Pipelines. RSTRENG and B 31G methods are very simple when compared with API 579. API 579 is very complex method of assessing defects but very useful for remaining life assessment of Pipelines. In this paper corrosion defects like general metal loss, localized metal loss, pitting corrosion, other defects like dents, gouges, cracks, their remediation methods assessed based on API 579 method and our experience in Oil Pipelines. Since API 579 doesn’t cover cross country pipelines explicitly, we have made a research applying API 579 to ASME B31.4. Even though, we have done research on all types of defects (Level 1 and Level 2 assessment), in this paper we have covered only General metal loss assessment.

A Novel Corrosion Monitoring and Prediction System Utilizing Advanced Artificial Intelligence

2021 ◽  
Author(s):  
Klemens Katterbauer ◽  
Waleed Dokhon ◽  
Fahmi Aulia ◽  
Mohanad Fahmi
Keyword(s):  
Real Time ◽  
Oil And Gas ◽  
Salt Water ◽  
Oil And Gas Industry ◽  
Training Dataset ◽  
Metal Loss ◽  
Corrosion Monitoring ◽  
Prediction System ◽  
Well Performance ◽  
Data Driven Approach

Abstract Corrosion in pipes is a major challenge for the oil and gas industry as the metal loss of the pipe, as well as solid buildup in the pipe, may lead to an impediment of flow assurance or may lead to hindering well performance. Therefore, managing well integrity by stringent monitoring and predicting corrosion of the well is quintessential for maximizing the productive life of the wells and minimizing the risk of well control issues, which subsequently minimizing cost related to corrosion log allocation and workovers. We present a novel supervised learning method for a corrosion monitoring and prediction system in real time. The system analyzes in real time various parameters of major causes of corrosion such as salt water, hydrogen sulfide, CO2, well age, fluid rate, metal losses, and other parameters. The data are preprocessed with a filter to remove outliers and inconsistencies in the data. The filter cross-correlates the various parameters to determine the input weights for the deep learning classification techniques. The wells are classified in terms of their need for a workover, then by the framework based on the data, utilizing a two-dimensional segmentation approach for the severity as well as risk for each well. The framework was trialed on a probabilistically determined large dataset of a group of wells with an assumed metal loss. The framework was first trained on the training dataset, and then subsequently evaluated on a different test well set. The training results were robust with a strong ability to estimate metal losses and corrosion classification. Segmentation on the test wells outlined strong segmentation capabilities, while facing challenges in the segmentation when the quantified risk for a well is medium. The novel framework presents a data-driven approach to the fast and efficient characterization of wells as potential candidates for corrosion logs and workover. The framework can be easily expanded with new well data for improving classification.

An Innovative Approach for Pipeline Repairs

2002 ◽  
Author(s):  
Don Robertson ◽  
Wayne Russell ◽  
Nigel Alvares ◽  
Debra Carrobourg ◽  
Graeme King
Keyword(s):  
Relational Databases ◽  
Cost Effective ◽  
Metal Loss ◽  
Final Report ◽  
Integrity Assessment ◽  
Maintenance Program ◽  
Oil Pipelines ◽  
New Methodologies ◽  
Reduced Costs

A strategic combination of integrity software, relational databases, GIS, and GPS technologies reduced costs and increased quality of a comprehensive pipeline integrity assessment and repair program that Greenpipe Industries Ltd. completed recently on three crude oil pipelines—two 6-inch and one 8-inch—for Enbridge Pipelines (Saskatchewan) Inc. Greenpipe analyzed metal loss data from recent in-line inspection logs, calculated real-world coordinates of defects and reference welds, prioritized anomalies for repair taking environmental risks into account, and prepared detailed dig sheets and site maps using PipeCraft™, Greenpipe’s advanced GIS-based pipeline integrity-maintenance software package. GPS technology was used to navigate to dig sites and the accuracy of the GPS approach was compared with traditional chainage methods. Pipelines were purged and all defects were cut out and replaced by new pipe during a two-day shutdown on each pipeline. A comprehensive set of data, including high-accuracy GPS location of anomalies, reference welds, and replacement pipe welds, was collected at each dig site and entered into the PipeCraft relational database. After all repairs were completed, the client was provided with a GIS-based electronic final report, allowing point-and-click access to all data collected in the field, including in-line inspection logs, dig information sheets and as-built drawings. The new methodologies employed on this project resulted in a high quality, comprehensive and cost-effective integrity maintenance program.

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

2021 ◽  
pp. 1748006X2110518
Author(s):  
Maria V Clavijo ◽  
Adriana M Schleder ◽  
Enrique Lopez Droguett ◽  
Marcelo R Martins
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Economic Losses ◽  
Gas Industry ◽  
Dynamic Positioning System ◽  
Failure Data ◽  
Total Failure ◽  
Drilling Operations ◽  
Maintainability Analysis ◽  
Ram Analysis

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.

Effectiveness of Ultraviolet Light For Mitigating Risk of Microbiologically Influenced Corrosion in Steel Pipeline

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
M. K. F. M. Ali ◽  
N. Md. Noor ◽  
N. Yahaya ◽  
A. A. Bakar ◽  
M. Ismail
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Microbiologically Influenced Corrosion ◽  
Metal Loss ◽  
Desulfovibrio Vulgaris ◽  
Pipeline System ◽  
Long Distance ◽  
Gas Industry ◽  
Internal Corrosion ◽  
Steel Pipeline

Pipelines play an extremely important role in the transportation of gases and liquids over long distance throughout the world. Internal corrosion due to microbiologically influenced corrosion (MIC) is one of the major integrity problems in oil and gas industry and is responsible for most of the internal corrosion in transportation pipelines. The presence of microorganisms such as sulfate reducing bacteria (SRB) in pipeline system has raised deep concern within the oil and gas industry. Biocide treatment and cathodic protection are commonly used to control MIC. However, the solution is too expensive and may create environmental problems by being too corrosive. Recently, Ultraviolet (UV) as one of the benign techniques to enhance mitigation of MIC risk in pipeline system has gained interest among researchers. An amount of 100 ml of modified Baar’s medium and 5 ml of Desulfovibrio vulgaris (strain 7577) seeds was grown in 125 ml anaerobic vials with carbon steel grade API 5L-X70 coupons at the optimum temperature of 37°C and pH 9.5 for fifteen days. This was then followed by exposing the medium to UV for one hour. Results from present study showed that UV radiation has the ability to disinfect bacteria, hence minimizing the risk of metal loss due to corrosion in steel pipeline. 

Development of Risk-Based Inspection Methodology in River Crossings

2017 ◽  
Author(s):  
Eduardo Lopes de Paula ◽  
Markus Moratti ◽  
Eduardo Henrique da Silva Rodrigues ◽  
Elivelton Pinheiro Scherrer
Keyword(s):  
Oil And Gas ◽  
Management Program ◽  
Third Party ◽  
Evaluation Methodology ◽  
Control Actions ◽  
Hydrological Hazards ◽  
Static And Dynamic Loads ◽  
Set Up ◽  
Definition Of ◽  
Survey Evaluation

The transportation system for hydrocarbons consists of an important and complex network of pipelines used by oil and gas logistics companies, designed to quickly and efficiently transport oil and gas from its origin, to areas of some demand along territory where operates. Currently Brazil has 15,000 km of transportation pipelines within about 7,500 km of right-of-way pipelines. Along its territorial extension it faces several influences along its route, being the main ones influenced by the external hazards from nature and by third party actions. TRANSPETRO has about 450 water crossings in cataloged water bodies currently. These crossings are currently characterized only according to their geometric characteristics, not considering several aspects inherent to them. The inspections at these crossings are laborious and have a high cost due to necessity of divers and bathymetry in some cases. To monitor the condition of all pipeline water crossings it is important to ensure the pipeline integrity. Depending on hydraulic phenomena, it is possible result in an exposure of the pipelines, free spans, changes in the original pipeline or excessive vibration. These changes can generate high mechanical stresses with both static and dynamic loads. The present study was characterized by the development of a methodology for assessing the susceptibility to the exposure of pipelines as a result of the hydrological hazards present at the crossings in which they are found. Moreover, this evaluation methodology offers a tool to define inspection extent and frequency, as well as the corresponding risk control actions. For this purpose, a pipeline management program has been set up, which consists in the definition of water crossings that constitute a potential hydrological hazard and where they can interact with the pipeline considering the probability of a specific hydrotechnical hazard leading the pipeline the exposure. As a result of this research it was defined a methodology to characterize pipeline crossing areas as well as field survey, evaluation of the susceptibility of pipeline exposure at crossings and the programming of control actions were defined according to the susceptibility found. Finally, the study has also presented a cost analysis of crossings inspections comparing the traditional method to the new premises adopted in this project.

Risk-Based Approach to Evaluate Casing Integrity in Upstream Wells

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Mohammed D. Al-Ajmi ◽  
Dhafer Al-Shehri ◽  
Mohamed Mahmoud ◽  
Nasser M. Al-Hajri
Keyword(s):  
Fresh Water ◽  
Oil And Gas ◽  
Probabilistic Approach ◽  
Metal Loss ◽  
Gas Wells ◽  
Wrong Decision ◽  
Average Value ◽  
Oil And Gas Wells ◽  
Proactive Measures ◽  
Casing Failure

Downhole casing leaks in oil and gas wells will highly impact the shallow water horizons and this will affect the environment and fresh water resources. Proactive measures and forecasting of this leak will help eliminate the consequences of downhole casing leaks and, in turn, will protect the environment. Additionally, downhole casing leaks may also cause seepage of toxic gases to the fresh water zones and to the surface through the casing annuli. In this paper, we introduced a risk-based methodology to predict the downhole casing leaks in oil and gas wells using advanced casing corrosion logs such as electromagnetic logs. Downhole casing corrosion was observed to assess the remaining well life. Electromagnetic (EM) corrosion logs are the current practice for monitoring the casing corrosion. The corrosion assessment from EM logs is insufficient because these logs cannot read in multiple casings in the well. EM tool gives average reading for the corrosion in the casing at a specific depth and it does not indicate the orientation of the corrosion. EM log does not assess the 360 deg corrosion profile in the casing and it only provides average value and this may lead to wrong decision. All of this makes EM logs uncertain tools to assess the corrosion in the downhole casing. A unified criterion to assess the corrosion in the casing and to decide workover operations or not has been identified to minimize the field challenges related to this issue. A new approach was introduced in this paper to enhance the EM logs to detect the downhole casing corrosion. Corrosion data were collected from different fields (around 500 data points) to build a probabilistic approach to assess the casing failure based on the average metal loss from the EM corrosion log. The failure model was used to set the ranges for the casing failure and the probability of casing failure for different casings. The prediction of probability of failure (PF) will act as proactive maintenance which will help prevent further or future casing leaks.

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