High Speed Data Communications and High Speed Leak Detection Models: Impact of Thermodynamic Properties for Heated Crude Oil in Large Diameter, Insulated Pipelines — Application Pacific Pipeline System

Author(s):  
Travis Mecham ◽  
Galen Stanley ◽  
Michael Pelletier ◽  
Jim C. P. Liou

Recent advances in SCADA and leak detection system technologies lead to higher scan rates and faster model speeds. As these model speeds increase and the inherent mathematical uncertainties in implicit method solutions are reduced, errors and uncertainties in measurement of the physical properties of the fluids transported by pipeline come to dominate the confidence calculations for computer generated leak alerts in the control center. The ability to collect more data must be supported by the need for better model data in order to achieve optimal leak detection system performance. This is particularly true when the products transported are non-homogeneous and have strong viscosity-vs-temperature relationships. These are characteristics of crude oils in California’s San Joaquin Valley where significant heating is required to pump these oils in an efficient manner. Proper characterization and correct mathematical expression of these physical properties in leak models has become critical. This paper presents these new developments in the context of an implementation of this new technology for the Pacific Pipeline System (PPS). PPS is a recently constructed and commissioned 209 km (130-mile), 50.8 cm (20″) diameter, insulated, hot crude oil pipeline between the southern portion of California’s San Joaquin Valley and refineries in the Los Angeles basin. Operational temperatures in this line vary from ambient to 82.2°C (180°F) with pressures ranging from 345 kPa (50 psi) to 11,720 kPa (1700 psi). Due to the unique geometry of the line, facilities along the route include pumping stations, metering stations and numerous “throttle-type” pressure reduction facilities. On PPS, a high-speed leak detection model is supported by a fiber optic (OC-1) communication backbone with data rate capacities in excess of 50 Megabits Per Second (MPS). Total scan times for the distributed communication system have been reduced to 1/4 second — each facility reports data to the SCADA host four times each second. A corresponding 1/4 second leak detection model cycle leads to selection of Methods of Characteristics segments on the order of 260 meters (850 feet). This resolution, in conjunction with the advanced instrumentation package of PPS, makes detection of very small leaks realizable. This paper starts with an overview of the system and combines a mix of the theoretical requirements imposed by the mathematical solutions with a practical description of the laboratory procedures and propagated experimental errors. The paper reviews temperature-related errors and uncertainties and their influence on leak detection performance.

Author(s):  
Harry SMITH ◽  
Kirsty MCNEIL ◽  
Tom RECORD ◽  
Dan BUZATU ◽  
Georgian ILIESCU ◽  
...  

Author(s):  
Joep Hoeijmakers ◽  
John Lewis

Prior to the year 2000, the RRP crude oil pipeline network in Holland and Germany was monitored using a dynamic leak detection system based on a dynamic model. The system produced some false alarms during normal operation; prompting RRP to investigate what advances had been made in the leak detection field before committing to upgrade the existing system for Y2K compliance. RRP studied the available leak detection systems and decided to install a statistics-based system. This paper examines the field application of the statistics based leak detection system on the three crude oil pipelines operated by RRP. They are the 177 km Dutch line, the 103 km South line, and the 86 km North line. The results of actual field leak trials are reported. Leak detection systems should maintain high sensitivity with the minimum of false alarms over the long term; thus this paper also outlines the performance of the statistical leak detection system over the last year from the User’s perspective. The leak detection experiences documented on this crude oil pipeline network demonstrate that it is possible to have a reliable real-time leak detection system with minimal maintenance costs and without the costs and inconvenience of false alarms.


Author(s):  
Joanna Mabe ◽  
Keefe Murphy ◽  
Gareth Williams ◽  
Andrew Welsh

This paper describes the process of incremental pipeline filling and the phased commissioning of a real-time leak detection system for the 1768 km long BTC crude oil pipeline. Due to stringent environmental requirements, it is essential for the leak detection system to work from the moment that crude oil is introduced into the pipeline. Without any prior operational data and with the pipeline partially filled, it is challenging for the leak detection system to monitor the integrity of the pipeline throughout the whole filling process. The application of the pig tracking software to track the oil front as the crude displaces nitrogen is also discussed.


Author(s):  
Rainer Beushausen ◽  
Stefan Tornow ◽  
Harald Borchers ◽  
Keefe Murphy ◽  
Jun Zhang

This paper addresses the specific issues of transient leak detection in crude oil pipelines. When a leak occurs immediately after pumps are switched on or off, the pressure wave generated by the transients dominates the pressure wave that results from the leak. Traditional methods have failed to detect such leaks. Over the years, NWO has developed and implemented various leak detection systems both in-house and by commercial vendors. These systems work effectively under steady-state conditions but they are not able to detect leaks during transients. As it is likely for a leak to develop during transients, NWO has decided to have the ATMOS Pipe statistical leak detection system installed on their pipelines. This paper describes the application of this statistical system to two crude oil pipeline systems. After addressing the main difficulties of transient leaks, the field results will be presented for both steady-state and transient conditions.


Author(s):  
XianYong Qin ◽  
LaiBin Zhang ◽  
ZhaoHui Wang ◽  
Wei Liang

Reliability, sensitivity and detecting time under practical operational conditions are the most important parameters of a leak detection system. With the development of hardware and software, more and more pipelines are installed with advanced SCADA (Supervisory Control and Data Acquisition) system, so the compatibility of the leak detection system with SCADA system is also becoming important today. Pipeline leakage generates a sudden change in the pipeline pressure and flow. The paper introduces leak detecting methods according to the pipeline pressure wave change. In order to improve the compatibility of the leak detecting system, “OPC (Ole for process Control)” technology is used for obtaining the pressure signals from the distributed data collection system. Special focus is given on analysis of the pressure signals. It is successful to denoise the signals by means of wavelet scale shrinkage, and to capture the leak time tag using wavelet transform modulus maximum for locating the leak position accurately. A leak detecting system is established based on SCADA system. Tests and practical applications show that it locates leak position precisely. Good performance is obtained on both crude oil pipeline and product pipeline.


2021 ◽  
Author(s):  
M. Rais

Indonesian oil and gas transporter, PT Pertamina Gas (Pertagas), has a special task to operate the Tempino to Plaju Crude Oil Pipeline (TPCOP) to deliver 15,000 barrel-oil per day (BOPD) crude oil. Pertagas faced a big challenge and concern in the operation due to the frequent illegal tapping activities and risk of pipeline product theft. In 2012, 748 illegal taps cases or equal to a daily average of 2 cases were reported. The loss from crude oil transportation was approximately 40% per day and loss revenue was more than $20 million a year. Moreover, illegal tapping by cutting into pipelines can cause pipeline ruptures and explosions, leading to human casualties, destruction of property, and damage to the environment. Pertagas reported that illegal taps have increased to 400% from year 2010 to the year 2013. Efforts were taken to minimize the illegal tapping frequency by developing an integrated system that includes supervision and security of assets along the pipeline called “Security and Oil Losses Management with Integrated Detection System (SOLIDS)”. This system consists of Asset Management System (AMS), Liquid Management System (LMS), Leak Detection System (LDS), security patrol, Emergency Response Team (ERT), and is supported by Corporate Social Responsibility (CSR) programs. The implementation of SOLIDS proved to be an effective oil loss detection technology and pipeline security control that detects product thefts quickly and locates illegal tapping points accurately, so protective measures could be applied immediately. The implementation showed a good result. Pertagas has been succeeded in reducing losses from illegal taps from 748 cases in 2012 to zero cases in 2018. Consistent implementation of this system will provide a solution in reducing losses and illegal tapping under all operational conditions.


Author(s):  
Peter W. Bryce ◽  
Peter Jax ◽  
Jie Fang

The Northstar project is the first crude oil production facility constructed offshore in the Beaufort Sea. Produced crude oil is transferred via a buried subsea pipeline to shore and overland to the Trans Alaska Pipeline Pump Station PS1 facility. During the permitting process, concern was expressed that a very small chronic leak in the subsea oil line would remain undetected during the winter months of continuous ice cover. Therefore, the US Army Corps of Engineers stipulated that a prototype leak detection system be installed that would capable of detecting a threshold leak less than 32 BOPD. This paper addresses the efforts to develop and install the LEOS leak detection system for arctic operations. The system is based on the well-established LEOS leak detection technology (manufactured by Framatome ANP, formerly by Siemens AG). The system comprises a perforated plastic tube with a thin water impermeable acetate outer sheath that allows hydrocarbon molecules to diffuse into the air filled tube. The air inside the tube is replaced periodically (every 24 hours) and is passed through a hydrocarbon-sensing module. The module contains resistors sensitive to the presence of very small concentrations of hydrocarbon molecules. The presence and location of a leak is determined by measuring the time taken for the localized concentration of hydrocarbon molecules associated with a leak to reach the end of the tube. LEOS components and materials were engineered to survive installation during arctic winter conditions. It was also necessary to protect the plastic LEOS sensor tube as it was lowered through the ice, attached to the pipeline, into a pre-excavated trench and then backfilled. The 10km long LEOS tube was delivered to site in 31-coiled 300m (1000-ft) bundles that were transported from Germany to Alaska. The LEOS sensing tube was preinstalled in a protective outer polyethylene tube which was unreeled through a reverse bending jig. Crude oil production started at the Northstar production facility in October 2001 and the LEOS system has been operational since then and is providing the highest degree of assurance that no oil is escaping from the pipeline.


Author(s):  
Subhash Chandra Agarwal

Due to capacity expansion of one of our refineries located in Western India, there was a need to evacuate additional products. Pipeline, being the most economical, reliable and environment friendly mode of transportation was the obvious choice. Laying a new pipeline would have required making substantial initial capital investment. However, a crude oil pipeline, owned by another oil company, was terminating at the refinery and was not in regular use. It was decided to convert this pipeline to product service. The pipeline was taken on lease, extensively cleaned, tested and successfully converted to product service with necessary hook-up/modifications at both the ends and in-between. The paper covers the experience gathered during the process of conversion of the crude oil pipeline to product service, including modifications carried out in the pipeline system, methodology adopted for cleaning, hydro-testing and commissioning of the system, and the lessons learnt.


2017 ◽  
Vol 12 (1) ◽  
pp. 112 ◽  
Author(s):  
Leksono Mucharam ◽  
Silvya Rahmawati ◽  
Rizki Ramadhani

Oil and gas industry is one of the most capital-intensive industry in the world. Each step of oil and gas processing starting from exploration, exploitation, up to abandonment of the field, consumes large amount of capital. Optimization in each step of process is essential to reduce expenditure. In this paper, optimization of fluid flow in pipeline during oil transportation will be observed and studied in order to increase pipeline flow performance.This paper concentrates on chemical application into pipeline therefore the chemical can increase overall pipeline throughput or decrease energy requirement for oil transportation. These chemicals are called drag reducing agent, which consist of various chemicals such as surfactants, polymers, nanofluids, fibers, etc. During the application of chemical into pipeline flow system, these chemicals are already proven to decrease pump work for constant flow rate or allow pipeline to transport more oil for same amount of pump work. The first application of drag reducer in large scale oil transportation was in Trans Alaskan Pipeline System which cancel the need to build several pump stations because of the successful application. Since then, more company worldwide started to apply drag reducer to their pipeline system.Several tedious testings on laboratory should be done to examine the effect of drag reducer to crude oil that will be the subject of application. In this paper, one of the testing method is studied and experimented to select the most effective DRA from several proposed additives. For given pipeline system and crude oil type, the most optimum DRA is DRA A for pipeline section S-R and for section R-P is DRA B. Different type of oil and pipeline geometry will require different chemical drag reducer. 


1995 ◽  
Vol 1995 (1) ◽  
pp. 459-464
Author(s):  
Mark A. Lowe ◽  
Eugene R. Mancini ◽  
Dilworth W. Chamberlain ◽  
Eric Greenwood ◽  
Sue Rankin ◽  
...  

ABSTRACT In April 1993, a pipeline rupture occurred adjacent to a primary California freeway on the north slope of the Tehachapi/San Emigdio Mountains leading into the San Joaquin Valley. An estimated 6,200 barrels of blended San Joaquin Valley crude oil (27° API gravity) sprayed on the freeway, and flowed downslope and into Grapevine Creek. The crude oil flowed 12 kilometers terminating at a containment dike constructed during the initial response. Cleanup activities were completed and approved by the lead regulatory agency within 21 days of the release. The release occurred at an elevation of 730 meters above sea level, spraying oil on to the northbound lanes of the freeway and closing it for 36 hours. After passing through engineered freeway drainage, the oil entered Grapevine Creek and flowed through 1,525 meters of riparian habitat and 8,500 meters of grassland habitat. Elevation at the terminus was 300 meters. Upper Grapevine Creek supports dense riparian vegetation that may have contributed to significant diurnal flow fluctuations and caused surface flows to retreat 1,500 meters from the terminus during the afternoon and early evening hours during response operations. Typical flow rates in Grapevine Creek during the response operations were less than 0.15 m3/s (less than 5 ft3/s). Cleanup activities included steam cleaning the freeway and engineered drainage system and hand cleanup in the riparian section. Cleanup efforts in the downstream grassland section were complicated by the fluctuating flow rates. A site in Grapevine Creek with continual surface flow was selected for stream-flow diversion. Utilizing portable irrigation equipment, the flow from the creek was used to irrigate 40 acres of adjacent grassland. The system was operated for 21 days and required 24-hour supervision to adjust for stream flow fluctuations. Approximately 3,400 barrels of crude oil were recovered as a liquid from two primary locations: a permanent concrete containment weir and the terminus containment dike. Recovered liquids were returned to tankage for subsequent processing. An estimated 1,200 barrels of crude oil were collected in 19,000 cubic yards of excavated soil and sediment. Thus, approximately 74 percent (4,600 barrels) of the spilled oil was recovered. The soil was converted into a road-base material and used to pave pipeline system facilities for dust control, at a cost of less than $30 a ton. Water samples collected during and after cleanup activities combined with surveys of macroinvertebrates, birds, and riparian habitat indicate only short-term and localized impacts. Dissolved hydrocarbons in surface waters declined rapidly. Benthic macroinvertebrate population density and diversity were similar to reference station within five months of the initial release.


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