When HDD Construction Shifts Happen: Insertion of a Casing Sleeve Mitigated a Major Threat to Completion of the Project

2014 ◽  
Author(s):  
G. Arthur Kanzaki ◽  
Stephen L. Grant ◽  
Jarrod R. MacKenzie
Keyword(s):  
No Value ◽  
Project Team ◽  
Pipeline System ◽  
Fraser River ◽  
Directional Drilling ◽  
Major Threat ◽  
Operational Issues ◽  
Optimum Solution ◽  
Surface Geology

This paper will discuss how the project team planned, designed and constructed a unique and innovative casing sleeve as one of the key solutions to overcome a major threat to the completion of a horizontal directional drilling (“HDD”) project (“Fraser River South Arm Crossing Upgrade Project” or “Fraser River Crossing”). In 2009 FortisBC Energy Inc. (“FortisBC”) started construction to upgrade its NPS 20 and NPS 24 pipeline crossings of the Fraser River, the largest river in the province of BC, Canada via HDD. Due to the poor surface geology at this location on the Fraser River, temporary surface casings were required on both sides of the crossing to get drilling activities into a formation suitable for conducting an HDD crossing. As a result, the Fraser River Crossing required an HDD rig to drill concurrently from either side of the crossing in order to create a continuous borehole (also known as an intersect crossing). During the pullback of the NPS 24 - 1.35 km crossing section, a major mechanical failure occurred when over 95% of the length had been pulled through. After multiple attempts to resume pullback by the HDD rigs and other onsite equipment were unsuccessful, the project team was left with the major challenge(s) of determining how else the crossing could be completed and the pipeline tied in on both sides of the river without incurring major business interruption in a busy industrial section of Richmond, BC. Moreover, FortisBC was faced with the possibility of having to abandon the project and the millions spent up to that point in time with no value. This paper will focus on how the project team overcame the challenge and mitigated long term operational issues that included maintaining adequate cathodic protection. Learn how the combined efforts of a multi-disciplined project team planned, designed, fabricated and ultimately successfully inserted an innovative casing sleeve, although unproven at the time and with its share of additional risks, after reviewing an extensive assessment of numerous alternatives as the optimum solution in order for FortisBC to finally complete the upgrade of its pipeline system.

Bedforms, bed material, and bedload transport in a salt-wedge estuary: Fraser River, British Columbia

1989 ◽  
Vol 26 (7) ◽  
pp. 1440-1452 ◽  
Author(s):  
R. A. Kostaschuk ◽  
M. A. Church ◽  
J. L. Luternauer
Keyword(s):  
British Columbia ◽  
River Discharge ◽  
Bedload Transport ◽  
Fraser River ◽  
Seasonal Fluctuations ◽  
Salt Wedge ◽  
Migration Rates ◽  
Material Load ◽  
Bed Material

The lower main channel of the Fraser River, British Columbia, is a sand-bed, salt-wedge estuary in which variations in velocity, discharge, and bedform characteristics are contolled by river discharge and the tides. Bed-material composition remains consistent over the discharge season and in the long term. Changes in bedform height and length follow but lag behind seasonal fluctuations in river discharge. Migration rates of bedforms respond more directly to river discharge and tidal fall than do height and length. Bedform characteristics were utilized to estimate bedload transport in the estuary, and a strong, direct, but very sensitive relationship was found between bed load and river discharge. Annual bedload transport in the estuary is estimated to be of the order of 0.35 Mt in 1986. Bedload transport in the estuary appears to be higher than in reaches upstream, possibly because of an increase in sediment movement along the bed to compensate for a reduction in suspended bed-material load produced by tidal slack water and the salt wedge.

scholarly journals Contribution of changing precipitation and climatic oscillations in explaining variability of water extents of large reservoirs in Pakistan

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ibrar ul Hassan Akhtar ◽  
H. Athar
Keyword(s):  
Water Availability ◽  
Regression Models ◽  
Precipitation Amount ◽  
Average Error ◽  
Linear Regression Models ◽  
Climatic Oscillations ◽  
Major Threat ◽  
Storage Reservoirs ◽  
Multiple Linear Regression Models

AbstractMajor threat that Pakistan faces today is water scarcity and any significant change in water availability from storage reservoirs coupled with below normal precipitation threatens food security of more than 207 million people. Two major reservoirs of Tarbela and Mangla on Indus and Jhelum rivers are studied. Landsat satellite’s data are used to estimate the water extents of these reservoirs during 1981–2017. A long-term significant decrease of 15–25% decade−1 in water extent is found for Tarbela as compared to 37–70% decade−1 for Mangla, mainly during March to June. Significant water extents reductions are observed in the range of −23.9 to −53.4 km2 (1991–2017) and −63.1 to −52.3 km2 (2001–2010 and 2011–2017) for Tarbela and Mangla, respectively. The precipitation amount and areas receiving this precipitation show a significant decreasing trend of −4.68 to −8.40 mm year−1 and −358.1 to −309.9 km2 year−1 for basins of Mangla and Tarbela, respectively. The precipitation and climatic oscillations are playing roles in variability of water extents. The ensuing multiple linear regression models predict water extents with an average error of 13% and 16% for Tarbela and Mangla, respectively.

A STATE-OF-THE-ART SHORE CROSSING

2005 ◽  
Vol 45 (1) ◽  
pp. 551
Author(s):  
E.P. Jas ◽  
A.T. McPhee
Keyword(s):  
Selection Process ◽  
High Energy ◽  
Design Guidelines ◽  
Pipeline System ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Trenchless Technology ◽  
Tourist Attractions ◽  
Western Victoria ◽  
Design And Construction

An insight is provided into the design and construction of the shore crossing of the export pipeline system for the Otway Gas Project in Western Victoria. The development of the Otway Gas Project, which is now underway, requires the installation of a 20-inch gas pipeline and a 4-inch glycol service line across the shoreline in the Port Campbell National Park along the Great Ocean Road, one of the major tourist attractions in Australia. An account is given of the landfall site selection process, the collection of required site data, the identification of geo-hazards, the development of a unique construction method based on a combination of retractable micro-tunnelling and horizontal directional drilling, and an outline of the construction challenges. These include the complex geo-technical conditions, the ever present high-energy Southern Ocean swell, and the environmental significance of the site. The design and construction work performed demonstrates that trenchless technology can successfully be applied for the installation of pipelines across shorelines provided detailed attention is paid to a number of design and construction aspects; bearing in mind that horizontal directional drilling design guidelines are generally limited with respect to these crossings.

Justification of a Novel Pipe in Tunnel Approach to a River Crossing

2008 ◽  
Author(s):  
Chas Jandu ◽  
Mike Taylor ◽  
Stephen Humphrey
Keyword(s):  
River Estuary ◽  
Pipeline System ◽  
Directional Drilling ◽  
Tunnel Wall ◽  
River Bank ◽  
Operational Conditions ◽  
Finite Element Software ◽  
Soil Loading ◽  
Modelling Techniques ◽  
Fit For Purpose

As part of a major pipeline construction project, Laing O’Rourke had a requirement to install a section of pipeline beneath a river estuary. Due to a number of reasons it was not possible to negotiate the crossing using conventional techniques such as horizontal directional drilling (HDD) and an alternate method had to be sought. A feasibility study was undertaken and it was decided that a pipe-in-tunnel approach was the most viable. Due to constraints at the points of entry and exit it was necessary to cut two vertical shafts, one on each river bank. Linepipe sections were to be welded together, in the entry shaft, and pulled through the 2.44m diameter tunnel on plastic rollers, which were later to become the permanent supports during operation. On completion of the installation within the tunnel, two vertical sections of pipeline were to be installed in the shafts for connection to the main pipeline system. Due to the length of the crossing it was decided that back filling the void between the pipe and the tunnel wall with a suitable grout was not viable. A particular consideration was the likely occurrence of voids which would reduce the effectiveness of the CP system. For this reason, following installation, the tunnel was to be sealed with a concrete plug and flooded with water, and the shafts are to be backfilled with soil. This unique design arrangement presented a number of challenges and hence a requirement for the use of more complex modelling techniques than would normally be required. Models of the pipeline in various stages of installation were produced using the finite element software ABAQUS, with a variety of element types. Sets of rollers and their contact with the linepipe were also modelled. Soil loading, pressure, weight, buoyancy and temperature were applied to simulate a range of construction, commissioning and operational conditions. These were analysed, and the results were assessed for compliance with appropriate standards. Based on the results of the study it was possible to show that with a number of modifications to the original proposed design configuration, the crossing would be fit-for-purpose.

Pipeline Installation in a Confined Location Under the Bow River by Horizontal Directional Drilling

2002 ◽  
Author(s):  
Joe Zhou ◽  
Alan Glover ◽  
Paul Rudge
Keyword(s):  
Population Density ◽  
Project Team ◽  
Gas Pipeline ◽  
Environmental Concerns ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Unique Challenge ◽  
Right Of Way ◽  
Innovative Solutions ◽  
The Town

In the summer of 2000, TransCanada PipeLines Ltd. (TransCanada) upgraded portions of the Western Alberta System (WAS) NPS 36 gas pipeline through the town of Cochrane Alberta. The pipeline upgrade required the installation of new sections of pipe to meet the higher Class Location designation due to population density increase. Environmental concerns, expressed by federal and provincial regulators and the Cochrane community for the in-stream disturbance associated with a conventional “open cutting” installation, prompted TransCanada to design a directionally drilled crossing. A unique challenge to this project was the Bow River crossing within a congested and restricted right of way. The project team developed and implemented a series of innovative solutions which led to the successful conclusion of the project in September 2000. This paper summarizes the unique design and construction implemented in this project.

Integrity Assessment of HP/HT Infield Pipelines: Experiences With a New Methodology Applied in the Norwegian Sea

2008 ◽  
Author(s):  
Birger Etterdal ◽  
Hroar Nes ◽  
Stig Olav Kvarme ◽  
Stian Svardal
Keyword(s):  
Hot Spot ◽  
Operating Conditions ◽  
Pipeline System ◽  
Operating Pressure ◽  
Assessment Methodology ◽  
Long Term Conditions ◽  
Norwegian Sea ◽  
Integrity Assessment ◽  
Analysis Models

The subsea pipeline development for the A˚sgard and Midgard fields in the Norwegian Sea has been challenging due to high operating pressure and temperature (HP/HT pipelines), uneven seabed conditions and the potential for trawl gear interference. A general experience from the first years of operation is that it is not easy to use design information as basis for an integrity assessment of the lines. This is mainly due to the complexity of the global buckling process and the significant load fluctuations applied to the lines. As a consequence of this, analysis models established during design may not represent the actual pipeline behaviour properly, and established design limits do not fit intermediate operational load conditions and configurations observed during surveys. StatoilHydro has developed an integrity assessment methodology where analysis models are calibrated according to the as-surveyed condition, and then exposed to operational cyclic loads in order to predict both intermediate long term conditions and a final design condition. In the assessment of long term fatigue accumulation, process parameters monitored during pipeline operation are used as input. The integrity condition of the HP/HT pipelines is assessed based on a staged approach, depending on the criticality of the considered failure mode. The first level is used for screening and initial ranking. At level two the risk of integrity failure is quantified based on general design criteria, covering relevant operating conditions and the most important input parameters. If the uncertainty related to the assessment of an individual hot-spot location is assumed too high, a detail level three assessment may be specified. The operating condition of the pipeline system is expressed as the risk of failure defined by a limited number of hot-spot locations. The risk matrix concept used for the HP/HT pipelines, provides for a consistent comparison between individual failure modes, between different locations and sections, and between different pipeline systems. StatoilHydro has worked in close cooperation with DNV to develop software tools required to implement this integrity assessment methodology. These tools are now used for integrity assessment and follow-up of all HP/HT pipelines operated by StatoilHydro in the Norwegian Sea. The objective of this paper is to show how the methodology is used in practice, discuss major results and findings, and give general recommendations with respect to operational integrity assessment of HP/HT pipelines.

scholarly journals Drivers of Housing Demolition Decision Making and the Impact on Timber Waste Management

2011 ◽  
Vol 11 (1) ◽  
pp. 1-14 ◽  
Author(s):  
Perry John Forsythe
Keyword(s):  
Decision Making ◽  
No Value ◽  
Process Model ◽  
Economies Of Scale ◽  
Market Value ◽  
Housing Demolition ◽  
The Impact ◽  
Expected Increase ◽  
Project Level

The study investigates housing demolition and timber waste recovery – with the aim to identify ways of improving recovery. Using case studies the research focused on demolisher decision making, their onsite processes and the associated network of participants that influence timber recovery. From the data, a process model was developed that identifies and orders the drivers of demolition decision making. One aspect of the model identified the initiators of demolition and the waste created, including issues revolving around the demolition feedstock. Another aspect covers organisational business drivers and includes site safety, productivity, economies of scale, market value of waste and supply chain entrepreneurship. A third component deals with project specific drivers including the recurring cost versus income equation that impacts on the viability of project level decisions. The model includes a typology of the operational onsite response to the above drivers. Here, the deconstruction approach was found to provide high timber recovery mainly used where high-value timber waste was involved; the miscellaneous salvage approach provided some recovery of high and low-value timber; the crunch and dump approach provided low recovery or dumping at landfill and was used where low and no-value timber was involved. An expected increase in supply of these latter timber categories creates a significant need to increase the market value of currently low value timber groups. Designing for deconstruction is also posed as a long term strategy for this. 

Teaching English to Kriol Speakers – Where on Earth Do I Start?

1987 ◽  
Vol 15 (4) ◽  
pp. 3-20 ◽  
Author(s):  
Joyce Hudson ◽  
Anthea Taylor
Keyword(s):  
No Value ◽  
School Performance ◽  
Literacy Skills ◽  
Teaching English ◽  
Adequate Explanation ◽  
Aboriginal Students ◽  
Aboriginal Children

Background DiscussionReadiness programmes are of little or no value. The door to reading for any [sic] beginning reader is his own language, used to express his own experiences.(Sloan and Latham, 1981)It is an irrefutable fact that most Aboriginal children are under-achieving scholastically. It is also fairly obvious that a contributing factor in this under achievement is poor literacy skills which can hold children back in most areas of school performance.Many different reading schemes and approaches have been tried, including Bridging and Headstart programs, which have met with very little success in the long term. As a result it is all too easy for educators to fall back on the deficiency model and blame the child and the home. This is neither profitable nor an adequate explanation for the under-achievement of Aboriginal students.

The Analyses for the Casing Improvements of the MPM-20 Engine

2015 ◽  
Author(s):  
K. Ratkovská ◽  
J. Čerňan ◽  
M. Cúttová ◽  
K. Semrád
Keyword(s):  
Emission Spectra ◽  
Infrared Emission ◽  
Point Of View ◽  
Thermally Induced ◽  
Operational Conditions ◽  
Term Operation ◽  
Structural Modifications ◽  
Operational Issues ◽  
Combustor Liner

The operational issues of a small turbojet engine MPM – 20 are discussed. The engine was created by modifying the Soviet turbostarter TS – 20B/21 designed for short-term operation. It is necessary to make structural modifications that allow for the long-term operational premise of the engine. For this purpose, several analyses were focused on the thermally stressed parts. The first, a material analysis carried out on the outer casing of the combustion chamber and on the combustor liner reveals information about the mechanical properties of these structural nodes. It was necessary since there is no documentation of the engine with this information. Another analysis of the infrared emission spectra is important for monitoring operational conditions, especially from the temperature point of view. Subsequent stress analysis of the casing is based on results from previous analyses. It was used to observe the behaviour of the casing as operational conditions changed. This revealed a dangerous increase of thermally induced stress levels as temperature increased up to 150°C. Various structural modifications can be made in the future with these results, such as an application of a protective coating on the casing and combustor liner of the engine.

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