Characterization of Thermal and Acoustic Profiles of Potential Underwater Pipeline Leaks

Reliable detection of small potential leaks is a topic of significant interest for remote offshore pipelines. Potential leak cases of interest are pinhole leaks out of the bottom of the pipe due to corrosion, weld or seam cracks, or damage due to third-party contact. There are several emerging technologies that may have the potential to provide a means of detecting such leaks over long segments of underwater pipe. These technologies include distributed acoustic and distributed temperature sensing. A key element of evaluating the applicability of these systems is to characterize the behavior of leaks. It is critically important to understand how leaks behave when employing a technology that has only been previously used for other conditions. A joint-industry program was initiated to evaluate the thermal and acoustic behavior of hypothetical underwater leaks. The environments studied range from shallow, Arctic applications to deep offshore installations. Analytical models were assessed to predict the jetting behavior of simulated leaks and their near-field thermal response. This analysis was performed for both liquid and gas media. These models were validated by means of laboratory experiments. Acoustic characteristics of hypothetical liquid and gas leaks were determined by means of testing with hydrophones. This information can be leveraged by a number of technologies as the data are independent of the measurement mechanism. While the motivation of this work is to evaluate distributed fiber-optic systems, the data on leak characteristics may also provide indications on applicability of other techniques for detecting potential underwater leaks. The data from this project will allow the industry to improve the understanding of potential leaks from underwater pipelines and, hence, lay the foundation for determining appropriate detection systems.

Access and Logistics Challenges in Mountain Terrain Pipeline Projects

Oil and gas production in Canada’s west has led to the need for a significant increase in pipeline capacity to reach export markets. Current proposals from major oil and gas transportation companies include numerous large diameter pipelines across the Rocky Mountains to port locations on the coast of British Columbia (BC), Canada. The large scale of these projects and the rugged terrain they cross lead to numerous challenges not typically faced with conventional cross-country pipelines across the plains. The logistics and access challenges faced by these mountain pipeline projects require significant pre-planning and assessment, to determine the timing, cost, regulatory and environmental impacts. The logistics of pipeline construction projects mainly encompasses the transportation of pipe and pipeline materials, construction equipment and supplies, and personnel from point of manufacture or point of supply to the right-of-way (ROW) or construction area. These logistics movement revolve around the available types of access routes and seasonal constraints. Pipeline contractors and logistics companies have vast experience in moving this type of large equipment, however regulatory constraints and environmental restrictions in some locations will lead to significant pre-planning, permitting and additional time and cost for material movement. In addition, seasonal constraints limit available transportation windows. The types of access vary greatly in mountain pipeline projects. In BC, the majority of off-highway roads and bridges were originally constructed for the forestry industry, which transports logs downhill whereas the pipeline industry transports large equipment and pipeline materials in both directions and specifically hauls pipe uphill. The capacity, current state and location of these off-highway roads must be assessed very early in the process to determine viability and/or potential options for construction access. Regulatory requirements, environmental restrictions, season of use restrictions and road design must all be considered when examining the use of or upgrade of existing access roads and bridges. These same restrictions are even more critical to the construction of new access roads and bridges. The logistics and access challenges facing the construction of large diameter mountain pipelines in Western Canada can be managed with proper and timely planning. The cost of the logistics and access required for construction of these proposed pipeline projects will typically be greater than for traditional pipelines, but the key constraint is the considerable time requirement to construct the required new access and pre-position the appropriate material to meet the construction schedule. The entire project team, including design engineers, construction and logistics planners, and material suppliers must be involved in the planning stages to ensure a cohesive strategy and schedule. This paper will present the typical challenges faced in access and logistics for large diameter mountain pipelines, and a process for developing a comprehensive plan for their execution.

If You Build It, Will They Come? Caribou Habitat Restoration for Pipeline Projects

The federal Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal Population in Canada, identifies coordinated actions to reclaim woodland caribou habitat as a key step to meeting current and future caribou population objectives. Actions include restoring industrial landscape features such as roads, seismic lines, pipelines, cut-lines, and cleared areas in an effort to reduce landscape fragmentation and the changes in caribou population dynamics associated with changing predator-prey dynamics in highly fragmented landscapes. Reliance on habitat restoration as a recovery action within the federal Recovery Strategy is high, identifying 65% undisturbed habitat in a caribou range as the threshold to providing a 60% chance that a local population will be self-sustaining. In alignment with the federal Recovery Strategy, Alberta’s Provincial Woodland Caribou Policy identifies habitat restoration as a critical component of long-term caribou habitat management. Habitat restoration initiatives of Alberta’s historical industrial footprint within caribou ranges began in 2001 and have largely focused on linear corridors, including pipelines. Initiatives include revegetation treatments, access control programs and studies, and restricting the growth of plant species that are favourable to moose and deer, the primary prey for wolves. Habitat restoration for pipelines also includes pre-construction planning to reduce disturbance and create line-of-sight breaks, and construction techniques that promote natural vegetation recovery. Lessons learned from habitat restoration programs implemented on pipeline projects in northeastern Alberta will be shared as an opportunity to improve common understanding of restoration techniques, the barriers to implementation, and potential outcomes.

An Integrated Approach to Welding, AUT and ECA for Pipeline Construction

An integrated approach for the development of welding, inspection, and alternative weld flaw acceptance criteria, as used for girth welds during pipeline construction is presented. Welding is typically the pace limiting step during pipeline construction and is critical element of pipeline integrity. As such it is vital that it be completed efficiently and with high quality. Each of these three elements is vitally important to welding productivity and quality. At the core of the approach is the coordination of the three elements such that they are developed in concert. By this coordinated effort, all design options are considered leading to optimization of the final outcome. The approach is described by providing an example alternative weld flaw acceptance criteria, and giving the logic pertaining to choices of welding setup, AUT setup, the standard used for design and construction, and the impact of choices within these three elements on the final outcome. The paper illustrates the importance of a unified approach on weld productivity and quality.

Leveraging HCA Results in an Advanced Pipeline Risk Assessment Model

Pipeline risk analysis is a common step carried out by operators in their overall Pipeline Integrity Management Process. There is a growing realization among operators of the need to adopt more proactive risk management approaches. This has brought about increased demand for more quantitative models to support risk reduction decision-making. Consequences of failure are a key component of these models where enhanced quantitative approaches can be deployed. Impacts to the environment and upon populations are key issues which both operators and regulatory bodies seek to minimize. Pipeline risk models and High Consequence Area (HCA) analyses play an increasingly important role in this context by allowing operators to identify a range of potential scenarios and the relative impact to receptors based upon the best available data sources. This paper presents the process and results of an HCA analysis project carried out by ROSEN for a major South American state-owned pipeline operator (hereafter referred to as ‘the Client’). This analysis was implemented using automated GIS processing methods and includes HCA analyses for approximately 2354 km of pipeline. The analysis was based on industry standards for both liquid and gas pipelines (i.e. American Petroleum Institute (API) and American Society of mechanical Engineers (ASME)), but customized for the specific needs of the Client and the South American geographical context. A key use for the results of this analysis is to serve as input for the pipeline risk assessment model jointly developed by ROSEN Integrity Solutions, MACAW Engineering and the Client. The methodology for development of this model is briefly discussed, and operational uses of HCA results are illustrated. The benefits of this project include, but are not limited to, identifying areas that could be severely impacted should a pipeline failure occur, being able to assess the risk profile of credible threats in HCAs, but also being able to prioritize preventative and mitigation measures at HCAs to either reduce the likelihood of failure or the impact of failure upon various receptors.

Economic Feasibility of Transporting Natural Gas Hydrates in Slurry Pipelines

Natural Gas Hydrates are cage-like structures that are composed of natural gas (methane, ethane, etc.) molecules contained or entrapped within a water lattice. The hydrate structure contains tightly packed gas in ratios of over 160 to 1. Thus, there is a huge conceived upside to transporting the gas in this mode efficiency-wise if one could transport hydrates to a central processing facility where the hydrate would be processed to meet natural gas pipeline grid specifications. The question is: can they be transported in slurry form with water or oil as a carrier fluid, and what are the pros and cons of such mode of transportation. This paper attempts to answer these questions, and presents a feasibility analysis of three pipeline transportation scenarios to transport equivalent of 116 MMSCFD of natural gas over 500 km distance. It was found that for transportation of natural gas in the form of hydrates to be economically feasible, it has to be combined with transportation of crude oil as a carrying fluid rather than water, so that the cost of transportation per unit energy of the combined hydrates/oil slurry mixture is shared between the two energy commodities. This will result in even a lower cost below that of conventional transportation of natural gas in gaseous (vapour) form.

Horizontal Directional Drilling Application in a Wide River Crossing in the Amazon Rain Forest

Horizontal Directional Drilling, as known as HDD, is a method of construction that requires few trenches or no continuous trenches, used for making crossings under rivers, roads and existing structures. In the oil and gas industry, it is most commonly used in offshore and onshore well drilling activities to better explore the reservoir from a single well. It is also very much used when laying pipelines, where no other feasible option is possible. This technology was widely applied in the Urucu-Manaus natural-gas pipeline construction by Petrobras, and Transpetro has been responsible for the operation and maintenance of this pipeline since November 2009, flowing Natural Gas from the heart of the Amazon forest mainly to the growing market of thermoelectric plants. Due to its extension in the forest, the crossing of numerous wide navigable rivers and other natural obstacles was unavoidable, and no other construction methods were more suitable than the HDD technology. This work shows the application of this method in the 1777m long crossing of the Solimões River during the construction of this 662km Natural Gas pipeline. It also shows the challenges faced due to the logistical adversities in the rainforest, as well as the operations by Transpetro.

A Case Study of Stress Analysis of Pipeline in River Crossing Tunnel

Tunnel by digging is accepted as one of the most effective methods for river-crossing in pipeline constructions, especially for large river-crossing. Pipeline is often installed on a series of low supports in the tunnel underneath river. Generally, pipeline in tunnel experiences various loadings during service period due to operational and environmental conditions, such as operation pressure fluctuation, external temperature variation or support damage. Under these loadings, high stress and huge longitudinal force may be accumulated in pipe that may eventually result in pipeline elongation or bending. These kinds of deformation have been found in pipelines in some river crossing tunnels. To investigate the mechanical behavior of pipeline in tunnel crossing, finite element models (FEM) are produced to simulate pipeline operation condition and the maximum design operation condition. With FEM, stress distribution and deformation of pipeline are analyzed. The result shows that 1) axial elongation of pipeline from finite element analysis is in accordance with that of on-site measurement, 2) pipeline is analyzed to be safe under operation condition or the maximum design operation condition, 3) supports should be designed and constructed with enough strength to resist the force from pipeline deformation, and 4) some treatments are proposed to solve the problems of pipeline in tunnel crossing. Finally, a new type of support with vertical constrained damping is designed for stress and deformation relief of pipeline in tunnel crossing.

Achieving Efficiency in Environmental Assessment Through Focused Selection of Valued Components

Some of the largest oil and gas projects in Canada are currently being proposed in British Columbia. Establishing a fulsome and scientifically and socially defensible scope for environmental assessments in the oil and gas sector is a serious challenge for government and proponents. The approach taken by the federal National Energy Board to scope effects assessments on pipelines is quite different than the approach taken by the British Columbia Environmental Assessment Office on other types of oil and gas projects. The NEB has published guidelines for scoping and conducting environmental and socio-economic assessments within its Filing Manual (National Energy Board [NEB] 2014). This manual sets out the expectations for scoping, baseline information, and effects assessments to be submitted as part of approval applications. Proponents are expected to provide all information necessary to meet the guidelines. In British Columbia, the environmental assessment process is dictated by the British Columbia Environmental Assessment Act and includes a negotiated terms of reference for the assessment, called the Application Information Requirements (AIR). The approach to selection of valued components is guided by provincial guidelines (EAO, 2013). The first draft of the AIR is prepared by the proponent and is then amended to address matters raised by federal and provincial agencies, local governments, and representatives of potentially affected First Nations. Through two to three revisions, the scope of assessment is jointly established and then formally issued by the government. While there are valid reasons for the differing federal and provincial approaches to scoping environmental assessments, each of these processes create risks for proponents in terms of project timelines and costs for preparing the environmental assessment. More specifically, the use of generic and negotiated guidelines can result in a number of issues including: • A scope of assessment that is broader than necessary to understand the potential for significant adverse effects • Inclusion of issues that are “near and dear” to a specific regulator or community but has no direct relationship to the effects of the project itself • Selection of valued components that do not allow for defensible quantification of effects or use of directly relevant significance thresholds • Selection of valued components that are only of indirect concern as opposed to focusing the assessment on the true concern. • Double counting of environmental effects • Risks in assessing cumulative effects This paper discusses where and how these risks occur, and provides examples from recent and current environmental assessments for pipelines and facilities in British Columbia. Opportunities to manage the scope of assessment while providing a fulsome, efficient, effective and scientifically/socially defensible assessment are discussed.

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

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.