Natural gas leakage from unmanned facilities, such as compressor stations, gathering sites, and block valve locations, can pose significant economic and safety impacts. Additionally, methane, the primary constituent of natural gas, is a powerful greenhouse gas with 84 times the global warming potential of carbon dioxide on a mass basis over a 20-year period (IPCC 2013). Due to the remote location of many of these facilities, fluid leaks can persist for extended periods of time. Continuous leak detection systems would facilitate rapid identification and repair of leaks. However, existing technologies, such as infrared cameras, are cost-prohibitive to be installed at a high number of sites and are instead used in periodic monitoring as part of leak detection and repair programs. Such periodic monitoring does not provide for quick detection of “fat tail” leaks that dominate the emissions from gathering and transportation systems (Mitchell et al. 2015, Subramanian et al. 2015). A unique and innovative arrangement of various stakeholders was utilized to initiate a technology development and testing program aimed at expedited deployment of low-cost technologies at high numbers of sites. The technologies targeted for this work were low enough in cost to economically justify the installation of such sensors at every gas gathering and transportation site. This work was driven by an environmental advocacy organization under a partnership with eight different oil and gas companies and technical oversight from various universities, non-profits, and government agencies to give a wide perspective on the needs of such technology. Four different technologies were developed and tested in realistic release environments. The technologies ranged from sensors modified from automobile-based technology to laser-based systems used for monitoring gases in coal mines. The systems were treated as “end-to-end” units whereby all components (e.g., sensor, data acquisition, enclosures, etc.) needed to perform according to the provided specifications. The testing involved controlled releases under numerous environmental conditions and with different gas compositions. The largest focus of the testing was on outdoor releases where the systems had to detect the transient nature of gas plumes. The primary objectives of the testing were to determine the readiness of the technologies for pilot testing in the field and identify continuous improvement opportunities. The project demonstrated that there are newly-developed technologies that could be deployed as low-cost continuous monitoring solutions for the gas industry.

To promote efficient recovery of bitumen hydrocarbons using the steam assisted gravity drainage (SAGD) process, it is vital that steam be used effectively because steam generation constitutes one of the largest operational expenses during the SAGD process. To optimize this process, steam-injection flow-control devices (FCDs) have been developed. These devices are designed to enhance the operator's ability to distribute steam along the wellbore and to cease steam injection at a particular injection point if necessary, as the steam chamber matures. This paper discusses the design and capabilities of FCDs.The project initiated with a design requirement of two core components-the axial distribution of steam exiting the device and a device to incorporate a sliding sleeve mechanism. The basis for FCD design decisions was developed initially by reviewing worst-case operating conditions FCDs could encounter and then using this information as the operating envelope criteria that the design should meet. SAGD completion tools are required to endure everything from temperature fluctuations and corrosive formation fluids to erosive wet steam and severe wellbore trajectories. To design a tool that would survive the erosive effects of varying steam quality, the critical velocities and erosive mechanisms were defined. API RP 14E provides a conservative basis to determine the maximum allowable fluid velocity in a given system, but several studies have sought to push the boundaries of acceptable fluid velocities. The most conservative nozzle exit velocities were used to limit risks to casing. The risks caused by high velocities in the nozzle inside/inner diameter (ID) to the injection tool were mitigated through the use of computational fluid dynamics (CFD) analyses and material selection/treatment.Because of the high temperatures under which SAGD operates, consideration of mechanical property degradation and possible deformation had to be considered, specifically to the collet of the sliding sleeve. To prevent diminishing performance during the operational lifetime, FCDs that use sliding sleeves with collet mechanisms require a robust design that recognizes and addresses maximum stress loads and limits plastic deformation at peak temperatures. The testing of the sliding sleeve was conducted throughout a wide range of temperatures where the forces to shift the sleeve were monitored and compared to previous finite elements analyses (FEA) for compliance.ISO 14998 Annex D provided the basis for function testing of the FCD (i.e., cycling the sleeve and pressure testing at temperature). All pressure and function testing was performed at or above the operating temperature, and pressure and results were qualified to ISO 14998 V1. Field performance is discussed in the paper.

Real-time leak monitoring of pipelines is a need that is growing with the aging of the assets and the rise of the population living in their close proximity. While traditional deployment of external monitoring solutions on legacy assets may require extensive construction and trenching on the pipeline right-of-way, a new class of self-powered and wirelessly communicating devices provides an intriguing alternative. These devices are installed on the right-of-way with no need for mechanical excavation and allow continuous monitoring of a pipeline over long distances. Their low-power requirement makes it possible to operate the monitoring system continuously on battery power and their wireless communication is established through a self-forming network. These attributes make real-time monitoring possible without requiring any wiring to be deployed on the right-of way. The devices take advantage of the pipe’s characteristics that guide the acoustic waves generated by the leak along the pipeline to detect leaks. These characteristics make the detection possible even from a device that is not in close proximity of the leak. Since device spacing is a key parameter in the cost of monitoring with the leak detection system, it is important to understand the parameters that govern the propagation of leak sound on pipelines. Testing was performed for this purpose to validate the ability of these novel acoustic sensors in an outdoor test facility under a variety of leak conditions. This testing evaluated the propagation of acoustic waves emanating from small leaks on a buried pipe. This was achieved by pressurizing the pipeline to different levels of pressure and inducing leaks through various orifice sizes. The acoustic disturbances induced by these leaks were measured by sensors deployed at various stations on the pipe. The results of this testing demonstrated the ability of such an approach to be used for detecting very small disturbances in soil from an offset position caused by leaking liquids.