Case, Raymundo (ConocoPhillips) | Rincon, Hernan (ConocoPhillips) | Tang, Xuanping (Institute for Corrosion and Multiphase Technology, Department of Chemical and Biomolecular Engineering, Ohio University)
ABSTRACT Fiber-reinforced composites have been used to repair a wide variety of structural defects in pipelines and pressure equipment with good success. Repaired defects range from non-leaking to through-wall damage generated by corrosion or other mechanisms. Primary design guidance for these repairs is given in ASME PCC2 Article 4.1, where Section 3.4.6 addresses the repair design of a leaking substrate. The design equations in this section are derived from thin film bulge testing which determines the load that initiates interfacial fracture between the repair and substrate. These equations typically assume a rigid substrate, which is appropriate when testing thin films, but fails to adequately describe repairs on pipes and pipeline components. As such, predicted failure pressures for repairs on long axial flaws have been found to typically be much higher than observed during testing. This paper will describe testing of composite repaired pipes with long axial flaws of various lengths. Variables, including repair thickness, width, and geometry, were also investigated. Two pipe diameters have also been tested to investigate the effects of substrate stress on the repair performance. INTRODUCTION Composite materials intended for the repair of metallic structural elements in civil and aerospace applications have been increasingly studied in recent year. Continuous fiber reinforced composites or polymers (FRP) possess improved strength to weight ratios and are easier to process for many repair approaches when compared to techniques using metallic materials. In addition to the repair of structural systems in civil and aerospace applications, the use of composite materials for the repair and rehabilitation of transmission and process piping has begun to increase. The Unites States alone is home to nearly 500,000 miles of gas and oil transmission lines, which must be regularly monitored and repaired if corrosion or mechanical damage is detected.
ABSTRACT The Bakken formation, spanning parts of Saskatchewan, Manitoba, North Dakota, and Montana, is a rich shale oil reserve with inherent challenges for producers. These challenges encroach on all stages, from drilling to fracturing to the successful management of production. Increased activity in the Bakken has created an environment where the risk for corrosion differs between similar wells in close proximity. This paper will review a study of selected wells in the southern Saskatchewan area of the Bakken formation, highlighting the factors that contribute to severe corrosion and treatment strategies to minimize it. INTRODUCTION The Bakken shale play is a large deposit of oil and natural gas in the United States and Canada that is a unique and highly variable producing region that poses many challenges for production chemical treatment.1 For the purposes of this paper, only wells drilled into the Bakken formation were focused on. Not only does the Bakken formation require a different perspective on chemical treatments, it also demonstrates that not all wells in this region behave similarly despite their close proximity. As a result, one must carefully assess chemical programs and application for both corrosion and scale. Until recently, the Bakken was considered to be marginal economically to produce; however, the discovery of vertical to sub-vertical natural fractures has made it an excellent candidate for horizontal drilling techniques, hence a desirable resource to develop. From late 2008 to date, numerous successful wells have been drilled with these new technologies and an explosion of interest now surrounds the oil shale formation. Production is also enhanced by artificially fracturing the rock via complex cross linked gels. These novel recovery enhancing techniques require large volumes of water and frac sand, which can add complexity to production chemical treating.
Fredj, N. (Materials & Metallurgical Engineering Department) | Burleigh, T.D. (Materials & Metallurgical Engineering Department) | Heidersbach, K.L. (NTNU, Department of Materials Science and Engineering) | Crowder, B.R. (NTNU, Department of Materials Science and Engineering)
ABSTRACT Traditional microbiological methods based on culturing procedures such as the Most Probable Number (MPN) technique have been used for many years to monitor microbial numbers in oilfield samples. However, such methods are far from ideal as it is estimated that only 0.01–10% of all micro-organisms present in environmental samples are culturable by these methods. In addition, without further extensive procedures being carried out, such methods cannot identify the variety of micro-organisms in the sample. Molecular microbiological methods (MMM) negate such problems, providing information on the majority of micro-organisms present in an environmental sample. However, traditional MMM do have their drawbacks, particularly if employed on offshore oil installations. Such problems include microbial population changes occurring during transportation from the installation to the testing laboratory; additionally, the transportation and use of hazardous chemicals employed in traditional DNA extraction procedures limit the use of these methods on offshore installations. One new technology for the oil and gas industry, described as „Nucleic Acid Extraction Card‟ (NAEC), offers a simple and convenient solution to sample transport and on-site DNA extraction problems. The cards are impregnated with chemicals that lyse the cells and preserve the extracted DNA, thus eliminating the need for hazardous DNA extraction / purification chemicals. Hence, the cards „fix‟ the DNA onto the card so that the microbial population at the point of sampling is preserved, eradicating concerns of changes in microbial populations occurring during sample transport. The paper will discuss the mode of operation of the NAEC, trials with the cards on oilfield samples, comparisons with traditional DNA extraction procedures and recent developments with the technology. The paper will conclude with an example of how NAEC technology has been used to develop proactive solutions to microbiological problems in the oil & gas industry.