Berry, Sandra L. (Baker Hughes, a GE Company) | Palm, Dustin C. (Baker Hughes, a GE Company) | Usie, Marty J. (Baker Hughes, a GE Company) | Schutz, Ronald W. (TiCorr LLC) | Walker, Heath W. (Arconic Energy Systems)
Matrix acidizing treatments containing hydrogen fluoride (HF) acid have been utilized in stimulation treatments of offshore wells to remove skin associated with fines migration for many years. In the last few years, operators have moved toward the use of organic acid - HF acid treatments due to corrosion concerns in the downhole tubular strings during the initial pumping of live acid and in the Titanium Stress Joints (TSJ) during the acid flow back through the production riser. A corrosion inhibitor to inhibit any unspent HF in the acid flowback returns would be beneficial to operators. Production of spent acid flowing back through the production riser is seriously being considered because significant cost savings may be realized over other acid flowback options. However, although most HF acid systems are mostly and/or highly spent during the reaction time with the formation mineralogy, even small concentrations of remaining free HF in the spent acid returns can result in severe bore surface corrosion (etching) and byproduct hydrogen absorption by the riser system TSJ. Lab studies were performed with several different inhibitor formulations added to two different spent organic - HF acid fluid systems to determine the ability for these candidate inhibitors to thwart corrosion (etching) and corresponding hydrogen uptake on ASTM Grade 29 titanium (Ti-29) test coupons. These candidate inhibitors were subjected to four-hour exposure tests conducted at 170 F under 3500 psi pressure with various inhibitor concentrations to determine if the package could meet screening criteria of corrosion/etch rate of less than 0.5 mils per day (0.5 thousandths of an inch) and hydrogen uptake limits consistent with ASTM product specification limits for the short term exposure (i.e., four hours). These lab test results are compared to those from recent published lab test studies on titanium in live and spent HF containing acid fluids, along with discussion on practical implications and considerations for their field use. Developing a corrosion inhibitor to inhibit the residual HF acid in the spent flowback returns and prevent etching and hydrogen uptake by the TSJ in the production risers not only yields effective protection of the TSJ, allowing flowback fluids to be returned thru the production riser, but also offers a significant operational cost savings.
Decision tree analysis and Monte Carlo simulation are the most commonly used tools in decision and risk analysis. But other tools such as optimization, options analysis, and combinations of these various tools can also be useful. This article examines the importance of data analysis and the nature and application of these other tools. Regardless of the principal tool used in risk analysis--Monte Carlo simulation or decision trees--empirical data may play an important role. Similarly, the input distributions selected for a Monte Carlo model are easier to justify when analogous data is available to support the choices of distribution type and value of defining parameters, such as mean and standard deviation.
Sanguinito, Sean (National Energy Technology Laboratory) | Cvetic, Patricia (National Energy Technology Laboratory) | Goodman, Angela (National Energy Technology Laboratory) | Kutchko, Barbara (National Energy Technology Laboratory) | Natesakhawat, Sittichai (National Energy Technology Laboratory)
It is becoming increasingly important to expand the fundamental understanding of geochemical interactions between CO2, fluids, and shale. These interactions will significantly impact the processes of 1) storing CO2 in hydraulically fractured shale formations, 2) using CO2 as a fracturing agent, and 3) enhancing hydrocarbon recovery in shales via CO2 flooding. In this work, we use in-situ Fourier Transform infrared spectroscopy (FT-IR), feature relocation scanning electron microscopy (SEM), and surface area and pore size analysis using volumetric gas sorption and density function theory (DFT) methods to characterize and quantify the reactions that occur between CO2, fluids, and shale. Several shale samples from across the U.S. were analyzed including the Marcellus, Utica, and Eagle Ford Shales. CO2 will be injected into shale formations where it will interact with shale surfaces (i.e. clays, organic matter), in-situ fluids (i.e. natural brines), and previously injected fracturing fluid. Currently, it is assumed that dry supercritical CO2 does not interact with or have any impact on reservoir rocks or seals. Our suite of measurements show CO2 interaction with clay and kerogen components of the shale, reactivity and etching of carbonate, and changes in pore sizes at the meso- and micro-scale. Very few studies are taking into account the reactivity of CO2 and fluids in the reservoir. The reactions that occur between CO2, fluids, and the shale may alter petrophysical properties such as porosity and permeability which may alter flow pathways potentially impacting the storage permeance of CO2 and the effectiveness of CO2 to behave as a fracturing agent or to mobilize hydrocarbons.
With increasing awareness and concern of CO2 emissions and climate change, there has been a shift in research efforts to evaluate the potential of shales to be used as CO2 storage reservoirs and effective natural seals for CO2 or hydrocarbons (Orr, F.M., 2009a.; Orr, F.M., 2009b; Romanov et al., 2015; Levine et al., 2016, Bacon et al., 2015). Current research is underway to determine the fundamental understanding of geochemical interactions between CO2, fluids, and shale. Fluids, such as formation fluids and fracturing fluids, can react with the CO2 and shale interface to alter formation properties (Jun, Y et al., 2013; Dieterich et al., 2016). This geochemical alteration of shale has been reported to directly affect porosity, permeability, flow paths, and integrity of the wellbore, seal, and formation (DePaolo and Cole, 2013). Additionally, the storage temperature and pressure conditions and the composition and chemistry of brine solution and hydraulic fracturing fluid have an impact on the geochemical alteration of the shale (specifically dissolution).
Elastomers are rubber or plastic materials used as a seal. They are commonly used in packers. There are many suitable elastomers on today's market to match almost any downhole condition. Care must be taken to ensure that the elastomer selected for the packer and seal assembly meets all the downhole conditions to which it will be subjected. There is no single best elastomer that will perform under all conditions combined, and selection must be tailored to suit individual well requirements and application.
Millions of workers are exposed to noise in the workplace every day and, when uncontrolled, noise exposure may cause permanent hearing loss. Research demonstrates exposure to certain chemicals, called ototoxicants, may cause hearing loss or balance problems, regardless of noise exposure. Noise is one of the harmful agents to health that is present in the various branches of economic activity. Hearing loss and tinnitus are among the most frequently reported complaints by workers exposed to occupational noise.
This study aimed to investigate the pulmonary functions of silica-exposed workers and their health-related quality of life in an insulator manufacturing industry. Exposure to welding fumes may result in disorders of the pulmonary, cardiovascular, and reproductive systems. Welders are also at a greater risk of developing symptoms similar to those seen in individuals with idiopathic Parkinson’s disease.
While drug use is a problem among industrial workers nationwide, it raises particular concern in the oil patch as US production surges to record levels in what is already one of the nation’s most dangerous sectors. Inhalation of crystalline silica dust is second only to asbestos as a hazard to construction workers. This video discusses important things to know. Evaluation of Occupational Ocular Trauma: Are We Doing Enough To Promote Eye Safety in the Workplace? The use of eye PPE among workers who sustain an eye injury in the workplace remains low.
The Advanced REACH Tool is a mechanistic higher-tier model to estimate inhalation exposure to chemicals using a Bayesian approach. This paper provides a discussion of the key modifying factors that should be considered to extend the model to include welding fume exposure. Increasing evidence suggests that welding-fume exposure is associated with systemic inflammation. Welding produces miscellaneous gases and particles that have various effects on respiratory systems, and long-term exposure may result in "welder's lung." The aim of this study is to describe radiological findings of welders' lung.
The US Occupational Safety and Health Administration, the National Institute for Occupational Safety and Health, the State of North Dakota, and the Bakken Basin Safety Consortium have signed an alliance to protect employees and promote safety and health in the oil and gas industry. The National Institute for Occupational Safety and Health is collaborating with partners in industry, government, academia, and labor and with other stakeholders to achieve successful and sustainable outcomes to improve worker safety and health across the oil and gas extraction industry. The tool, called the Field Analysis of Silica Tool, works with commercially available Fourier-transform infrared analyzers to determine a worker’s exposure to respirable crystalline silica dust, providing detailed results immediately following a worker’s shift. Millions of workers are exposed to noise in the workplace every day and, when uncontrolled, noise exposure may cause permanent hearing loss. Research demonstrates exposure to certain chemicals, called ototoxicants, may cause hearing loss or balance problems, regardless of noise exposure.
OSHA’s efforts to require employers to report occupational fatalities and certain injuries in a timely manner lack “sufficient guidance on how to detect and prevent underreporting,” the Department of Labor Office of Inspector General states in its semiannual report to Congress. To better protect workers exposed to respirable crystalline silica, OSHA has issued two new standards: one for construction and another for general industry and maritime. OSHA will begin enforcing most provisions of the standard for general industry and maritime on 23 June. Millions of workers are exposed to noise in the workplace every day and, when uncontrolled, noise exposure may cause permanent hearing loss. Research demonstrates exposure to certain chemicals, called ototoxicants, may cause hearing loss or balance problems, regardless of noise exposure.