Proton Nuclear Magnetic Resonance (1H-NMR) Methodology for Monolefin Analysis:Application to Aquaprocessing-Upgraded Bitumen

Olefins are problematic components of petroleum products responsible for gum formation, polymers, and solid deposition in oil facilities. This work presents a methodology developed for monolefin analysis of whole oils, diluted bitumen, and partially upgraded heavy oils. A proton nuclear magnetic resonance (1H-NMR) technique calibrated with naphtha fractions of known monolefin contents is proposed. Internal standard addition (IS, dioxane) makes the method independent of the sample C/H atomic ratios (i.e., paraffin/aromatic hydrocarbon ratios). The developed method was applied for monolefin determination of partially upgraded whole bitumen processed under mild catalytic steam cracking (CSC) conditions and is also identified as aquaprocessing (AQP). Large viscosity reductions for AQP-upgraded products (up to 99%) were determined with associated monolefin contents <1.2 wt %

Effect of Particle Size on the HDS Activity of Molybdenum Sulfide

More than half of the total world oil reserves are heavy oil, extra heavy oil, and bitumen; however their catalytic conversion to more valuable products is challenging. The use of submicronic particles or nanoparticles of catalysts suspended in the feedstock may be a viable alternative to the conversion of heavy oils at refinery level or downhole (in situ upgrading). In the present work, molybdenum sulfide (MoS2) particles with varying diameters (10000–10 nm) were prepared using polyvinylpyrrolidone as capping agent. The prepared particles were characterized by DLS, TEM, XRD, and XPS and tested in the hydrodesulfurization (HDS) of a vacuum gas oil (VGO). A correlation between particle size and activity is presented. It was found that particles with diameters around 13 nm show double the HDS activity compared with the material with micrometric particle sizes (diameter ≈ 10,000 nm)

Evaluation of Cyclic Gas Injection in Enhanced Recovery from Unconventional Light Oil Reservoirs: Effect of Gas Type and Fracture Spacing

Production from ultra-low permeability shale plays requires advanced technologies such as horizontal wells with multistage hydraulic fracturing treatment. In this study, a cyclic gas injection method with two pumping schedules is introduced as an enhanced oil recovery (EOR) method. Fracture spacing and type of injection gas in a horizontal well from the Bakken formation are analyzed through numerical simulations. The economic profitability and reservoir performance are also investigated. Rate transient analysis is used to anticipate hydraulic fracture and effective fracture permeability. Different fracture spacings are selected as the major determinant factor in generating an effective reservoir contact area. Compositional simulations are conducted to model incremental oil recovery after cyclic injection of three gases (ethane, CO2, and natural gas). Economic indicators of net present value (NPV), internal rate of return (IRR) and oil recovery factor are compared to determine the best alternative among the proposed investment scenarios. Current market and a certain time-frame (2015&#8211;2035) are used to assess the investment viability of unconventional oil plays. Cyclical injection of ethane and CO2, remarkably improved oil recovery from the Bakken example. Natural gas injection however, led to inferior results and in terms of investment, may not guarantee the long-term success. Some scenarios are identified as profitable for high oil-API but do not achieve positive outcomes from lower oil specific gravities. The results from this study highlight the impact of fracture spacing in incremental oil recovery. Producing a majority of the cumulative oil during the first years makes most of the scenarios viable only for short terms. To maintain the long-term cost-effectiveness, performing cyclic gas injection through hydraulic fractures is recommended. Cycle sizes directly impact the propagation of injectant and the extent of the drainage area. Increasing the number of fracking stages can be an alternative strategy to gas injection in reservoirs with lower oil-API

Kinetic Modeling of Arab Light Vacuum Residue Upgrading by Aquaprocessing at High Space Velocities

Aquaprocessing (AQP) is a novel method that offers higher conversion level under asphaltenes stability limit. It is a process of steam catalytic cracking using unsupported ultradispersed catalyst. Following a 2011 published work by Fathi and Pereira on upgrading a paraffinic residuum from Arab Light Vacuum Residue (ALVR) by AQP, this work investigates a proposed lumped kinetic model for the upgrading of ALVR via AQP for the first time. The model is evaluated based on experimental results conducted in a continuous upflow open tubular pilot-plant reactor under short-space times and under conditions distant from coke formation. The proposed model is based on five cascaded lumps generated at and below the asphaltenes stability limit: 540 °C+ ALVR, VGO (455–540 °C), distillates (204–455 °C), naphtha (IBP–204 °C), and gases. The model compositions are found close to the experimental values with mean absolute percentage errors (MAPEs) of <5.5%

Effect of Particle Size on the HDS Activity of Molybdenum Sulfide

More than half of the total world oil reserves are heavy oil, extra heavy oil, and bitumen; however their catalytic conversion to more valuable products is challenging. The use of submicronic particles or nanoparticles of catalysts suspended in the feedstock may be a viable alternative to the conversion of heavy oils at refinery level or downhole (in situ upgrading). In the present work, molybdenum sulfide (MoS2) particles with varying diameters (10000–10 nm) were prepared using polyvinylpyrrolidone as capping agent. The prepared particles were characterized by DLS, TEM, XRD, and XPS and tested in the hydrodesulfurization (HDS) of a vacuum gas oil (VGO). A correlation between particle size and activity is presented. It was found that particles with diameters around 13 nm show double the HDS activity compared with the material with micrometric particle sizes (diameter ≈ 10,000 nm).Peer Reviewe