Browsing by Author "Zhang, Ping"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Laboratory investigation of co-precipitation of CaCO3/BaCO3 mineral scale solids at oilfield operating conditions: Impact of brine chemistry
    (IFP Energies nouvelles, 2020) Zhang, Zhang; Kan, Amy T.; Tomson, Mason B.; Zhang, Ping
    Oilfield mineral scale deposition can become severe flow assurance challenge especially for offshore deepwater productions. Hazards arising from scale formation and subsequent deposition include production system throughput reduction and eventually blockage. Among various types of scales, carbonates are among the most frequently observed scales in oilfield operations. Similar to many natural and industrial processes, co-precipitation of multiple scales can commonly be observed in oilfield operations. Although extensive research efforts have been made in the domain of understanding the thermodynamics of scale formation, there are limited studies to investigate the kinetic aspect of scale formation, particularly the kinetics of co-precipitation of multiple scales. In this study, the kinetic characteristics of CaCO3/BaCO3 co-precipitation have been experimentally investigated at representative oilfield conditions of 80 °C and 1 M NaCl condition. The focus was given to the investigation of the impact of different brine chemistry conditions such as mineral saturation level and Ca to Ba molar ratio. The experimental results suggest that CaCO3 saturation level, substrate material and molar ratio can impact the nature and morphology of the carbonate scales formed. An elevation of CaCO3 saturation index from 0.6 to 2 will change the formed carbonate solids from calcite to aragonite. In addition, at a Ca:Ba molar ratio of 1:15 with an excessive aqueous Ba species available, Ba species can partition into CaCO3 crystal lattice to distort CaCO3 lattice, resulting in almost 2-fold increase in aqueous Ca concentration. The results and conclusions from this study have the potential to benefit oilfield scale control strategy development, particularly the one related to carbonate scale formation control.
  • Thumbnail Image
    Item
    Nanocarboneous materials in water: Interaction of nanocarbon(60) with soil and organic pollutants
    (2008) Zhang, Ping; Tomson, Mason B.
    The property of nanosized colloidal C 60 (nano-C 60 ) suspensions prepared by ultra sonication method was examined for electrochemical properties and stability under different physiochemical conditions. Adsorption experiments of such materials to Lula soil and other two types of sediments were evaluated to investigate the interaction of nano-C 60 colloidal particles with soil organic carbon. Transport of nano-C 60 in porous media was examined in column tests at different ionic strength and flow rates. Interactions of nano-C 60 with two model organic pollutants 2,2',5,5'-polychlorinated biphenyl and phenantherene were studied by batch adsorption-desorption experiments and facilitated column transport experiments. It was found that the sorption of nanoparticles to different porous media and sorption of organic pollutants to nanoparticles can be modeled by a linear sorption isotherm and nano-C 60 can serve as carrier for the organic compounds, leading to further migration of these hydrophobic organic pollutants.
  • Thumbnail Image
    Item
    Synthesis and application of phosphonate scale inhibitor nanomaterials for oilfield scale control
    (2011) Zhang, Ping; Tomson, Mason B.
    In this study, several synthesis routes were adopted to prepare nanometer sized metal-phosphonate particles to expand their use in the delivery of phosphonate mineral scale inhibitors into formation porous media for oilfield scale control. An aqueous solution of calcium chloride or zinc chloride was mixed with a basic phosphonate solution to form nanometer sized particles. The physical and chemical properties of the fabricated nanomaterials and their solutions have been carefully evaluated. The obtained nanomaterial suspensions were stable for a certain period of time at 70°C in saline solutions. The nanomaterials demonstrated a good migration performance through formation porous media. Transportability was affected by both the flow velocity and the surface chemistry of the nanomaterials as well as the formation medium. The transport of these nanomaterials can be enhanced, when the formation materials were pre-flushed by surfactant solutions. The potential application of the synthesized nanomaterials for scale treatment in oilfields has been investigated by a series of laboratory squeeze simulation tests. The synthesized nanomaterials were injected into formation medium and retained on the medium surfaces. After a shut-in period, the inhibitor nanomaterials slowly released phosphonates into the produced fluid to prevent scale formation. It has been observed that the prepared nanomaterials are able to return phosphonates in a similar return profile as that of the conventional acidic pills. Moreover, the crystalline phase Ca-DTPMP nanomaterials, developed from their amorphous precursors, demonstrate a long term phosphonate return behavior with a stable phosphonate return concentration for an extended period of time. The long term flow back performance of metal-phosphonate nanomaterials can be interpreted by their solubility product in brine solutions.