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Characterizing and Exploring the Formation Mechanism of Salt Deposition by Reusing Advanced-softened, Silica-rich, Oilfield-produced Water (ASOW) in Superheated Steam Pipeline.

Dong B, Xu Y, Lin S, Dai X - Sci Rep (2015)

Bottom Line: In addition, the solubility of the deposition was about 99%, suggesting that it is very different from traditional scaling.The results of a simulation experiment and thermal analysis system (TGA and TG-FTIR) proved that Na2CO3 and Si(OH)4 (gas) are involved in the formation of Na2Si2O5, which is ascribed mainly to the temperature difference between the superheated steam and the pipe wall.These findings provide an important reference for improving the reuse of ASOW and reducing its deposition.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.

ABSTRACT
To dispose of large volumes of oilfield-produced water, an environmentally friendly method that reuses advanced-softened, silica-rich, oilfield-produced water (ASOW) as feedwater was implemented via a 10-month pilot-scale test in oilfield. However, salt deposition detrimental to the efficiency and security of steam injection system was generated in superheated steam pipeline. To evaluate the method, the characteristics and formation mechanism of the deposition were explored. The silicon content and total hardness of the ASOW were 272.20 mg/L and 0.018 mg/L, respectively. Morphology and composition of the deposition were determined by scanning electron microscope-energy dispersive spectrometry (SEM-EDS), inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS). Na2Si2O5, Na2CO3 and trace silanes were identified in the deposition. In addition, the solubility of the deposition was about 99%, suggesting that it is very different from traditional scaling. The results of a simulation experiment and thermal analysis system (TGA and TG-FTIR) proved that Na2CO3 and Si(OH)4 (gas) are involved in the formation of Na2Si2O5, which is ascribed mainly to the temperature difference between the superheated steam and the pipe wall. These findings provide an important reference for improving the reuse of ASOW and reducing its deposition.

No MeSH data available.


XRD pattern of the cluster crystals on the surface of the deposition.
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f5: XRD pattern of the cluster crystals on the surface of the deposition.

Mentions: The structural morphology of the solid sample was studied by SEM-EDS. Figure 4 provides the basic layered structure and corresponding elemental composition of the deposition. A distinct three-layered structure is presented in Fig. 4(A). Some cluster crystals appeared on the surface of the deposition (Fig. 4A (a)), whereas block-like crystals appeared in the middle (Fig. 4A (b)) and vitreous crystals formed on the internal surface of the pipeline (Fig. 4 A (c)). However, there was a big difference between (a) and (b) in the relative content of the Si and C elements. The XRD pattern of the cluster crystal is presented in Fig. 5. Clearly, the cluster crystal was sodium carbonate (Na2CO3).


Characterizing and Exploring the Formation Mechanism of Salt Deposition by Reusing Advanced-softened, Silica-rich, Oilfield-produced Water (ASOW) in Superheated Steam Pipeline.

Dong B, Xu Y, Lin S, Dai X - Sci Rep (2015)

XRD pattern of the cluster crystals on the surface of the deposition.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660299&req=5

f5: XRD pattern of the cluster crystals on the surface of the deposition.
Mentions: The structural morphology of the solid sample was studied by SEM-EDS. Figure 4 provides the basic layered structure and corresponding elemental composition of the deposition. A distinct three-layered structure is presented in Fig. 4(A). Some cluster crystals appeared on the surface of the deposition (Fig. 4A (a)), whereas block-like crystals appeared in the middle (Fig. 4A (b)) and vitreous crystals formed on the internal surface of the pipeline (Fig. 4 A (c)). However, there was a big difference between (a) and (b) in the relative content of the Si and C elements. The XRD pattern of the cluster crystal is presented in Fig. 5. Clearly, the cluster crystal was sodium carbonate (Na2CO3).

Bottom Line: In addition, the solubility of the deposition was about 99%, suggesting that it is very different from traditional scaling.The results of a simulation experiment and thermal analysis system (TGA and TG-FTIR) proved that Na2CO3 and Si(OH)4 (gas) are involved in the formation of Na2Si2O5, which is ascribed mainly to the temperature difference between the superheated steam and the pipe wall.These findings provide an important reference for improving the reuse of ASOW and reducing its deposition.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.

ABSTRACT
To dispose of large volumes of oilfield-produced water, an environmentally friendly method that reuses advanced-softened, silica-rich, oilfield-produced water (ASOW) as feedwater was implemented via a 10-month pilot-scale test in oilfield. However, salt deposition detrimental to the efficiency and security of steam injection system was generated in superheated steam pipeline. To evaluate the method, the characteristics and formation mechanism of the deposition were explored. The silicon content and total hardness of the ASOW were 272.20 mg/L and 0.018 mg/L, respectively. Morphology and composition of the deposition were determined by scanning electron microscope-energy dispersive spectrometry (SEM-EDS), inductively coupled plasma-mass spectroscopy (ICP-MS), X-ray diffraction (XRD), laser Raman spectroscopy (LRS) and X-ray photoelectron spectroscopy (XPS). Na2Si2O5, Na2CO3 and trace silanes were identified in the deposition. In addition, the solubility of the deposition was about 99%, suggesting that it is very different from traditional scaling. The results of a simulation experiment and thermal analysis system (TGA and TG-FTIR) proved that Na2CO3 and Si(OH)4 (gas) are involved in the formation of Na2Si2O5, which is ascribed mainly to the temperature difference between the superheated steam and the pipe wall. These findings provide an important reference for improving the reuse of ASOW and reducing its deposition.

No MeSH data available.