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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.


Raman spectra of the simulated product (a) and salt deposition (b).
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f8: Raman spectra of the simulated product (a) and salt deposition (b).

Mentions: The simulated products were characterised by XRD and LRS. As shown in Fig. 7, sodium silicate (Na2Si2O5), natrosilite (Na2Si2O5) and sodium carbonate (Na2CO3) were the main crystalline phases identified in the simulated products. In addition, the degree of matching was greatest for the sodium silicate (Na2Si2O5). The Raman spectra of the salt deposition and the simulated products are presented in Fig. 8 and show similar patterns, suggesting that the main compounds have similar structural units. The strong Raman bands at 1073 cm−1 (Fig. 8(a)) and 1065 cm−1 (Fig. 8(b)), which are usually associated with the stretching vibrations of the terminal nonbridging oxygens (ν(Si-O−)) of the Na2Si2O5 species, appear in the 1100–1050 cm−1 region22. Meanwhile, the bands at 463 cm−1, 518 cm−1, 482 cm−1 and 536 cm−1 are presented in the 700–400 cm−1 region, which is attributed to the stretch vibration of the Si-O-Si modes. In addition, the bands at 398 and 336 cm−1 are attributed to the Na-O vibration of the natrosilite (Na2Si2O5). In Fig. 8(a), the Na-O vibration of the sodium silicate (Na2Si2O5) is characterised at 386 and 338 cm−1, while the bands at 1012 cm−1 and 961 cm−1 can also be attributed to a small quantity of structural units in chains and dimmers23, respectively.


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)

Raman spectra of the simulated product (a) and salt deposition (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f8: Raman spectra of the simulated product (a) and salt deposition (b).
Mentions: The simulated products were characterised by XRD and LRS. As shown in Fig. 7, sodium silicate (Na2Si2O5), natrosilite (Na2Si2O5) and sodium carbonate (Na2CO3) were the main crystalline phases identified in the simulated products. In addition, the degree of matching was greatest for the sodium silicate (Na2Si2O5). The Raman spectra of the salt deposition and the simulated products are presented in Fig. 8 and show similar patterns, suggesting that the main compounds have similar structural units. The strong Raman bands at 1073 cm−1 (Fig. 8(a)) and 1065 cm−1 (Fig. 8(b)), which are usually associated with the stretching vibrations of the terminal nonbridging oxygens (ν(Si-O−)) of the Na2Si2O5 species, appear in the 1100–1050 cm−1 region22. Meanwhile, the bands at 463 cm−1, 518 cm−1, 482 cm−1 and 536 cm−1 are presented in the 700–400 cm−1 region, which is attributed to the stretch vibration of the Si-O-Si modes. In addition, the bands at 398 and 336 cm−1 are attributed to the Na-O vibration of the natrosilite (Na2Si2O5). In Fig. 8(a), the Na-O vibration of the sodium silicate (Na2Si2O5) is characterised at 386 and 338 cm−1, while the bands at 1012 cm−1 and 961 cm−1 can also be attributed to a small quantity of structural units in chains and dimmers23, respectively.

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.