Journal of
Petroleum and Gas Engineering

  • Abbreviation: J. Petroleum Gas Eng.
  • Language: English
  • ISSN: 2141-2677
  • DOI: 10.5897/JPGE
  • Start Year: 2010
  • Published Articles: 107

Full Length Research Paper

Effect of pH on interfacial tension and crude oil–water emulsion resolution in the Niger Delta

Olanisebe, E. B.
  • Olanisebe, E. B.
  • Department of Petroleum Engineering, University of Ibadan, Nigeria.
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Isehunwa, S. O
  • Isehunwa, S. O
  • Department of Petroleum Engineering, University of Ibadan, Nigeria.
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  •  Accepted: 19 December 2013
  •  Published: 31 December 2013

Abstract

It is important to know the produced volumes and to effectively separate the oil and water phases in oil well effluents to the surface during production. While it is known that the effectiveness of separating the phases and hence the accuracy of measurements are often affected by the nature of the fluids, the specific contributions of the physical parameters of the fluids are little known. In this study, the effect of crude oil PH on emulsion resolution was investigated. Crude oil samples from the Niger Delta with known amounts of water present were obtained. After obtaining the pH and interfacial tension, the oil and water phases were separated by centrifuge at different speeds. The results were used to establish a relationship between interfacial tension, pH and the basic sediments and water (BSW). The results show that without the use of de-emulsifiers, separation of between 66 and 90% was achieved in the light crude oil samples, but less than 30% in heavy crudes.  Oil pH was found to affect emulsion resolution and has implications on the choice of de-emulsifiers. On the other hand, interfacial tension was independent of the volume of water and hence BSW of the crude oil samples.

Key words: Oil production, interfacial tension, basic sediments and water (BSW), Niger Delta, bottle test.