Merdhah, Amer Badr and Mohd Yassin, Abu Azam (2008) Scale formation in oil reservoir during water injection at high-barium and high-salinity formation water. In: 2008 SPE Saudi Arabia Section Technical Symposium, 10-12 May 2008, Alkhobar, Saudi Arabia.
Scale deposition is one of the most serious oil field problems that inflict water injection systems primarily when two incompatible waters are involved. Two waters are incompatible if they interact chemically and precipitate minerals when mixed. Typical examples are sea water, with high concentration of sulfate ion and formation waters, with high concentrations of calcium, barium, and strontium ions. Mixing of these waters, therefore, could cause precipitation of calcium sulfate,barium sulfate and/or strontium sulfate. This study was conducted to investigate the permeability reduction caused by deposition of calcium, strontium, and barium sulfates in sandstone cores from mixing of injected sea water and formation water that contained high concentration of calcium,barium and strontium ions at various temperatures (50-80Â°C) and differential pressures (100-200 psig). The solubility of common oil field scales formed and how their solubilities were effected by changes in salinity and temperatures (40-90Â°C) were also studied. The morphology and particle size of scaling crystals formed as shown by Scanning Electron Microscopy (SEM) were also presented. The results showed that a large extent of permeability damage caused by calcium, strontium and barium sulfates that deposited on the rock pore surface. The rock permeability decline indicates the influence of the concentration of calcium,barium and strontium ions. At higher temperatures, the deposition of CaSO4 and SrSO4 scales increases and the deposition of BaSO4 scale decreases since the solubilities of CaSO4 and SrSO4 scales decreases and the solubility of BaSO4 increases with increasing temperature. The deposition of CaSO4, SrSO4, and BaSO4 scales during flow of injection waters into porous media was shown by Scanning Electron Microscopy (SEM) micrographs.
|Item Type:||Conference or Workshop Item (Paper)|
|Subjects:||T Technology > T Technology (General)|
|Divisions:||Chemical and Natural Resources Engineering (Formerly known)|
|Deposited By:||Norhani Jusoh|
|Deposited On:||17 Oct 2008 09:17|
|Last Modified:||01 Jun 2010 15:45|
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