High saline water formed halite deposition in oil well

Title : High saline water formed halite deposition in oil well

Abstract:

This work is aimed to study the formation and mitigation of depositions formed in oil well. Static tests are performed to measure the amount of formed deposits based on ion responsible deposits remained in aqueous phase. In this test the key parameter is temperature (Max. 85 ˚C). Dynamic test, tube blocking test (TBT), are concerned with formation rate of any deposits at both temperature and pressure. The formation rate of deposits are measured as a function of pressure build-up versus time. X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques are used to identify quantitative composition and morphology of deposits.

Results of water analysis showed a high content of ions such as sodium, Na⁺. In general, static tests at ambient and top surface production facilities temperatures showed a high rate of formation of halite salt (NaCl). The rate of halite formation at high temperature (85 ˚C) is less than at ambient temperature (25 ˚C). Phosphonate and polymeric based inhibitors are recommended to prevent the formation of deposits. The maximum efficiency achieved was 19 %. Adding low saline water (i.e. brackish water with salinity less than 15,000 mg/L) is one of the common methods used to prevent formation of halite salt. The amount of halite salt was reduced by 90% by adding 2% vol/vol of brackish water. As the salinity of produced water in oil well is changing considerably by time and the salinity increases, calcium carbonate scale is formed and precipitated with halite salt. XRD results for collected scale from static test showed a quantitative measurements as the following: halite salt (64%) as a major deposit, Aragonite (28%) and Calcite (8%).

Biography:

Majeda Mohamed Erraes holds a B.Sc. in Chemical Engineering from Tripoli University, Libya, and has been working at the Petroleum Research Centre (PRC), Libya, since 2004, primarily in the Scale Laboratory. His professional experience focuses on the study, analysis, formation, and prevention of inorganic scales in Libyan oilfields. He has been actively involved in various research and field projects, including scale analysis and the separation of organic and inorganic scales, compatibility studies, scale inhibitor evaluation using tube-blocking and static testing methods, and the characterization and analysis of scale inhibitors. His expertise also includes investigating the formation and prevention of inorganic scales in oilfield operations, evaluating demulsifiers for emulsion treatment through chemical methods, and understanding corrosion mechanisms, their causes, and mitigation techniques. Additionally, he is proficient in the use of scale prediction software, including Oddo-Tomson, Pitzer, and Multiscale 7.1, for assessing and managing scale-related challenges in petroleum production systems.