Loading...

Experimental Investigation of Fractures’ Water Shut-off in Low Salinity Water Injection Using Preformed Particle Gels

Sanandaji, Farshid | 2021

459 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 53902 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Fatemi, Mobin; Ghazanfari, Mohammad Hossein
  7. Abstract:
  8. As the reservoir matures, especially in fractured reservoirs, oil production is usually accompanied by the production of some unwanted water. Water production causes environmental problems and imposes high costs on the production system, including the cost of separating water and oil, corrosion of facility, and sometimes, leading to abandoning well. One way to solve this problem is to use gels as a blocking agent. Today, preformed particle gels are used as an alternative to in situ gels, which can solve some issues of in-situ gels, such as uncertainty in gelling time and penetration depth.This research comprises three main parts. In the first part, four samples of preformed particle gels with different concentrations of Nano Silica were synthesized in the laboratory by using the free radical polymerization method. In the second part, synthesized preformed particle gel samples was investigated through bulk tests. In this section, the effect of various factors such as salinity, type of pure salt, and oil-water interactions on the samples of synthesized particle gel was investigated. Fluid rheology properties for these samples in formation and seawater were analyzed using frequency sweep test, strain sweep and shear stress, and viscosity test. In addition, the FESEM test of dry particles was performed to confirm the presence of Nano Silica and its effects on the synthesized samples. In the third part, the dynamic strength of the synthesized particle gel samples during formation water and seawater injection was studied using water residual resistance factor values in the Hell-Shaw cell setup.The results of bulk tests showed that the swelling of the particles initially increased and then decreased the swelling with increasing the concentration of Nano Silica so that the gel particles containing 0.4% by weight of nano Silica had the highest swelling. Also, in bulk tests, it was shown that the type of salt, salt concentration, and the existence of interactions between oil and water affect the swelling. The presence of interactions between oil and water and decreasing the salt concentration increase the swelling of the gel particles. The results of the FESEM and EDS test confirmed the presence of Nano Silica in the gel structure. The results of the rheology test showed that the strength of gel particles initially increases and then decreases with increasing the concentration of Nano Silica so that the highest strength is related to particles with 0.8% by weight of Nano Silica. The results of shear stress diagrams also showed that the swollen gel particles exhibit plastic-like behavior. Hell-Shaw cell tests showed that Nano Silica improved the dynamic strength and performance of the gel particles against water flow. The dynamic strength of gel particles initially increases and then decreases with increasing concentration of Nano Silica. The best performance of the gel particles is observed for the sample swollen in seawater containing 0.8% by weight of Nano Silica
  9. Keywords:
  10. Preformed Particle Gel ; Nanosilica ; Low Salinity/Smart Waterflooding ; Fracture Plugging ; Unwanted Water Production ; Water and Oil Interactions on Gel Swelling Effect ; Free Radicals Polymerization

 Digital Object List

 Bookmark

No TOC