Study on the optimization of the performance of preformed particle gel (PPG) on the isolation of high permeable zone

Abstract

Unwanted water production is a critical problem in fractured reservoirs. Corrosion of facilities and reduction of oil relative permeability are some of the consequences of high water production. Preformed particle gel (PPG) injection is one of the conformance control methods, which initiated in 2007, has been used to control water production and increase sweep efficiency. There are several parameters which affect the performance of PPG such as stability at reservoir condition, salinity of makeup solution and PPG particle size and concentration. Although the study of the application of PPG in fracture plugging attracted a lot of attention in recent years, there are limited studies to investigate the effect of PPG physical properties on its application in water production control. In this study, the application of a super absorbent polymer on fracture plugging has been investigated. The results of swelling tests indicated that this type of PPG had significant high resistance even at high temperatures and wide range of salinities. In addition, the results of rheology tests showed that the PPG solution was stable even at high salinity and high shear rate condition. In order to study the mechanism of improvement of sweep efficiency through PPG injection, visual investigation using glass etched micromodel was performed. The results showed that the main mechanism for PPG treatment is water diversion into the low permeability zone as the consequence of fracture plugging. Also, core flooding tests were performed to check the performance of PPG in a heterogeneous carbonate porous media. According to the results, PPG was able to reduce the permeability, and this permeability reduction is related to swelling ratio which is controlled by makeup solution salinity. The results of this study revealed the potential of super absorbent polymers as preformed particle gel in unwanted water production through fracture plugging.