Plugging performance of preformed particle gels in fractures and its influencing factors

"Preformed particle gels (PPG) has been successfully applied to combat the water channeling caused by fractures or fracture-like channels. Understanding the placement and plugging of PPG in fractures is crucial for gel treatment design. The objective of the dissertation is to explore the plugging performance of three PPG products in two types of fracture models, the partially and fully open fractures. The following studies has been conducted and conclusions have been drawn based on the results and analysis. First, the placement and plugging performance of conventional PPG was investigated using core flooding experiments conducted partially open fractures. The plugging efficiency of PPG was revealed to be greater in this specific type of fractures than the treatment conducted in fully open fractures. Second, supplementary core flooding experiments were performed to study the effect of fracture dimensions, matrix permeability, and residual oil on the PPG behaviors in partially open fractures. The dehydration of placed PPG positively related to the placement volume in fracture volume. Third, a novel CO₂-responsive preformed particle gel (CR-PPG) was examined using swelling tests to characterize the CO₂-responsive swelling and using supercritical CO₂ flooding to evaluate the CO₂-plugging performance in open fractures. The CR-PPG could effectively plug CO₂ and achieved a significant residual resistance factor. Finally, a novel re-crosslinkable preformed particle gel (RPPG) was evaluated as an agent specifically designed for healing large fractures. The evaluation of oxidizing breakers for the re-crosslinked RPPG was provided. Among the tested breakers, NaOH-activated Na₂S₂O₈ was most effective one with relatively wider practical ranges in breaker concentration and gel concentration"--Abstract, page iv.

Name thesis:degree_name

Ph. D. in Petroleum Engineering

Grantor

Missouri University of Science and Technology

Author dc:creator

• Wang, Ze

• Dehydration
• Fractures
• Gel treatment
• Preformed particle gel
• Water management
• Petroleum Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2796

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3801