Doctoral Dissertations

Keywords and Phrases

acid diversion; conformance control; degradable; gel treatment; particle gel; re-crosslinkable


"Acid stimulation and conformance control are two major methods to improve oil production. This study systematically evaluates two newly developed gels: Degradable Preformed Particle Gel (DPPG) and Re-crosslinkable Preformed Polymer Gel (RPPG). DPPG is designed to be a temporary plugging agent for acid stimulation and can self-degrade into a water-like fluid. RPPG is designed for reservoir sweep efficiency improvement and can re-crosslink to each other and form an immobile bulk gel after being placed in fractures or fracture-like conduits.

For DPPG, this study evaluates the effect of monomer, crosslinker, and initiator concentration on the swelling and degradation performance. Results show that DPPG can swell up to 70 times its original size by absorbing water and can self-degrade in 10% HCl at 80 °C. Core flooding reveals that DPPG can serve as an excellent diverter for acid stimulation while it has very little damage to matrix after degradation.

For RPPG, this study evaluates the fiber types and concentrations, swelling ratio, and fracture width effect on the injection pressure, water breakthrough pressure, and residual resistance factor (Frr). Results show that fiber can increase RPPG strength with an optimized fiber concentration. With increasing swelling ratio, the stable gel injection pressure decreases and water breakthrough pressure and Frr increases. Dehydration study reveals that the water content change significantly affects the RPPG properties. The dehydration behavior is related to the dehydration time which is related to the gel injection rate. Results show that at lower gel injection rate, the dehydration increases along the fracture, but decreases at higher gel injection rate"--Abstract, p. iv


Bai, Baojun

Committee Member(s)

Schuman, Thomas P.
Dunn-Norman, Shari
Wei, Mingzhen
Flori, Ralph E.
Sun, Xindi


Geosciences and Geological and Petroleum Engineering

Degree Name

Ph. D. in Petroleum Engineering


Missouri University of Science and Technology

Publication Date

Fall 2022


xv, 120 pages

Note about bibliography

Includes_bibliographical_references_(pages 113-119)


© 2022 Shuda Zhao, All Rights Reserved

Document Type

Dissertation - Open Access

File Type




Thesis Number

T 12211