Title

Development and Evaluation of Ultra-High Temperature Resistant Preformed Particle Gels for Conformance Control in North Sea Reservoirs

Abstract

Preformed particle gels (PPGs), a type of hydrogel, have been widely applied to control the conformance of reservoirs owing to their robust gel chemistries. Traditional PPGs are polyacrylamide-based hydrogel compositions which can withstand neither higher temperatures nor high salinity conditions. There are many deep oilfield reservoirs worldwide which demand PPG products with a long term hydrolytic and thermal stability at the temperatures of higher than 120 °C. Current PPGs neither remain hydrated nor retain polymer integrity at these temperatures. A unique high temperature-resistant hydrogel composition (HT-PPG) was developed with exceptional thermal stability for greater than 18 months in North Sea formation temperature (~130 °C) and formation water environments. HT-PPG described herein can swell up to 30 times its initial volume in brines of different salinity for North Sea. The effects of salinity and temperature on swelling, swelling rate, and rheological behavior was studied. These HT-PPGs exhibit excellent strength with storage modulus (G') of over 3,000 Pa at the swelling ratio of 10. Thermostability evaluations were performed in North Sea brines with variable salinity at temperatures of 130 °C and 150 °C and found to be stable for 18 months with no loss of molecular integrity at the higher temperature. Laboratory core flooding tests were conducted to test its plugging efficiency to fracture. HT-PPGs showed good plugging efficiency by reducing the permeability of open fracture and did not wash out during waterflooding. Overall, HT-PPG is a novel product with excellent hydrothermal stability that make it an ideal candidate for conformance problems associated with reservoirs of high temperature and salinity conditions.

Meeting Name

SPE Annual Technical Conference and Exhibition (2021: Sep. 21-23, Dubai, UAE)

Department(s)

Chemistry

Second Department

Geosciences and Geological and Petroleum Engineering

Comments

The authors would like to acknowledge funding from our Preformed Particle Gel Conformance Control Consortium company members: ConocoPhillips, Occidental Petroleum, Daqing Xinwantong Technology Developing Company, Ltd. and Petrochina that supported this work.

Keywords and Phrases

Enhanced Recovery; Conformance Improvement; Water Management; Upstream Oil and Gas; Thermal Stability; Pressure Gradient; Equilibrium; North Sea Seawater; North Sea Brine; Water Flooding

International Standard Book Number (ISBN)

978-161399786-4

International Standard Serial Number (ISSN)

2638-6712

Document Type

Article - Conference proceedings

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2021 Society of Petroleum Engineers (SPE), All rights reserved.

Publication Date

15 Sep 2021

Share

 
COinS