A Recrosslinkable Preformed Particle Gel for Conformance Control in Heterogeneous Reservoirs Containing Linear-Flow Features

Abstract

Summary Preformed particle gels (PPGs) have been successfully applied to control conformance for mature oil fields because of their advantages over conventional in-situ gels. However, field applications have demonstrated that current particle gels cannot efficiently plug open fractures, fracture-like channels, or conduits that exist in many mature oil fields. The objective of this study is to systematically evaluate a new recrosslinkable-PPG (RPPG) product that can be used to efficiently control the conformance for abnormal features. The RPPG can swell to 38 times its initial volume, and the equilibrium swelling ratio is independent of the brine salinity. Temperature and the particle size showed a gradient effect on the swelling rate of the gel. Additionally, the particle gels can recrosslink to form a rubber-like bulky material in the large-opening features after placement that significantly enhances the plugging efficiency. We systematically evaluated the effect of temperature and RPPG swelling ratio on the recrosslinking time, the gel strength after crosslinking, and the gel thermostability. Coreflooding tests were run to test whether RPPG can significantly improve the fracture-plugging efficiency compared with a traditional PPG that cannot recrosslink after pumping. The RPPG can be customized for mature reservoirs with a temperature from 23 to 80°C with a controllable size from tens of nanometers to a few millimeters. The recrosslinking time can be controlled from 2 to 80 hours, depending on the swelling ratio and temperature. The gel elastic modulus after recrosslinking can achieve from 300 to 10 800 Pa, depending on the swelling ratio and the temperature. Coreflooding tests showed that the breakthrough pressure of the recrosslinked RPPG can reach up to 300 psi/ft for a fracture with a 0.2-cm aperture, which is more than five times higher than that of the conventional PPG.

Review of Microgels for Enhanced Oil Recovery: Properties and Cases of Application

“…One of the cheapest and environmentally friendly [ 16 ] reagents that is used for this is polyacrylamide (PAM), which costs about USD 2.00–4.00 per kg [ 17 ]. There are several approaches for PAM application in mature reservoirs: polymer flooding [ 18 , 19 , 20 ], bulk gels [ 21 , 22 ], preformed particle gels [ 17 , 23 ], and their combinations. The following comprehensive reviews are dedicated to polymer gels systems, including preformed particle gels and its application for enhanced oil recovery [ 17 , 24 , 25 , 26 ].…”

Water shutoff and conformance improvement: an introduction

“…17 through 23 was based on work with moderated-to-high molecular-weight HPAM cross-linked with Cr(III) acetate. However, we anticipate that the behavior will be mimicked by any gel formed from polymers with a similar degree of polymerization and using any cross-linker, including guar-borate gels (Seright 2003a), HPAM cross-linked with polyethylene imine (Al-Muntasheri et al 2007a, b, 2006Lane 2012, 2013;Zhu et al 2019), phenol-formaldehyde (Alvarez et al 2001;Amaury et al 2002), hydroquinone-hexamethylenetetramine (Dovan et al 1997;Glasbergen et al 2014;Unomah et al 2018), and preformed particle gels (PPGs) (Alhuraishawy et al 2019;Bai and Zhang 2011;Imqam et al 2015Imqam et al , 2017Pu et al 2019;Sun et al 2020;Wang and Bai 2018;Wang et al 2019).…”

“…There are an immense number of materials that have been proposed for conformance improvement or water shutoff (Al-Muntasheri et al 2006;Amaury et al 2002;Bae et al 1996;Chan 1988;Creel and Crook 1997;El-karsani et al 2014;Glasbergen et al 2014;Jurinak and Summers 1991;Kabir 2001;Kantzas et al 1999;Lenchenkov et al 2019;Marty et al 1991;Moradi-Araghi et al 1993;Mumallah 1988;Perez et al 1997;Pu et al 2019;Schmidt et al 1984;Seright 1988Seright , 1993Seright and Liang 1995;Sun et al 2020;Sydansk 1990;Sydansk and Romero-Zeron 2011;Vossoughi 2000;Wang et al 2019;Whitney et al 1996). Rather than try to discuss them all, we suggest that the key question to be asked is: What do you want the material to do in your particular application?…”

Systematic Evaluation of a Novel Self-Healing Poly(acrylamide-co-vinyl acetate)/Alginate Polymer Gel for Fluid Flow Control in High Temperature and High Salinity Reservoirs

“…The swelled Alg-IPNG particles were aged at 65 • C, 80 • C, and 110 • C, with a controlled water uptake ratio varying from 10:1 to 40:1. Since the self-healing process was designed to be delayed, and healing is not an instantaneous process, we defined the self-healing times as the starting time, completion time, and time interval, same as in our previous publications [23]. The starting time was the time when some weak associations among the particles formed.…”