Developments of polymer gel plug for temporary blocking in SAGD wells

Wu, Hao; Ge, Jijiang; Liu, Yang; Yu-yao, Yang; Zhang, Tian-Ci; Guo, Hongbin

doi:10.1016/j.petrol.2021.109650

Cited by 10 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For instance, acids stimulate the decomposition of HMTA into formaldehyde, facilitating the cross-linking process from gelant to bulk gel [ 38 ]. Resorcinol and hydroquinone suffer from oxidation side reaction due to O 2 , probably leading to a reduction in cross-linking sites and a poor gel strength [ 39 ]. Research results reveal that the acid gas and O 2 contained in flue gas would have a more intricate effect on cross-linker behaviors.…”

Section: Introductionmentioning

confidence: 99%

Probing the Effect and Mechanism of Flue Gas on the Performance of Resorcinol/Hexamethylenetetramine-Based Polymer Gel in Flue Gas Flooding Reservoir

Qiao

Zhang

et al. 2022

Gels

View full text Add to dashboard Cite

Polymer gel plugging is an effective method for gas mobility control in flue gas flooding reservoirs. However, the effect and mechanism of flue gas on the performance of polymer gels have rarely been reported. In this study, a polymer gel was prepared by cross-linking hydrolyzed polyacrylamide (HPAM) and resorcinol/ hexamethylenetetramine (HMTA) to illuminate the influencing mechanism of flue gas composition on gel. The gel rheological testing results showed that flue gas promoted gelation performance, whereas it seriously threatened gel long-term stability, especially at high pressure conditions. The influence of CO2 on the polymer gel had the characteristic of multiplicity. The hydrodynamic radius (Rh) and the initial viscosity of HPAM solution decreased in the presence of CO2. Nonetheless, the dissolved CO2 expedited the decomposition rate of HMTA into formaldehyde, which promoted the cross-linking process of the HPAM, leading to a shorter gelation time. Oxidation–reduction potential (ORP) tests and Fourier transform infrared spectroscopy (FTIR) analysis indicated that O2 played a leading role in the oxidative degradation of HPAM compared to CO2 and threatened the gel long-term stability at elevated gas pressures. To address the adverse effects caused by flue gas, it is highly desirable to develop polymer gels by adding oxygen scavengers or strengthening additives.

show abstract

Section: Introductionmentioning

confidence: 99%

Probing the Effect and Mechanism of Flue Gas on the Performance of Resorcinol/Hexamethylenetetramine-Based Polymer Gel in Flue Gas Flooding Reservoir

Qiao

Zhang

et al. 2022

Gels

View full text Add to dashboard Cite

show abstract

“…At present, the commonly used polymer gel systems are mainly cross-linked polymer gels based on polyacrylamide and modified cross-linked polymer gels based on acrylamide. , Freedman et al have developed a series of degradable hydrogels by combining covalent network degradable cross-linking agents and hydrolyzable ionic cross-linked backbone polymers, and these hydrogels have shown high mechanical properties, adhesion, and degradability in tests up to 16 weeks; Jia et al have studied a new type of high-strength degradable nanocomposite gel, and this system can be gelled within 20–50 min at 75 ∼ 105 °C, boasting excellent shear resistance . However, the existing similar hydrogel plugging agents cannot be easily adopted in medium and low-temperature plugging operations due to problems such as poor breaking performance, nonspontaneous degradation, and reservoir pollution, leading to great difficulty and high risks in on-site constructions. − Quaternary ammonium ester cross-linkers are an important class of cross-linkers for hydrogels, and compared to other common cross-linkers, quaternary ammonium ester cross-linkers applied to hydrogels can achieve low- and medium-temperature self-degradation. − …”

Section: Introductionmentioning

confidence: 99%

Synthesis and Performance Study of Self-Degradable Gel Plugging Agents Suitable for Medium- and Low-Temperature Reservoirs

Zou,

Wang,

et al. 2024

ACS Omega

View full text Add to dashboard Cite

Aiming at the problems of current similar hydrogel plugging agents, such as poor breaking performance, nonspontaneous degradation, and reservoir pollution which have been plaguing their application in temporary plugging operations, this study has synthesized a cross-linking agent for hydrogels with dimethylaminoethyl acrylate and dibromo-p-xylene as raw materials. With Fourier transform infrared, 1 H nuclear magnetic resonance, and thermogravimetric analyses as representations of the structure and thermal stability of the crosslinking agent, a set of self-degrading hydrogel systems has been developed with the cross-linking agent as the core so as to make evaluations on the temperature resistance, plugging performance, and core damage performance of the hydrogel and conduct a study on its gelation kinetics. The research results show that the cross-linking agent shows good thermal stability. When applied in the hydrogel system, the hydrogel has shown high temperature resistance, maintaining gel strength for 5−10 days at 50−90 °C, with viscosity after complete degradation lower than 10 mPa•s. The excellent bearing strength of the hydrogel system has led to a core damage rate below 5%. The study on gelation kinetics of the hydrogel system shows that, with the increase in the concentration of the cross-linking agent, the gelation time of the hydrogel system is shortened, with the reaction order between the cross-linker concentration and the gelation time at about 0.6 under the condition of 50−90 °C.

show abstract

“…Gels can be prepared by replacing the traditional metal ions or phenolic system with crosslinking agents such as polyethylenimine (PEI). In this way, people have prepared polymer gels that are stable at the highest evaluation temperature used of 177 • C [28][29][30][31][32][33]. Although these gels have good temperature and salt resistance, they have an obvious deficiency: a high concentration of PEI crosslinker needs to be used, which makes this approach uneconomical.…”

Section: Introductionmentioning

confidence: 99%

Optimization of the Methods to Develop Stable Polymer Gels for Water Management in Medium- and Ultra-High-Salinity Reservoirs

Ding

et al. 2023

Gels

View full text Add to dashboard Cite

Polymer gels suffer from a serious syneresis issue when exposed to high-temperature and high-salinity (HTHS) conditions, which limits their use as water-treatment agents in this type of reservoir. In this paper, the effects of the polymer type/concentration, deoxidizers, and stabilizers on the long-term stability of polymer gels were systematically studied; thus, the methods to develop stable polymer gels for two typical levels of salinity were optimized. The results show the following: (1) For a medium-salinity condition (TDS: 33,645.0 mg/L) at 125 °C, conventional HPAM gels completely dehydrate within only 1 day, and the addition of a deoxidizer hardly improved their stability. Some special polymers, e.g., AP-P5, MKY, and CPAM, are able to form stable gels if a high concentration of 0.8% is used; the syneresis rate of these gels is about 10% after 30 days. However, the addition of the complexant sodium oxalate significantly improves the stability of gels formed by all five of these different polymers, which behave with a 0% syneresis rate after 30 days pass. Complexants are the most economical and feasible agents to develop stable gels in medium-salinity water. (2) Gels enhanced using the methods above all become unstable in a more challenging ultra-high-saline condition (TDS: 225,068.0 mg/L). In this case, special calcium- and magnesium-resistant polymers are required to prepare stable gels, which show 0% syneresis rates after 30 days, have relatively low strengths, but do produce a good plugging effect in high-permeability cores.

show abstract

Developments of polymer gel plug for temporary blocking in SAGD wells

Cited by 10 publications

References 22 publications

Probing the Effect and Mechanism of Flue Gas on the Performance of Resorcinol/Hexamethylenetetramine-Based Polymer Gel in Flue Gas Flooding Reservoir

Probing the Effect and Mechanism of Flue Gas on the Performance of Resorcinol/Hexamethylenetetramine-Based Polymer Gel in Flue Gas Flooding Reservoir

Synthesis and Performance Study of Self-Degradable Gel Plugging Agents Suitable for Medium- and Low-Temperature Reservoirs

Optimization of the Methods to Develop Stable Polymer Gels for Water Management in Medium- and Ultra-High-Salinity Reservoirs

Contact Info

Product

Resources

About