Laboratory Evaluation of Crosslinked Polymer Gels for Water Diversion

Summers, L.E.; Purkaple, J.D.; Allison, Joe D.

doi:10.1007/978-1-4757-1985-7_22

Cited by 3 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For each concentration, the experiment was performed in triplicate. Gel time (t gel ) is defined as the intercept of the extrapolations from the two straight line portions of the viscosity-times curves (Summers et al, 1988) and the rate of gelation (r gel ) as the slope of the curve as marked on the figure. The reported values of t gel and r gel are averages of each triplicate indicates a degree of heterogeneity resulting from the direct addition of calcium chloride.…”

Section: Monovalent and Divalent Cation Acceleratorsmentioning

confidence: 99%

Use of bacterial ureolysis for improved gelation of silica sol in rock grouting

MacLachlan¹,

Mountassir²,

Lunn³

2013

Géotechnique Letters

View full text Add to dashboard Cite

Low pH silica-based grouts suitable for penetrating fine aperture fractures are increasingly being developed for use in engineering applications. Silica sol has an initial low viscosity and mixing with an accelerator destabilises the suspension producing a gel. The influence of sodium, calcium and ammonium chloride accelerators on gel time, rate of gelation and shear strength of the resulting gel were investigated in this study. For the first time the potential use of bacterial ureolysis as an accelerator for the destabilisation of silica sol was also explored. This study demonstrates that bacterial ureolysis can be used to control the gelation of silica sol. The rate of ureolysis increases with increasing bacterial density, resulting in faster gel times and higher rates of gelation. In addition, for grouts with similar gel times, using bacterial ureolysis to induce destabilisation results in a higher rate of gelation, a higher final shear strength and a more uniform gel than direct addition of the corresponding chemical accelerator. These results suggest that bacterial ureolysis could potentially be used in rock grouting to achieve long gel times and hence greater penetration, while also maintaining sufficiently rapid gelation to minimise issues related to fingering and erosion of the fresh grout

show abstract

Section: Monovalent and Divalent Cation Acceleratorsmentioning

confidence: 99%

Use of bacterial ureolysis for improved gelation of silica sol in rock grouting

MacLachlan¹,

Mountassir²,

Lunn³

2013

Géotechnique Letters

View full text Add to dashboard Cite

show abstract

“…The critical parameters to be considered in the application of gels for plugging high permeability zones are gelation time and yield strength (Nguyen et al 2012;Summers et al 1988;Vasquez et al 2003). The gelation time indicates the time required for a cross-linked polymer to change from a free-flowing solution to a gel or semi-gel state and becoming difficult to pump (Hardy et al 1999).…”

Section: Introductionmentioning

confidence: 99%

Gelation behavior as a function of concentration of sodium thiosulfate for PAM gels cross-linked with chromium

Al‐Hajri

Mahmood

Akbari

et al. 2018

J Petrol Explor Prod Technol

View full text Add to dashboard Cite

Existing reducing agents for cross-linking polymers are expensive and toxic and mostly limited for water shut off applications. A gelation study was performed on a safer, cheaper, more soluble, and short-lived gel by cross-linking polyacrylamide and chromium as a cross-linking agent using a rheometer and bead-pack porous media. The effect of concentration of sodium thiosulfate as the reducing agent was investigated to determine conditions for optimum yield strength and the gelation time and behavior which has never been published before. For a fixed minimum concentration (for the gel to form) of polyacrylamide and sodium dichromate, the gel yield strength vs. sodium thiosulfate concentration showed a somewhat bell-shaped curve initially increasing, reaching a peak at 2000 ppm, and then starting to decrease. The gelation formed by sodium thiosulfate was comparatively weak and short lived as compared to the ones formed by other reducing agents. Gel started to form instantaneously, reached a peak in 2 h, began to decrease, and then stabilized at 40 cp. The mobility reduction trends were similar to the yield strength curve. The short-lived gel could be useful to improve the waterflood mobility ratio far away from the wellbore without compromising on ease of injectivity.

show abstract

Polymer Gelants for High Temperature Water Shutoff Applications

Bryant¹,

Bartošek

Lockhart

et al. 1997

SPE Journal

View full text Add to dashboard Cite

Polymer gelants are a well established means for shutting off water in lower temperature formations, but extending their application to hot reservoirs (>80°C) presents a number of technical challenges, particularly in matrix reservoirs. Achieving reliable high temperature performance requires programmable gelation delay, good injectivity good propagation of gelant components and durability of the permeability reduction. The performance of a gelant against these criteria is dictated by a relatively small set of chemical and physical phenomena. A discussion of these phenomena provides a rational background for assessing the advantages and disadvantages of currently available gelants This also helps to identify the best avenues for improving polymer gelant systems. This approach is particularly relevant when seeking gelants for high temperature matrix applications. because increased temperature renders it much more difficult to satisfy the four performance features simultaneously. Introduction Lower operating margins have led to a strong push to identify and eliminate problems that add to operating costs. This focus has drawn close attention to the problem of produced gas and water in oil wells over the last few years. Several technological alternatives are available to the field engineer faced with such water production problems. These include relatively simple procedures such as setting a bridge plug or using cement to isolate the lower portion of a well. These low cost procedures may be extremely effective if the water is known to enter at the bottom of the well. More expensive and less reliable interventions include remedial cementing to reduce channeling behind pipe and well workover in order to mechanically isolate the water producing zone. Polymer gel treatments have emerged as another effective tool. These treatments are carried out with aqueous polymer solutions that are pumped into the formation while still fluid. Cross-linking of the polymer solution, by means of which it is transformed into a robust, viscoelastic solid (gel), is triggered by the formation temperature. Presently, the most widely used polymer gel-forming compositions (gelants) employ a polyacrylamide (PAAm) or an acrylamide co-polymer and a chromium [Cr(III)] cross-linker.1,2 Gelants using organic cross-linkers are being applied with increasing frequency in high temperature formations.3,4 Polymer gels can greatly reduce the permeability of porous rock and can be formulated to resist considerable drawdown.5 The ability of polymer gelants to penetrate deeply within a fracture (>10 m) and to a significant depth (>1 m) in matrix formations means that fluid flow can be blocked or redirected even at a significant distance from the wellbore. This can be very important to the success of water and gas shut-off treatments, and constitutes an essential difference between this technology and mechanical isolation or cement treatments. Gels also have the mechanical strength to shut off flow through conductive fractures, and have been widely employed for this purpose in naturally fractured formations.6 The ability of fluid polymer gelants to penetrate through narrow openings also makes them an attractive alternative to remedial cementing to shut off flow behind pipe. The versatility of polymer gels is not a substitute for careful analysis of the causes of the unwanted fluid production. Without a good knowledge of the nature of the problem, it is much more difficult to design an effective treatment, both from technological and economic points of view. Whatever the application, four characteristics of a gelant are generally desirable:programmable gelation delaygood injectivitygood propagation of gelant componentsdurability of the permeability reduction

show abstract

Laboratory Evaluation of Crosslinked Polymer Gels for Water Diversion

Cited by 3 publications

References 3 publications

Use of bacterial ureolysis for improved gelation of silica sol in rock grouting

Use of bacterial ureolysis for improved gelation of silica sol in rock grouting

Gelation behavior as a function of concentration of sodium thiosulfate for PAM gels cross-linked with chromium

Polymer Gelants for High Temperature Water Shutoff Applications

Contact Info

Product

Resources

About