Investigation of a High Temperature Organic Water Shutoff Gel: Reaction Mechanisms

Al-Muntasheri, Ghaithan A.; Nasr‐El‐Din, Hisham A.; Peters, J. A.; Zitha, Pacelli L.J.

doi:10.2118/97530-ms

Cited by 20 publications

(20 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More C13 NMR experimental details are reported elsewhere. 17 The chemical shifts of all carbons reported in this work agree with those reported in literature for carbonyl carbons at the amide groups (179.6 ppm) and those at the carboxylate groups (182.8 ppm). 21 Fig .…”

Section: Experimental Studies Materialssupporting

confidence: 90%

Gelation Kinetics of an Organically Cross Linked Gel at High Temperature and Pressure

Nasr‐El‐Din¹,

Zitha²

2006

Proceedings of First International Oil Conference and Exhibition in Mexico

View full text Add to dashboard Cite

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractDue to their thermal stability, organically cross-linked gels have been used to control water production in high temperature applications. Most of these gels consist of a polyacrylamide-based polymer and an organic cross-linker. Polyethyleneimine (PEI) has been used as an organic crosslinker for polyacrylamide-based copolymers.Recent work indicated that PEI can form ringing gels with polyacrylamide homopolymers (PAM). However, no study reported on the kinetics of PAM/PEI gels. The gelling system examined in the present study is based on a PAM cross-linked with PEI. This paper will show for the first time the possibility of cross-linking polyacrylamide with PEI at high temperatures and pressures.Therefore, the gelation time of the PAM cross-linked with PEI at high temperatures up to 285 o F (140 o C) and pressures up to 435 psi (30 bars) was measured. The effects of polymer concentration, cross-linker concentration, temperature, salinity and the initial degree of hydrolysis of the polymer on the gelation time were examined in detail. All measurements were conducted in the steady shear mode at low shear rates using an Anton-Paar high temperature/high pressure viscometer. C13 Nuclear Magnetic Spectroscopy (C13 NMR) was extensively used to relate gelation time to changes in the structure of the polymer and hence, explain the variation in the gelation time in terms of the system chemistry.Thermally stable gels were obtained by cross-linking PEI and PAM at high temperatures (120 o C) for at least 2 weeks. The activation energy of this system at high temperatures in distilled water was found to be 71.3 kJ/mol. The addition of sodium ions increased the activation energy to 88 kJ/mol.

show abstract

Section: Experimental Studies Materialssupporting

confidence: 90%

Gelation Kinetics of an Organically Cross Linked Gel at High Temperature and Pressure

Nasr‐El‐Din¹,

Zitha²

2006

Proceedings of First International Oil Conference and Exhibition in Mexico

View full text Add to dashboard Cite

show abstract

“…The PAtBA copolymer used in this work has a molecular weight of 250 to 500 kDaltons, a degree of hydrolysis of nearly zero and an ester content of around 5 mol% as per the manufacturer and previous literature reports on the same product (Al-Muntasheri et al, 2006). The PEI crosslinker was used to crosslink the PAtBA.…”

Section: Methodsmentioning

confidence: 99%

Water Shut-off With Polymer Gels in a High Temperature Horizontal Gas Well: A Success Story

Al-Muntasheri

Sierra

Garzón

et al. 2010

Proceedings of SPE Improved Oil Recovery Symposium

View full text Add to dashboard Cite

A horizontal hot deep gas well was not on production due to high water cut. The well had a bottom hole temperature of 300 o F (149 o C) and a bottom hole pressure of 7,000 psi. The well was completed into a carbonate reservoir with an average permeability ranging from 2 to 3 mD. It was completed with a 7 in liner at a measured depth (MD) of 13,611 ft. The open-hole section extends from 13,611 to 16,456 ft. After the well completion operation, water was observed entering the open-hole section at the toe at a depth of 14, 677 ft. The exact water producing zone was identified by the resistivity log run on the subject well. Therefore, a mechanical packer was set in the open-hole section at 14,677 ft to isolate the water producing interval. The packer did not solve the problem. The water production continued to occur.Due to their versatility, polymer gels were considered for remediating this problem and to revive the well. A gel system based on a low molecular weight polymer crosslinked with an organic crosslinker was considered. A serious challenge was the high temperature of the reservoir. The high temperature conditions imposed the use of a retarder to elongate the onset gelation time during the polymer gel placement. The available mixing waters in this field contained significant amounts of salts (a total dissolved solids content of 1,188 ppm). These solids caused compatibility problems upon contact with the commercially available retarder. Therefore, a new retarder was developed. The retarder was cost-effective, efficient and compatible with the available saline mixing water. The retarder's placement was examined in porous media under conditions similar to those encountered in the field (55 minutes placement time). The gel did not show any injectivity problems indicating the efficient nature of the retarder. The initial recommended recipe of the gel showed syneresis due to the extra amount of the crosslinker suggested. This was addressed by reducing the crosslinker concentrations in the gel recipe.The treatment utilized a pre-flush to displace the reservoir fluids around the wellbore and to cool down the near wellbore area. This helped reduce the near wellbore area temperature from 300 to 240 o F according to the temperature simulations. The gelant contained 250 gal/1000 gal of polymer with a 10 gal/1000 gal of crosslinker. After the gelant placement, the well was shut-in for three days. Once opened, the well showed an increase in gas production by a factor of 7.7 with a water cut reduction of 42 %.

show abstract

“…The degree of hydrolysis of PAM was measured to be less than 0.1 mol% using the equipment and methods described elsewhere 6 . Both chemicals were supplied in aqueous solutions form.…”

Section: Methodsmentioning

confidence: 99%

Gel under Dynamic Stress in Porous Media: New Insights using Computed Tomography

Al-Muntasheri

Zitha

2009

SPE Saudi Arabia Section Technical Symposium

View full text Add to dashboard Cite

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractCrosslinked polymer gels are widely utilized to reduce water production from oil and gas producing wells. Zitha et al. (2002) developed a theory accounting for the basic mechanisms of gel extrusion by water through matrix porous media, i.e., compression, yield and flow. Their model predicted pressure drop and saturation changes over the gel-treated porous media during gel yield and extrusion by brine. The pressure drops were successfully compared to yield and displacement of an organically crosslinked gel formed insitu by water from Berea sandstone cores. This paper reports for the first time the measurements of saturation changes during such yield, and displacement experiments using X-ray Computed Tomography (CT) scanning. The experiments were performed using Bentheimer sandstone cores treated with gels containing 3 wt% polyacrylamide polymer (PAM) and 2 wt% polyethyleneimine crosslinker (PEI) shut-in at 55 o C (131 o F) for 22 hours under high pressure drops up to 89 bars (1,291 psi). Total organic carbon analyses indicated that no polymer retention or adsorption took place during gelant placement into Bentheimer sandstone cores. CT images indicated that the displacing brine saturations were independent of position, although, saturations increased with time. In addition, the breakthrough pressure occurred at a relatively later time compared to the critical pressure. New insights into the existing saturation models are given, which will provide a better understanding of the pressure and saturation changes with time.

show abstract

Investigation of a High Temperature Organic Water Shutoff Gel: Reaction Mechanisms

Cited by 20 publications

References 28 publications

Gelation Kinetics of an Organically Cross Linked Gel at High Temperature and Pressure

Gelation Kinetics of an Organically Cross Linked Gel at High Temperature and Pressure

Water Shut-off With Polymer Gels in a High Temperature Horizontal Gas Well: A Success Story

Gel under Dynamic Stress in Porous Media: New Insights using Computed Tomography

Contact Info

Product

Resources

About