A Relative Permeability Modifier for Water Control: Candidate Selection, Case Histories, and Lessons Learned after more than 3,000 Well Interventions

Vasquez, Julio Estuardo; Eoff, Larry

doi:10.2118/165091-ms

Cited by 15 publications

(8 citation statements)

References 10 publications

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“…The end point effective permeability can reflect changes of the relative permeability after RPM displacements. ,− The end point effective water and oil permeability calculated using Darcy’s equation (eq ) are included in Table . As expected, the end point effective permeability agrees with the trends observed in Figure , demonstrating that the brine has undergone a larger reduction in its effective permeability.…”

Section: Resultsmentioning

confidence: 99%

Mechanistic Aspects of Polymeric Relative Permeability Modifier Adsorption onto Carbonate Rocks

et al. 2020

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Relative permeability modifiers (RPMs) are chemicals that can be injected into a reservoir to change its fluid/gas transport characteristics. For example, RPMs can reduce the relative permeability to water in a subterranean reservoir while having minimal impact on hydrocarbon production. Most commercially available RPMs are specifically designed for silica surfaces which are dominant in sandstone reservoirs. However, the concentration of silica in carbonate rocks is very low and many of these RPMs are unsuitable for carbonate reservoirs (which hold a significant portion of the remaining 60% hydrocarbon reserves). Furthermore, carbonate reservoirs tend to have more complex permeability and porosity characteristics and as such few research publications report the utilization of RPMs in the reservoirs of this type. The main mechanism of RPMs is either chemical adsorption onto, or functionalization of, a rock surface. However, as carbonates have distinctly different chemistry compared to silica, a new RPM formulation is required. The approach reported here overcomes this obstacle by using sodium silicate to functionalize the carbonate rock surface thereby converting it into a surface that in many ways exhibits the chemistry of silica. This has been confirmed by sodium silicate adsorption tests and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis. The other components consist of an amine-containing silylation reagent which reacts with the newly formed silicate surface, a polymer containing amine functional groups, and a linker molecule that reacts with the amines on the silane immobilizing the polymer. The chemistry is confirmed using five different chemical solutions to investigate their adsorption onto carbonate rocks using static tests. The results show that carbonate particles treated by the RPM have the highest adsorption weight, 7.33 mg/g and according to the measurements of X-ray photoelectron spectroscopy (XPS), the atomic percentage of Si 2p and N1s is 9.89% and 7.51% respectively, indicating the adsorption of RPM onto carbonate particles. To further verify the performance of RPM under reservoir conditions (1500 psi and 60 °C), three core flooding tests have been conducted. The results show that relative permeability to water decreased much more than oil. RRF to water in sample indinana-2 can reach up to 5.21, but RRF to oil is less than 2. The disproportionate ratio (RRF brine /RRF oil ) is 3.1, indicating the good performance of RPM under reservoir conditions. This work first introduced sodium silicate and APTES to make polyacrylamides as a new RPM material strongly stabilized onto carbonate rock surfaces, which provided further insights into the effectiveness of this approach applied in carbonate reservoirs.

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Section: Resultsmentioning

confidence: 99%

Mechanistic Aspects of Polymeric Relative Permeability Modifier Adsorption onto Carbonate Rocks

et al. 2020

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“…Similarly, Vasquez and Eoff state that the wettability alteration stage for oil-wet media to water-wet should be done first so that the RPM agents can effectively adsorb onto the rock surface. 68 As we mentioned earlier after treatment fluids may segregate differently due to pore size and/or wettability alteration. Therefore, for recognition purposes, the segregation mechanism after RPM settlement should be called "final fluid segregation".…”

Section: Polymer Adsorptionmentioning

confidence: 88%

“…For most polymers used as relative permeability modifiers, the polymer is immobilized on the rock surface in an adsorption process dominated by rock/brine/polymer interactions. This in turn depends on the polymer ionic charge and rock surface charge. ,,,,,− …”

Section: Polymer Adsorptionmentioning

confidence: 99%

Rock/Fluid/Polymer Interaction Mechanisms: Implications for Water Shut-off Treatment

et al. 2021

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Several disproportionate permeability reduction (DPR) mechanisms have been proposed in the literature for water shutoff treatment using polymer relative permeability modifiers (RPM). However, none appear to be universally accepted. The lack of agreement may be because no single factor determines the success of DPR treatment. Moreover, there is still a lack of understanding of DPR mechanisms and the order of how these mechanisms work together. This paper provides a comprehensive review of the mechanisms behind the RPMs. We identify that sufficient polymer adsorption onto the rock surface is a primary condition for water shutoff treatment, while rock surface initial wettability and fluid−polymer−rock interaction/attraction plays a significant role in polymer adsorption. Furthermore, polymer concentration, polymer molecular weight, aging time, polymer injection volume, polymer injection rate, and reservoir temperature are also vital for polymer adsorption. After polymer adsorption, the mechanisms such as fluid segregation and wall effect help accomplish the required DPR. We also find that there is a more consistent agreement among the published studies on the order of DPR mechanisms e.g. initial rock wettability effect comes first, followed by initial segregation, adsorption wall effect (i.e., steric, lubrication, wettability alteration, and swelling/shrinkage), and then the final segregation. Depending on the RPM implementation, which depends on pore size, the polymer layer thickness can be adjusted after the placement permanently or temporarily by controlling swelling/shrinkage. The subject matter investigated in this review helps us understand the factors responsible for optimal performance of polymer solutions in controlling excess water production from hydrocarbon reservoirsthus assisting in more efficient oil/gas production.

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“…However, the presence of a neighboring aquifer poses a risk of increased water influx; in such an application a RPM is typically utilized as a separate slug or as a chemical additive in the fracturing or acidizing fluid mixture. Several cases in the past show this method as suitable for effectively reducing water cut [6][7][8] . RPMs, in general, function by introducing a viscous drag on the water layer (blue in Fig.…”

Section: Introductionmentioning

confidence: 98%

Next Generation Relative Permeability Modifier Application in Acid Stimulation Treatments: An Effective Water Management Strategy for Mature Fields in Ecuador

et al. 2014

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The paper combines a brief case history of applications with supporting laboratory data, for using a new relative permeability modifier (RPM) in conjunction with a conventional acid stimulation treatment. This design was targeted at mature oil wells with high water cuts in Ecuador. The recommendation was proposed after mineralogical characterization of core samples, using scanning electron microscopy (SEM) followed by laboratory core flooding with treatment fluids. The methodology described in the paper comprises stimulation of certain areas of the sandstone formation with an acid followed by a RPM treatment to prevent the water from the stimulated water-bearing zones from entering the wellbore. Coiled tubing is used for effective placement of the treatment.Conventional stimulation treatments in the Hollin sandstone formation in Ecuador result in high water cuts because of encroaching water from an active aquifer. The acidizing technique with RPM improved the economic life of many mature wells in the field. Both laboratory and field data indicate excellent results from the treatments. The overall water cut in the treated wells decreased (by 8 to 15%), while oil production increased (~200%). Coiled tubing enables accurate placement of the acid and RPM into the desired zones, with the benefits from this targeted treatment far outweighing the cost of using coiled tubing units.Successful implementation of the laboratory core flood results in the field resulted in field-wide protocols aimed at oil wells producing water at unacceptable rates. The optimized stimulation treatment increases oil production and selective placement of RPM using coiled tubing decreased water cut, thereby prolonging the economic viability of mature wells.

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A Relative Permeability Modifier for Water Control: Candidate Selection, Case Histories, and Lessons Learned after more than 3,000 Well Interventions

Cited by 15 publications

References 10 publications

Mechanistic Aspects of Polymeric Relative Permeability Modifier Adsorption onto Carbonate Rocks

Mechanistic Aspects of Polymeric Relative Permeability Modifier Adsorption onto Carbonate Rocks

Rock/Fluid/Polymer Interaction Mechanisms: Implications for Water Shut-off Treatment

Next Generation Relative Permeability Modifier Application in Acid Stimulation Treatments: An Effective Water Management Strategy for Mature Fields in Ecuador

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