Understanding the Rate of Clean Up for Oil Zones after a Gel Treatment

Seright, R.S.; Lindquist, W. Brent; Cai, Rong

doi:10.2118/112976-ms

Cited by 11 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5). The rate of increase in oil permeability was roughly the same for the two porous media (Seright et al 2008). The rapid jump in oil saturation in Berea between 0 and 0.1 PV may have occurred simply because the oil finger fortuitously swept the imaged volume.…”

Section: Imbibition and Drainage As A Function Of Throughput After Gementioning

confidence: 76%

“…Wettability tests produced Amott-Harvey indexes of 0.7 for the brine (1% NaCl, 0.1% CaCl 2 )/oil (hexadecane)/Berea sandstone system and −0.8 for the brine/oil/porous polyethylene system-confirming the water-wet character of Berea sandstone and the hydrophobic character of porous polyethylene. On the basis of XMT analysis, the two porous media have very similar pore size distributions (Seright et al 2006(Seright et al , 2008. Table 1 summarizes the core properties (Seright et al 2002(Seright et al , 2006Prodanovic et al 2006Prodanovic et al , 2007.…”

Section: Core Propertiesmentioning

confidence: 99%

“…(The coordination number is the number of exits from a pore.) More detailed descriptions of the microscopic core properties can be found in Seright et al 2008 and in the other references in this paragraph.…”

Section: Core Propertiesmentioning

confidence: 99%

“…Consequently, high oil saturations were usually seen in the smallest detected polyethylene pores. The important message here is that, for the pore sizes involved with our porous media, access to pores (through effective films) is at least as important in determining residual saturations as capillary pressure, interfacial tension, or applied pressure gradient (Seright et al 2006(Seright et al , 2008. We also studied oil and water saturations in pores as a function of water and oil throughput in porous polyethylene cores (Prodanović et al 2006).…”

Section: Imbibition and Drainage Before Gel Placementmentioning

confidence: 99%

See 3 more Smart Citations

Pore-Level Examination of Gel Destruction During Oil Flow

2009

Self Cite

View full text Add to dashboard Cite

Pore-scale X-ray computed microtomography (XMT) images were obtained at a variety of oil (hexadecane) throughput values after gel placement in cores [involving a pore-filling Cr(III)-acetatehydrolyzed polyacrylamide (HPAM) gel]. For each pore in our image volume, we followed oil and water saturations as a function of oil throughput. These studies were performed both in water-wet Berea sandstone and in hydrophobic porous polyethylene cores. In hydrophobic porous polyethylene, oil saturations increased and gel was destroyed (presumably dehydrated) quite quickly in the smallest pores. Also, oil saturations increased and gel was destroyed quickly in the largest pores. In contrast, oil saturations rose much more gradually for the most common or intermediate-size pores (around 10 −4 mm 3). The minimum in oil saturation vs. pore size may result from a balance between gel dehydration by oil film growth vs. gel extrusion. In contrast, in water-wet Berea sandstone, increases in oil saturation occurred evenly over all pore sizes (10 −6 to 0.02 mm 3) for all oil throughput values. Consistent with imbibition and drainage studies performed before gel placement, oil apparently had equal access to Berea pores of all sizes and, thus, uniformly dehydrated gel in pores of all sizes. Gel extrusion did not appear to be significant in the Berea pores.

show abstract

Section: Imbibition and Drainage As A Function Of Throughput After Gementioning

confidence: 76%

Section: Core Propertiesmentioning

confidence: 99%

Section: Core Propertiesmentioning

confidence: 99%

Section: Imbibition and Drainage Before Gel Placementmentioning

confidence: 99%

See 2 more Smart Citations

Pore-Level Examination of Gel Destruction During Oil Flow

2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…For production treatments, such as RPM, it has been observed that the time to restore the oil production can be substantial (Seright 2008). The clean up time can be derived using fractional flow theory and the modified oil and water permeabilities.…”

Section: Clean Up Timementioning

confidence: 99%

How to Apply the Flow Velocity as a Design Criteria in RPM Treatments

Stavland

2009

8th European Formation Damage Conference

View full text Add to dashboard Cite

The effect of water control using Relative Permeability Modification (RPM) depends strongly on the well's flow rate. This is because the permeability reduction decreases as the flow velocity increases. This will affect the amount of volume as well as the properties of the injected RPM fluid. This paper discusses how the velocity dependent permeability reduction can be accounted for in the job design. The approach is to introduce a velocity dependent permeability reduction and to solve the Darcy law for Non-Newtonian flow.Core flood experiments report permeability reduction as residual resistance factors (RRF w and RRF o ). In scaling up to field situations the reduction in productivity is a better measure. Designing an RPM treatment to a fixed reduction in water productivity demonstrated that low volume -high permeability reduction is better than larger volumes with lower permeability reduction. In high productive wells there may be situations where certain RPM systems fail to reduce the water productivity adequately. By including pressure constraints on the injection of the RPM fluid, the planned pumping schedule is derived.The criteria for increased oil production are reported as a balance between the increased drawdown, based on the water-cut reduction and improved lift, and the reduction in oil productivity. The critical oil productivity depends on the water productivity, initial water-cut, density difference between the water and the hydrocarbon phase, and depth (TVD). It is clearly demonstrated that the potential for increased oil production increases by increasing the ratio between the oil and the water productivity reduction (M). In addition, M increases as RRF w increases and the volume decreases.The time to restore the productivity from the oil zone, the clean up time, can be understood based on the fractional flow theory. In theory, the clean up time can be derived from relative permeability curves or the saturation profiles during the oil back production. Also the clean up time was reduced by the use of low volume -high water permeability reduction.

show abstract

Surface Tension-Induced Gel Fracture. Part 1. Fracture of Agar Gels

et al. 2012

View full text Add to dashboard Cite

This work involves an experimental investigation of the spreading of liquids on gel layers in the presence of surfactants. Of primary interest is the instability that accompanies the cracking of gels through the deposition and subsequent spreading of a drop of surfactant solution on their surfaces. This instability manifests itself via the shaping of crack-like spreading "arms", in formations that resemble starbursts. The main aim of this study is to elucidate the complex interactions between spreading surfactants and underlying gels and to achieve a fundamental understanding of the mechanism behind the observed phenomenon of the cracking pattern formation. By spreading SDS and Silwet L-77 surfactant solutions on the surfaces of agar gels, the different ways that system parameters such as the surfactant chemistry and concentration and the gel strength can affect the morphology and dynamics of the starburst patterns are explored. The crack propagation dynamics is fitted to a power law by measuring the temporal evolution of the length of the spreading arms that form each one of the observed patterns. The values of the exponent of the power law are within the predicted limits for Marangoni-driven spreading on thick layers. Therefore, Marangoni stresses, induced by surface tension gradients between the spreading surfactant and the underlying gel layer, are identified to be the main driving force behind these phenomena, whereas gravitational forces were also found to play an important role. A mechanism that involves the "unzipping" of the gel in a manner perpendicular to the direction of the largest surface tension gradient is proposed. This mechanism highlights the important role of the width of the arms in the process; it is demonstrated that a cracking pattern is formed only within the experimental conditions that allow S/Δw to be greater than G', where S is the spreading coefficient, Δw is the change in the width of the crack, and G' is the storage modulus of the substrate.

show abstract

Understanding the Rate of Clean Up for Oil Zones after a Gel Treatment

Cited by 11 publications

References 21 publications

Pore-Level Examination of Gel Destruction During Oil Flow

Pore-Level Examination of Gel Destruction During Oil Flow

How to Apply the Flow Velocity as a Design Criteria in RPM Treatments

Surface Tension-Induced Gel Fracture. Part 1. Fracture of Agar Gels

Contact Info

Product

Resources

About