An experimental study of inaccessible pore volume on polymer flooding and its effect on oil recovery

2020 ◽  
Author(s):  
Boni Swadesi ◽  
Erdico Prasidya Saktika ◽  
Mahruri Sanmurjana ◽  
Septoratno Siregar ◽  
Dyah Rini
Keyword(s):  
Experimental Study ◽  
Oil Recovery ◽  
Pore Volume ◽  
Polymer Flooding ◽  
Inaccessible Pore Volume

Inaccessible Pore Volume in Polymer Flooding

1972 ◽  
Vol 12 (05) ◽  
pp. 448-452 ◽  
Author(s):  
Rapier Dawson ◽  
Ronald B. Lantz
Keyword(s):  
Porous Media ◽  
Mathematical Models ◽  
Pore Volume ◽  
Polymer Solutions ◽  
Polymer Flooding ◽  
Reservoir Rock ◽  
Front Edge ◽  
Polymer Molecules ◽  
The Core ◽  
Inaccessible Pore Volume

Abstract We have found that solutions of typical waterflooding polymers do not occupy all of the connected pore volume in porous media. The remainder of the pore volume is inaccessible to polymer. This inaccessible pore volume is occupied polymer. This inaccessible pore volume is occupied by water that contains no polymer, but is otherwise in equilibrium with the polymer solution. This allows changes in polymer concentration to be propagated through porous media more rapidly than propagated through porous media more rapidly than similar changes in salt concentration. At the front edge of a polymer bank the effect of inaccessible pore volume opposes the effect of adsorption and pore volume opposes the effect of adsorption and may completely remove it in some cases. This paper presents three experimental polymer floods showing the effect of inaccessible pore volume in the presence of varying amounts of adsorption. Results of these floods clearly show that about 30 percent of the connected pore volume in the rock samples used was not accessible to The polymer solutions. The changes required to include polymer solutions. The changes required to include inaccessible pore volume in mathematical models of polymer flow and in held prediction methods are discussed. Introduction One way o improving the mobility ratio during waterflooding operations is by addition of a water-soluble polymer to the flood water. Several different polymers have been proposed and a number of investigators have presented results on the behavior of these polymer solutions in porous media. In addition, mathematical models have been developed for predicting the field behavior of polymer flooding. In all these studies movement polymer flooding. In all these studies movement of the polymer bank through the reservoir rock is of great importance. One phenomenon that has been repeatedly observed in polymer flooding is the removal of polymer from solution by adsorption on the reservoir rock. As a polymer bank propagates through porous media, the polymer bank propagates through porous media, the front edge is gradually denuded of polymer. The amount of polymer lost from a bank may be large or small, depending on the nature of the polymer and rock surface. This loss of polymer must be measured and included in any realistic mathematical model of polymer behavior. It has been widely assumed that polymer behavior. It has been widely assumed that adsorption is the most significant factor causing polymer to propagate through porous media at a polymer to propagate through porous media at a velocity different from that of water. In this paper we present data that demonstrate that all of the pores may not be accessible to polymer molecules and that this "inaccessible polymer molecules and that this "inaccessible pore volume" can affect polymer propagation pore volume" can affect polymer propagation significantly. In addition to the experimental results, we discuss the changes in interpretation and in mathematical models that are required to include this phenomenon. EXPERIMENTAL The experiments described in this paper were single-phase displacement of polymer solutions through consolidated sandstone. All the cores were prepared by evacuating and saturating with brine; prepared by evacuating and saturating with brine; the pore volumes of the cores were measured at this time. The experimental floods reported here were then done in three steps.An "initial solution" was injected until the core was at complete equilibrium with that solution.A bank of a different solution was injected into the core.Injection of the initial solution was resumed and continued until the end of the experiment. During each experiment the effluent from the core was collected in small samples; the analyses of these samples for polymer and salt content gave the basic data which is presented here. In plotting the results we used a "concentration fraction" defined as (Ce -Ci)/(Cb -Ci), where C is concentration and the subscripts e, i and b refer to the effluent, initial inlet and bank inlet values, respectively. All the solutions used were mixed in distilled water; concentrations are given in weight percent or in ppm by weight. Two polymers were used; one was a polyacrylamide (Pusher 700, The Dow Chemical Co.); the other a polysaccharide (XC biopolymer, Xanco, Div. of Kelco Co.). SPEJ P. 448

Some Aspects of Polymer Retention in Porous Media Using a C14-Tagged Hydrolyzed Polyacrylamide

1975 ◽  
Vol 15 (04) ◽  
pp. 323-337 ◽  
Author(s):  
M.T. Szabo
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Pore Volume ◽  
Produced Water ◽  
Polymer Concentration ◽  
Oil Saturation ◽  
Polymer Flow ◽  
Hydrolyzed Polyacrylamide ◽  
Polymer Retention ◽  
Inaccessible Pore Volume

Abstract Numerous single-phase flow and oil-recovery tests were carried out in unconsolidated sands and Berea sandstone cores using C14-tagged, hydrolyzed polyacrylamide solutions. The polymer-retention polyacrylamide solutions. The polymer-retention data from these flow tests are compared with data obtained from static adsorption tests. Polymer concentrations in produced water in Polymer-flooding tests were studied using various Polymer-flooding tests were studied using various polymer concentrations, slug sizes, salt polymer concentrations, slug sizes, salt concentrations, and different permeability sands. Results show that polymer retention by mechanical entrapment had a dominant role in determining the total polymer retention in short sand packs. However, the role of mechanical entrapment was less in the large-surface-area Berea cores. In oil-recovery tests, high polymer concentrations were noted at water breakthrough in sand-pack experiments, an indication that the irreducible water was not displaced effectively ahead of the polymer slug. However, in similar tests with Berea cores, a denuded zone developed at the leading edge of the polymer slug. polymer slug. The existence of inaccessible pore volume to polymer flow is shown both in sand packs and in polymer flow is shown both in sand packs and in sandstone cores. Absolute polymer-retention values show an almost linear dependency on polymer concentration. The effect of polymer slug size on absolute polymer retention is also discussed. Distribution of retained polymer in sand packs showed an exponential decline with distance. The "dynamic polymer-retention" values in short sand packs showed much higher vales than the ‘static packs showed much higher vales than the’ static polymer-adsorption" values caused by mechanical polymer-adsorption" values caused by mechanical entrapment. The mechanism of polymer retention in silica sands and sandstones is described, based on the observed phenomenon. Introduction It is widely recognized that, as polymer solution flows in a porous medium, a portion of the polymer is retained. It is evident that both physical adsorption and mechanical entrapment contribute to polymer retention. The question of the relative importance of these retention mechanisms has not been studied adequately. The effect of residual oil saturation on polymer retention and the polymer retention during the displacement of oil from porous media has also been studied inadequately. Mungen et al. have reported a few data on polymer concentration in produced water in oil-recovery tests. However, no produced water in oil-recovery tests. However, no comparison was made between polymer retention at 100-percent water saturation and at partial oil saturation. It has been shown that the actual size of the flowing polymer molecules, with the associated water, can approach the dimensions of certain smaller pores found in porous media. Therefore, an inaccessible pore volume exists in which no polymer flow occurs. In this study, the existence polymer flow occurs. In this study, the existence of inaccessible pore volume is shown clearly, both in sand and sandstone. Although polymer-retention values have been reported for various conditions, correlation is difficult because of the differing conditions of measurements. The effect of slug size, polymer concentration, salinity, and type of porous media on polymer retention has not been systematically studied. The purpose of this study was to develop answers to these questions, rather than to provide adsorption data for actual field core samples. For this reason, unconsolidated silica sands were used in most of the experiments reported. This permitted identical, uniform single-layer and multilayer porous media to be constructed for repeated experiments under varying test conditions. Some experiments were also carried out in Berea sandstone cores to determine whether sand-pack results can be extrapolated to consolidated sandstones. Using a C 14-tagged polymer provided a very rapid, simple, and accurate polymer-concentration determination technique. SPEJ P. 323

Study of the Well-Posedness of Models for the Inaccessible Pore Volume in Polymer Flooding

2016 ◽  
Vol 114 (1) ◽  
pp. 65-86 ◽  
Author(s):  
Sindre T. Hilden ◽  
Halvor Møll Nilsen ◽  
Xavier Raynaud
Keyword(s):  
Pore Volume ◽  
Polymer Flooding ◽  
Well Posedness ◽  
Inaccessible Pore Volume

Field vs. Laboratory Polymer-Retention Values for a Polymer Flood in the Tambaredjo Field

2014 ◽  
Vol 17 (03) ◽  
pp. 314-325 ◽  
Author(s):  
R.N.. N. Manichand ◽  
R.S.. S. Seright
Keyword(s):  
Oil Recovery ◽  
Pore Volume ◽  
High Surface ◽  
High Surface Area ◽  
High Permeability ◽  
Permeable Rock ◽  
Polymer Flood ◽  
Production Wells ◽  
Polymer Retention ◽  
Inaccessible Pore Volume

Summary During a polymer flood, polymer retention can have a major impact on the rate of polymer propagation through a reservoir, and consequently on oil recovery. A review of the polymer-retention literature revealed that iron and high-surface-area minerals (e.g., clays) dominate polymer-retention measurements in permeable rock and sand (>100 md). A review of the literature on inaccessible pore volume (IAPV) revealed inconsistent and unexplained behavior. A conservative approach to design of a polymer flood in high-permeability (>1 darcy) sands would assume that IAPV is zero. Laboratory measurements using fluids and sands associated with the Sarah Maria polymer flood in Suriname suggested polymer retention and IAPV values near zero [0±20 μg/g for retention and 0±10% pore volume (PV) for IAPV]. A procedure was developed using salinity-tracer and polymer concentrations from production wells to estimate polymer retention during the Sarah Maria polymer flood in the Tambaredjo reservoir. Field calculations indicated much higher polymer-retention values than those from laboratory tests, typically ranging from approximately 50 to 250 μg/g. Field cores necessarily represent an extremely small fraction of the reservoir. Because of the importance of polymer retention, there is considerable value in deriving polymer retention from field results, so that information can be used in the design of project expansions.

scholarly journals Experimental Study of Chemical Flooding of Suizhong 36-1 Oilfield

2015 ◽  
Vol 8 (1) ◽  
pp. 392-397 ◽  
Author(s):  
Pi Yanfu ◽  
Guo Xiaosai ◽  
Pi Yanming ◽  
Wu Peng
Keyword(s):  
Oil Recovery ◽  
Pore Volume ◽  
Polymer Flooding ◽  
Oil Field ◽  
Water Flooding ◽  
Chemical Flooding ◽  
Recovery Efficiency ◽  
Displacement Efficiency ◽  
Displacement Effect ◽  
Binary Combination

Aim at the reservoir characteristics of Suizhong 36-1 Oil Field, this paper has developed typical two-dimensional physical model in parallel between the layers and studied the macroscopic displacement effect of polymer flooding and binary compound flooding, and studied the interlayer spread law and oil displacement efficiency of polymer flooding and binary combination flooding by using saturation monitoring system deeply. The results show that: when the multiples of pore volume injected for polymer was 0.3 after water flooding, the recovery efficiency increased by 10.3%, and when the multiples of pore volume injected for binary combination flooding was 0.3 after polymer flooding and the recovery efficiency could also increase by 19.3%, and the effect of enhanced oil recovery was obvious during the binary combination flooding and polymer flooding; Saturation monitoring data showed that there formed oil wall and increased the flow resistance and expanded the swept volume during the stage of polymer flooding and binary combination flooding, effective use of low-permeability layer was the key to improve oil recovery.

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