Research on the Relationship Between the Pore Structure Characteristics of Reservoir and Performance of Cr3+ Polymer Gel

2021 ◽  
Author(s):  
Xiaodong Kang ◽  
Zhe Sun ◽  
Xiujun Wang ◽  
Jian Zhang ◽  
Shanshan Zhang
Keyword(s):  
Pore Structure ◽  
Physical Simulation ◽  
Research Work ◽  
Experimental Studies ◽  
Water Flooding ◽  
Good Effect ◽  
Polymer Gel ◽  
Oil Saturation ◽  
Structure Characteristics ◽  
Reservoir Conditions

Abstract Cr3+ polymer gel flooding technology is very important for enhancing oil recovery and its field trails have obtained significantly oil increment effect. However, its laboratory physical simulation experiments are rarely carried out according to real reservoir conditions. Therefore, it is very important to carry out relevant research work. Aiming at the reservoir condition of Bohai Oilfield (an offshore oilfield in China), the experimental studies on the pore structure characteristics of reservoir on the properties of Cr3+ polymer gel are carried out. The effect of different core permeability (500, 1500 and 5000 ×10−3μm2), clay content (4.5%, 9.0% and 18%), mineral type (kaolinite, montmorillonite and illite), oil saturation (79.2%, 65.4% and 49.3%) and dynamic gelation effect are thoroughly studied. Finally, its application is introduced and analyzed. Research results show that, with the increase of reservoir permeability and pore throat size, the gelation effect improves. Also, the loose cementation degree is helpful for rapid gelation. In additional, with the decrease of the content of clay and oil saturation, the gelforming effect gets better. However, the dynamic gelation strength is very low in porous media. And after chemical injection, suspension of water flooding could promote the gel-forming performance. From the field test results, this technology has obtained good effect in Bohai oilfield, due to the high permeability, severe heterogeneity, loose cementation and high water cut. In conclusion, it is very important to study on the gelation effect under the real reservoir conditions deeply. Therefore, the relevant experimental studies have been carried out comprehensively. And its mechanism are further explored. Furthermore, its field application has also been also summarized, which is vital to the success of this technology.

scholarly journals Differences of microscopic seepage mechanisms of water flooding and polymer flooding and prediction models of final oil recovery for conglomerate reservoir

2019 ◽  
Vol 74 ◽  
pp. 13
Author(s):  
Fengqi Tan ◽  
Changfu Xu ◽  
Yuliang Zhang ◽  
Gang Luo ◽  
Yukun Chen ◽  
...  
Keyword(s):  
Pore Structure ◽  
Polymer Solution ◽  
Oil Recovery ◽  
Particle Surface ◽  
Polymer Flooding ◽  
Water Flooding ◽  
Residual Oil ◽  
Displacement Efficiency ◽  
Oil Saturation ◽  
Oil Displacement Efficiency

The special sedimentary environments of conglomerate reservoir lead to pore structure characteristics of complex modal, and the reservoir seepage system is mainly in the “sparse reticular-non reticular” flow pattern. As a result, the study on microscopic seepage mechanism of water flooding and polymer flooding and their differences becomes the complex part and key to enhance oil recovery. In this paper, the actual core samples from conglomerate reservoir in Karamay oilfield are selected as research objects to explore microscopic seepage mechanisms of water flooding and polymer flooding for hydrophilic rock as well as lipophilic rock by applying the Computed Tomography (CT) scanning technology. After that, the final oil recovery models of conglomerate reservoir are established in two displacement methods based on the influence analysis of oil displacement efficiency. Experimental results show that the seepage mechanisms of water flooding and polymer flooding for hydrophilic rock are all mainly “crawling” displacement along the rock surface while the weak lipophilic rocks are all mainly “inrushing” displacement along pore central. Due to the different seepage mechanisms among the water flooding and the polymer flooding, the residual oil remains in hydrophilic rock after water flooding process is mainly distributed in fine throats and pore interchange. These residual oil are cut into small droplets under the influence of polymer solution with stronger shearing drag effect. Then, those small droplets pass well through narrow throats and move forward along with the polymer solution flow, which makes enhancing oil recovery to be possible. The residual oil in weak lipophilic rock after water flooding mainly distributed on the rock particle surface and formed oil film and fine pore-throat. The polymer solution with stronger shear stress makes these oil films to carry away from particle surface in two ways such as bridge connection and forming oil silk. Because of the essential attributes differences between polymer solution and injection water solution, the impact of Complex Modal Pore Structure (CMPS) on the polymer solution displacement and seepage is much smaller than on water flooding solution. Therefore, for the two types of conglomerate rocks with different wettability, the pore structure is the main controlling factor of water flooding efficiency, while reservoir properties oil saturation, and other factors have smaller influence on flooding efficiency although the polymer flooding efficiency has a good correlation with remaining oil saturation after water flooding. Based on the analysis on oil displacement efficiency factors, the parameters of water flooding index and remaining oil saturation after water flooding are used to establish respectively calculation models of oil recovery in water flooding stage and polymer flooding stage for conglomerate reservoir. These models are able to calculate the oil recovery values of this area controlled by single well control, and further to determine the oil recovery of whole reservoir in different displacement stages by leveraging interpolation simulation methods, thereby providing more accurate geological parameters for the fine design of displacement oil program.

scholarly journals Application of Polymer Based Nanocomposites for Water Shutoff—A Review

Fuels ◽  
2021 ◽  
Vol 2 (3) ◽  
pp. 304-322
Author(s):  
Velima Obino ◽  
Upendra Yadav
Keyword(s):  
Thermal Stability ◽  
Oil Recovery ◽  
Experimental Studies ◽  
High Water ◽  
Polymer Gel ◽  
Polymer Hydrogels ◽  
Undesirable Characteristic ◽  
Gel Treatment ◽  
Reservoir Conditions ◽  
Thermal Stability Of

One highly undesirable characteristic of mature assets that inhibits oil recovery is high water production. Polymer gel treatment is a popular conformance improvement technique applied in this regard due to its cost effectiveness and proved efficiency. Despite this popularity, optimum performance of polymer hydrogels in water shut off is inhibited by excessive aggregation, difficulty in controlling gelation, and their instability at high temperature and high salinity reservoir conditions. To address these shortcomings, research on the application of nanoparticles (NPs) in polymer hydrogels to manage thermal stability and salinity sensitivity has significantly increased in the recent past. By incorporating metal-based NPs, silica or graphene at nanoscale; the gel strength, storage modulus, salinity tolerance and thermal stability of commonly used polymers have been greatly enhanced. In this paper, the advances in experimental studies on polymer-based nanocomposites are discussed and field experiences from adoption of polymer composites reviewed.

scholarly journals Experiment on the Influence of Vertical Heterogeneity of Reservoir on the Steam Drive Effect

2015 ◽  
Vol 8 (1) ◽  
pp. 415-419
Author(s):  
Pang Jin ◽  
Yue Yixing ◽  
Peng Xu ◽  
Chen Guiping ◽  
Li lu
Keyword(s):  
Physical Simulation ◽  
Experimental Studies ◽  
Displacement Effect ◽  
Beneficial Effects ◽  
Steam Drive ◽  
Vertical Heterogeneity ◽  
Reservoir Conditions ◽  
Productive Process ◽  
Drive Effect ◽  
Swept Volume

This paper carried out experimental studies on the influence of vertical heterogeneity of reservoir on the steam drive effect after multiple-round steam stimulations. Taking the actual productive process of a heavy oil reservoir as an example, a physical model for the vertical heterogeneity was established. First, under the initial reservoir conditions, conduct multiple rounds of steam stimulations to obtain the initial reservoir conditions of steam drive, and then carry out physical simulation of steam drive, including the simulation of the horizontal reservoir and the tilted one. The development of temperature field and the oil-water output changes indicate that when the steam drive is conducted after the steam stimulations, the steam advances along the high permeability layer with better steam stimulation effect, once it gets a breakthrough, the swept volume will not change. For the tilted reservoir, due to the beneficial effects of the gravity drainage, its displacement effect is better than the horizontal one, which provides an important basis for the adjustment of layers and the section of methods of gas injection when the steam simulation is converted into steam drive.

Development of pore structure characteristics of a weathered crust elution-deposited rare earth ore during leaching with different valence cations

2021 ◽  
Vol 201 ◽  
pp. 105579
Author(s):  
Lingbo Zhou ◽  
Xiaojun Wang ◽  
Chengguang Huang ◽  
Hao Wang ◽  
Huachang Ye ◽  
...  
Keyword(s):  
Rare Earth ◽  
Pore Structure ◽  
Structure Characteristics ◽  
Weathered Crust

Research on the Wire Drawing Die Pass Parameter Calculation Based on the Least Square Algorithm

2012 ◽  
Vol 591-593 ◽  
pp. 850-853
Author(s):  
Huai Xing Wen ◽  
Yong Tao Yang
Keyword(s):  
Pore Structure ◽  
Least Squares ◽  
Least Squares Method ◽  
Piecewise Linear ◽  
Wire Drawing ◽  
Least Square ◽  
Structure Characteristics ◽  
Drawing Die ◽  
The Wire ◽  
Drawing Dies

Drawing Dies meter A / D acquisition module will be collected from the mold hole contour data to draw a curve in Matlab. According to the mold pore structure characteristics of the curve, the initial cut-off point of each part of contour is determined and iteratived optimization to find the best cut-off point, use the least squares method for fitting piecewise linear and fitting optimization to find the function of the various parts of the curve function, finally calculate the pass parameters of drawing mode. Parameters obtained compare with the standard mold, both of errors are relatively small that prove the correctness of the algorithm. Also a complete algorithm flow of pass parameters is designed, it can fast and accurately measure the wire drawing die hole parameters.

Advance Water-Flooding to Reduce the Stress Sensitivity Affect on Low Permeability Reservoir Development

2011 ◽  
Vol 361-363 ◽  
pp. 520-525
Author(s):  
Jun Feng Yang ◽  
Han Qiao Jiang ◽  
Han Dong Rui ◽  
Xiao Qing Xie
Keyword(s):  
Physical Simulation ◽  
Physical Property ◽  
Stress Sensitivity ◽  
Water Flooding ◽  
Low Permeability ◽  
Formation Pressure ◽  
Exponential Relationship ◽  
Low Permeability Reservoir ◽  
Reservoir Development ◽  
Water Cut

Physical simulation experiments were made to research on the stress sensitivity on physical property of low permeability reservoir rocks. The experimental results shown that effective pressure had good exponential relationship with reservoir permeability. Combining with materaial balance method, reservoir engineering and rational deducation was made to reserach on water-flooding timing of low permeability reservoir development. Several production targets were obtained by these method, such as formation pressure, water and oil production, water cut and so on. The results shown that advanced water-flooding was very important in low permeability reservoir development to reduce the bad impact of stress sensitivity on formation permeability and maintain formation pressure.

Matrix Acidization with Highly Reactive Acids

1971 ◽  
Vol 11 (04) ◽  
pp. 390-398 ◽  
Author(s):  
J.A. Guin ◽  
R.S. Schechter
Keyword(s):  
Mathematical Model ◽  
Pore Structure ◽  
Pore Size ◽  
Acid Treatment ◽  
Explicit Knowledge ◽  
Experimental Studies ◽  
Design Procedure ◽  
Permeability Change ◽  
Pore Size Distributions ◽  
Matrix Acidization

Abstract A mathematical model representing the changes in pore structure attending the invasion of a porous material by a reactive fluid tending to dissolve the solid bas previously been tested and found to be valid. This mathematical model is solved by a simulation procedure using Monte Carlo techniques. The results so obtained are indicative of the acidization of sandstone using a last-reacting acid (diffusion limited). A correlation relating the permeability improvement to the change in porosity is presented and found to be applicable to a wide class of initial pore-size distributions. This means that the designer need not have explicit knowledge of the initial pore structure to utilize the correlation. The generality of the correlation stems from the fact that after exposure to fast-acting acids (diffusion-controlled reactions) wormholing tends to occur in all porous matrices, and the acid allows preferentially through these channels. Thus, the process is independent of the fine pore structure since the fine pores receive no acid Wormholing bas been observed in almost all experimental studies of acidization, thus further confirming the validity of the model. Introduction Matrix acidization as practiced in the petroleum industry is a simple operation. Acids treated so as to prevent their corrosive attack on metal parts contacted are pumped down the wellbore and forced into the pore spaces of an oil-bearing rock. The rate of penetration is normally maintained small enough to prevent fracturing of the reservoir The aim of matrix acidization is to enhance the permeability of the region around the wellbore by permeability of the region around the wellbore by dissolving either a portion of the rock or of the foreign impurities that may have been introduced during the drilling operations. The success of this technique of oilwell stimulation is attested to by the fact that a significant fraction of the acids used for stimulation are injected at matrix rates. There were, moreover, in excess of 87 million gal of hydrochloric acid used last year in carbonate formations with many other special purpose acids such as acetic and formic having also been used for stimulation purposes. Despite the fact that acids have long been routinely used as a means of stimulating oil wells to greater production, there is, as yet, no reliable design procedure incorporating all of the essential features into a prediction of the new production that will result from a given acid treatment of a particular well. This lack of a design procedure particular well. This lack of a design procedure has been responsible for the rather minimal efforts expended in obtaining meaningful reaction rate data, for there is very little enthusiasm for obtaining data which cannot be put to practical application. This paper is an extension of some recently reported work on predicting the permeability change resulting from acid treatment of an oil-bearing rock. It has been proposed that the changes in the microstructure owing to acidization in a porous rock can be simulated by considering the effect of acidization of a collection of small, randomly distributed capillaries that are interconnected to the extent that a fluid will be conducted from point to point under the influence of an external pressure gradient. This model, the capillaric model, has been used with varying success in understanding the behavior of porous media. The use of the capillaric model in determining only the results of the evolution of a pore-size distribution, rather than as a vehicle for predicting a number of mare or less independent phenomena, such as capillary pressure curves and dispersion, is, as has been pressure curves and dispersion, is, as has been noted by Schechter and Gidley, a more limited and perhaps attainable goal. Taking the capillaric model to be correct, Guin et al. have shown that an equation relating the porosity change and the permeability change caused by an ideally retarded permeability change caused by an ideally retarded acid can be derived without any assumptions. SPEJ P. 390

Effect of walnut shell ash on pore structure characteristics during Zhundong coal sintering

2021 ◽  
Vol 221 ◽  
pp. 106923
Author(s):  
Hao Zhou ◽  
Jiawei Luo ◽  
Zhaowen Wang ◽  
Mengting Ji ◽  
Mingrui Zhang
Keyword(s):  
Pore Structure ◽  
Walnut Shell ◽  
Structure Characteristics ◽  
Zhundong Coal
Sign in / Sign up

Export Citation Format

Share Document