SPE Journal最新文献

{"title":"Enhanced Filtration Performance of Cellulose Nanofiber/Bentonite Water-Based Drilling Fluids with Temperature- and Salt-Resistant Polymers for Extreme Conditions","authors":"Muhammad Arqam Khan, Kaihe Lv, Jinsheng Sun, Fengbao Liu, Haokun Shen, Yang Ding, A. Noor, Shaine Mohammadali Lalji, Chaozheng Liu, Mei‐Chun Li","doi":"10.2118/228402-pa","DOIUrl":"https://doi.org/10.2118/228402-pa","url":null,"abstract":"Summary Drilling fluids play a crucial role in transporting cuttings to the surface, maintaining wellbore stability, and controlling formation pressures. However, high temperatures, high pressures, and high salinities frequently impair their effectiveness in deep and intricate formations. In recent years, cellulose nanofibers (CNFs) have gained attention due to their high surface area, aspect ratio, and fiber-like structure, making them promising candidates for rheology and filtration modification in bentonite water-based drilling fluids (BT-WBDFs). Nevertheless, their filtration performance under high-salinity and high-temperature conditions has been found insufficient. For this study, we used acrylamide (AM), 2-acrylamide-2-methylpropane sulfonic acid (AMPS), and dimethyl diallyl ammonium chloride (DMDAAC) to synthesize a series of polymers, including poly(AM-AMPS) (AA), poly(AM-DMDAAC) (AD), and poly(AM-AMPS-DMDAAC) (AAD), with excellent temperature and salt resistance. These polymers were evaluated for their ability to enhance the filtration performance of CNF/BT-WBDFs under extreme conditions. Experimental results revealed that terpolymer AAD demonstrated the best salt and thermal resistance under conditions of 26 wt% NaCl concentration and aging at 200°C for 16 hours. Further optimization of the monomer ratio for AAD showed that when the AM/AMPS/DMDAAC molar ratio was adjusted to 3:2:1, the API fluid loss and high-pressure, high-temperature (HPHT) fluid loss were minimized to 7.3 mL and 70 mL under the same extreme conditions. Mechanistic analysis suggested that maintaining the uniform dispersion of BT and CNFs is critical for reducing fluid loss, with AAD exhibiting the strongest ability to preserve colloidal stability. These findings pave the way for developing sustainable drilling fluids with improved thermal stability and filtration control tailored for challenging drilling environments.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 09","pages":"5327-5349"},"PeriodicalIF":0.0,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147893426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental Study of the Interface Bond Properties and Microstructures of Nanosilica-Modified Epoxy Resin Cement Materials","authors":"Xin Tang, Yaning Lu, Yan Yang, Bin Yuan, Xiangyin Li","doi":"10.2118/228318-pa","DOIUrl":"https://doi.org/10.2118/228318-pa","url":null,"abstract":"Summary The bond properties of the cement sheath in the annulus are critical to maintaining the sealing integrity of oil and gas wells. However, there is no agreement on how to test and evaluate the bond properties, and there is still no effective method for improving the interfacial bond strength. For this study, we established a tensile bond strength (TBS) setup and a novel nanosilica-modified epoxy resin (MER) cement slurry for enhancing the interfacial bond properties. The test samples were cured at 50°C, 70°C, and 90°C under a pressure of 21 MPa for 7 days. Experimental results demonstrated that the incorporation of MER significantly enhanced TBS values. Specifically, when 3% modified silica nanoparticles were added to the epoxy resin, a substantial increase in TBS was observed at both the first (between the casing and cement sheath) and second (between the cement sheath and formation) interfaces. The influence of core permeability on TBS was found to be negligible. The silica nanoparticles provided nucleation sites that facilitated the formation of hydration products. Based on the test results, the improved bonding performance of the resin-modified cement can be attributed to mechanisms of mechanical interlocking and interfacial chemical reactions. These findings suggest that MER is a promising additive for cement slurries aimed at enhancing interfacial bond strength and promoting cement hydration, thereby significantly improving the sealing integrity of oil and gas wells.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 08","pages":"4645-4658"},"PeriodicalIF":0.0,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147877539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Adhesive Strength and Water Resistance Performance of an Improved Sodium-Lithium Silicate Bonding Agent for Enhanced Drilling in Unconsolidated Formations","authors":"Yinghui An, Huanan Liu, Ying Li, Wei Wang, Maosen Wang, Mingyi Guo","doi":"10.2118/228314-pa","DOIUrl":"https://doi.org/10.2118/228314-pa","url":null,"abstract":"Summary Water-induced degradation often constrains the use of sodium silicate (SS) as a bonding agent in drilling operations, thereby compromising its long-term adhesive strength. In this study, we introduce an adhesive composed of SS (modulus = 2.0), lithium silicate (LS), and silicon phosphate (SP), capable of binding sand particles together into a cohesive, waterproofing aggregate. The optimal formulation (10% SS, 5% LS, and 0.5% SP) achieved a Brazilian splitting tensile strength of 1.458 MPa under dry conditions, exhibiting 93.7% retention (1.367 ± 0.035 MPa) after 2 hours of water immersion and preserving structural integrity for 48 hours with 72.1% residual strength (1.052 MPa). Microstructural analyses via optical microscope, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) revealed that the interparticle connections were strengthened by rigid bonding bridges and water-resistant films, predominantly composed of amorphous silica. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) results demonstrate that LS increased silica sources and promoted Si-O-Si network formation while confirming lithium ions’ competitive displacement of sodium ions within the silicate gel framework. Through this study, we provide a potential method for improving the stability of unconsolidated formations using a composite silicate binder, offering new insights into the development of chemical bonding agents in complex geological and engineering environments.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 08","pages":"4726-4740"},"PeriodicalIF":0.0,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147918559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Additives for a Metakaolin-Fly Ash-Based Geopolymer Cementing Slurry System at 70°C","authors":"Zhen Zhang, Yuhuan Bu, Shenglai Guo, Xuan Wang, Chang Lu, Huajie Liu, Xinyang Guo","doi":"10.2118/228309-pa","DOIUrl":"https://doi.org/10.2118/228309-pa","url":null,"abstract":"Summary The issues of short thickening time of geopolymer at higher temperature conditions are significant barriers to broader application. In this study, the effects of raw material proportions and additives (activators, retarders, and fluid loss agents) on the performance of metakaolin (MK)-fly ash (FA)-based geopolymer under conditions of 70°C were investigated, and the effect mechanism of retarders was analyzed. The results indicate that when sodium silicate is combined with sodium hydroxide, the geopolymer exhibits high strength. Specifically, when the FA/MK ratio is 6:4 and the water/solid ratio is 0.7, the geopolymer exhibits high strength and favorable rheological properties. The addition of 0.9% barium chloride dihydrate (BaCl2·2H2O), 4% zinc sulfate heptahydrate (ZnSO4·7H2O), 10% ethylene glycol (EG), or 10% ethylenediaminetetraacetic acid disodium salt (EDTA-2Na) significantly increases the setting time, but this adversely affects the strength. This occurs primarily due to the products formed from the reaction between the retarder components and water glass or mineral components, which cover the surface of the raw materials and reduce the reaction rate. When utilizing a combined dosage of 0.9% barium chloride dihydrate (BaCl2·2H2O) and zinc sulfate heptahydrate (ZnSO4·7H2O) as a retarder, the thickening time of the geopolymer significantly increases. Furthermore, the addition of 0.5% carboxymethylcellulose sodium (CMC-Na) effectively controls water loss, with the initial setting time exceeding 45 minutes and strength of up to 8 MPa, demonstrating satisfactory settlement stability, but it adversely affects rheological properties.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 08","pages":"4627-4644"},"PeriodicalIF":0.0,"publicationDate":"2025-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147901165","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polymeric Barium and Strontium Sulfate Scale Inhibitors P(Maleic Anhydride/Acrylic Acid/Dimethyl Diallyl Ammonium Chloride/Sodium Styrene Sulfonate) with Quaternary Amine for Downhole Squeeze Application in Sandstone Reservoir at 120°C Seawater Condition","authors":"Minggui Chen, Kangning Xu, Xiaochun Tan, Lei Qiu","doi":"10.2118/225439-pa","DOIUrl":"https://doi.org/10.2118/225439-pa","url":null,"abstract":"Summary In the Weizhou Oilfield, located in the South China Sea, seawater flooding containing SO42− with formation water rich in Ba2+ and Sr2+, severe barium sulfate (BaSO4), and strontium sulfate scale formation reduces reservoir production. A quaternary polymer scale inhibitor was synthesized through aqueous solution polymerization to counteract the formation of barium/strontium sulfate scale during reservoir production. This process used acrylic acid (AA), maleic anhydride (MA), dimethyl diallyl ammonium chloride (DMDAAC), and sodium styrene sulfonate (SSS) as monomers, and it utilized ammonium persulfate as the initiator and isopropanol as the chain transfer agent (CTA). The resulting terpolymer P(MA/AA/DMDAAC) and quaternary copolymer p(MA/AA/DMDAAC/SSS) scale inhibitors were characterized by Fourier transform infrared (FTIR) and 1H-nuclear magnetic resonance (NMR). The study investigated the effects of scale inhibitor dosage, temperature, and pH value on scale inhibition efficiency, the minimum inhibitor concentration (MIC) of scale inhibitors, and the adsorption-desorption performance of scale inhibitors. The optimized synthetic condition of the P(MA/AA/DMDAAC/SSS) scale inhibitor was determined by the ratio of n(MA):n(AA):n(DMDAAC) = 0.35:1:0.125. Additionally, the amount of SSS was set at 10% of the total mass of the main monomer (MA and AA), the amount of ammonium persulfate as the initiator was 6% of the total weight of the monomer, the amount of isopropanol as the CTA was 2% of the total weight of the monomer, and the polymerization time was set at 5 hours, with a polymerization temperature of 75°C. The measured scale inhibition efficiency of the P(MA/AA/DMDAAC/SSS) polymer was 94.4%, and the scale inhibitor showed good compatibility with seawater. The static MICs of the P(MA/AA/DMDAAC) and P(MA/AA/DMDAAC/SSS) scale inhibitors were 80 mg/L and 60 mg/L, respectively, in the dynamic loop test. It was observed that the performance of scale inhibitors is greatly affected by the pH value, and it was found that the two scale inhibitors performed best at a pH value of 9. This indicates that the chelating performance of dual carboxylate groups in the copolymer backbone works best with Ba2+. When the temperature reached 120°C, the P(MA/AA/DMDAAC/SSS) scale inhibition efficiency after aging for 16 hours was greater than 85%. Furthermore, dynamic adsorption and desorption performance tests show that the adsorption performance of the P(MA/AA/DMDAAC/SSS) scale inhibitor with the cationic group was found to be better than that of the polyepoxysuccinic acid (PESA) scale inhibitor with the anionic group. This suggests that including cationic quaternary ammonium groups in polymeric scale inhibitor molecules improves their ability to adsorb on anionic surface charges found in sandstone reservoirs. Finally, an analysis using environmental scanning electron microscopy (SEM) showed that using P(MA/AA/DMDAAC/SSS) scale inhibitors resulted in smaller inorga","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 05","pages":"2707-2725"},"PeriodicalIF":0.0,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147882500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluid States and Movable Fluid Distribution from Conventional Reservoirs to Unconventional Reservoirs Based on Nuclear Magnetic Resonance Characterization","authors":"Shuai Yuan, Minghui Li, Yuan Li, Maoqin Yang, Bin Wang, Tianbo Liang, Erdong Yao, Fujian Zhou","doi":"10.2118/225456-pa","DOIUrl":"https://doi.org/10.2118/225456-pa","url":null,"abstract":"Summary Driven by the depletion of conventional reservoirs and the escalating global energy demand, the focus has shifted toward unconventional reservoirs. These reservoirs exhibit intricate fluid flow behaviors due to their lower permeability and smaller pore sizes compared with conventional reservoirs. Traditional characterization techniques, such as nitrogen adsorption and mercury injection capillary pressure (MICP), are significantly limited in accurately characterizing fluid flow in these complex reservoirs. Nuclear magnetic resonance (NMR) emerges as a nondestructive and highly precise method, providing valuable insights into fluid-rock interactions, pore-size distribution, and fluid identification at the pore scale. This study investigates the behavior of typical oleic and aqueous fluids, including both single-component and multicomponent fluids, in both conventional and unconventional reservoirs. The 1D and 2D NMR properties of these fluids are characterized in both bulk state and porous media. The impacts of fluid composition and pore size on T1, T2, and T1–T2 spectra are examined to distinguish NMR behaviors in nanoscale and microscale pores. In the bulk fluid state, 1D NMR reveals that T1 and T2 spectral peaks decrease with increasing fluid viscosity. Meanwhile, T1–T2 spectra show that fluids with different viscosities are distributed within a T1/T2 ratio range of 0.5–2, shifting leftward and downward as viscosity increases. In porous media, increased fluid viscosity causes a leftward shift in T1 and T2 spectra, consistent with bulk fluid behavior. In high-permeability cores (HPCs), T1 and T2 spectra of single- and multicomponent fluids exhibit unimodal distributions, aligning with pore size distribution. In contrast, in low-permeability cores (LPCs), T1 spectra of all fluids remain unimodal, while T2 spectra of multicomponent fluids become bimodal due to diffusion relaxation effects. This is attributed to differences in diffusion coefficients and enhanced internal gradient fields in nanoscale pores. Thus, T1 spectra are more suitable for characterizing multicomponent fluid distribution in low-permeability reservoirs with nanoscale pores. Core centrifugation tests combined with NMR scans are used to assess fluid mobility changes influenced by viscosity and centrifugal pressure. For fluid mobility in different porous media, cutoff values of T1 and T2 and movable fluid saturations are determined through centrifugation tests. The deviation of T2 spectra from the real pore structure does not affect the calculation of movable fluid saturation. However, T1 spectra provide a more accurate representation of fluid distribution during centrifugation, despite longer measurement times. This study validates the adaptability of 1D NMR for characterizing the pore structure and fluid distribution of unconventional reservoirs. It provides a reliable reference for multifluid identification in real underground conditions. The study enhances the understan","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 05","pages":"3048-3064"},"PeriodicalIF":0.0,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147908039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Displacement Mechanisms of Modified Carbon Black Nanofluid as a Novel Flooding System in Ultralow-Permeability Reservoirs","authors":"Lihao Liang, Siwei Meng, Jiaping Tao, Changping Gong, Man Shen, Jin Xu, Hongtao Fu","doi":"10.2118/224436-pa","DOIUrl":"https://doi.org/10.2118/224436-pa","url":null,"abstract":"Summary Emerging as an innovative flooding system tailored specifically for ultralow permeability reservoirs characterized by traits such as low permeability, low porosity, and pronounced heterogeneity, the underlying displacement mechanism of modified carbon black (MCB) nanofluid within these reservoirs remains unclear. This study aims to illuminate the characteristics and displacement mechanisms of this new system through a comprehensive investigation employing macroscopic displacement, microscopic visualization, and various other experimental techniques. Macroscopic core flow experiments demonstrated that MCB nanofluid effectively exerted moderate profile control in tiny fractures, expanding the displacement area and achieving a notable 10.55% increase in total oil recovery compared with tetradecyl hydroxypropyl sulfobetaine (THSB) surfactant. Nuclear magnetic resonance (NMR) analysis detection revealed that MCB nanofluid initially removed the oil film on the surface of tiny fractures, and then enhanced the following water’s effectiveness in mobilizing the remaining oil in the matrix through moderate profile control. The microscopic visualization results showed that MCB nanofluid achieved efficient oil washing through multiple mechanisms, including reducing the oil-water interfacial tension (IFT) to 10-2 mN/m, altering the wettability, emulsifying oil droplets, and aggregating oil into belts, which was attributed to the active functional groups on the surface of MCB nanoparticles. Moreover, MCB nanoparticles could accomplish moderate profile control through three behaviors, including particles adsorption, aggregation, and bridging within the high-permeability channels, resulting in a higher swept volume. MCB nanofluid could enhance oil recovery through a dual mechanism of efficient oil washing and moderate profile control.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 05","pages":"2909-2922"},"PeriodicalIF":0.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147885819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Polymer Development Creates New High-Temperature, High-Pressure Cement Slurry Suspending Agent","authors":"Chengwen Wang, Lifang Song, Jingping Liu, Chengli Wang, Hongtao Wang, Zedong Xue, Aipu Shi","doi":"10.2118/224441-pa","DOIUrl":"https://doi.org/10.2118/224441-pa","url":null,"abstract":"Summary A high-temperature suspending agent with temperature resistance up to 200°C has been developed to address the challenges of high-temperature, high-density cement slurry (2.0–2.6g/cm3) settling and destabilization during cementing in deep wells (4500–6000 m) and ultradeep wells (>6000 m). This suspending agent is designed to introduce modified nano-silica (nano-SiO2) and long hydrophobic side-chain temperature-sensitive monomers. The inclusion of modified nano-SiO2 enhances the temperature resistance of the suspending agent and improves the suspension stability of solid-phase particles in high-density cement slurries. Concurrently, the long hydrophobic side chains increase the viscosity of the cement slurry at high temperatures through hydrophobic bonding. The synergistic effect of these components can delay settling of high-density cement slurries at high temperatures. In performance evaluations adhering to American Petroleum Institute (API) standards, the addition of 0.6 wt% of the suspending agent to a high-density cement slurry (density of 2.35 g/cm³) reduced the density difference between the top and bottom of the slurry from 0.897 g/cm³ to 0.028 g/cm³ after curing at 200°C, surpassing the local (Chinese) standard requirement of 0.05 g/cm³. This contributes to maintaining the overall uniformity of solid-phase particles in high-density cement slurry at high temperatures. It ensures the proper development of slurry consistency and cement strength properties. This advancement can help to reduce the risks associated with deep well cementing, supporting the quality of cementing operations in deep and ultradeep wells, and holds promise for starting some field tests.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 04","pages":"1773-1788"},"PeriodicalIF":0.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147888526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Elastomer Microsphere Particles as Water-Based Drilling Fluid Lost Circulation Material","authors":"Lili Yang, Zhiting Ou, Xiangyang Chang, Jiale Wu, Haozhe Chen, Jiang Guancheng, Jiaying Ma, Tengfei Dong, Yunpeng Wu, Changjiang Yu, Shangjiang Feng","doi":"10.2118/224416-pa","DOIUrl":"https://doi.org/10.2118/224416-pa","url":null,"abstract":"Summary Lost circulation is a common issue during oil and gas well drilling, presenting significant safety hazards and resulting in substantial economic losses. Bridging materials typically exhibit limited deformation and poor adaptability to formation pores and fractures, primarily due to size mismatching. Polymer gel materials have the potential to address these issues effectively. While strength is a crucial factor affecting plugging performance, other properties—such as the toughness and elasticity of polymer gel particles—are often overlooked. In this research, we introduce a novel elastomer plugging material that exhibits high toughness and elasticity. The material is composed of polyampholytes, which are synthesized through the copolymerization of an acrylate monomer with long alkyl side groups and a pair of oppositely charged monomers. The acrylic monomer enhances the mobility of the polymer chain, while the oppositely charged monomer generates a gradient interaction, resulting in the formation of ionic aggregates with a broad range of sizes and stiffness. The multigradient strong interaction affords the elastomer remarkable strength and elasticity, which, in turn, safeguards the structural integrity of microsphere particles when subjected to elevated pressure and shear stress. Additionally, the presence of weak interactions, enabled by high mobility, promotes gradual energy dissipation, ultimately enhancing the toughness of the material. PABD [poly (AMPS-BXSZ-DMDAAC)] microsphere particles possess the ability to effectively plug leakage channels by infiltrating pore cracks that are smaller than their own size. Additionally, they can form an elastomer block layer to seal cracks that are larger than their own size, which is facilitated by self-healing through the accumulation of particles and the intermolecular forces between them. As the pressure increases, the plugging layer compresses and becomes more dense, thereby effectively preventing the leakage of drilling fluid into the formation. The experimental results demonstrate that PABD microsphere particles effectively obstruct 8-darcy and 180-darcy consolidated sand trays at temperatures as high as 150°C. Moreover, these particles can be used to seal unconsolidated sand beds of 40−60 mesh, and their plugging performance is significantly enhanced when combined with traditional rubber. This study emphasizes the considerable application potential of elastomer materials in drilling operations.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 03","pages":"1190-1205"},"PeriodicalIF":0.0,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147883333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Salt Resistance Study of Different Monomer Combinations of Polyacrylamide-Based Slickwater Drag Reducers","authors":"Gaofeng Fu, Xiping Ma, Zhipeng Hou, Ke Xu, Cunchuan Zheng","doi":"10.2118/224411-pa","DOIUrl":"https://doi.org/10.2118/224411-pa","url":null,"abstract":"Summary Slickwater fracturing fluids are commonly used in the extraction of unconventional oil and gas reservoirs. However, their efficacy is significantly diminished in the presence of elevated salt concentrations. A pivotal component of slickwater fracturing fluids, the salt resistance of a drag reducer determines its overall performance. In this paper, we focus on the salt resistance of different monomer combinations of polyacrylamide (PAM)-based slickwater drag reducers using a selection of common drag-reducer functional monomers, including acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and methacryloyloxyethyltrimethylammonium chloride (DMC). Reverse-phase emulsion polymerization was used to synthesize 30 PAM-based drag reducers of six types with different monomer combinations. The successful synthesis of the product was confirmed by Fourier transform infrared (FT-IR) spectroscopy. The viscous averaged molecular weights were all greater than 2.4×106 g/mol, and the monomer conversion rate was greater than 90%. The dissolution experiments showed that the acrylamide (AM)/DMC monomer combination achieved the best dissolution performance at a dissolution time of 40 seconds. The steady-state shear viscosity test showed that in clean water, the monomer combination AM/AA had the best viscosity-increasing performance, with a viscosity of 328.9 mPa·s after steady-state shear. In salt solution, the monomer combination AM/AMPS/DMC showed the best salt resistance, with a viscosity retention rate of 39.30% in 20×104 mg/L CaCl2 solution. The amphoteric ionic drag reducer exhibits excellent salt resistance. It was shown in the drag reduction performance test that the AM/DMC monomer combination had the best drag reduction performance in clean water, with a drag reduction rate of 80.1%. In salt solution, the monomer AM/AMPS/DMC exhibited the highest drag reduction with a retention rate of 92.15%. The microscopic effects of salt concentration on the molecules of the drag reducer were illustrated using hydrodynamic radii and zeta potentials. The results of this research are of great significance for the development of salt-resistant drag reducers that can facilitate the efficient development of unconventional oil and gas reservoir resources.","PeriodicalId":22252,"journal":{"name":"SPE Journal","volume":"30 03","pages":"1134-1147"},"PeriodicalIF":0.0,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147902909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}