ACS Omega
·
2024
·
IF 3.7
Kai Shan,Zhengsong Qiu,Qi Yin,Qingzhen Cui,Dandan Su,Hanyi Zhong,Xin Zhao
For the purpose of efficient temporary plugging and self-removal of the plugging of reservoir formations, the thermally induced expandable and acid-generating temporary plugging agent (TAPA) was prepared with acrylonitrile (AN), methacrylic acid (MAA), N,N-dimethylacrylamide (DMAA), and butyl acrylate (BA) as the shell monomers as well as the carboxylate esters with high boiling points as the core material. The TAPA was structurally characterized, and the properties were studied. The results showed that the TAPA had a good spherical structure with a median particle size (D50) of 16.03 μm. The initial expansion temperature Tstart of the TAPA was 134.75 °C, and its maximum expansion temperature Tmax was 197.77 °C. The surface was hydrophilic and negatively charged, with excellent shear strength and sealing. The TAPA was suitable for temporary plugging and self-removal of the plugging of the reservoir formation with a temperature of 160 °C. The release of core materials and the effect on self-removal of plugging were not significantly affected with different salinities, weak acid or weak alkali environments, or a small quantity of hydrocarbons. With addition of 1–3 wt % TAPA, the rheological property of water-based drilling fluid changed slightly, but the filtration loss reduced, suggesting a good compatibility of the TAPA with the drilling fluid. Results of plugging and plugging removal experiments in fractured reservoir formations and permeable reservoir formations showed that the TAPA improved the strength of the temporary plugging layer with the elastic deformation due to thermal expansion and realized self-removal of the plugging by corroding the temporary plugging layer with carboxylic acid hydrolyzed from the carboxylic ester released, thereby decreasing the backflow pressure of oil and gas wells in the production stage. The results provided a new method and technological idea for efficient temporary plugging and self-removal of the plugging of reservoir formations.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Petroleum Science
·
2024
·
IF 6
Zhe Xu,Jin-Sheng Sun,Jing-Ping Liu,Kai-He Lv,Xiao-Dong Dong,Zong-Lun Wang,Tai-Feng Zhang,Yuan-Wei Sun,Zhi-Wen Dai
As drilling wells continue to move into deep ultra-deep layers, the requirements for temperature resistance of drilling fluid treatments are getting higher and higher. Among them, blocking agent, as one of the key treatment agents, has also become a hot spot of research. In this study, a high temperature resistant strong adsorption rigid blocking agent (QW-1) was prepared using KH570 modified silica, acrylamide (AM) and allyltrimethylammonium chloride (TMAAC). QW-1 has good thermal stability, average particle size of 1.46 μm, water contact angle of 10.5°, has a strong hydrophilicity, can be well dispersed in water. The experimental results showed that when 2 wt% QW-1 was added to recipe A (4 wt% bentonite slurry+0.5 wt% DSP-1 (filtration loss depressant)), the API filtration loss decreased from 7.8 to 6.4 mL. After aging at 240 °C, the API loss of filtration was reduced from 21 to 14 mL, which has certain performance of high temperature loss of filtration. At the same time, it is effective in sealing 80–100 mesh and 100–120 mesh sand beds as well as 3 and 5 μm ceramic sand discs. Under the same conditions, the blocking performance was superior to silica (5 μm) and calcium carbonate (2.6 μm). In addition, the mechanism of action of QW-1 was further investigated. The results show that QW-1 with amide and quaternary ammonium groups on the molecular chain can be adsorbed onto the surface of clay particles through hydrogen bonding and electrostatic interaction to form a dense blocking layer, thus preventing further intrusion of drilling fluid into the formation.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Gels
·
2022
·Vol. 9
·期 1
·23
·
IF 4.432
Hongyan Du,Kaihe Lv,Jinsheng Sun,Xianbin Huang,Haokun Shen
With the exploration and development of unconventional oil and gas, the use frequency of oil-based drilling fluid (ODF) is increasing gradually. During the use of ODFs, wellbore instability caused by invasion of drilling fluid into formation is a major challenge. To improve the plugging property of ODFs, nano-sized poly(styrene-lauryl acrylate) (PSL) rubber nanogels were synthesized using styrene and lauryl acrylate through soap-free emulsion polymerization method and were characterized using FTIR, NMR, SEM, TEM, particle size analysis and TGA. The results show that, due to good dispersion stability and oil-absorbing expansion ability, the PSL rubber nanogels have a wide range of adaptations for nano-scale pores to deposit a layer of dense filter cake on the surface of filter paper with various pore diameters, reducing the filtration of mineral oil and W/O emulsion significantly. Due to the unique wettability, the PSL rubber nanogels can be adsorbed stably at the oil–water interface and form a dense granular film to prevent droplets coalescing, which improves the emulsification stability of W/O emulsion. Furthermore, the PSL rubber nanogels are soap-free and compatible with ODFs without foaming problems. The PSL rubber nanogels can increase the hole-cleaning performance of ODFs by raising viscosity and yield point. The PSL rubber nanogels outperformed hydrophobic modified nano silica and polystyrene nanospheres in plugging and filtration reduction. Therefore, the PSL rubber nanogels are expected to be used as a new plugging agent in oil-based drilling fluid. This research provide important insights for the use of organic nanogels in ODFs and the optimization of plugging conditions.Keywords:oil-based drilling fluid;nanogels;plugging agent;emulsion stability
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Gels
·
2024
·Vol. 10
·期 2
·112
·
IF 5
Quanyang Wang,Chenghua Zhou,Honghu Zhang,Xue Zhang,Xinxin Wen,Jiexin Bai,Hui Mao
Deep wells and ultra-deep wells often encounter cracks, karst caves, and other developed strata, which can lead to leakage during drilling. Conventional bridge slurry plugging technology is prone to leaking due to the poor plugging effect of the plugging agent. The gel plugging agent possesses characteristics of flexible plugging and adaptive matching of formation leakage channels. It can fill cracks or caves and enhance the pressure-bearing capacity of the formation. A controllable crosslinking plugging agent based on low-molecular-weight polyacrylamide was studied. Polyacrylamide with different molecular weights is synthesized from acrylamide and an initiator. A crosslinking time-controllable polymer is synthesized from low-molecular-weight polyacrylamide by adding crosslinking agent and retarder. The low-molecular-weight polyacrylamide plugging agent has low viscosity before gelation and good fluidity in the wellbore. After being configured on the ground, it is transported by pipeline and sent underground to reach the thickening condition. The gel solution rapidly solidifies, and its strength improves after high-temperature crosslinking. The synthesis conditions of the polymer were as follows: a monomer concentration of 9%, initiator 3.5%, synthesis temperature of 65 °C, and hydrogen peroxide initiator. The optimal formula of the gel plugging agent is as follows: a polymer concentration of 6%, a crosslinking agent concentration of 1%, and a retarder concentration of 8%. The generated polymer molecular structure contains amide groups. This crosslinking time-controllable plugging agent based on low-molecular-weight polyacrylamide has stable rheology, and its temperature resistance can reach 150 °C. At 150 °C, the gelation time can be controlled by adjusting the concentration of retarder, and the longest can reach 4 h. The plugging efficiency of the gel plugging agent is more than 95%. With the increase in seam width, the pressure of the gel plugging agent gradually decreases.
研究领域:
石油工程
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PHYSICS OF FLUIDS
·
2023
·Vol. 35
·期 8
·
IF 4.6
Yang Hongbin,Lv Zhiqi,Li Zhe,Guo Bumin,Zhao Jian,Xu Yantao,Xu Wenjiang,Kang Wanli
In order to solve the uncontrollable swelling ratio and degradation time and insufficient strength of conventional self-degradable temporary plugging agent (CSD-TPA), a controllable self-degradable temporary plugging agent (SD-TPA) was proposed. A series of SD-TPA were prepared with free radical polymerization, and the SD-TPA was synthesized by different mass ratios of acrylamide, acrylic acid, hydrophobic monomer, and modified nanoparticles. The effects of modified nanoparticles content, hydrophobic monomers content, temperature, and salinity on its swelling performance, self-degradable performance, and rheological properties were researched systematically. The plugging and unblocking performance of SD-TPA were studied by a core displacement test. The experimental results showed that SD-TPA can be gelatinization after 4 h at 40 °C. Under the formation condition, SD-TPA had better viscoelasticity, shear resistance, and higher yield stress than CSD-TPA. The core plugging rate increased from 86.44% to 91.41%, and the formation damage rate decreased to 14.11%. This work provides a new temporary plugging material during hydraulic fracturing process and the swelling ratio, degradation time, and insufficient strength of SD-TPA can be adjusted according to the requirement of fracturing.
研究领域:
石油工程
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.9
Haiyan Dong,Tianle Li,Shaocong Pang,Yuxiu An
There are a large number of nano-micron pores on the surface of the rock layer, and during the drilling process, water molecules will penetrate into the formation through these nano-micron pores, causing hydration and expansion of the rock, causing instability of the wellbore and other problems. Nano-micron plugging agents can effectively seal the nano-micron pores in the formation, reducing the hydration and expansion of the formation. This paper synthesized the ternary copolymer (AAK) using modified nano silica (KH-570), acrylamide (AM), and 2-acrylamide-2-methyl-1-propane sulfonic acid (AMPS) as raw materials, and used it as a plugging agent in water-based drilling fluids. The characterization and performance of AAK were studied using Fourier transform infrared spectroscopy, particle size analyzer, transmission electron microscopy, and thermogravimetric experiments. The plugging performance was evaluated using microporous filter membrane temperature and pressure tests, liner swelling tests, immersion test, and contact angle tests. In addition, its tackiness and salt resistance were also tested. The results indicate that the particles of AAK are nanoscale particles, which can effectively seal the nano and micro pores in rock blocks. At the same time, AAK has good temperature and salt resistance. The addition of AAK does not significantly change the rheological properties of the drilling fluid and can be used as a plugging agent in water-based drilling fluids.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2019
·
IF 4.561
Caili Dai,Chenglin Gu,Baoche Liu,Yahui Lyu,Xue Yao,Haonan He,Jichao Fang,Guang Zhao
Steam channeling is a commonly occurring phenomenon during steam flooding in heavy reservoirs. In this study, low-temperature expandable graphite was prepared to be employed as a steam plugging agent to resolve this problem. The preparation process was divided into two stages: (1) preoxidation and (2) deep oxidation and intercalation. The effects of the reagents and expansion temperature on the expansion capability were studied. An improved preparation formula for expandable graphite employed a mass ratio of graphite: H 2 O 2 :HClO 4 :KMnO 4 : acetic acid (HAc) as 1:2:6:0.5:1, and the expansion volume at 300 °C was 273 mL/g. Moreover, the initial expansion temperature was approximately 140 °C. In a water environment, the graphite particles demonstrated an expansion, which is less than that in a dry environment, and most layers maintained a good connection to ensure that the graphite sheets exhibited better anti-breaking strength. The Fourier transform infrared spectroscopy and X-ray diffraction analysis indicated that the intercalation reagents (HClO 4 and HAc) successfully entered the graphite layers, and the crystallinity of graphite decreased gradually during the reaction process. The oxidants (H 2 O 2 , KMnO 4 ) oxidized the edges of the graphite layers and slightly opened them, which provided the channels for the intercalation agents to enter the interlayer space. After expanding at 300 °C, a worm-like particle was formed. Through direct plugging, bridge plugging, and expansion capability, the low-temperature expandable graphite can control steam channeling. This study established a complete preparation technique of low-temperature expandable graphite that can be used for controlling steam channeling. This may serve as a reference for the preparation of steam plugging agents and an efficient development of heavy oil.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2024
·
IF 3.9
Hao Yanjun,Zheng Xuecheng,Fan Wei,Chen Siqi,Ye Zhongbin,Tai Lei
In view of the extremely developed bedding of shale formations, which are dominated by micro-nano pores and fractures, traditional sealing agents make it difficult to produce a tight seal on shale formations due to their huge particle sizes. Combining the bridging effect of inorganic nanoparticles and the deformation properties of organic particles, this article synthesized a core-shell structure nano-blocking agent through emulsion polymerization, which was called P(MMA-St-BD)/KH570-SiO 2 . The structure of the synthesized nano-plugging agent was characterized utilizing Fourier transform infrared spectroscopy (FT-IR), particle size distribution, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). Performance characterization was carried out through the effect of nano-blocking agents on emulsion stability, rheological properties, microporous filter membrane plugging experiments, and core pressure-bearing capacity tests. The findings demonstrate that P(MMA-St-BD)/KH570-SiO 2 ’s structure satisfies design specifications, and that the nano-plugging agent has outstanding thermal stability, homogeneous particle size distribution, and good dispersion. Its decomposition temperature also exceeds 400 °C. This study analyzed the plugging efficiency of nano-blocking agents from the temperature perspective, indicating that the nano-blocking agents seal shale formations tightly. Ultimately, through mechanism analysis, nanomaterials can squeeze and deform through the polymer shell and enter the shale micropores and micro-cracks for sealing, forming a high-strength sealing zone.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
Petroleum Science
·
2024
·
IF 6
Hai-Rong Wu,Geng-Lin Li,Guo-Rui Xu,Jia-Wei Chang,Kun-Peng Hou,Wen-Hao Shao,Ji-Rui Hou
Inadequate strength and stability of active crude oil emulsions stabilized by conventional surfactants always lead to a limited plugging rate of plugging agents. Thus, to address this issue, the synthesis of amphiphilic Janus nanosheets was effectively carried out for enhancing the system performances and subsequently characterized. Based on the outcomes of orthogonal tests, an assessment was conducted on the nanosheet and surfactant formulations to optimize the enhancement of emulsion properties. The experimental demonstration of the complex system has revealed its remarkable emulsifying capability, ability to decrease interfacial tension and improve rheological behavior at high temperature (80 °C) and high salinity (35,000 ppm) conditions. Involving probable mechanism of the system performance enhancement is elucidated by considering the synergistic effect between surfactants and nanosheets. Furthermore, variables including water-to-oil ratio, salinity, temperature and stirring intensity during operation, which affect the properties of prepared emulsions, were investigated in detail. The efficacy and stability of the complex system in obstructing medium and high permeability cores were demonstrated. Notably, the core with a high permeability of 913.58 mD exhibited a plugging rate of 98.55%. This study establishes the foundations of medium and high permeability reservoirs plugging with novel active crude oil plugging agents in severe environments.
研究领域:
石油工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Xuechen Tang,Hongbin Yang,Yongbo Gao,Zeeshan Ali Lashari,Changxiao Cao,Wanli Kang
A kind of silica-reinforced polymer microspheres was proposed and prepared by inverse suspension polymerization, in which the nano-silica modified by 3-(methacrylyloxy) propyl trimethoxysilane (MPS) was used as reinforcing material. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and dynamic light scattering (DLS) were utilized to analyze their structural properties. The effects of SiO 2 on swelling capability, mechanical shear resistance, stability and viscoelastic property were studied. Plugging behavior was examined by sand pack model experiments. The results show that SiO 2 can effectively adjust swelling behavior, and greatly improve mechanical shear resistance of polymer microspheres. Compared with conventional polyacrylamide microspheres, these silica-reinforced polymer microspheres displayed better dispersion stability and viscoelastic property. In addition, these microspheres exhibited an improved thermal stability, where the maximum degradation temperature was 11 °C higher than that of conventional ones. The plugging rate can be 83.87% and was promoted by 11.54% in sand pack model. This work can provide a viable candidate material for the deep conformance control in oilfields, and supply theoretical support for its application.
研究领域:
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Chenwei Zou,Caili Dai,Yifei Liu,Qing You,Fei Ding,Yongping Huang,Ning Sun
In recent years, the liquid temporary plugging agent has drawn extensive attention, especially in the repeated fracturing operation for stimulating unconventional oil and gas reservoir production. This paper developed a novel self-degradable gel (SDG) as a liquid temporary plugging agent for high-temperature reservoirs. The gelation process, viscoelasticity, pressure-bearing capacity, self-degradation, and formation protection performance of the SDG were systematically investigated. Moreover, the gelation and self-degradation mechanism of the SDG were revealed by studying the viscosity variation and the microstructures. Considering the gelation time and gel strength, the composition of the SDG was optimized as 6.0–10.0 wt% monomer, 0.004–0.012 wt% initiator, and 0.2–0.4 wt% crosslinker. The SDG transformed from liquid to solid-like gel within 30 to 90 min at 90–130 °C. The rheological results showed that the duration of the low viscosity state exceeded 75 % of the total gelation process at high temperatures, which was conducive to the injection of the SDG. In addition, the viscosity of the SDG after gelation was more than 100 Pa·s, which ensured its effective plugging in fractures. The experimental results with fractured cores showed that the bearing pressure of the SDG remained above 30 MPa/m in fracture with a width of 2.05–5.04 mm, which could meet the requirements of the repeated fracturing operation. Moreover, the SDG could spontaneously degrade from solid-like gel to liquid with a viscosity of lower than 10 mPa·s in 10–105 h at 90–130 °C. The broken-gel liquid could be completely displaced out of the fractured core, and the core damage rate was less than 5.0 %, which ensured the restoration of conductivity of the previously existing fractures. Micrographs showed that the dense three-dimensional network structure with high viscosity was formed by polymerization and crosslinking. Then, the acrylic acids in the polymer chain were broken at high temperatures, resulting in the gradual destruction of the gel and the spontaneous degradation of SDG.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY AND TECHNOLOGY OF FUELS AND OILS
·
2020
·Vol. 56
·期 4
·601-611
·
IF 0.405
Zhang Yihang,He Miao,Song Jianjian,Xu Mingbiao,Xu Peng
Carbonate reservoirs in Asmari block of Missan oilfield are characterized by complex geological characteristics. Temporary plugging is commonly used for effective damage control caused by the working fluid when drilling in such complex multi-pressure reservoirs and for preventing leakage, blowout, and collapse in long open hole wells. In this paper a new temporary plugging drilling fluid formulation system is proposed, designed for the low permeability carbonate reservoir containing H 2 S and CO 2 in the target block. The system contains a specially designed acid-soluble temporary plugging agent DSK-1 combined with HCOONa and modified biopolymer VS-A flow pattern regulator; modified starch water loss reduce agent, and DSP antioxidant. The parameters of the system, including temperature stability, resistance to formation water pollution, inhibition capacity, and stability to acids and acid gases, were evaluated in a series of experimental tests. The plugging ability was evaluated by experiments on cores received from the target block. The results showed that the plugging removal and recovery rate of the drilling fluid system was up to 86.3%, which can effectively meet the target requirements, and provide guidance and reference for the follow-up study of temporary plugging in low permeability carbonate reservoirs.
研究领域:
石油工程
·
地质学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）