高温交联对钻井液的影响

随着我国深井钻井技术的快速发展,抗高温钻井液的研究面临着越来越突出的技术难题。其中钻井液的效果在高温油气井的钻进过程中起关键作用,对施工进度和钻速有重要影响。因此,钻井液在高温下的滤失性、流变性控制也是抗高温钻井液技术的难点。本文通过展开室内实验,对国内现有部分抗高温钻井液处理剂（如磺化处理剂和降滤失剂）的抗温性能进行了实验测试和综合评价。对钻井液中的高温交联反应进行分析,如何控制该体系的流变性和滤失性,详细论述了处理剂交联反应的影响因素以及交联程度对钻井液性能的影响,如温度、时间、pH、聚合物类型、粘土等,提出适度交联改善钻井液性能的观点。     

钻井液高温保护剂EGC-D的评价

针对常用钻井液聚合物降滤失剂高温降解后导致钻井液流变性及滤失性变差,在室内开展了钻井液高温稳定剂的实验。发现了一种简单易得的低分子量有机物可作为钻井液高温保护剂,研究探讨了其作用效果以及与现有钻井液体系的应用融合;评价了高温保护剂EGC-D对聚合物降滤失剂及磺化类降滤失剂抗温性的影响。结果表明,加入质量分数为1%EGC-D时,钻井液经过220℃老化16 h后高温高压滤失量为10.0 mL,滤失量降低。该剂能提高聚合物降滤失剂及磺化类降滤失剂抗温能力,使其发生适当的高温交联,对其黏度有很好的的维护,同时改善了动塑比,有利于体系携岩。     

P（AMPS-AM-AOETAC-AA）聚合物钻井液防塌降滤失剂的合成

采用氧化-还原引发体系,以2-丙烯酰氨基-2-甲基丙磺酸、丙烯酰胺、丙烯酰氧乙基三甲基氯化铵、丙烯酸为原料,合成了P（AMPS-AM-AOETAC-AA）聚合物钻井液防塌降滤失剂。通过均匀设计优化了反应条件,初步评价了共聚物的钻井液性能。结果表明,P（AMPS-AM-AOETAC-AA）聚合物作为钻井液处理剂具有热稳定性好和抗温能力强的特性,在淡水、盐水、饱和盐水和复合盐水钻井液中均具有较好的降滤失作用。经过150℃高温老化后仍能较好地控制钻井液的滤失量,且具有较好的防塌效果。     

P（AMPS-DMAM）共聚物钻井液降滤失剂的合成

采用氧化-还原引发体系,以2-丙烯酰氨基-2-甲基丙磺酸、N,N-二甲基丙烯酰胺为原料,通过均匀设计优化,合成了P（AMPS/DMAM）共聚物钻井液降滤失剂,借助红外光谱对聚合物进行了结构表征,初步评价了共聚物的钻井液性能。结果表明,P（AMPS/DMAM）共聚物作为钻井液处理剂,热稳定性好,抗温能力强,在淡水、盐水和饱和盐水钻井液中均具有较好的降滤失作用,经过220℃高温老化后仍能较好地控制钻井液的滤失量。     

论述纳米材料钻井液在油田中的应用

本文通过分析设计对纳米材料的表面性能进行了改进,在此基础上研制了一种纳米封堵降滤失剂,通过引入强的吸附基团和疏水基团,聚合物分子的疏水性、氢键等协同作用形成空间的网架结构,使合成的纳米封堵降滤失剂分散在钻井液中,不仅具备优秀的降滤失性能,同时还具备良好的柔性可变形性。之后,以此降滤失剂为核心处理剂,对配套使用的纳米润滑剂和抑制剂进行优选。     

干热岩抗高温钻井液体系研究

为了满足干热岩的开发需要,研制了一种抗温性能达到260℃的高温水基钻井液;主要通过研制的高温护胶剂HDC保持钻井液体系中的各种胶粒的稳定,配合相应的高温降滤失剂和高温封堵剂等其它配伍性处理剂的协同增效作用,来提高钻井液的抗温性能。结果表明,该钻井液抗温性能好,稳定性高,经过260℃高温老化后,仍能保持稳定的流变性能和滤失性能,适合各种类型的高温井的钻井作业。     

抗钙钻井液降滤失剂P(AMPS-DEAM)聚合物的合成

采用氧化-还原引发体系,以N,N-二乙基丙烯酰胺和2-丙烯酰基-2-甲基丙磺酸为原料,合成了P(AMPS-DEAM)共聚物抗高温抗钙钻井液降滤失剂。通过正交实验优化了配方及合成条件:m(DEAM):m(AMPS)=0.9:1、反应温度40℃、单体质量分数25%、引发剂用量0.22%,用红外光谱对聚合物的结构进行了表征,初步评价了共聚物的钻井液性能。结果表明,P(AMPS-DEAM)共聚物热稳定性好,作为钻井液处理剂,在淡水、盐水、饱和盐水和CaCl_2钻井液中均具有较好的降滤失作用。经过180℃超高温老化后仍能较好地控制钻井液的滤失量,体现出了良好的抗温、抗盐和抗钙性能。     

环保型高分子聚合物油基钻井液降滤失剂的合成及性能评价

目前油基钻井液中常用的降滤失剂处理剂主要是沥青类和腐殖酸等作为降滤失剂。但沥青类处理剂污染严重不利于环保,且对钻进过程中的机械钻速有很大影响,腐殖酸、胺类、木质素和高分子聚合物类处理剂加量大导致成本增加等问题。因此,以三聚氰酸三烯丙酯为交联剂,利用苯乙烯和癸酸乙烯酯为主要聚合单体,合成了一种新型的油基降滤失处理剂。研究测试表明该降滤失剂无毒、安全环保、对转速影响小、加量低等特点,并且拥有良好的抗温性能,在200℃时滤失量为4.8 mL。     

耐高温合成类水溶性聚合物水基钻井液处理剂研究进展

深井、超深井下的高温条件严重影响钻井液的性能和钻井工程的安全运行。耐高温水溶性聚合物水基钻井液处理剂是深井钻探成败的关键。文章综述了国内外水基钻井液中耐高温合成类水溶性聚合物的研究与应用情况,其广泛用于钻井液的降滤失剂、增粘剂、降粘剂和防塌剂等。     

抗高温高密度钻井液的室内研究

针对深井、超深井钻井过程中钻井液悬浮稳定性与流变调控难题,通过研选处理剂,形成了纳米有机硅与膨润土复配的悬浮剂、抗高温降滤失剂,并对重晶石粒径进行了筛选,形成了一套抗高温高密度钻井液。室内评价表明,抗高温高密度钻井液在高温下流变性好、滤失量小、岩心渗透率恢复率高,在保证钻井液良流变的情况下有效解决了高温老化后悬浮稳定性难题。     

Preparation of a salt-responsive Gemini viscoelastic surfactant for application to solids-free drilling fluids

In order to solve the problem of poor rheological properties of solid-free drilling fluids in salt-bearing formations and prevent drilling accidents such as lost circulation, formation collapse, and wellbore instability, it is crucial to develop a new type of viscosifier. In this study, a salt-responsive Gemini viscoelastic surfactant (NT-1) was synthesized by using erucamide as a hydrophobic chain and introducing a benzene ring and a carboxyl group into the linker. In addition, it is used as a viscosifier for solid-free drilling fluids. The structure of the surfactant was characterized by ¹H nuclear magnetic resonance (NMR), ¹³C NMR, Fourier transform infrared spectroscopy, and electrospray ionization tandem mass spectrometry (ESI-MS), and its physicochemical properties were determined by surface tensiometer, thermogravimetric-differential scanning calorimetry, dynamic lighting scattering and rheometer. Its performance in solid-free drilling fluids was evaluated according to the American Petroleum Institute (API) standard. The results show that the surfactant has a low critical micelle concentration (31.74 μmol/L), excellent thermal stability and water solubility. In particular, NT-1 can self-assemble into worm-like micelles under the action of salt, and the spatial network structure formed by the interweaving of these micelles can endow the drilling fluid with good rheology and viscoelasticity. NT-1 is compatible with conventional drilling fluid polymer additives, which can effectively improve solid-free drilling fluids' rheological properties and fluid loss properties in salt layers. The temperature resistance in drilling fluid systems can reach 120°C. This work verifies the feasibility of using viscoelastic surfactants as viscosifiers in solid-free drilling fluids and provides new ideas for developing salt-responsive smart drilling fluids.     

Synthetic copolymer (AM/AMPS/DMDAAC/SSS) as rheology modifier and fluid loss additive at HTHP for water-based drilling fluids

In the petroleum industry, high temperature and high pressure (HTHP) would dramatically worsen rheological properties and increase fluid loss volumes of drilling fluids. Synthetic polymer as an indispensable additive has attracted more and more attention recently. In this article, a new copolymer (named AADS) of 2-acrylamide-2-methylpropanesulfonic acid, acrylamide, dimethyl diallyl ammonium chloride, and sodium styrene sulfonate was synthesized through aqueous solution polymerization. The chemical structure of the copolymer was characterized by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Moreover, its thermal stability was simultaneously analyzed using a differential scanning calorimetry. The results showed that the synthetic polymer contained all the designed functional groups, and its structure was consistent to the desired one. Under contamination of sodium chloride, AADS solution maintained relatively high viscosity in high concentration brine, showing a good antisalt capacity. Furthermore, the effect of AADS content and temperature on rheological behavior and fluid loss volume of the water-based drilling fluid (WBDF) containing the synthesized product were investigated according to the American Petroleum Institute standard. Results showed that the rheological and filtration properties of the prepared WBDF were improved with the increase in the AADS concentration before and after the thermal aging test. In addition, in the temperature range of 80–240 °C, a reversible rheological behavior was observed during the heating–cooling process, and the HTHP fluid loss was controlled within 22.5 mL, suggesting that the copolymer AADS was suitable for making WBDF s with high temperature resistance. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47813.     

国内外黏土水化抑制剂研究现状与发展趋势

黏土水化抑制剂在钻井液中的添加可有效降低钻井事故发生,但存在效果不明显、抗温性能尚待提高等缺点。本文简述了国内外黏土水化抑制剂研究现状并分析了其发展趋势。从研究历程来看,黏土水化抑制剂大体上经过了从无机离子型向有机铵（胺）型过渡并逐步成熟于聚合物型的过程。从最新研究结果来看,聚醚胺型抑制剂为主流研究对象,由此形成的高性能水基钻井液在国内外广泛应用;超支化聚合物型抑制剂因具有体型结构而具有较好抗温、抗盐性能而颇具发展优势;传统共聚物型抑制剂分子量大,在高温高密度钻井液中难以适用,仍有改进空间。指出了今后发展趋势是充分利用生物质资源,开发绿色、环保高效的黏土水化抑制剂;研究低聚物抑制剂,提高抑制剂的抗温性、普适性和一剂多效性;摆脱传统钻井液处理剂之间化学作用力观念束缚,探索超支化抑制剂的开发,积极有效结合纳米技术与钻井流体之互补点,以促进钻井液及相关技术发展。     

High-temperature performance and cross-linking mechanism of different types of gel systems in saline environment

Profile modification of injection wells or water plugging of production wells are the most common ways to improve oil recovery with the continuous development of oil reservoirs. For high temperature and high-salt oil and gas reservoirs, the plugging agent is required to have certain stability under high temperature and high-salt conditions. Polymer gel is one of the commonly used plugging agents in oil fields. This article conducted detailed experimental research and mechanism analysis on six gel systems composed by two types of polymer (hydrolyzed polyacrylamide [HPAM] and terpolymer L-1) and three types of cross-linker systems (phenol/hexamethylenetetramine [HMTA], resorcinol/HMTA and bisphenol-A/HMTA). The mechanisms of cross-linker systems and polymer were studied, and the experimental researches were done on their gelation process, long-term thermal stability, salt resistance, microstructure observation, rheological properties, and so on. The number of high-temperature resistant cross-linking points determines the performance of the gel system formed by cross-linker systems with the polymer. The cross-linker systems of bisphenol-A/HMTA have four high-temperature resistant cross-linking points, and its performance was the best. Due to the introduction of ATBS and NVP groups on the polymer chain, the performance of gel system formed by the terpolymer L-1 was significantly more stable than that of formed by HPAM. This study shows that the bisphenol-A/HMTA-L-1 gel has excellent long-term thermal stability and salt tolerance, and can be used in ultrahigh temperature (150°C) and high-salt oil and gas reservoirs to improve oil recovery.     

耐高温水基压裂液研究进展

随着勘探技术的发展,油气勘探向纵深发展,而越往深井发展地层温度越高,国内外对高温油藏的开发愈加重视。水基压裂液由于其施工方便、价格低廉以及性能优异等优点,一直是应用最为普遍的压裂液。但早期压裂液的耐温性能较差,无法满足高温油藏的压裂施工需求。因此开发可用于耐高温油气藏的水基压裂液具有重要的研究价值和实际应用价值。本文介绍了国内外耐高温水基压裂液的研究进展,对于胍胶压裂液,通过提高稠化剂用量,进行稠化剂、交联剂的改性,以提高其耐温性能;耐温清洁压裂液稠化剂类型由早期的阳离子、阴离子型向双子及复合型发展,近年还有学者将纳米体系用于改性表面活性剂;耐温合成聚合物压裂液发展较快,多是通过设计多元共聚物提升耐温能力。对于胍胶压裂液体系,研发满足特高温油藏压裂施工需求的低浓度胍胶压裂液还是今后的主要研究方向。文中指出清洁压裂液体系成本过高,无法大规模使用;合成聚合物压裂液耐温性能好,研究含有支链聚合单体或磺酸基团等的多元共聚物,引入合适的疏水基团作为稠化剂,是合成聚合物的研究方向。     

Polyoxyalkyleneamine as shale inhibitor in water-based drilling fluids

According to the conventional evaluation methods of drilling fluids, the inhibitive property of polyoxyalkyleneamine (POAM), which was prepared in the laboratory, to sodium montmorillonite (Na-MMT) was investigated, and the shale cuttings recovery ratio and the rheological properties of drilling fluids were measured before and after adding POAM in several water-based drilling fluids. The results showed that POAM was completely water-soluble, exhibited the superior performance to inhibit the hydration of Na-MMT and reduced the swelling or hydration of shale cuttings effectively. In addition, the determination of the biological toxicity and compatibility of POAM indicated that POAM was low toxic and compatible with other common drilling fluid additives.     

页岩气开发钻井液技术研究

由于页岩气井特殊的储层特征,对钻井液的抑制性以及润滑性等提出了很高的要求,油基钻井液虽然能够满足页岩气水平井钻井的需要,但其环保问题以及成本问题等成为制约其大规模应用的瓶颈.为此,针对页岩气储层的特点,室内开展了适用于页岩气水基钻井液的抑制剂、增粘剂、降滤失剂以及润滑剂的优选,形成了一种高性能的页岩气水基钻井液体系.并对该体系进行了综合性能的评价,结果表明,体系具有良好的流变性能,在90 ℃下老化16 h后的高温高压滤失量仅为5.6 mL,摩阻系数为0.11;体系的钻屑热滚回收率达到了98.88%,具有良好的抑制性能;体系在150 ℃高温下老化后仍可保持较好的流变性能和降滤失性能,表明体系具有较强的抗温能力;体系在加入5%的粘土和氯化钠后流变性变化不大,说明体系具有较强的抗污染能力.说明优选的高性能页岩气水基钻井液体系具有优良的综合性能,能够满足页岩气水平井钻井的需要.     

Hydrophobic-associated polymer-based laponite nanolayered silicate composite as filtrate reducer for water-based drilling fluid at high temperature

Wellbore instability caused by water invasion is the main problem in oil and gas drilling operation. This study reports the utilization of a hydrophobic-associated polymer-based laponite nanolayered silicate composite as a filtrate reducer in water-based drilling fluids (WDFs). The thermal performance and micromorphology of the composite were analyzed by thermogravimetric analysis, transmission electron microscope, and field emission scanning electron microscopy. The results indicated that the composite possessed a “bean pod” structure and a good thermal stability. The rheological properties of the composite solution were evaluated. The results showed that the hydrophobic association interaction of the composite is weak but existent, and the crosslink network structure is variable. The applied performances of WDFs containing the composite were also evaluated. Evaluation results showed that the composite could improve the properties of the thermal stability, salt tolerance, and fluid loss control of WDFs. The particle size distribution of WDFs and the micrographs of filter cakes explained the improving. The composite was expected to be applied as an efficient filtrate reducer for developing high performance drilling fluids. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48608.