烧结温度对添加镁渣制备陶粒支撑剂性能的影响

采用山西阳泉铝矾土和煤矸石为主要原料,工业废弃物镁渣为添加剂,在1180～1350℃下烧结制备陶粒支撑剂.对比分析各温度下陶粒体积密度,视密度和破碎率的变化趋势,利用XRD和SEM对陶粒的物相及微观形貌进行了表征.探讨了烧结温度对添加镁渣制备陶粒支撑剂性能的影响,同时明确了最好性能陶粒支撑剂对应的最佳烧结温度.结果表明:烧结温度为1250℃时,陶粒支撑剂的体积密度为1.39 g/cm3,视密度为2.84 g/cm3,48 MPa闭合压力下破碎率为6.87％,52 MPa闭合压力下破碎率为8.64％.在该温度下,陶粒的性能较好,烧结致密度很高.     

以ZnO作添加剂覆膜陶粒支撑剂的制备与性能研究

以低成本的高岭土为主要原料,以ZnO作为添加剂,结合常压烧结技术,制备出低密度高强度的陶粒支撑剂。研究了ZnO的添加量、烧结温度对陶粒支撑剂性能的影响。采用树脂覆膜的方法进一步优化了陶粒支撑剂的性能,使其适用于更高要求的油气井。研究结果表明,当加入2%的ZnO并且烧结温度为1 300℃时,陶粒支撑剂的体积密度为1.42 g/cm³,视密度为2.61 g/cm3,视密度为2.61 g/cm³,35 MPa闭合压力下的破碎率为7.28%。当环氧树脂的用量为支撑剂的12%,固化剂的用量为环氧树脂的14%时,覆膜支撑剂的体积密度为1.32 g/cm3,35 MPa闭合压力下的破碎率为7.28%。当环氧树脂的用量为支撑剂的12%,固化剂的用量为环氧树脂的14%时,覆膜支撑剂的体积密度为1.32 g/cm³,视密度为2.27 g/cm3,视密度为2.27 g/cm³,69 MPa闭合压力下的破碎率仅为1.16%。     

锑同位素标记压裂支撑剂的制备及作用机制研究

以铝矾土为主要原料,以Sb_2O_3为标记物质,在1320℃下合成了同位素标记陶粒压裂支撑剂,研究了标记物质的加入对烧结和支撑剂破碎率的影响。标记元素进入了晶相,并且在压裂支撑剂载体内分布均匀。当加入的Sb_2O_3小于10%时,69 MPa闭合压力下的破碎率低于4.0%,符合行业标准要求,适用于中深油气井压裂裂缝形态及支撑剂位置监测。     

MgO作矿化剂对多孔轻质陶粒支撑剂结构和性能的影响

以山西忻州高铝煤矸石为主要原料,碳粉为造孔剂,采用常压烧结法,制备出了密度较低的石油压裂支撑剂,但造孔作用使得支撑剂的强度变低.为了能够在降低支撑剂密度的同时保证强度,添加MgO作矿化剂来改善支撑剂的强度.通过分析检测表明:引入适量的氧化镁做矿化剂,可促进液相烧结,对抑制莫来石晶粒长大有利,改善了支撑剂强度.当碳粉添加量为10wt％,氧化镁添加量为2wt％,烧结温度为1350℃时,获得的支撑剂性样品能最佳,体密度仅为1.35 g/cm3,视密度为2.41 g/cm3,35 MPa下破碎率为4.58％.     

以ZnO作添加剂覆膜陶粒支撑剂的制备与性能研究

以低成本的高岭土为主要原料,以ZnO作为添加剂,结合常压烧结技术,制备出低密度高强度的陶粒支撑剂。研究了ZnO的添加量、烧结温度对陶粒支撑剂性能的影响。采用树脂覆膜的方法进一步优化了陶粒支撑剂的性能,使其适用于更高要求的油气井。研究结果表明,当加入2%的ZnO并且烧结温度为1 300℃时,陶粒支撑剂的体积密度为1.42 g/cm~3,视密度为2.61 g/cm~3,35 MPa闭合压力下的破碎率为7.28%。当环氧树脂的用量为支撑剂的12%,固化剂的用量为环氧树脂的14%时,覆膜支撑剂的体积密度为1.32 g/cm~3,视密度为2.27 g/cm~3,69 MPa闭合压力下的破碎率仅为1.16%。     

超低密压裂支撑剂的制备及性能研究

以二级铝矾土(65wt％Al2O3)和钾长石为原料,在添加不同含量的白云石的基础上制备了超低密高强的压裂支撑剂,并研究了白云石的添加量对烧成温度和石油压裂支撑剂性能的影响.结果表明:在原料中加入适量的钾长石,不仅可以降低烧结温度,同时还能降低压裂支撑剂的密度;添加白云石能有效降低支撑剂的烧结温度和破碎率,同时白云石和钾长石共同作用,促进了烧结致密化的进行,有利于棒状莫来石的生长发育,从而提高了支撑剂的强度.当白云石的添加量为2wt％,烧结温度为1330 ℃时,所制备的压裂支撑剂性能最优,其体密仅为1.30 g/cm3,52 MPa下的破碎率为4.51wt％.     

固定烧结温度下制备陶粒时煤矸石掺入量研究

为了对固定烧结温度下制备陶粒支撑剂时煤矸石的掺入量展开研究。本文以山西阳泉铝矾土为主要原料,工业废弃物煤矸石为添加剂,按照铝矾土煤矸石的质量比为7:3、6:4、5:5、4:6的比例分别混料,根据前期研究结果,选取1300℃的烧结温度烧结制备陶粒支撑剂,对比分析各配比下陶粒的体积密度、视密度和破碎率的变化趋势,并用XRD和SEM对陶粒的物相及微观形貌进行表征,结果表明：在本文的实验条件下,满足工业标准的煤矸石最大掺入量为50wt%,此时,35MPa闭合压力下破碎率为9.12%。掺入30wt%煤矸石时,制备的陶粒性能最好,此时陶粒支撑剂的体积密度为1.2881g/cm³,视密度为3.2485g/cm³,35MPa闭合压力下破碎率为7.91%。     

煤矸石对焦宝石基低密度高强度陶粒支撑剂性能的影响

采用焦宝石、煤矸石为主要原料制备了低密度高强度陶粒支撑剂,研究了煤矸石加入量及烧结温度对陶粒支撑剂视密度及破碎率的影响,并利用XRD、SEM等手段对不同温度烧结的陶粒支撑剂的物相组成和微观形貌进行了分析。结果表明:煤矸石的加入促使支撑剂内部形成大量闭气孔,使得视密度和抗破碎能力均呈下降趋势。陶粒的主晶相为莫来石相和石英相,随着烧结温度的升高,材料中气孔被排除,致密化程度提高,有助于提高陶粒的抗破碎能力。在过高的烧成温度下,液相增多,会导致抗破碎能力下降。当煤矸石加入量为15 wt%,烧成温度为1410°C时,陶粒支撑剂的视密度为2.65 g/cm~3,69 MPa下的破碎率为7.9%,产品具有低密度、高强度、低成本的特点。     

树脂包覆免烧超低密度支撑剂性能研究

滑溜水压裂液是页岩储层改造的首选体系.为解决滑溜水压裂中支撑剂沉降速度快,不能完全充填产层及充填层泥化问题,采用固体废渣为基体材料制备了树脂包覆免烧超低密度压裂支撑剂.运用XRD、MIP、SEM和筒压法分析了支撑剂物相组成及树脂浸渍包覆对其体积密度、视密度、抗破碎能力、显气孔率、气孔孔径分布和微观形貌的影响.通过比较树脂改性前后支撑剂力学性能,得到树脂浓度为25wt％时填充效果最佳,显气孔率比支撑剂基体降低了80.1％,其结构致密、破碎率低;当支撑剂浸渍体包覆树脂含量6％时,颗粒表面和内部孔洞得到二次填充,颗粒显气孔率降低至7.13％,其体积密度为0.86 g/cm3,视密度为1.29 g/cm3,浊度为3.65 NTU,酸溶解度为0.35％,在35 MPa和52 MPa闭合压力下破碎率分别为7.3％和9.0％.     

煤矸石掺量对陶粒支撑剂性能的影响

以铝矾土和煤矸石为主要原料,通过调整二者质量比(1:1,2:3和3:7),经造粒成球、不同温度烧结制备得到陶粒支撑剂。结果表明:当煤矸石掺入量为60%(质量分数)、35 MPa闭合压力下,满足破碎率行业标准的烧结温度范围为1 250～1 450℃,在该温度区间内,随着烧结温度的升高,样品的结晶相转变为棒状莫来石相,形成一种致密的网状交联结构,进而提高了陶粒支撑剂的抗破碎能力;当烧结温度为1 450℃时,体积密度及视密度分别为1.49和2.76 g/cm~3,破碎率指标达到最低值3.0%,证实利用煤矸石替代铝矾土可以制备出用于煤层气井开采用的陶粒支撑剂。     

白云石对焦宝石陶粒晶粒发育及性能的影响

以陶粒的新原料-焦宝石为主要原料,白云石为熔剂性辅料利用陶瓷烧结工艺成功制备了粒径425~850 μm满足35 MPa闭合压力下使用的支撑剂.重点研究了助熔剂白云石的不同添加量对焦宝石陶粒支撑剂晶粒发育及性能的影响.利用SEM和XRD分别对含有不同添加量的白云石的陶粒支撑剂进行了显微形貌和物相结构的分析,并多次测试了陶粒支撑剂的体密、视密和破碎率,结果揭示了白云石的添加有助于促进棒状莫来石晶粒的发育,同时在保证破碎率低于9%的前提下具有降低陶粒支撑剂体密/视密的作用.     

压裂支撑剂的覆膜改性技术

针对油气田开发对压裂支撑剂的性能要求愈来愈高的产业重大需求,油田化学领域运用现代化学理论与技术,开展了一系列卓有成效的压裂支撑剂化学覆膜改性研究和产品研发,为油气工业的快速发展做出了突出贡献。本文从化学和工程两个视角,系统阐述了压裂支撑剂化学覆膜改性的研究方向。化学角度,主要研究方向包括：在支撑剂表面涂层构成化学覆膜、通过化学手段科学改变支撑剂表面特性、化学涂层与改性并举。工程角度,大致分为三个重要研究方向：一是通过在石英砂、陶粒等支撑剂表面涂敷覆膜来提升支撑剂强度;二是通过在石英砂、陶粒等支撑剂表面涂敷覆膜来降低整个支撑剂的相对密度（如自悬浮涂层技术等）;三是石英砂、陶粒等支撑剂表面涂敷覆膜实现堵水疏油的功能。本文还简要阐述了树脂覆膜支撑剂、疏水支撑剂、憎水憎油支撑剂、自悬浮支撑剂、自聚型支撑剂、无机聚合物涂覆支撑剂以及功能性支撑剂等主要产品的特性。展望支撑剂未来的发展趋势,提出支撑剂应向多功能、高性能、小尺寸和智能化方向发展以及开发出更加适合无水压裂的支撑剂和原位生成型自支撑压裂体系。     

Sintering mechanism of high-intensity and low-density ceramic proppants prepared by recycling of waste ceramic sands

Waste ceramic sands were effectively used to prepare the high-intensity and low-density ceramic proppants, realising the recycling of the waste ceramic sands. The technology involved the pelletising in an intensive mixer, in which the waste ceramic sands and other starting materials were added, and followed by heat-treatment under different sintering conditions. The sintering temperature, holding time and heating rate were optimised by investigating the crystalline phase, microstructure, density and breakage ratio of the obtained proppants. The results showed that the proppants sintered at 1260°C for 2?h with a heating rate of 5°C?min^–1 under air atmosphere exhibited high crush resistance and low density, with the breakage ratio of 8.5% under 52?MPa closure pressure and bulk density of 1.65?g?cm^–3. The proppants prepared by bauxite, waste ceramic sands and sintering aids are promising candidates as high-intensity and low-density fracturing proppants in future applications.     

V2O5掺杂对莫来石晶须增强型陶粒支撑剂的性能影响

以高岭石质煤矸石为主要原料,V2O5为添加剂,于1400 ℃下制备了莫来石晶须增强的陶粒支撑剂,讨论了V2O5促进莫来石晶须生长机制及其添加量对支撑剂样品性能的影响.结果表明:随着V2O5的加入,支撑剂样品的主晶相莫来石逐渐生长形成莫来石晶须;当V2O5添加量为1wt％时,试样的性能最佳;体积密度1.25 g/cm3,视密度2.69 g/cm3,52 MPa闭合压力下的破碎率5.18％.     

Preparation of heat resisting poly(methyl methacrylate)/graphite composite microspheres used as ultra‐lightweight proppants

Ultra‐lightweight heat resisting poly(methyl methacrylate) (PMMA)/graphite microspheres were successfully prepared via in situ suspension polymerization. The Fourier transform infrared and X‐ray powder diffraction results confirmed the successful preparation of the composite microspheres. Field emission scanning electron microscope analysis illustrated that the graphite particles were dispersed in microspheres and the PMMA/graphite composite microspheres had good sphericity and roundness. Furthermore, density analysis indicated that the apparent density of composites microspheres was about 1.055–1.135g/cm³ which was suitable for the transmission with water carrying. The results from thermodynamic test revealed that the thermal stability of the composite was significantly improved with increasing graphite content, which could be used as ultra‐lightweight proppant in deep underground. In addition, the crushing rate decreased to 0.5% with graphite ratio of 3.0% at the pressure of 69 MPa. Therefore, PMMA/Graphite composite microspheres exhibit a promising application in petroleum or gas exploitation as water carrying fracturing proppants. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41924.     

添加金属氧化物及氟化钙对压裂支撑剂性能的影响

运用单因素法研究了MnO2、Fe2O3、MgO和CaF2作添加剂对非金属矿压裂支撑剂的性能影响,根据行业标准中的测试方法,测试了样品的体积密度、视密度和破碎率等关键指标.采用XRD和SEM等技术对试样的晶相结构和形貌进行表征.结果表明,MnO2、Fe2O3的加入能够显著降低试样的焙烧温度;MgO、CaF2的加入有利于微晶结构形成,提高支撑剂样品的强度,降低破碎率,并且MgO、CaF2的加入量分别为3%、1%时试样具有较优的性能.     

MnO2和Fe2O3对氧化铝质压裂支撑剂微观结构和抗破碎能力的影响

采用无压烧结技术制备了软锰矿掺杂的高强度氧化铝质压裂支撑剂.通过X射线衍射、压汞式孔隙分析、扫描电子显微镜和筒压法分别研究了由软锰矿引入的MnO2和Fe2O3对支撑剂物相组成、孔结构、晶粒尺寸和抗破碎能力的影响.结果表明:当软锰矿掺杂量为0～5%(质量分数,下同)时,烧结样品中包括氧化铝、莫来石和钛酸铝相,软锰矿的掺入未明显改变晶体结构;当软锰矿掺量为5%时,Fe3+取代Al3+与组分中的TiO2反应并形成固溶体,MnO2固溶于Al2O3晶粒中,促进了Al2O3晶粒生长,过剩的Fe2O3和MnO2存在于陶瓷晶界处并在高温煅烧F形成液相促进致密化烧结;未掺杂样品中存在大量连通气孔,显气孔率为14.79%:掺入5%软锰矿后,显气孔率降低至5.29%,样品内部多为均匀分布的近球形闭气孔;在52MPa压力条件下,5%软锰矿掺杂样品的破碎率与未掺杂样品相比减少80.95%,抗破碎能力显著提高.     

PEG-based polymer coated proppants in supercritical CO2: A new approach in current fracturing protocols

Liquified carbon dioxide (CO₂) can be used in hydraulic fracturing fluids to provide nonaqueous alternatives to conventional water-based fluids as it is more environmentally benign and minimizing depletion of natural-source freshwater. However, conventional CO₂-based fluids are not sufficiently viscous to suspend proppants that are added to fracturing fluids to hold open subterranean fractures. Because of this reduced ability to suspend proppants, CO₂-based fluids have not found its niche yet as future fracturing fluids. Accordingly, a need exists for nonaqueous hydraulic fracturing fluids that adequately support and suspend proppant particles. The present study presents a green alternative of developing a poly(ethylene glycol) based polymers coated proppants which can swell in supercritical CO₂ so as to decrease the entire density of the proppant during fracturing process.     

Preparation and Properties of a New Mediumdensity and High-strength Ceramic Proppant

Based on the needs of the market,a new 52 MPa medium-density and high-strength ceramic proppant was prepared by adopting third grade bauxite and clay as raw materials and using the solid phase sintering method,and the effect of the firing temperature on the microstructure,phase composition and mechanical properties of the ceramic proppant was studied. The broken resistance mechanism of this ceramic proppant was also discussed. The results show that the main phases of the prepared ceramic proppant are mullite and corundum; the broken rates are 3. 92% and 7. 21% under 52 MPa and69 MPa,respectively.