油气钻采领域功能胶黏材料研究进展及前景

通过概述功能胶黏材料的组成、分类及性能表征,阐述了功能胶黏材料的吸附/界面反应、扩散、机械互锁和静电吸附等黏结作用机理,综述了其在防漏堵漏、井壁稳定、水力压裂和调剖堵水等油气钻采工程领域的研究现状、应用挑战及应用展望。依据现阶段功能胶黏材料在油气钻采领域的应用,提出了功能胶黏材料在油气钻采领域的重点研究方向:(1)对热塑性树脂进行共混改性或设计可固化热塑性树脂,提高黏结堵漏剂的黏结性能和承压能力;(2)在聚合物中引入低成本黏附性基团和正电荷结构,降低黏结固壁剂成本,提高其在井壁的黏附性能;(3)在热固性树脂中引入热可逆共价键,预防支撑剂回流,提高黏结支撑剂抗压强度;(4)在热塑性聚合物中引入热可逆共价键,提高黏结堵水剂的抗温抗盐能力和堵水性能。

油基钻井液用改性碳纳米管纳微米封堵剂

为改善页岩油气水平井钻进过程中因钻井液封堵性能差而引起的井壁失稳问题,首先,对川南龙马溪组页岩组成和井壁失稳的原因进行了分析;然后,以十六烷基三乙氧基硅烷、氨丙基三乙氧基硅烷和活性碳纳米管为原料,合成了油基钻井液用纳微米封堵剂(NP-1),分别利用红外光谱分析、热重分析、透射电镜和表面润湿性测试分析其结构和物理化学特性,考察了其与油基钻井液的配伍性;最后,通过岩心突破压力、压力传递、三轴抗压强度等测试评价其封堵性能,分析了纳微米封堵剂的作用机理,并进行了现场应用。结果表明,川南龙马溪组页岩纳微米孔喉较发育,毛细自吸现象严重,使得液相不断侵入井壁,最终导致井壁失稳。NP-1的直径为30~50nm,长度处于微米级别,表面疏水亲油,在385.2℃以下的热稳定性良好。NP-1与油基钻井液具有良好的配伍性和稳定性。在常规油基钻井液中加入3%NP-1,在180℃下老化热滚16 h后的高温高压滤失量由2.8 mL降至1.8 m L。含有NP-1的油基钻井液能有效封堵岩心端面,从而提高岩心突破压力,阻止岩心压力传递,稳定岩心内部结构和抗压强度,实现维持井壁稳定的目的。现场应用结果表明,NP-1能有效改善邻井因钻井液封堵能力弱而引起的井漏、井壁失稳等技术难题,处理后的平均井径扩大率仅为5.61%。该纳微米封堵剂在油基钻井液中对页岩具有优异的封堵效果,为川南类似复杂页岩气井的高效钻探提供了借鉴。

Research progress and application prospect of functional adhesive materials in the field of oil and gas drilling and production

By summarizing the composition,classification,and performance characterization of functional adhesive materials,the adhesion mechanisms of functional adhesive materials,such as adsorption/surface reaction,diffusion,mechanical interlocking,and electrostatic adsorption,are expounded.The research status of these materials in oil and gas drilling and production engineering field such as lost circulation prevention/control,wellbore stabilization,hydraulic fracturing,and profile control and water plugging,and their application challenges and prospects in oil and gas drilling and production are introduced comprehensively.According to the applications of functional adhesive materials in the field of oil and gas drilling and production at this stage,the key research directions of functional adhesive materials in the area of oil and gas drilling and production are proposed:(1)blending and modifying thermoplastic resins or designing curable thermoplastic resins to improve the bonding performance and pressure bearing capacity of adhesive lost circulation materials;(2)introducing low-cost adhesive groups and positive charge structures into polymers to reduce the cost of wellbore strengthening agents and improve their adhesion performance on the wellbore;(3)introducing thermally reversible covalent bond into thermosetting resin to prevent backflow of proppant and improve the compressive strength of adhesive proppant;(4)introducing thermally reversible covalent bonds into thermoplastic polymers to improve the temperature resistance,salt-resistance and water shutoff performance of adhesive water shutoff agents.

裂缝性恶性井漏地层堵漏技术研究进展与展望

通过系统论述裂缝性地层钻井液漏失和堵漏机理,对不同类型堵漏材料及其在裂缝性恶性漏失地层中的适用性及作用机理进行了分类归纳,同时基于所用堵漏材料分析了不同类型堵漏工艺的优缺点及应用效果,明确了目前国内外恶性漏失地层堵漏技术存在的关键问题,进而提出未来恶性井漏堵漏技术发展方向。未来应综合地质、工程、材料等学科,实现恶性井漏堵漏技术的一体化、智能化与系统化,重点应开展5个方面的研究:①注重钻井液漏失和堵漏机理研究,为科学选择堵漏材料及配方、堵漏方法和工艺提供依据;②注重自适应堵漏材料研发,提高堵漏材料与裂缝漏失通道级配关系;③注重三维裂缝空间强驻留强充填堵漏材料研发,增强堵漏材料在漏失通道中的驻留和充填程度,改善封堵效果;④注重抗高温堵漏材料研发,保证深层高温漏失地层的长期封堵效果;⑤注重发展数据化和智能化堵漏技术,促进堵漏技术向数据化和智能化方向发展。

裂缝封堵层形成机理及堵漏颗粒优选规则

针对裂缝性地层封堵层形成机理和封堵规则尚不明晰的问题,基于封堵实验和颗粒物质力学方法研究了裂缝性地层封堵层的形成过程,分析了封堵层组成及颗粒配比,揭示了封堵层形成的本质及破坏的驱动能量,提出了钻井液防漏堵漏颗粒优选规则。研究表明封堵层的形成过程经历了从惯性流、弹性流到准静态流的流态变化过程。封堵层由封端颗粒、架桥颗粒和填充颗粒组成,3种堵漏颗粒的配比是设计堵漏体系的重要依据。封堵层形成的本质是体系发生非平衡性Jamming相态转变,封堵层颗粒体系对压力的响应由熵力驱动,熵越大封堵层越稳定。根据提出的规则优选了堵漏材料、优化了堵漏体系,封堵效果优于其他常用规则,可有效提高封堵层承压能力,为解决裂缝性地层漏失提供了理论和技术依据。

高强度可固化树脂堵漏剂PMMM研制与评价

裂缝性地层恶性漏失是油气钻井工程重大技术难题之一,可固化树脂和井下交联聚合物是常用堵漏材料,但存在井下交联可控性差、固化强度低等问题。研制了一种部分醚化改性氨基树脂PMMM,利用拉曼光谱分析了其分子结构,并揭示了固化机理。PMMM固化时间随着固化剂加量增加或温度升高而缩短,在80~130℃温度下可做到1~10 h可控,固化后不收缩,最高抗10%水基钻井液污染。PMMM固化后抗压强度随着CaSO_(4)纳米晶须增加先增加后降低,0.5%纳米晶须加量下,80℃养护24 h后PMMM抗压强度最高达56 MPa,高于常规水泥堵漏材料。基于100~130℃下黏度数据,利用修改的阿伦尼乌斯黏度方程,拟合得到PMMM黏度-温度-时间曲线方程,方程预测90℃下黏度变化规律与实测数据相吻合,基本反映了PMMM堵漏材料加热条件下的黏度变化规律。整体而言,PMMM树脂固化堵漏材料具备配方简单、固化条件可控、固化后强度高等优点,在裂缝性地层恶性井漏中具有一定应用前景。

裂缝性地层固化类堵漏材料井下运移仿真模拟研究

固化类堵漏材料常用于裂缝性地层恶性漏失堵漏,在裂缝近井壁处形成完整的固结段塞,是堵漏成功的前提。固化类材料进入井筒后难免会与地层流体发生共混,堵漏浆-地层流体两相体积分布随着空间和时间变化,与流体理化性质、施工参数、裂缝几何形貌等有密切关系。为此,采用CFD仿真模拟方法,研究了固化堵漏浆密度和流变参数对堵漏浆裂缝体积分布及流速的影响规律,几何模型选择三维井筒-垂直裂缝模型,模拟压差为1.9 MPa,堵漏浆入口流速为2.5 m/s,两相流模型为VOF模型,井筒和裂缝中原始流体为水基钻井液。模拟结果表明,堵漏浆密度和动切力对其在井筒和裂缝中运移影响少,稠度系数和流性指数对堵漏浆裂缝驻留性能影响显著。稠度系数或流性指数越高,堵漏浆裂缝中流速越小,体积分数越高,低于临界值后,裂缝中将一直以堵漏浆-钻井液共混流体存在。流性指数相比稠度系数对于堵漏浆裂缝驻留能力影响更为显著,牛顿流体和剪切增稠型堵漏浆更利于在裂缝中形成完整段塞。该仿真模拟工作为固化堵漏浆流变性优化提供一定理论基础,有利于提升固化堵漏技术一次成功率。

超高温水基钻井液技术研究现状及发展方向

随着油气钻井不断向深部发展,钻遇深部超深部地层温度也越来越高,对钻井技术特别是钻井液技术提出了更高要求。在结合超高温钻井实际需求的基础上,分析了水基钻井液在超高温下的技术壁垒、超高温对水基钻井液效能影响作用,综述了超高温水基钻井液的关键处理剂及其所构建的水基钻井液体系的研究现状,并探讨了超高温水基钻井液的未来发展方向。

Research progress and prospect of plugging technologies for fractured formation with severe lost circulation

By reviewing the mechanisms of drilling fluid lost circulation and its control in fractured formations, the applicability and working mechanisms of different kinds of lost circulation materials in plugging fractured formations have been summarized. Meanwhile, based on the types of lost circulation materials, the advantages, disadvantages, and application effects of corresponding plugging technologies have been analyzed to sort out the key problems existing in the current lost circulation control technologies. On this basis, the development direction of plugging technology for severe loss have been pointed out. It is suggested that that the lost circulation control technology should combine different disciplines such as geology, engineering and materials to realize integration, intelligence and systematization in the future. Five research aspects should be focused on:(1) the study on mechanisms of drilling fluid lost circulation and its control to provide basis for scientific selection of lost circulation material formulas, control methods and processes;(2) the research and development of self-adaptive lost circulation materials to improve the matching relationship between lost control materials and fracture scales;(3) the research and development of lost circulation materials with strong retention and strong filling in three-dimensional fracture space, to enhance the retention and filling capacities of materials in fractures and improve the lost circulation control effect;(4) the research and development of lost circulation materials with high temperature tolerance, to ensure the long-term plugging effect of deep high-temperature formations;(5) the study on digital and intelligent lost circulation control technology, to promote the development of lost circulation control technology to digital and intelligent direction.

油基钻井液用改性锂皂石增黏提切剂

以正辛基三乙氧基硅烷和锂皂石为原料,利用溶胶-凝胶法一步合成了油基钻井液用增黏提切剂改性锂皂石MLap-1,分别利用红外光谱、热重分析、透射电镜和表面润湿性对其单体进行表征,证明其合成成功。通过对改性锂皂石MLap-1单剂评价发现,该剂能够提高油水比为80∶20乳液的乳化效率和破乳电压,在0.3%加量下,乳液破乳电压值达到1200 V以上,使得乳液的表观黏度和动切力由12 mPa·s和0 Pa增大至23 mPa·s和10 Pa,同时能够抗200℃高温。以改性锂皂石MLap-1为基础构建的高密度油基钻井液在200℃老化后,其动切力维持在4 Pa以上,低剪切速率切力维持在3 Pa以上,破乳电压高于1000 V,滤失量低于5.0 mL,很好地维护了钻井液的悬浮稳定性,保持了良好的乳化稳定性和降滤失效果。为油基钻井液进一步钻探深井、超深井提供了技术支持。

一种抗高温高密度无土相油基钻井液提切剂

针对油基钻井液体系高温环境下沉降稳定性不足的难题,将二聚脂肪酸和二乙烯三胺以物质的量比1∶2反应合成了一种小分子脂肪酸酰胺型抗高温提切剂FAA,并对其进行了结构表征、机理分析和性能评价。流变实验和显微镜观察结果表明,提切剂FAA主要通过在乳液滴之间桥联形成凝胶网络结构来有效提高油基钻井液的结构强度,从而改善其固相悬浮能力及沉降稳定性。在柴油基钻井液体系中的评价结果表明,FAA可有效提高体系的动切力、φ6/φ3读数以及动塑比,并可有效改善体系的高温沉降稳定性,使体系在220℃下静置5 d后沉降因子SF小于0.52,无明显沉降现象出现。

环保型页岩抑制剂SGI-1的合成与性能研究

针对页岩地层钻井作业过程中井壁失稳的难题,以自然界资源丰富的木质素为原料,利用(3-氯-2-羟丙基)三甲基氯化铵对其进行季铵化改性制备了一种抑制性和环保性兼顾的水基钻井液页岩抑制剂SGI-1。通过线性膨胀实验、页岩滚动回收实验评价了抑制剂SGI-1的抑制性;通过接触角实验、水活化度实验及Zeta电位实验对SGI-1抑制机理进行分析;对SGI-1生物毒性及对钻井液性能的影响进行评价。结果表明:抑制剂SGI-1加量为2.0%时,16h后页岩滚动回收率为94.10%、线性膨胀率5.81%,优于2.0%聚胺;SGI-1可以改变岩石润湿性,页岩接触角由20.4°增大至69.9°;SGI-1可以降低水活度,增强抑制剂对自由水的束缚程度;SGI-1表面所带的阳离子基团可以与黏土颗粒吸附,并在其表面形成疏水膜减少钻井液滤液侵入。此外,SGI-1与钻井液具有较好的配伍性、较低的生物毒性,对钻井液流变性及失水造壁性影响较小。

基于微纳米结构疏油剂提高页岩气井井壁稳定性

采用Pickering乳液聚合法在聚苯乙烯表面镶嵌改性的纳米二氧化硅颗粒,研发出具备微纳米粗糙度的疏油剂OL-1,分析其对岩石表面性能的影响和抑制油相渗吸性能,评价新型疏油剂提高页岩气井井壁稳定性的效果及其机理。实验结果表明:疏油剂OL-1在岩石表面吸附成膜,构建微纳米双级粗糙度,将岩石表面能降至0.13 mN/m,进而使白油在岩石表面接触角由16.39°升至153.03°;添加疏油剂前后,毛细管浸入3号白油中,毛管压力由273.76 Pa反转为−297.71 Pa,油相在毛细管中渗吸高度由31 mm降至低于外部液面33 mm,页岩岩心油相浸入量减少64.29%;岩心浸入含1%疏油剂的油基钻井液中,孔隙度降幅仅为4.5%,与不含疏油剂的油基钻井液相比,岩心内聚力提高24.9%,说明疏油剂通过抑制油相渗吸可显著提高岩石的力学稳定性。

油基钻井液用抗高温树脂类封堵剂的研制

近年来,随着非常规油气的不断开发,钻井所面临的难度逐渐增加,油基钻井液的使用频率也逐渐增加,加强油基钻井液的封堵能力,对于预防井壁失稳具有重要的作用。以苯乙烯(ST)、甲基丙烯酸甲酯(MMA)和丙烯酸十八酯为单体,采用乳液聚合法,制备了一种油基钻井液用丙烯酸树脂类封堵剂。利用中压砂床封堵实验、高温高压静态砂床封堵实验对封堵剂的承压封堵性能进行了综合评价,并且研究了封堵剂对油基钻井液流变、滤失性能的影响。实验结果表明:180℃老化后,封堵剂对不同目数范围的砂床仍均有良好的封堵效果,且具有较高的封堵强度,突破压力可达6MPa。同时,该封堵剂对油基钻井液体系的流变性影响较小,200℃老化后,钻井液仍具有较低的API滤失量和高温高压滤失量,该封堵剂具有优异的抗高温性能和封堵性能。

Experimental Study for Improving the Toughness of Harden Cement Using Carbon Fiber

Many measures, such as water injection, acid fracturing, thermal recovery, have been taken in the oilfield development. These can easily induce brittle fracture of set cement. Most of all, there are greater potential for fractures in set cement in slim holes. Therefore, it is necessary to improve the toughness of the cement mantle. Results obtained from experiments show that carbon fiber, with a concentration of 0.12%-0.19% in cement and a length of 700 to 1,400μm, plays an important role in improving cement quality. Addition of carbon fiber can improve the bending strength of set cement by up to 30%. At the same time, the increase in fiber concentration can lower the elastic modulus and increase the Poisson＇s ratio of set cement. Thin-section analysis shows that fiber can effectively prevent the propagation of fractures and enhance the plasticity of the matrix and the ability to prevent fracture.

Mechanism and performance of a lithium chloride accelerator

To address present concerns about thickening time and high early-strength in deepwater cementing at low temperatures when using conventional accelerators, a new type of set-accelerating admixture comprising of lithium chloride, aluminium hydroxide and alkaline metal chlorides, named as LS-A, was studied in this paper. Mechanism analysis and performance tests show that the accelerator LS-A accelerated the hydration of tri- and dicalcium silicates （C3S and C2S） at low-temperatures by speeding up the breakdown of the protective hydration film and shortening the hydration induction period. Therefore, LS-A could shorten the low-temperature thickening time and the transition time of critical gel strength from 48 to 240 Pa of the Class-G cement slurry, and improve the early compressive strength of set cement at low-temperatures. It exhibited better performance than calcium chloride and had no effect on the type of hydration products, which remain the same as those of neat Class-G cement, i.e. the calcium silicate gel, Ca（OH）2 crystals and a small amount of ettringite AFt crystals. LS-A provides an effective way to guarantee the safety of cementing operations, and to solve the problems of low temperature and shallow water/gas flowing faced in deepwater cementing.

Micro/nano structured oleophobic agent improving the wellbore stability of shale gas wells

Through embedding modified nano-silica particles on the surface of polystyrene using the method of Pickering emulsion polymerization,a kind of nano/micro oleophobic agent named OL-1 was developed.The effects of OL-1 on the rock surface properties and its performance in inhibiting the oil phase imbibition into the rock were explored.The performance and mechanisms of OL-1 in improving the wellbore stability of shale gas wells were evaluated and analyzed.OL-1 could absorb on the surface of the shale core to form a membrane with a micro-nano two-stage roughness,making the surface energy of the core decrease to 0.13 mN/m and the contact angle of the white oil on the core surface increase from 16.39°to 153.03°.Compared with the untreated capillary tube,when immersed into 3#white oil,the capillary tube treated by OL-1 had a reversal of capillary pressure from 273.76 Pa to-297.71 Pa,and the oil imbibition height inside the capillary tube decreased from 31 mm above the external liquid level to 33 mm below the external liquid level.The amount of oil invading into the rock core modified by OL-1 decreased by 64.29%compared with the untreated one.The shale core immersed into the oil-based drilling fluids with 1%OL-1 had a porosity reduction rate of only 4.5%.Compared with the core immersed in the drilling fluids without OL-1,the inherent force of the core treated by 1%OL-1 increased by 24.9%,demonstrating that OL-1 could effectively improve the rock mechanical stability by inhibiting oil phase imbibition.

Formation mechanisms of fracture plugging zone and optimization of plugging particles

As formation mechanisms of plugging zone and criteria for fracture plugging remain unclear,plugging experiments and methods testing granular material mechanical properties are used to study the formation process of the plugging zone in fractured formations,analyze composition and ratios of different sizes of particles in the plugging zone,and reveal the essence and driving energy of the formation and damage of the plugging zone.New criteria for selecting lost circulation materials are proposed.The research results show that the formation of the plugging zone has undergone a process from inertial flow,elastic flow,to quasi-static flow.The plugging zone is composed of fracture mouth plugging particles,bridging particles and filling particles,and the proportion of the three types of particles is an important basis for designing drilling fluid loss control formula.The essence of the construction of the plugging zone is non-equilibrium Jamming phase transition.The response of the plugging zone particle system to pressure is driven by entropy force;the greater the entropy,the more stable the plugging zone.Lost circulation control formula optimized according to the new criteria has better plugging effect than the formula made according to conventional plugging rules and effectively improves the pressure-bearing capacity of the plugging zone.The research results provide a theoretical and technical basis for the lost circulation control of fractured formations.

超分子凝胶形成机理及其在油气钻采工程领域应用现状和前景

超分子凝胶是通过非共价键相互作用自组装形成的具有可逆结构与高性能特征的凝胶网络体系。优异的机械性能、环境响应性以及自愈合能力使超分子凝胶在组织工程、生物材料以及工业生产方面起着举足轻重的作用。针对超分子凝胶在国内外的研究现状及应用情况,综述了不同非共价相互作用形成超分子凝胶的机理,并详细阐述了氢键、静电、主-客体以及配位键作用形成超分子凝胶的作用机制和性能特点。结合超分子凝胶的适用性及作用机理,系统介绍了超分子凝胶在钻井堵漏、提高采收率等油气钻采工程领域的应用现状。同时,对不同非共价相互作用形成超分子凝胶的形成机理和应用情况进行了分析总结,明确了目前超分子凝胶存在的关键问题,提出了未来超分子凝胶在油气钻采工程领域的应用前景。

高分子材料的力学状态转变机理及在钻井液领域的应用展望

通过系统论述高分子材料在不同条件下的力学状态转变机理,并对其在钻井液封堵、防漏堵漏、固壁和降滤失领域的研究进展和应用进行了梳理,分析了其在钻井液领域应用中存在的问题,进一步展望了其在封堵、防漏堵漏、固壁和降滤失领域的应用前景。高分子材料作为封堵剂,可通过链纠缠、范德华力和氢键等作用,有效封堵地层微小孔隙;作为随钻防漏/堵漏剂,可通过机械互锁或化学键结合等作用黏连架桥,形成高强度胶结封堵层;作为固壁剂,可通过高分子链扩散、纠缠、静电和氢键等作用吸附聚集于井壁和微裂缝,维持井壁稳定;作为降滤失剂,可与黏土、聚合物协同作用,在井壁形成一层致密的高强度滤饼,降低钻井液滤失量。高分子材料在钻井液领域的研究将进一步促进钻井液处理剂技术的飞速发展。