Laponite:a promising nanomaterial to formulate high-performance water-based drilling fluids

High-performance water-based drilling fluids(HPWBFs)are essential to wellbore stability in shale gas exploration and development.Laponite is a synthetic hectorite clay composed of disk-shaped nanoparticles.This paper analyzed the application potential of laponite in HPWBFs by evaluating its shale inhibition,plugging and lubrication performances.Shale inhibition performance was studied by linear swelling test and shale recovery test.Plugging performance was analyzed by nitrogen adsorption experiment and scanning electron microscope(SEM)observation.Extreme pressure lubricity test was used to evaluate the lubrication property.Experimental results show that laponite has good shale inhibition property,which is better than commonly used shale inhibitors,such as polyamine and KCl.Laponite can effectively plug shale pores.It considerably decreases the surface area and pore volume of shale,and SEM results show that it can reduce the porosity of shale and form a seamless nanofilm.Laponite is beneficial to increase lubricating property of drilling fluid by enhancing the drill pipes/wellbore interface smoothness and isolating the direct contact between wellbore and drill string.Besides,laponite can reduce the fluid loss volume.According to mechanism analysis,the good performance of laponite nanoparticles is mainly attributed to the disk-like nanostructure and the charged surfaces.

High temperature and high pressure rheological properties of high-density water-based drilling fluids for deep wells

To maintain tight control over rheological properties of high-density water-based drilling fluids, it is essential to understand the factors influencing the theology of water-based drilling fluids. This paper examines temperature effects on the rheological properties of two types of high-density water-based drilling fluids （fresh water-based and brine-based） under high temperature and high pressure （HTHP） with a Fann 50SL rheometer. On the basis of the water-based drilling fluid systems formulated in laboratory, this paper mainly describes the influences of different types and concentration of clay, the content of a colloid stabilizer named GHJ-1 and fluid density on the rheological parameters such as viscosity and shear stress. In addition, the effects of aging temperature and aging time of the drilling fluid on these parameters were also examined. Clay content and proportions for different densities of brine-based fluids were recommended to effectively regulate the rheological properties. Four theological models, the Bingham, power law, Casson and H-B models, were employed to fit the rheological parameters. It turns out that the H-B model was the best one to describe the rheological properties of the high-density drilling fluid under HTHP conditions and power law model produced the worst fit. In addition, a new mathematical model that describes the apparent viscosity as a function of temperature and pressure was established and has been applied on site.

Carbon nanotube enhanced water-based drilling fluid for high temperature and high salinity deep resource development

Drilling fluids face failure during drilling deep reservoir with high temperature and high salt.The experimental results show that high temperature and salinity reduce the negative charge on the surface of bentonite in the drilling fluid and cause the coalescence of bentonite particles.As a result,the particles coalesce,the grid structure is destroyed,and the rheological properties,rock-carrying capacity and filtration properties are lost.To resolve the foregoing,in this study,0.05-wt%carbon nanotubes are introduced into a 4%bentonite drilling fluid under conditions where the temperature and concentration of added Na Cl reach 180°C and 10 wt%,respectively.The carbon nanotubes adsorb on the bentonite surface and increase the space among bentonite particles.The steric hindrance prevents the coalescence of bentonite in high temperature and high salt environment.Thus bentonite maintains the small size distribution of bentonite and supports the bentonite grid structure in the drilling fluid.As a result,the rock-carrying capacity of the drilling fluid increases by 85.1%.Moreover,the mud cake formed by the accumulation of small-sized bentonite particles is dense;consequently,the filtration of bentonite drilling fluid reduced by 30.2%.

A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid

Three high-temperature resistant polymeric additives for water-based drilling fluids are designed and developed:weakly cross-linked zwitterionic polymer fluid loss reducer(WCZ),flexible polymer microsphere nano-plugging agent(FPM)and comb-structure polymeric lubricant(CSP).A high-temperature resistant and high-density polymeric saturated brine-based drilling fluid was developed for deep drilling.The WCZ has a good anti-polyelectrolyte effect and exhibits the API fluid loss less than 8 mL after aging in saturated salt environment at 200°C.The FPM can reduce the fluid loss by improving the quality of the mud cake and has a good plugging effect on nano-scale pores/fractures.The CSP,with a weight average molecular weight of 4804,has multiple polar adsorption sites and exhibits excellent lubricating performance under high temperature and high salt conditions.The developed drilling fluid system with a density of 2.0 g/cm^(3)has good rheological properties.It shows a fluid loss less than 15 mL at 200°C and high pressure,a sedimentation factor(SF)smaller than 0.52 after standing at high temperature for 5 d,and a rolling recovery of hydratable drill cuttings similar to oil-based drilling fluid.Besides,it has good plugging and lubricating performance.

Laboratory Study on 210°C High Temperature and Salt Resistant Drilling Fluid

Combined with the current research status in this area at home and abroad, with the improvement of salt and high temperature resistance as the research goal, the laboratory research of salt and high temperature resistant drilling fluid system has been carried out, and lubricants, inhibitors and stabilizers have been optimized. The final drilling fluid formula is: water + 3% sepiolite + 0.3% Na2CO3 + 3% RH-225 + 3% KCOOH + 3% G-SPH + 3% CQA-10 + 1.5% ZX-1 + Xinjiang barite, density 2.2 g/cm3, using hot-rolling furnace, environmental scanning electron microscope, high temperature and high pressure plugging instrument and Zeiss microscopes and other instruments use core immersion experiments, permeability recovery value experiments, and static stratification index methods to perform temperature resistance, reservoir protection, plugging performance, and static settlement stability performance of the configured drilling fluid., Inhibition performance, biological toxicity, salt resistance, anti-pollution performance have been tested, and it is concluded that the temperature resistance is good under the condition of 210°C, and the salt resistance can meet the requirements of 20% NaCl + 0.5% CaCl2 concentration. It has a good reservoir protection effect, the permeability recovery value can reach more than 90%, the performance of restraining water dispersion and cuttings expansion is good, the heat roll recovery rate can reach more than 85%, and the SSSI value shows that its settlement stability performance is good;Its plugging performance is good under high temperature and high pressure. It laid the foundation for the next step to promote the field application of the drilling fluid system.

Study on a Polyamine-Based Anti-Collapse Drilling Fluid System

In complex strata, oil-based drilling fluid is the preferred drilling fluid system, but its preparation cost is high, and there are hidden safety risks. Therefore, the new progress of high-performance anti-collapse water-based drilling fluid at home and abroad is analyzed. It is difficult to prevent and control the well collapse. Once the well wall instability problem occurs, it will often bring huge economic losses to the enterprises, and the underground safety accidents will occur. In order to ensure the stability of the well wall and improve the downhole safety, the key treatment agent of water-based collapse drilling fluid is selected, the anti-collapse drilling fluid system is formulated, the evaluation method of drilling fluid prevention performance is established, and a set of water-based drilling fluid system suitable for easy to collapse strata in China is selected to ensure the downhole safety. The development trend of high performance anti-collapse water-based drilling fluid is expected to provide a reference for the research of high performance anti-collapse water-based drilling fluid system and key treatment agent.

抗超高温高密度聚合物饱和盐水钻井液体系

设计并研制了3种聚合物类水基钻井液抗高温处理剂,即弱交联结构两性离子聚合物降滤失剂、柔性聚合物微球纳米封堵剂和梳型聚合物润滑剂,构建了能够满足深部地层钻井的抗超高温高密度聚合物饱和盐水钻井液体系。研究表明:弱交联结构两性离子聚合物降滤失剂具有良好的反聚电解质效应,200℃、饱和盐环境老化后API滤失量小于8 mL;柔性聚合物微球纳米封堵剂通过改善泥饼质量降低体系的滤失量,对纳米级孔缝具有良好的封堵效果;梳型聚合物润滑剂重均相对分子质量为4804,具有多个极性吸附位点,高温高盐条件下润滑性能优异。构建的密度为2.0 g/cm^(3)的钻井液体系流变性能良好,200℃的高温高压滤失量小于15 mL,高温静置5 d沉降因子小于0.52,对易水化岩屑的滚动回收率与油基钻井液接近,具有良好的封堵性能和润滑性能。

长庆油田页岩油井5000 m水平段高性能水基钻井液钻井实践

长庆页岩油井区在2019年完成亚洲陆上首口4000 m级水平段水平井的基础上,2021年施工完成了5000 m级水平段水平井,该井采用了水基钻井液技术进行施工。超长水平段水平井的关键问题是钻井液润滑性和井眼清洁,为了较好地解决这两个技术难题,以天然材料为骨架,通过基团接枝、发酵等方式进行改性,自主研发了高性能提切剂TQ-8和高效润滑剂HTZ,并以这2种处理剂为核心研制了5000 m水平段高性能水基钻井液体系。体系的主剂配方为(4%~6%)高效润滑剂HTZ+(0.5%~2%)高性能提切剂TQ-8+(0.5%~2%)泥岩抑制剂YYZ-1+(1%~2%)PAC-LV+(1%~2%)BLA-LV+(3%~4%)成膜封堵剂FDJ-1+(20%~80%)可溶性加重剂+烧碱,该体系在井眼清洁、润滑性和抗污染等方面,均比4000 m水平段水基钻井液性能更优。该技术在长庆页岩油华H90-3井进行了试验应用,下套管前的钻具摩阻为400 kN,下完套管后钩载余17 t,具备将水平段长度进一步延长的能力。

钻井液抗高温降滤失剂CQ-1的合成与性能评价

以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、N-乙烯基吡咯烷酮(NVP)、二甲基二烯丙基氯化铵(DMDAAC)为共聚单体,过硫酸铵与亚硫酸氢钠(摩尔比为1∶1)为引发剂,通过自由基水溶液聚合制备了一种抗高温聚合物降滤失剂CQ-1。利用FT-IR、^(1)H NMR及热重分析对CQ-1的结构和热稳定性进行了表征,并通过单因素实验优化了降滤失剂的合成条件。实验结果表明,优化反应条件为:n(AM)∶n(AMPS)∶n(NVP)∶n(DMDAAC)=70∶20∶2∶8,单体总质量分数为20%,引发剂质量分数为0.5%,反应温度55℃,反应时间5 h。在此条件下,CQ-1抗温达240℃,在质量分数为1%时,240℃老化后钻进液中压滤失量为16.2 mL,180℃高温高压滤失量为48.8 mL,优于Driscal D、Dristemp等同类产品。

高性能水基钻井液在中原小井眼侧钻水平井中的应用

中原工区为挖潜老油田的剩余产能、降低钻井成本,逐渐部署开窗侧钻水平井。开窗侧钻水平井存在泥页岩含量高、井壁易失稳,短半径水平井模式狗腿度大、定向易托压,小井眼环空压耗高、携岩带砂难度大等难题。因此,本研究研制具有强抑制、强封堵、高润滑和流型好的高性能水基钻井液,首批现场应用2口井,结果表明:该钻井液对沙一段至沙三段泥岩井壁稳定周期较长;润滑性好,定向正常,起下钻摩阻低;流变参数稳定,携岩能力强,保证了井眼清洁及岩屑床的清除;缩短了钻完井周期,实现了老浆的回收再利用,降低了钻井成本,对推动老油田剩余产能挖潜具有重大意义。

大位移井高温水基钻开液用抗高温润滑剂的研制与应用

针对大位移井高温储层水基钻开液高负荷、高盐度、高温条件下液体润滑剂润滑性能不足问题,基于润滑剂作用机理分析,通过油性剂组分和极压抗磨组分的筛选,开发了适用于大位移井高温钻开液的高温润滑剂。采用极压润滑仪评价了润滑剂在高温钻开液中润滑性能,结果表明加入1%LUBE HT高温钻开液热滚前和热滚后的摩擦系数分别降低了95%和82%;采用润滑模拟评价装置(LEM)评价了润滑剂在高温钻开液中150℃高温下的润滑性能,结果表明加入1%LUBE HT高温钻开液摩擦系数降低了67%。渤海油田渤中区块某井五开6"井段高温钻开液中加入15kg/m3 LUBE HT,钻进扭矩由加入前23~25kN·m降至19~21kN·m,空转扭矩由加入前17~19kN·m降至12~14kN·m,保障了后续作业顺利高效完成,这说明LUBE HT具有优良的降摩减阻性能。

高性能水基钻井液在哥伦比亚HUILA省Gigante油田的应用

哥伦比亚HUILA省Villeta地层为大段泥、页岩层,因页岩层理和微裂缝发育导致井壁失稳严重,钻井事故频发,安全钻达目的层极其困难。为解决该地层的井壁失稳,通常采用油基钻井液。但随着哥伦比亚环保政策越趋严格,废弃油基钻井液和油基钻屑不可避免地带来环境问题。采用强封堵高抑制性的高性能水基钻井液,成功地解决了HUILA省Villeta地层中的钻井失稳问题。本文分析了Villeta地层井壁失稳原因,在考虑环境和物流限制下研究了一种高性能水基钻井液,通过实验确定了高性能水基钻井液配方,监测现场性能参数,通过实践在现场Villeta地层得到了很好的运用,为哥伦比亚HUILA省Villeta地层钻井液运用提供了借鉴。

大港油田千米桥潜山水基钻井液技术

千探1井是目前大港油田部署的最深风险探井,构造位置为千米桥潜山板深4构造高点,完钻井深6165.77 m,垂深5990 m。该井所在区块下部地层地温梯度高,完钻井底温度高达204℃,创大港油田井底最高温度纪录,三开地层易塌、易漏,四开井段高含H_(2)S,新勘探地层岩性未知,要求钻井液体系能够兼顾储层保护和井下安全的需要。千探1井三开井段优选BH-KSM体系,通过强化物理封堵,优化施工措施,解决了地层易塌、易漏等问题。四开钻遇泥页岩后,在现场小型试验结果的基础上,将体系转为抗高温无固相钻井液体系;施工中体系抗温性能良好,被H_(2)S污染后易处理,封堵性强,平均井径扩大率6.59%,井壁稳定效果好,固井质量优质,机械钻速高达5.59 m/h,创潜山井段机速最高纪录。全井施工零事故,创多项油田、区块施工纪录,为大港油田深层潜山勘探积累了宝贵经验。

抗高温水基钻井液作用机理及性能研究

为了了解抗高温水基钻井液的作用机理以及性能,从高温对水基钻井液的影响以及水基钻井液的高温作用机理出发,开展抗高温水基钻井液作用机理分析,从流变性和高温高压流变性出发,对抗高温水基钻井液的性能进行研究。研究表明:高温是影响钻井液性能的重要因素,随着老化温度的逐渐提升,钻井液的动切力将会呈现先降低后升高的趋势;在高温高压条件下,抗高温水基钻井液仍然具有很好的流变性,其性能受高温高压环境的影响相对较小。

江苏油田盐城1侧井施工分析

针对盐城地区井壁稳定性差、坍塌压力高、机械钻速低、钻井周期长等问题,总结盐城1侧井的钻井施工经验,分析对比强攻击性钻头+高效螺杆+LWD地质导向钻进、进口贝壳钻头+旋导仪器等提速工艺的使用效果,分析钻具浮阀断裂的原因,介绍对于频繁垮塌和井漏的处理方法和针对阜二段易垮塌地层的钻井液,形成了低成本优快钻井技术、复配粒径堵漏技术、高性能水基钻井液等技术体系,为东部地区页岩油钻井提供了重要的参考。

国外高性能水基钻井液介绍

近年来高性能水基钻井液(又称胺基钻井液)在国外应用较广,它被认为是替代油基钻井液且又能安全钻进的一类高性能水基钻井液,并于2006年被列为一种新的钻井液体系分类。高性能水基钻井液的实质是应用了一种新的阳离子胺基聚合物———醚乙二醇聚胺类,该胺盐有更高的抑制能力和防泥包能力,符合环保要求,并具有成膜作用,高性能水基钻井液的应用效果与油基钻井液相当。介绍了新胺盐的抑制效果、防泥包数据、利用崩散性试验仪和硬度测试仪2种新仪器测出的各类钻屑的硬度数据和回收率数据,以及国外一家钻井液公司使用该体系的实例和在现场测定聚合物浓度的方法。

国外高性能水基钻井液研究的最新进展

介绍了国外一种在性能、费用、环境保护等方面能够取代油基钻井液与合成基钻井液的高性能水基钻井液。通过对该钻井液的基本组成及主要处理剂的作用机理、室内评价方法和在世界部分油田的现场应用情况进行综述得知,高性能水基钻井液在抑制敏感性泥岩、提高页岩膜效率、防止钻头泥包、提高机械钻速等方面远好于常规抑制性强的水基钻井液,而且在满足钻井要求、环境保护和经济方面完全可以替代油基钻井液;高性能水基钻井液无论是对陆上钻井还是对海上钻井,都具有广阔的应用前景,特别适合含大量泥岩段的重点探井使用。

高性能水基钻井液特性评价实验新方法

鉴于高性能水基钻井液具有超强抑制防塌、防泥包、防阻卡、有助于提高钻速等优越性能,分析了高性能水基钻井液的特性及其作用机理,介绍了中国石油大学(华东)有关高性能水基钻井液特性评价实验方法研究新进展。

非离子型有机胺提高钻井液抑制性的室内研究

近年来,国外的高性能水基钻井液体系备受关注,认为其主要特点是引入了一类新型的阳离子型胺盐抑制剂。评价了2种与之类似的非离子型有机胺Amine-1和Amine-2,它们均属于"边缘"表面活性剂。结果表明,Amine-1和Amine-2有一定降低表面张力的作用,对黏土矿物的水化分散有较强的抑制作用,且对于已分散的黏土体系具有明显的降黏和降滤失作用,因此,它们有望在多种水基钻井液中用作抑制剂。

国外高性能水基钻井液技术发展现状

介绍了贝克休斯公司开发的高性能水基钻井液的基本组成、优良性能以及在世界部分油田的现场应用情况。该钻井液具有油基钻井液的各种性能,可有效稳定页岩、提高岩屑整体性和机械钻速、减小扭矩和阻力,且有利于环保,已被广泛应用于各种钻井。从应用效果看,无论是PDC钻头还是牙轮钻头,机械钻速都达到了27.4m/h,实现了较低的稀释率和较高的固相清除率,其摩擦系数与油基钻井液相同,最大程度地减少了钻头泥包和聚结现象。与油基钻井液相比,可大幅度节省钻井期间的完井时间,解决了高性能钻井与环保要求的协调问题。