分支井连接井段井壁破坏特性分析

目前，分支井井眼连接井段失效问题是分支井技术面临的新的挑战，因为这可能导致井眼报废而无法达到预期的目的，因此，针对分支井分支处连接段井壁力学特性，首次研究了分支连接处的应力分布和破坏规律，应用有限元法模拟了造斜半径和造斜方位对连接段井壁应力分布和破坏的影响，以及连接处破坏的程度及变化规律；同时总结出连接井段井眼最稳定时的最佳分支造斜方位是沿着最大水平主应力方向。     

3D finite element modelling of multilateral junction wellbore stability

Wellbore failure can occur at different stages of operations. For example, wellbore collapse might happen during drilling and/or during production. The drilling process results in the removal of an already stressed rock material. If the induced stresses near the wellbore exceed the strength of rock, wellbore failure occurs. The production process also changes the effective stresses around the wellbore. Such changes in stresses can be significant for high drawdown pressures and can trigger wellbore failure. In this paper, the Mohr–Coulomb failure criterion with a hyperbolic hardening is used. The model parameters are identified from triaxial compression tests. The numerical simulations of laboratory tests showed that the model can reproduce the mechanical behaviour of sandstone. In addition, the simulations of multilateral junction stability experiments showed that the model was able to reproduce yielding and failure at the multilateral junction for different levels of applied stresses. Finally, a numerical example examining multilateral junction stability in an open borehole during drilling and production is presented. The results illustrate the development of a localized failure zone proximate to the area where two wellbore tracks join, particularly on the side with a sharp approaching angle, which would significantly increase the risk of wellbore collapse at the junction.     

分支井构型对疏松砂岩油藏临界生产压差的影响

对疏松砂岩稠油油藏,无论采用哪种构型的分支井,主分井筒接合部区域的稳定性都很差。即使生产压差低于1 MPa,该处也会发生井壁失稳垮塌,堵塞分支井眼,削弱分支对产能的贡献。因此,必须对接合部地层进行特殊处理,以提高分支井系统整体稳定性,提高生产压差。在正断型地应力场条件下,不考虑主分井筒接合部的影响,主分井筒延伸方向应尽可能沿原地最小水平主应力方向延伸。分支造斜率对接合部地层的破坏程度和破坏区域有明显影响,相同压差下,随分支造斜率增大,主、分井筒接合部塑性破坏深度呈幂函数关系减小;在主、分井筒长度及主、分井筒夹角一定时,采用较大造斜率设计的分支井系统具有更高的井眼稳定性。分支间距是影响分支井系统稳定性的另一个重要因素。当分支处于主井眼同侧时,分支间距大于45 m后分支间影响可忽略;当分支处于主井眼异侧时,分支间距大于40 m后分支间影响可忽略。在裸眼和主井筒下筛管两种完井方式下,分支接合部破坏深度、出砂波及区域随生产压差增大均呈指数增大。     

四川盆地高温高压含硫气井五级分支井钻完井技术

MX023-H1井是四川盆地龙王庙组气藏的一口五级分支井,目的是为验证分支井技术在深层碳酸盐岩气藏高效开发的适应性。该井作为国内第一口高温高压含硫五级分支气井,分支井眼钻完井作业面临完井级别高、作业程序多、井身质量要求严格、复杂套管串下入难度大、固井水泥环防气窜性能要求高等技术难题。为此,通过增加窗口强度、选择稳定地层开窗等手段以确保后期开采期间分支井眼与主井眼连接处的稳定性;设计平滑的井眼轨道和提高钻井液防塌性能可保证井径规则,降低了下套管难度;采用新设计的?177.8 mm弯套管,完成了近5 000 m井深?215.9 mm分支井眼通井作业,满足了分支井眼重入和通井要求,为分支井眼套管顺利下入创造了良好的井眼条件;壁挂式悬挂器壁钩前端开口槽间隙由21.66 mm增至25.66 mm,提高了壁挂成功率;三凝水泥浆体系配合控压平衡法固井技术,保障了分支井眼溢漏同存条件下的固井质量,一界面合格率97.6%、二界面合格率100%。现场应用表明,配套技术能够满足深层高温高压含硫五级分支井钻完井作业要求,该分支井钻完井作业的成功实施可为后续五级分支井技术的推广应用提供借鉴。     

鱼刺分支水平井在稠油油藏中的应用

鱼刺分支水平井根据油藏条件设计井眼并进行井眼空间分布,能有效增加油层的裸露面积,提高油藏动用程度,增大蒸汽波及体积,最终达到提高采收率的目的.杜84-兴H238Z井是辽河油田在超稠油油藏中部署和实施的第一口鱼刺分支水平井,共4个分支,水平段总长837 m.该井在井身结构优化、钻井技术、储集层保护技术、完井技术等方面均取得了实质性突破,为进一步推广应用鱼刺分支井提供了一定的参考依据.悬空侧钻技术是鱼刺分支水平井的关键技术.利用LWD随钻测井技术进行地质导向钻井作业,可以有效地提高储集层判别精度和轨迹控制精度,从而提高实施效果.杜84-兴H238Z井投产后蒸汽吞吐最高日产量达到152.6 t,平均日产量是同区块常规水平井的1.41～1.85倍,效果显著.     

韩城矿区煤层气L型水平井套管钻井技术

地质条件与工程技术匹配程度决定了煤层气开发效果,为进一步摸索适合韩城矿区煤储层特点的开发技术,不断改善该区煤层气开发效果,在总结该区丛式井组射孔压裂及多分支水平井技术开发效果基础上,结合该区煤储层低孔、低渗及低压的特点,应用L型水平井套管钻井技术。该技术三开采用套管钻进,完钻后不进行固井作业,直接射孔完井。结果表明该类开发技术具有一般水平井开发技术的优点,与多分支水平井相比能够保持井壁的稳定性,同时避免固井作业及压裂改造带来的不利影响,产气效果明显趋好。     

Simulation of Progressive Borehole Failure at Multi-Lateral Junctions

Multi-lateral junction failure, one of the challenges introduced by employing multi-lateral technology to improve production of oil and gas wells, has imposed significant impacts on the employment of this new technology. Therefore, a powerful computer simulator is required for analyzing the issues of both fracturing and collapse at the multi-lateral junction. In this study, we present such a simulator, Rock Failure Process Analysis (RFPA^2D), in which rock is assumed to be heterogeneous at a mesoscopic level and an elastic-damage based constitutive law is used to describe the constitutive law of elements. The applicability of RFPA^2D to simulate progressive borehole failure processes at junction locations is demonstrated through (1) successful comparisons of the simulated distribution of stress concentration factors with the known analytical solutions for the elastic case; (2) successful comparisons of the simulated borehole failure patterns with experimental observations reported in previous studies; and (3) simulations of progressive borehole failure processes under a variety of geometrical and loading conditions.     

张海39-39Z分支井钻井液技术

张海39-39Z分支井是大港油田第一口真正意上的四级分支井。根据该地区地层特性,综合考虑该井的井身结构、工艺特点、分支井眼工序复杂、保护油气层以及环境保护对钻井液的要求等,结合以往该地区钻井所用钻井液体系应用效果及其现场技术,张海39-39Z分支井在主井眼一开浅地层采用膨润土-聚合物钻井液钻进,二开明化镇组采用聚合物钻井液、进入馆陶组转化为硅基防塌钻井液钻进,主井眼三开及分支井眼均采用有机盐钻井液钻进,较好地满足了分支井不同阶段钻井与其它作业施工要求,钻井液性能稳定,效果明显。该井以合理的流变性能解决了井眼净化问题,以控制合理的有机盐含量和膨润土含量保证了钻井液抑制性、稳定性问题,运用合理的钻井液密度等解决了井壁稳定问题,为今后采用常规钻井液体系及其现场技术完成类似分支井作业提供了借鉴意义。      

各向异性地层中斜井井壁失稳机理

深部层理性地层井壁稳定性必须考虑地层物理力学性质的各向异性,然而目前井壁稳定设计方面仍粗略地将其近似为各向同性体,使得预测的维持井壁稳定的坍塌压力和破裂压力不能满足安全钻井的需要。笔者在研究层理地层岩石力学特性的基础上,获得了一种考虑地层方向特性的井壁围岩应力分布公式,分析了横观各向同性地层的井壁应力分布特征,建立了新的斜井地层井壁稳定分析模型。研究结果表明,岩石的弹性模量、地应力和地层倾斜度的变化对井壁围岩的应力分布和坍塌、破裂压力均会产生影响,克服了常规各向同性井壁稳定分析模型不能准确预测层理性地层斜井井壁稳定的难题。因此在钻井施工设计当中,须根据地层特性选择合适的分析模型,以更好地指导现场实践。     

广安002-Z2鱼刺状多级分支水平井钻井技术

广安002-Z2是一口4井眼、2分支鱼刺井,在主井眼采用斜向器侧钻第1分支井,在第1分支井中采用悬空裸眼侧钻第2分支井,主导眼采用筛管完井,分支井采用裸眼完井。在斜向器回收未成功的情况下,采用绕障钻通主导眼实现压力连通。该井成功采用多种侧钻技术顺利完钻,累计水平段长达2031.71m,钻遇3个储层,大大地增加了天然气产量。该技术具有广阔的推广应用价值。     

Stability Assessment of a Dual-Opposing Well Junction

The enhancement of well drilling and construction techniques during the 1990s helped the multilateral technology to become increasingly viable and conventional. Dual-opposed is one of the configurations of this technology, in which one lateral goes down dip and the second one up dip in the formation. The stability of the dual-opposed junction is a crucial issue and several factors are involved in this matter, including in-situ stress magnitude and distribution as well as laterals trajectories. In this research, this issue is evaluated assuming different circumstances for the previously mentioned factors using FLAC3D numerical code. The Normalized Yielded Zone Area (ratio of surrounding yielded cross-sectional area to initial area of well) is determined to be the criterion for assessing the stability of the junction. For each stress regime, the lowest mud pressure is calculated in different laterals orientations in stable condition. Then, the optimum mud pressure along with the favorable trajectory of laterals is selected. The results show that, generally, by the increase of inclination (i.e., reduction of angle between the two opposed laterals), the junction gets more stable. Also, the direction of σ_H is, in general, the optimum direction in all considered stress regimes.     

?170 mm四级分支井重入工具丢手装置研制

为了解决预先设置导向装置的四级分支井重入工具的送入与回收问题,研制了?170 mm四级分支井重入工具丢手装置。该装置可将四级分支井重入工具送入井眼连接器中,并解锁完成丢手,亦可完成重入工具的回收作业。使用低压差液压丢手方式,易丢手。有紧急解锁结构设计,机械丢手无剪钉。通过有限元数值模拟分析与室内试验,证明该装置安全可靠,符合现场使用要求,操作简易,可提高四级分支井重入作业的施工效率,具备推广价值。     

A prediction method of borehole stability based on seismic attribute technology

Borehole instability in drilling engineering can bring about serious problems of drilling quality and safety. Based on the close relationships between seismic and well log information, the prediction method of borehole stability is presented to effectively control borehole instability. Conventional and nonlinear seismic attributes are extracted from borehole-side seismic traces of impending drilling well and drilled offset well respectively. Then the optimal attributes combinations sensitive to log properties are selected by using genetic algorithm and wavelet neural network technology together. A series of mapping models which reflect the nonlinear relationships between seismic attributes and acoustic and density log data of various formation intervals in drilled well are constructed through neural network modeling. With analysis of cutting logging data, seismic attributes of the formation under bit and corresponding mapping model can be used to predict acoustic and density log curves of this formation. Based on the predicted log data, log interpretation method, analysis technology of in-situ stress and mechanics model of borehole stability are employed to calculate in-situ stress, pore pressure, collapse pressure and fracture pressure, thus the safe drilling fluid density window which can keep borehole stable is determined. Prediction precision and real-time operation ability of the proposed method are satisfying, which have been proved in practical application in TR oil field.     

地震资料在车古201块储层建模中的应用

1. Introduction Generally, reservoir property parameter modeling isbased on facies control. Firstly, a sedimentary faciesmodel is established, then interwell interpolation orrandom modeling is made for each facies (sand body) toestablish reservoir paramet…     

Modeling of Fishbone Multilateral Well Productivity in Row Well Pattern

The technology of fishbone multilateral wells has been extensively applied worldwide in oilfield development. However there are few published models about fishbone multilateral wells' productivity. Based on conformal transformation and mirror image theory, a semianalytical model was derived for horizontal wells and fishbone multilateral wells' productivity in row well pattern, and verified through the electrolytical model experiment. The matching result showed there was only 12.15% maximum error.     

桩1-支平1井钻井液工艺技术

桩1－支平1井位于胜利长堤油田桩1块中部构造较高位置，目的层是馆陶组上段9小层，该井是胜利油田第一口分支井，钻探目的是利用分支水平井技术控制更大面积储量，抑制底水锥进，增大泄油面积，提高采收率，针对分支水平井对钻井液的特殊要求，及分支井施工钻井液在裸眼井段静止时间长，要求钻井液具有很好的悬浮携带能力，稳定性能，流变性能和油层保护性能，采用聚合醇防塌钻井液体系，聚合醇钻井液以聚合醇为主要处理剂，正电胶，两性离子聚合物为辅助处理剂，经现场应用表明，聚合醇在钻井液中加量为3％时，具有很强的润滑性，抑制性和防塌性能，携岩能力和保护油气层能力强；生物毒性小，LC50值大于30800g/mL，利于环境保护，满足了该水平井钻井的要求。     

五级分支井技术在河3-支平1井的应用（） 引用格式:聂云飞，吴仲华，张辉，等.五级分支井技术在河3-支平1井的应用［J］.石油钻采工艺，2012，34（2）:13-16.

河3-支平1井为双分支水平井,钻探目的是利用分支水平井技术完善区块开发效果。采用了主套管窗口液力密封技术,通过在主套管内开窗后,主井眼内下入母板,分支井眼内下入分支井眼连接器,并通过分支井眼连接器上的密封实现了窗口连接处的液力密封性能,同时实现了后期投产施工时分支井眼的选择性再进入。河3-支平1井达到了五级分支井完井水平,满足了该区块的开发需要。     

胜利油田鱼骨状水平分支井钻井技术

为寻求一种更有效、科学和经济的储量动用方式和油藏开发方式,胜利油田开展了鱼骨状水平分支井技术研究与应用。从鱼骨状水平分支井的设计原则着手,对该技术的钻进方式、井身结构、裸眼分支井侧钻技术、钻具组合、地质导向钻井技术、油气层保护技术、完井技术等关键要素进行了研究,同时进行了5口井的现场试验。试验结果表明,试验井产量是普通定向井或直井的3倍多,能极大地提高油藏的动用程度,提高油气藏开发利用率和采收率。鱼骨状水平分支井的成功实施为胜利油田提高油气藏综合开发效益提供了一套全新的技术路线,也为今后该技术的推广应用积累了丰富的经验。     

煤层气定向羽状水平井数值模拟技术应用

定向羽状水平井技术是近几年兴起的一项煤层气的增产技术。目前，在煤层气数值模拟的研究方面国内外已经作了大量的工作，但数学模型多为直井压裂井，没有专门描述煤层气定向羽状水平井开采特征的数学模型。对渗流所编制的定向羽状水平井开采煤层气数值模拟软件做了进一步的改进，首先介绍了定向羽状水平井数值模拟软件的数学模型，然后利用该软件对大宁DNP02井进行了产能预测，并计算得出最佳的排采压力。分析预测结果证明，该软件用于煤层气产能预测是可靠的。通过产能预测量化了该地区煤层气勘探开发的前景，最佳井底压力的确定可以对煤层气开发方案设计提供参考，实现了煤层气数值模拟的目的。软件的应用对这一项新技术在我国的推广应用和煤层气的大规模开采能够起到重要的指导作用，并取得较好的经济效益。     

基于膨胀管定位系统的多分支井钻完井技术

基于膨胀管定位系统开发了膨胀管定位多分支井技术:在分支井钻井、完井甚至后续的采油、修井以及油层改造等作业中,各种工具均根据井下膨胀坐挂定位装置进行定位并作业的一种新型多分支井技术,具有工艺简单,完井后通径大和可以在小尺寸井眼内钻多个分支等特点,达到了国际TAML 4级完井水平.该技术通过膨胀坐挂定位装置实现了对斜向器的可靠定位;并可承受极大的钻压和扭矩,完全满足开窗、侧钻、等施工要求.在海上油田3口井中的成功应用证明该技术和装备成熟可靠,整套施工工艺和作业难度低,作业安全可靠性高,各工序施工信号明显,司钻易于操作.初步形成了主套管为177.8 mm(7 in)和244.5 mm(9%in)两个系列的膨胀管定位多分支井工具和工艺技术.图9参19