【作者】 亚尔巴（Yarbane El Houssein）；

【导师】 孙友宏；

【作者基本信息】 吉林大学 ， 地质工程， 2012， 博士

【摘要】 由于复杂储层和复杂地质条件、低压油气资源开发、后期老油气田的改造和稠油等，对21世纪的资源勘探开发提出了更高的要求，而泡沫井技术能够很好的克服钻井作业中遇到的技术难题，并能减少对油气层的伤害、有效保护油气层、提高油气井的产量、实时发现地质异常情况、及时评价低压油气层，能够有效控制漏失、减少和避免压差卡钻等井下复杂情况的发生，具有提高机械钻速、延长钻头使用寿命、缩短钻井周期和降低钻井成本等优点。近五十年来，虽然该技术得到了广泛的应用，但仍存在许多问题急需解决。其中消泡问题和水平井泡沫携岩屑问题尤为突出。由于没有合理的消泡方法,泡沫钻井中存在泡沫流体一次性使用量大，重复利用率低的缺点，不仅增加钻井成本而且污染环境。因此,如何节约泡沫剂的使用量，降低泡沫钻井的成本及满足日益严格的环保要求成为泡沫钻井的一大难题。另外人们对于泡沫携岩屑的基础理论研究较少，理论研究严重滞后于工艺的发展，所发表的论文主要是针对携岩屑工艺的描述。泡沫在大多数直井中流速达到0.3m/s左右就足够了，因此在直井钻井过程中泡沫携岩屑基本没有什么问题。但在水平井钻井中，由于颗粒的沉降速度和泡沫流动方向垂直，致使岩屑沉积在井筒底部，如果沉积在下侧井壁的岩屑床得不到较好的清洗和控制，将会造成诸多问题。这些问题主要有：卡钻、高摩阻和扭矩、粘附卡钻、不能有效将钻压传至钻头、不能解释井的方向变化、泡沫液漏入产层而影响最终采收率等等。因此,解决消泡问题和水平井岩屑沉积问题是推进泡沫钻进技术研究进程、扩大其应用领域的关键问题。针对上述问题，本文开展了实验和数值模拟研究，得出以下几点结论：1、化学消泡剂已经历了四次更新换代，但到目前为止仍没有一种万能的消泡剂适用于所有的消泡领域，对消泡剂消泡机理也没有统一的定论。通过实验测试了消泡剂加入量、泡沫剂种类、温度对消泡剂的消泡和抑泡性能的影响规律。证明了消泡剂加入量存在最优值。同时也证明了泡沫剂种类对消泡剂的消泡能力有很大的影响。在本试验中，阴离子型发泡剂的消泡性较好而复合型发泡剂的抑泡性较好。因此，建议利用化学消泡剂之前应做实验测试以确定消泡剂的适用性。另外随着消泡体系温度的升高，消泡剂的消泡速度加快，但温度超过60℃后，消泡速度基本不再变化；而抑泡时间随着消泡体系温度的升高呈下降趋势。2、建立了实验台，并在该实验台上测试了消泡压力、气液比、泡沫稳定性、喷射速度、贮能管等因素对消泡器消泡能力的影响。实验结果表明，消泡率与泡沫稳定性有密切关系。随着泡沫稳定性降低，机械消泡性降低；消泡压力与消泡率呈直线关系；实验得出长1m、直径20cm的贮能管，气液比α为100～200，垫片厚度为0.6mm的条件下，消泡效果最佳。另外借助FLUENT软件对消泡器扩散管和消泡管内部的压力分布及贮能管中泡沫流动速度与泡沫压力的变化进行数值模拟与分析，模拟结果与实验结论相符。3、研制了适合大口径水文水井泡沫钻进的XP-400型消泡器。目前,在深水井钻探中采用泡沫钻进,解决了一系列的钻进难题，取得了良好的应用效果。在干旱缺水地区、高山供水困难地区以及低压漏失和永冻地区,泡沫钻井是一种快速、高效、很有发展前景的钻进方法。研制该消泡器（XP-400型）将有效解决近年来影响泡沫钻井在水文水井中应用的消泡问题。4、泡沫在环空中携岩屑能力的高低是泡沫钻井成功与否的关键。在水平井钻井过程中，由于颗粒的沉降速度和泡沫流动方向垂直，给水平井泡沫携岩屑能力带来巨大挑战。本文首先阐述了泡沫流体的基本性质，包括泡沫质量、泡沫流体的粘度、泡沫的腐蚀性、泡沫的滤失性、泡沫的热物理性、泡沫的导电性、泡沫稳定性、泡沫流体的流变性等。建立了水平井岩屑运移模型，分析了泡沫携岩屑机理与携岩屑规律。同时分析了环空泡沫的密度、环空泡沫压力、环空泡沫流体的有效粘度、泡沫流体环空流体的摩阻系等因素对水平井泡沫携岩屑能力的影响。另外，本文对水平井泡沫携岩屑过程中岩屑沉降与环空返速之间的关系进行了计算分析，得出泡沫流体的携岩屑率随泡沫环空返速的增大而提高，但环空返速增加到一定程度后会冲刷井壁,严重的可能会导致井塌，因此存在一个临界环空返速。通过数值模拟表明，随泡沫环空返速的增大，颗粒体积分数减小。我们认为在水平井钻井中，环空返速为0.8m/s左右较为合理。5、设计了一台模拟井筒装置，将加工后开展影响泡沫携岩屑能实验研究。特别是泡沫环空返速、钻柱旋转、泡沫密度,钻柱偏心、钻进速度及泡沫流变性及岩屑尺寸等等因素。总之，通过上述几个方面的创新，为泡沫钻井发展与推广应用提供了新的创造性的思维理念。特别是为新的联合消泡方法提供了理论依据，提出一种新的消泡方法即机械为主化学为辅的联合消泡方法。另外本文所有的实验结果与文献中的结论与模拟结果是相符的，这也验证了本文所采用的研究方法和技术路线的正确性。更多还原

【Abstract】 Due to Complex reservoirs and complex geological conditions, the highpressure on oil and gas resource development, the transformation of the old oil andgas fields and heavy oil, etc., in this21stcentury has led to a higher demand forexploration and development. Foam drilling technology has come to stay and can wellovercome the technical problems normally encountered in drilling operations, andreduce damage to the reservoir, and can also ensure effective protection of thereservoir, oil and gas well production, real-time detection of geological anomalies,timely evaluation of the low pressure reservoir. This can also effectively control theleakage, reduce and avoid the occurrence of the down hole pressure differentialsticking, etc., which will in turn improve the drilling rate, shorten drilling cycle andreduce drilling costs.For nearly five decades now, although the technology has been widely used, butthere are still many problems and technicalities that need to be resolved; especiallydefoaming and horizontal wells cutting Transport with Foam particularly beingprominent.Since there is no reasonable method for defoaming, foam drilling fluid foam usesa large amount of disposable repeated low rate drawback; which not only increase thecost of drilling but a significant source of pollution to the environment. Therefore,how to save the use of foam agent to reduce foam drilling costs and meetsincreasingly stringent environmental requirements has become a major problem offoam drilling.The theoretical research on foam cuttings is seriously lagging behind in terms ofprocess of development, all studies published mainly for the description of the FoamCuttings Transport process is in terms of vertical well drilling at about flow rate of0.3m/s, which is sufficient.Therefore, no much problem exists in the vertical well drilling process for foam Cuttings Transport. However, in the horizontal well drilling,because of grain settling velocity the foam flow direction is vertical, resulting indebris deposited at the bottom of the wellbore.Against The above problems, this paper carried out experimental and numericalstudies and obtained following conclusions:1. One chemical defoamer has gone through four replacements, but so far stillthere is not a panacea defoamer applicable to all areas of anti-foaming, defoamersdefoaming mechanism also has no uniform conclusion. A defoamer dosage tested byexperiment, the type of foaming agent, the temperature influence of defoamersdefoaming and antifoaming performance. Defoamer dosage proved optimal value. Italso shows that the type of foaming agent to defoamer defoaming ability have a greatimpact. In this experiment, the anionic foaming agents, defoaming better suppressionfoam blowing agent compound is found to be better. Therefore, we recommend theuse of chemical defoamer should be done before the experimental test to determinethe applicability of the defoamer. In addition, as the defoaming system temperatureincreases, defoamer defoaming speed is also cause to accelerate, but the temperatureis above60℃, defoaming velocity does not change; and this will increase defoamingtime proportionally to defoaming system temperature trend.2. In response to these issues, this paper carried out experimental and numericalstudies, to draw the following conclusion; the experimental results show that thedefoaming rate is closely related to foam stability. As the foam stability decreased, thedefoaming rate is reduced; a linear relationship between the defoaming pressure anddefoaming rate is achieve at an experimental length of about1m and20cm indiameter storage pipe, gas-liquid ratio of α100to200, the gasket thickness of0.6mm.The antifoaming effect conditions were measured in addition with the FLUENTsoftware. Defoaming device diffusion tubes and storage pipe internal pressuredistribution and storage can take control of the flow velocity of the foam and the foampressure changes in the numerical simulation and analysis and simulation results areconsistent with the experimental conclusion.3. Developed for large diameter Water Well foam drilling XP-400foam breaking device used in the drilling of deep wells foam drilling to solve a series of drillingproblems, and achieved good application. In arid areas and mountains water supply isdifficult and low pressure loss and permafrost regions, the bubble is a fast, efficientdrilling, promising drilling methods. The development of the defoaming (XP-400)will effectively address the impact of foam drilling in recent years in the Water Welldefoaming research.4. The level of foam in the annulus to bring the rock capacity is the key to thesuccess of foam drilling. In the horizontal drilling process, due to particle settlingvelocity and bubble flow direction is vertical to horizontal wells, this brings a hugechallenge. This paper first describes the basic properties of the foam fluid, includingthe foam quality, foam viscosity of the fluid, corrosiveness of the bubble, the filtrationof the foam, foam thermal physics, electrical conductivity of foam, foam stability,foam fluid flow degeneration and other aspects of foam drilling. Horizontal wellcuttings transport model is used to analyze the mechanism of foam to bring rock lawinto place. Annular bubble density, bubble pressure of the annulus, the effectiveviscosity of the annulus foam fluid, foam fluid annulus fluid friction and other factorswere all considered on the ability of foam to bring the rock to horizontal wells. Inaddition, the process of horizontal wells foam to bring rock cuttings settlement andthe relationship between annulus velocities were calculated and analyzed. To bringrock ratio derived foam fluid foam annulus velocity increases improve, but the ringempty return the speed to a certain extent after erosion sidewall, and when this getssevere may lead to the well collapse, so there is a critical annulus velocity. Numericalsimulation shows that, with the foam annular return velocity increases, the particlevolume fraction decreases. We believe that horizontal drilling annulus velocity atabout0.8m/s is more reasonable.5. Experimental study will be carried out on the design of a simulated wellboredevice that affects the foam to bring rock and this will be processed. In particular,foam annular speed, the rotation of the drill string, foam density, eccentric drill string,drilling speed and foam rheology and cuttings size, among other factors.In short, these aspects of innovation in foam drilling development will promote the use of a new concept of creative thinking. In particular, this provides a theoreticalbasis for the new joint anti-foaming method, proposed a new defoaming machinerybased chemistry, supplemented by joint anti-foaming method. In addition all theexperimental results, conclusions and the simulation results are consistent with whatis in the literature, which also verified the correctness of this line of research methodsand techniques.更多还原