【作者】 熊志敏；

【导师】 张人杰；

【作者基本信息】 山东大学 ， 油田化学， 2007， 硕士

【摘要】 在胜利油田的金家、郑家、单家寺等油区的储层均存在不同程度的强水敏效应,油层保护问题比较突出。在进行射孔作业时,如果采用普通水基射孔液,不可避免地会对储层产生较大伤害,会大大降低前期使用强抑制性钻井液保护油层的作用,造成前期成本的浪费,不能真正实现保护油气层已达到增油上产的目的。因此有必要进行新型的强抑制性保护油气层射孔液的研究,并配合保护油气层钻井液进行现场应用,才能最大程度地实现增油上产。通过本项目研究,对解决目前胜利油田钻探水敏性地层中遇到的油气层保护等工程技术难题,有重要作用,能够显著提高油气勘探开发综合效益。本文首先进行了射孔液保护油层作用机理的研究,研究分析表明,引起强水敏性储层损害的原因是;其一,储层中水敏性矿物含量较高,蒙脱石极易发生水化膨胀,其二,高岭石易发生分散运移,从而导致渗透率降低。为此,必须尽可能提高钻井液的抑制性和包被能力。以此为指导优选出具有强抑制性的新型阳离子抑制剂,和合适的表面活性剂,并合理应用暂堵剂,尽量降低射孔液对地层的伤害,研制出适用于水敏性地层的新型保护油气层射孔液。最后确定保护油气层射孔液的基本配方为;清水+0.2%增粘降滤失剂+0.3%两性离子聚合物FA367+3%阳离子聚合物粘土稳定剂YNJ+3%细目CaC03+0.2%SK-2+1%解水锁剂JSS+1%缓蚀剂ZH-Ⅲ+加重剂(根据实际要求的密度添加)。对研制出的新型射孔液与目前常用射孔液进行对比评价,评价结果表明新型射孔液具有很强的抑制性、流变性好,失水小于10mL,可抗120℃高温,抗腐蚀能力强、性能稳定、渗透率恢复值高,油气层保护效果好。本研究采用的关键技术有三点;第一,选用了一种新型阳离子强抑制剂,能够减少储层表面的离子交换,减少空间电性作用,从而阻止颗粒运移,阻止粘土膨胀、保持储层有良好的油气通道,显著提高射孔液的抑制性能;第二,合理应用暂堵剂,有效降低射孔液的滤失量,减少滤液进入储层;第三,应用合适的表面活性剂,可降低射孔液的表面张力,使侵入地层的流体易从储层反排,改善和缓解对储层的伤害。在室内研究工作的基础上,对保护油气层射孔液进行了现场试验和应用,在滨南采油厂进行了5口井的现场试验。现场应用表明,该保护油气层射孔液体系流变参数合理、抑制性强、性能稳定、保护油气层效果良好,适用于强水敏地层的射孔施工,有利于保证射孔作业的顺利施工和保护油气层,有助于实现增油上产,取得了良好的经济效益和社会效益。更多还原

【Abstract】 There are large areas of water-sensitive formations facing severe reservoir damage problems in Wangzhuang, Jinjia and Shanjiasi oil district of Shengli Oil Field. The application of ordinary water-based drilling fluid is limited to carry through perforating because of its inevitable disadvantages, such as high formation damage and cost waste. It can’t protect formation well. According to geological analysis of Wangzhuang, Jinjia and Shanjiasi oil district, a new kind of high inhibitive water-based drilling fluid with good environment acceptability and reservoir protection effect has been developed.First, the reservoir damage mechanism of water-sensitive formations in Shengli Oil Field has been studyed. It is mainly because the hydration&swelling of large amounts of water-sensitive clay minerals, especially montmorillonite, and dispersion&migragation of kaolinite, that caused the reduction of reservoir permeability. So the inhibition effect of the drilling fluid must be enhanced as high as possible. By doing a lot of inhibition and compatible experiments, main component chemicals have been selected, such as positive shale stabilizer CETA, zwitterion polymer FA367, polyalcohols and organic positive colloid BPS. Finally, the formulation of this system has been optimized as below: 4% Bentonite base mud+ 0.3% CETA+ 0.2% XC+ 3.5% mixed anti-sloughing agent+ 0.15% FA367+ 0.3% mixed fluid loss additives+ 2% BPS+ 2% Polyalcohols.The evaluation results show that this new system performs many excellent properties. It has super high inhibit and anti-sloughing property, nice reological properties, fine temperature stability, low filer loss, resisting the temperature of 120℃, high permeability recovery rate, favorable lubrication property and low toxicity toenvironment.The key points of have been got as follow, first, a kind of new-style cationic inhibitor is applied to decrease ion exchange on reservoir surface. Second, temporary plugging agent is applied to decrease filter loss of perforating fluid .Third, appropriate surfactants are applied to decrease the surface tension of perforating fluid, and reduce the damage of reservoir.Till now, this drilling fluid system has been put into use in more than 5 wells in Binnan Oil Plant. The field application effects have shown that this system is helpful to keep the well wall stable, enhance mechanical drilling speed and drilling efficiency, and protect the oil reservoir effectively. Meanwhile, this system can largely reduce drilling cost compared with OBM. Considerable economic benefits have been gained for using this new system.更多还原