【作者】 王媛慧；

【导师】 孙玉学；

【作者基本信息】 大庆石油学院 ， 油气井工程， 2010， 硕士

【摘要】 尽管人们对井壁失稳的基本原因已有深刻认识,但由于地质特点及地层条件等各方面的差异,仍必须对具体油田进行具体分析。勘探开发过程当中,吉林油田海坨子地区存在着缩径、掉块、漏失、坍塌等问题。针对这一情况,本文利用X射线衍射、电镜扫描、分光光度法、滚动回收率测试、膨胀率测试和定向度测试等室内实验手段,对海坨子地区岩样的组构及理化性能进行了系统分析,通过分析认识到海坨子地区嫩江组地层属强膨胀中～弱分散中等～弱定向泥页岩地层,姚家组、青山口组和泉头组属弱膨胀弱分散良好定向泥页岩地层。考虑到上述实验工作量大,周期长等原因,在对泥页岩理化性能及组构特征进行预测时引入了人工神经网络技术,建立了评价模型。经验证,所建立的模型准确可靠。在泥页岩地层分类评价基础上,对井壁失稳的原因进行了探讨,然后从失稳原因入手进行适合该地区钻井液体系的研究,在室内实验的基础上研制出了适合该地区地层钻进的钻井液体系——不渗透钻井液体系。现场试验结果表明,该钻井液体系能有效控制该地区的井壁失稳,大幅度降低井下复杂情况的发生。更多还原

【Abstract】 Though the basic reasons of wellbore instability have been profoundly understood, due to differences in geological characteristic and formation condition and so on, detailed analysis of each oilfield should be carried out. some problems have been encountered, such as borehole shrinkage, loss, sidewall collapse and blocks falling off during exploration and exploitation of Haituozi area in Jilin Oilfield. In view of this situation, the physical-chemical properties and orientation of rock samples of Haituozi area are analyzed systematically by X-ray diffraction, spectrophotometry, cuttings roller recovery measuring and expansion rate measuring. The conclusion is got by systematical analyses that the mud shale of Nenjiang formation belongs to the type of strong expansion, medium to weak dispersity and medium to weak orientation, Yaojia formation, Qingshankou formation and Quantou formation belong to the type of medium to weak expansion, medium to weak dispersity and good orientation. Considering the time taken in experiments and large workload and so on, artificial neural network has been introduced into evaluation, evaluation model has been instructed. The accuracy and credibility of the model has been proved. On the basis of evaluating physical-chemical properties and orientation of shale, the paper discusses the wellbore instability reason of ground in this area. According to the reason, the impermeable drilling fluid suitable to the formation penetration of Haituozi area is developed on the basis of laboratory experiments. The results of field test show that this kind of drilling fluid can control the wellbore instability of this area and decrease the occurring of borehole complexities substantially.更多还原