【作者】 刘丹；

【导师】 艾池； 汝俊显；

【作者基本信息】 大庆石油学院 ， 石油与天然气工程， 2007， 硕士

【摘要】 龙虎泡油田地层岩性和构造较为复杂,泥页层段坍塌压力较大,在钻井过程中,井壁坍塌、卡钻现象时有发生,这不仅降低了钻井效率,提高了钻井成本,而且严重影响了井身质量和固井质量。本文首先分析了龙虎泡地区井壁失稳的主要形式,研究在钻井过程中导致井壁失稳的关键因素,应用声波测井资料计算地层岩石弹性参数及力学参数,在室内试验的基础上建立地层岩石动、静态弹性参数的相关模型;利用密度测井资料计算上覆岩层压力,结合现场实际压裂资料进行地应力反演,回归出本研究区块内的构造应力系数,建立三向地应力计算模型;采用线弹性理论建立井壁力学模型,选择合理的破坏准则计算保持井壁稳定的坍塌压力和破裂压力,从而为龙虎泡油田钻井工程设计提供有效的技术指导,确定安全合理的钻井液密度,减少钻井事故的发生,提高经济效益,确保油田的进一步勘探开发。本文是对龙虎泡油田井壁稳定性进行的一次较为系统的理论研究。更多还原

【Abstract】 In the process of drilling in the Longhupao oilfield, there occurs some complex drilling accidents which include borehole wall sloughing and borehole sticking because of the more complex nature of rock and formation structure in this area and the larger collapsed pressure in mud shale. These complex drilling accidents not only have a serious impact on the efficiency of drilling and on increasing of the drilling costs, but also make borehole quality seriously affected as well as the cement job quality. Initially, this paper analyzes the main form of instability of borehole wall and researches the key element of making the borehole wall instability in the process of drilling to calculate the rock elastic parameters and mechanical parameters by sonic logging and to set up the relationship model of dynamic and static elastic parameter based on laboratory. By using the data of density logging, the thesis calculates the overburden rock pressure, inverts the earth stress combining the fracture experiment data to regress the tectonic stress factor of Longhupao oilfield in order to establish the calculation model of three-dimensional stress. In addition, thesis also sets up the mechanical model of stability of borehole wall by using linear elasticity theory. By choosing reasonable destruction guideline, the thesis calculates the caving pressure and the fracturing pressure in order to make the borehole wall stability as well as the establishment of the security drilling fluid density window, hence, it provides effective technological guidance for drilling engineering in Longhupao oilfield to ensure the further exploration and development of oilfields and reduces drilling accidents in order to enhance economic efficiency. The paper is a systematic theoretical research on the stability of the borehole wall in Longhupao oilfield.更多还原