红河油田煤层井壁失稳力学机理研究

发布时间：2018-06-15 21:24

本文选题：煤岩 + 井壁稳定　；参考：《西南石油大学》2015年硕士论文

【摘要】：红河油田作为中石化华北分公司石油产量的主力区块,探明储量4.53×108t。然而,在红河油田水平井钻井过程中延安组的多套煤层井壁坍塌问题,导致红河油田水平井在钻进、起下钻、测井、通井过程中遇阻卡钻等一系列井下复杂情况,使得红河油田水平井平均机械钻速偏低、钻井周期较长,严重制约了红河油田整体开发效率的提升。为有效解决红河油田煤层井壁坍塌问题,本文首先结合红河油田实钻情况,通过室内实验确定红河油田煤岩微观结构类型、力学特性参数以及孔渗特性参数；其次,从力学角度出发,结合红河油田煤岩力学特性与孔渗特性、煤岩地应力状态、煤岩强度破坏准则,建立红河油田煤岩坍塌压力计算模型；再次,根据建立的红河油田煤岩坍塌压力计算模型,利用Mathcad软件编程计算,研究了地应力、井眼轨迹、煤岩割理发育程度、煤岩孔渗特性、钻井液渗流时间等对红河油田煤岩坍塌压力的影响。最后,利用试验井进行实例计算,探讨分析了红河油田煤层井壁防塌控制措施,通过现场应用对本文建立的红河油田煤岩坍塌压力计算模型及提出的煤层防塌措施进行了效果评价。论文研究表明：①红河油田煤岩井壁失稳以力学失稳为主,且煤岩龟裂系数越低,煤岩强度越低,煤岩坍塌压力则越大；煤层综合渗透系数越小,煤层坍塌压力越小,煤层综合渗透系数越大,煤层坍塌压力则越大。②红河油田煤层井壁稳定控制措施包括：控制合理的钻井液密度与钻井液性能,适当提高钻井液封堵抑制能力,严格控制起下钻速度、减少钻柱对煤岩碰撞、尽量以小井斜快速穿过延安组多套煤层。③红河油田煤岩坍塌压力计算模型及煤岩防塌措施在红河油田具有较高的适用性,值得在红河油田推广运用。总之,红河油田煤层井壁失稳机理、红河油田煤层坍塌压力及其影响因素、红河油田煤层防塌措施的系统研究,对缩短红河油田钻井周期、降低钻井成本、提高红河油田开发效率具有积极意义。
[Abstract]:As the main oil production block of Sinopec North China Branch, Honghe Oilfield has proved reserves of 4.53 脳 108 t. However, in the process of horizontal well drilling in Honghe Oilfield, the collapse of multiple sets of coal seam wall in Yan'an formation leads to a series of complicated downhole conditions such as drilling, logging, and blocking in the process of drilling. The average mechanical drilling speed of horizontal wells in Honghe Oilfield is low and the drilling period is long, which seriously restricts the improvement of the overall development efficiency of Honghe Oilfield. In order to effectively solve the problem of coal seam wall collapse in Honghe Oilfield, this paper firstly combines the actual drilling situation of Honghe Oilfield, and through laboratory experiments, determines the microstructure type, mechanical property parameter and pore permeability characteristic parameter of coal and rock in Honghe Oilfield. From the mechanical point of view, combined with the mechanical characteristics of coal and rock in Honghe Oilfield, the characteristics of pore and permeability, the state of in-situ stress of coal and rock, and the criterion of strength of coal and rock, the calculation model of collapse pressure of coal and rock in Honghe Oilfield is established. According to the calculation model of coal and rock collapse pressure in Honghe Oilfield, and using Mathcad software to calculate, the ground stress, borehole trajectory, coal rock cleavage development degree, coal and rock pore permeability characteristics are studied. Influence of percolation time of drilling fluid on collapse pressure of coal and rock in Honghe Oilfield. Finally, by using the test well to carry on the example calculation, discussed and analyzed the Honghe oil field coal seam wall to prevent the sloughing control measure, The calculation model of coal and rock collapse pressure in Honghe Oilfield and the measures to prevent coal seam sloughing are evaluated by field application. The research shows that the instability of coal and rock wall is mainly mechanical instability, and the lower the crack coefficient of coal and rock, the lower the strength of coal and rock, the greater the collapse pressure of coal and rock, the smaller the comprehensive permeability coefficient of coal seam, the smaller the collapse pressure of coal seam. The bigger the comprehensive permeability coefficient of coal seam is, the greater the collapse pressure of coal seam is. 2. The stable control measures of coal seam lining in Honghe Oilfield include: controlling reasonable drilling fluid density and drilling fluid performance, improving the plugging and inhibiting ability of drilling fluid appropriately. Strictly controlling the down drilling speed, reducing the collision of drill string to coal and rock, making use of small well slant to pass through Yanan formation multiple sets of coal and rock collapse pressure calculation model of Honghe oilfield and coal rock collapse prevention measures have high applicability in Honghe oilfield, as far as possible. It is worth popularizing in Honghe Oilfield. In a word, the mechanism of coal seam wall instability in Honghe Oilfield, the collapse pressure of coal seam and its influencing factors, and the measures of preventing coal seam collapse in Honghe Oilfield are studied systematically, which can shorten the drilling period and reduce the drilling cost in Honghe Oilfield. It is of great significance to improve the development efficiency of Honghe Oilfield.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE28

【参考文献】