振动管式钻井液密度检测系统的建立及其性能研究

发布时间：2018-08-11 12:12

【摘要】：钻井过程中,钻井液具有十分重要的作用,能否精确地检测出钻井液的密度以实现对钻井液各组成成分的物料比进行控制关系到能否安全、高效地钻井。目前,市场上存在多种用于液体密度检测的设备和装置,如浮子式密度计、静压式密度计、电容式流体密度计以及放射性同位素密度计以及振动管式液体密度计等。然而,上述各种用于检测液体密度的设备和装置均有其使用的局限性,此外,又由于钻井现场较为恶劣的环境因素,所以,上述各种密度检测设备和装置均不能很好地满足对钻井液的密度进行精确、安全、高效检测的要求。为了能够实现对钻井液的密度进行精确、安全、高效检测的要求,在设计液体密度计时,应充分考虑钻井现场的振动条件和温度条件,同时,结合钻井液的流速条件、压力条件以及钻井液的物理性质和化学性质等,最终,提出并建立了振动管式钻井液密度检测系统,并在此基础上,对检测系统的核心部件——振动管式液体密度计进行了设计,开发出一种悬臂梁式钻井液密度计,并对该密度计的各项性能进行了有限元分析。完成的主要工作如下:(1)总结并分析了国内外液体密度检测设备和装置的研究现状,确定了选择振动管式液体密度计来实现对钻井液密度进行检测的方案。结合钻井现场的振动条件和温度条件以及钻井液的压力条件和流速条件等各项限制条件,提出并建立了振动管式钻井液密度检测系统。(2)综合考虑振动管式钻井液密度检测系统中各组成模块的功用,可知该钻井液密度检测系统的各项性能可由振动管式钻井液密度计的各项性能表征。结合钻井液的物理和化学性质,提出了一种新型的振动管式液体密度计——以悬臂梁和测量管组成的部件为敏感元件的悬臂梁式钻井液密度计,同时,完成了该密度计的设计计算。(3)对悬臂梁和测量管组成的敏感元件S2进行了模态分析,得出了敏感元件S2的第一阶振型及其对应的固有频率,确定了激振频率的下限值为1591.0Hz,上限值为1691.0Hz,步长为0.01Hz。对该密度计的壳体进行了模态分析,分析结果表明,壳体不会与悬臂梁和测量管组成的敏感元件S2产生共振,验证了悬臂梁式钻井液密度计结构和尺寸设计的合理性。(4)对敏感元件S2进行了谐响应分析,分析结果表明,在激振力的作用下,敏感元件S2的等效应力和等效应变均主要集中在悬臂梁的a端和b端相过度的位置附近,即当悬臂梁式钻井液密度计工作时,悬臂梁的a端与b端相过度的位置附近容易发生破坏。(5)对敏感元件s2进行了受钻井现场外界振动作用时的谐响应分析,分析结果表明,外界振动引起的敏感元件s2产生的沿z轴方向的位移很小,可近似认为外界振动对悬臂梁式钻井液密度计的振动性能不产生影响:外界振动引起的悬臂梁式钻井液密度计的质量流量测量误差为0.0011%,该值远小于密度计质量流量的测量精度要求2%;此外,外界振动不影响敏感元件s2的固有频率,可知外界振动对悬臂梁式钻井液密度计的质量流量和密度的测量影响很小,振动性能优好,能够适应钻井现场的振动条件。(6)对悬臂梁式钻井液密度计进行了温度场作用下的模态分析,分析结果表明,钻井现场的极限温度引起的悬臂梁式钻井液密度计的密度测量误差为0.0075g/cm3,该值满足密度计密度的测量精度要求0.01g/cm3,可知,钻井现场的温度变化引起的密度测量误差很小,悬臂梁式钻井液密度计的温度性能优好;(7)对悬臂梁式钻井液密度计进行了热-结构耦合分析,分析结果表明,钻井现场的极限温度引起的左侧悬臂梁和右侧悬臂梁上拾振点处对应的节点产生的沿z轴方向的位移相同,即钻井现场的温度条件不会对左侧悬臂梁和右侧悬臂梁的振动造成位移差,可知,温度对悬臂梁式钻井液密度计的质量流量测量影响很小,温度性能优好,能够适应钻井现场的温度条件。(8)对敏感元件s2进行了压力作用下的模态分析,分析结果表明,当钻井液的压力为设计极限时,极限压力引起的悬臂梁式钻井液密度计的密度测量误差为0.0022g/cm3,该值满足密度计密度的测量精度要求0.01g/cm3,可知,钻井液的压力变化引起的密度测量误差很小,悬臂梁式钻井液密度计的压力性能优好。(9)对悬臂梁式钻井液密度计进行了流-固耦合分析,分析结果表明,当钻井液的压力达到设计上限时,敏感元件s2产生的沿各方向位移均极小,极限压力引起的悬臂梁式钻井液密度计的质量流量测量误差为0.0003%,该值远小于密度计质量流量的测量精度要求2%,可知,悬臂梁式钻井液密度计的质量流量测量受压力影响很小,压力性能优良,能够适应极限工作压力条件。此外,敏感元件s2产生的最大等效平均应力远小于所用材料的最大许用应力。(10)综合考虑密度计本身的系统误差、外界振动、温度以及钻井液压力引起的密度和质量流量的测量误差,可知,悬臂梁式钻井液密度计密度测量的总误差为0.0097g/cm3,质量流量测量的总误差为0.0014%,二者均能满足密度计的测量精度要求,故悬臂梁式钻井液密度计的振动性能、温度性能以及压力性能优好,均能够满足钻井现场的工作条件。
[Abstract]:Drilling fluid plays a very important role in the drilling process. Whether the density of drilling fluid can be accurately detected to control the material ratio of each component of drilling fluid is related to whether the drilling fluid can be drilled safely and efficiently. However, all the above-mentioned devices and devices used to detect liquid density have their limitations in use. In addition, due to the harsh environmental factors on the drilling site, the above-mentioned density testing equipment and devices are not available. In order to achieve the requirement of accurate, safe and efficient detection of drilling fluid density, the vibration and temperature conditions on the drilling site should be fully considered in the design of fluid density timing. At the same time, the flow velocity and pressure conditions of drilling fluid should be considered. Finally, a vibrating tubular drilling fluid density measuring system is proposed and established. On this basis, a vibrating tubular liquid densimeter, which is the core component of the testing system, is designed, and a cantilever drilling fluid densimeter is developed. The main work is as follows: (1) Summarize and analyze the research status of fluid density testing equipment and devices at home and abroad, and determine the scheme of choosing vibrating tubular liquid densimeter to realize the detection of drilling fluid density. (2) Considering the function of each module in the vibrating tubular drilling fluid density testing system, it is known that the performances of the drilling fluid density testing system can be characterized by the performances of the vibrating tubular drilling fluid densimeter. Physical and chemical properties of a new type of vibrating tube type liquid densimeter, a cantilever type drilling fluid densimeter with the components of cantilever beam and measuring tube as sensing elements, are presented. At the same time, the design and calculation of the densimeter are completed. (3) The modal analysis of the sensitive element S2 composed of cantilever beam and measuring tube is carried out, and the sensitivity is obtained. The lower limit value of excitation frequency is 1591.0 Hz, the upper limit value is 1691.0 Hz, and the step length is 0.01 Hz. The modal analysis of the shell of the densimeter is carried out. The results show that the shell will not resonate with the sensitive element S2 composed of the cantilever beam and the measuring tube, and the cantilever beam type is verified. (4) The harmonic response analysis of the sensor S2 is carried out. The results show that the equivalent stress and strain of the sensor S2 are mainly concentrated in the vicinity of the excessive phases of the a-end and b-end of the cantilever beam when the cantilever drilling fluid densimeter works. (5) Harmonic response analysis of sensitive element S2 under the action of external vibration in drilling site is carried out. The results show that the displacement along Z axis caused by external vibration of sensitive element S2 is very small, which can be approximated to the density of the cantilever drilling fluid. The measuring error of mass flow rate of the cantilever drilling fluid densimeter caused by external vibration is 0.0011%, which is far less than 2% of the measuring accuracy of the densimeter mass flow rate; moreover, the external vibration does not affect the natural frequency of the sensitive element s 2, so the quality of the cantilever drilling fluid densimeter is known. (6) The modal analysis of the cantilever drilling fluid densimeter under the action of temperature field is carried out. The results show that the density measurement error of the cantilever drilling fluid densimeter caused by the limit temperature of the drilling site is 0.0075g/cm3. This value meets the density measurement accuracy requirement of 0.01g/cm3. It can be seen that the density measurement error caused by the temperature change in the drilling site is very small, and the temperature performance of the cantilever drilling fluid densimeter is excellent. (7) The thermal-structural coupling analysis of the cantilever drilling fluid densimeter is carried out, and the results show that the limit temperature in the drilling site causes the density measurement error. The displacement along the Z axis produced by the node corresponding to the vibration pickup point on the left cantilever beam and the right cantilever beam is the same, that is, the displacement difference between the vibration of the left cantilever beam and the right cantilever beam will not be caused by the temperature condition in the drilling site. It is known that the temperature has little influence on the mass flow measurement of the cantilever drilling fluid densimeter and the temperature performance is good. (8) The modal analysis of the sensitive element S2 under pressure is carried out. The results show that when the drilling fluid pressure is the design limit, the density measurement error of the cantilever drilling fluid densimeter caused by the limit pressure is 0.0022g/cm3, which meets the density measurement accuracy requirement of the densimeter 0.01. G / cm 3, it is known that the density measurement error caused by the pressure change of drilling fluid is very small, and the pressure performance of the cantilever drilling fluid densimeter is excellent. (9) The fluid-solid coupling analysis of the cantilever drilling fluid densimeter is carried out. The results show that when the pressure of drilling fluid reaches the design upper limit, the displacement of the sensitive element S2 is uniform along all directions. The mass flow measurement error of the cantilever drilling fluid densimeter caused by the extreme pressure is 0.0003%, which is far less than 2% of the measurement accuracy of the densimeter mass flow. The maximum equivalent average stress produced by the inductor S2 is far less than the maximum allowable stress of the material used. (10) Considering the systematic error of the densimeter itself, the measurement error of density and mass flow caused by external vibration, temperature and drilling fluid pressure, the total error of density measurement of the cantilever drilling fluid densimeter is 0.0097g/cm3, and the total error of quality measurement is 0.0097g/cm3. The total error of flowrate measurement is 0.0014%. Both of them can satisfy the measuring accuracy requirement of the densimeter. Therefore, the vibration performance, temperature performance and pressure performance of the cantilever drilling fluid densimeter are excellent, which can meet the working conditions of the drilling site.
【学位授予单位】：济南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE254

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