管道连续压力波传递及其在随钻测量与悬挂试压中的应用

发布时间：2018-05-13 20:02

本文选题：随钻测量 + 信号传递　；参考：《哈尔滨工业大学》2015年博士论文

【摘要】：在管道中普遍存在着压力的连续波动,这种波动有时是有利的,有时是有害的。在无线随钻测量(Measurement While Drilling,MWD)过程中,利用钻柱内的钻井液压力波动将井下的测量信息传递到地面,能够提高钻井作业精度,降低作业成本。但是在传递数据的过程中,存在信号时有时无的问题,因此需要找出信号在钻井液中传输的规律,确保数据的稳定可靠传输;在悬挂器试压过程中,由于测试管道中压力急剧上升并且伴随剧烈波动,导致对悬挂器动作压力的测量误差很大,面临着如何抑制管道内压力波动,提高测量精度的问题。无论对压力波动的利用还是抑制,都需要对波动的传递规律和特性进行深入研究,探寻问题的本质和影响因素。本文从脉冲波动理论出发,建立了管道中连续压力波动的矩阵传递模型,利用传递函数对管道中连续波动规律进行了深入研究。该模型不但可以解释钻柱内连续波动的传递情况,解决MWD载波频率的选择问题,还可以用于分析试压管道中连续波动的传递情况,设计滤波管道结构,为解决悬挂器试压过程中压力测量精度差的问题提供理论基础。本文主要研究了以下几个方面内容:首先,针对传统波动理论无法准确有效分析管道中连续波动衰减的问题,通过研究连续压力波动的传递现象,建立了基于双向传递系数的连续波动传递模型,能够准确描述波动传递与管道的尺寸、阻力和流体特性之间的关系。传递系数的实部代表管道对波动幅值的衰减,虚部代表管道对波动相位的影响,对于大倾角管道来说,两个传递系数的实部是不同的,说明沿着重力方向的波动传递情况与逆着重力方向的波动传递情况是不一样的,体现了重力对波动传递的影响。由于长管道对于连续波动传递来说,与输电线路中电压和电流的波动有相似性,从而可以定义管道的阻抗和特征阻抗表达式,利用输电线路的分析方法分析管道中的连续压力波动。其次,针对MWD过程中,载波频率选择困难的问题,通过研究管道两端的压力与流量的波动情况,建立了用于描述管道波动传递的传递矩阵模型和传递函数。通过对模型的分析,得到了压力波动在管道中的分布情况,即在连续波动情况下,管道中的压力波动呈现驻波状态。通过对传递函数的分析,得到了管道的幅值频率特性,该特性表明管道对不同频率波动的衰减是不一样的,整个传递趋势呈现波动衰减,低频衰减小而高频衰减大,管道对于高频波动来说,相当于低通滤波器,从而解释了在无线随钻测量过程中井下信号时强时弱的原因。基于上述研究结果,提出了用于钻井液MWD的载波频率的动态选择方法,并通过管道的幅值频率实验,验证了管道对不同频率波动传递的影响。再次,针对传统波动理论无法有效分析各种结构管道中波动传递的问题,基于管道中连续波动传递模型,改进了结构管道中波动传递的矩阵分析模型,用于分析各种地面结构管道对连续波动传递的影响。由于地面管道大部分是水平状态或倾角很小,可以将连续波动传递模型简化后得到适用于地面水平管道的波动传递模型,对于复杂结构的管道,可以通过影响函数来体现分支管道和容器对主管道的影响,得到连续波动在管道结构中传递的计算方法。基于该模型设计了带容器的管道结构,并进行了幅值频率实验,实验结果表明不同频率波动在结构管道中的传递情况与模型计算结果是一致的。最后,针对悬挂器试压过程中压力波动剧烈的问题,通过研究封闭分支管道和容器对波动信号的影响,得出了可以利用结构管道对波动进行抑制的结论。利用该波动抑制特性,设计了用于悬挂器试压过程中抑制泵压波动的管道结构,进行了试压实验,实验结果表明了结论的正确性,解决了试压过程中由于压力波动大,导致测试误差大的问题。
[Abstract]:The continuous fluctuation of pressure is common in the pipeline, which is sometimes beneficial and sometimes harmful. In the process of Measurement While Drilling (MWD), the drilling fluid pressure fluctuation in the drill string transfers the underground measurement information to the ground, which can improve the drilling accuracy and reduce the operating cost. In the process of transferring data, there are sometimes no problems in the presence of signals. Therefore, it is necessary to find out the law of signal transmission in the drilling fluid and ensure the stable and reliable transmission of the data. In the suspension test pressure process, the measurement error of the suspension action pressure is very large because of the sharp rise in the pressure in the test pipe and the severe fluctuation in the test pipe. The problem of how to restrain the pressure fluctuation in the pipeline and improve the measurement accuracy is to be studied in detail, regardless of the use or suppression of the pressure fluctuation. In this paper, the matrix transfer mode of the continuous pressure fluctuation in the pipeline is built on the basis of the pulse wave theory. This model can not only explain the continuous wave propagation in the drill string, but also solve the selection of the carrier frequency of the MWD. It can also be used to analyze the transmission of the continuous wave in the pressure test pipeline and design the structure of the filter pipe to solve the suspension test. This paper provides a theoretical basis for the poor precision of pressure measurement. This paper mainly studies the following aspects: firstly, the continuous wave attenuation in the pipeline can not be accurately and effectively analyzed by the traditional wave theory. Through the study of the transmission phenomenon of continuous pressure fluctuation, a continuous wave transfer model based on the two-way transfer coefficient is established. The real part of the transfer coefficient represents the attenuation of the amplitude of the wave, and the virtual part represents the effect of the pipe on the wave phase. For a large dip pipe, the real part of the two transfer coefficients is different, indicating the wave propagation in the direction of gravity. It is different from the wave transfer in the direction of gravity, which reflects the influence of gravity on the wave propagation. Because the long pipeline is similar to the fluctuation of the voltage and current in the transmission line for the continuous wave transfer, the impedance and characteristic impedance expressions of the pipeline can be defined, and the analysis method of the transmission line is used to analyze the tube. The continuous pressure fluctuation in the channel. Secondly, in view of the difficulty of carrier frequency selection in the MWD process, through the study of the pressure and flow fluctuation at both ends of the pipeline, the transfer matrix model and transfer function used to describe the transmission of the pipeline wave are established, and the distribution of pressure fluctuation in the pipeline is obtained by analyzing the model. Under continuous fluctuation, the pressure fluctuation in the pipeline presents a standing wave state. Through the analysis of the transfer function, the amplitude frequency characteristics of the pipeline are obtained. This characteristic shows that the attenuation of the pipeline is different from the frequency fluctuation, the whole transmission trend is fluctuant, low frequency attenuation is small, high frequency attenuation is large, and the pipeline is high frequency fluctuation. It is equivalent to low pass filter, which explains the reason that the downhole signal is strong and weak in the process of wdri measurement. Based on the above results, a dynamic selection method for carrier frequency of drilling fluid MWD is proposed, and the effect of the pipeline on the transmission of different frequency waves is verified by the amplitude frequency experiment of the pipeline. The traditional wave theory can not effectively analyze the problem of wave transfer in various structural pipes. Based on the continuous wave transfer model in the pipeline, the matrix analysis model of the wave transfer in the structure pipeline is improved, which is used to analyze the influence of various ground structure pipes on the continuous wave transfer. Because most of the ground pipes are horizontal or dip angles. It is very small that the continuous wave transfer model can be simplified to get the wave transfer model suitable for the horizontal pipeline. For the pipeline of complex structure, the influence of the branch pipe and the vessel to the main pipe can be reflected by the influence function, and the calculation method of the continuous wave propagation in the pipe structure is obtained. Based on this model, the container is designed. The pipeline structure and the amplitude frequency experiment are carried out. The experimental results show that the transmission of different frequency fluctuations in the structure pipeline is consistent with the model calculation results. Finally, the influence of the closed branch pipe and the vessel on the wave signal is studied, and the effect of the pressure fluctuation in the suspension test pressure is studied. Using the structure pipe to restrain the fluctuation, using the fluctuation suppression characteristic, the pipe structure which is used to restrain the pressure fluctuation of the pump pressure in the suspension test pressure is designed. The test pressure test is carried out. The experimental results show the correctness of the conclusion and solve the problem that the pressure fluctuation is big and the test error is big during the test pressure.

【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TE271

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