井间电磁探测与介质识别技术研究

发布时间：2018-07-16 13:08

【摘要】：目前国内的原油采收率偏低,约67%的原油以剩余油的形式埋藏于地层中,井间是剩余油存在的主要区域,研究油气田剩余油开采的探测理论和方法具有重要的意义。本文在国家自然基金的资助下,开展了井间电磁探测与介质识别的研究和探索。本文建立了基于线源的井间电磁探测方法,以一口井的套管作为发射线源,另一口井中放置接收仪器,以实现井间的电磁探测。利用了套管为良导体的特点对其施加发射电流,直接作为发射源,相比于井内磁偶极子发射的方式,线源发射的方式能够有效消除套管对电磁信号的衰减和屏蔽作用,从而实现远距离探测。针对线源和磁偶极子建立发射和接收模型,研究了井间电磁发射参数与接收信号之间的关系,分析了地层中发射频率、发射电流、线源长度以及接收点位置等参数变化对接收井中的磁场值的影响规律,提出了提高探测距离的措施和方法。研究了井间异常体介质的电阻率、异常体薄板的倾角和水平位置对于井间电场线分布的作用,分析了不同电阻率介质和异常体水平位置对分界面电场的影响规律,得出了异常体薄板随倾角角度增加,电场分布异常范围逐渐减小的结论。根据瞬变电磁原理与二次场响应信号的特性,考虑了影响波形的几种因素和噪声干扰以及抑制方法,选择合适的电子元器件,开发了相关的发射电路与探测电路,研制了全系统的电源电路。对研制的电路进行了调试,解决了电路调试中遇到的各种问题,并研究了线源接收与线圈接收的探测性能,测试了探测线圈所处位置对探测性能的影响,以及探测系统对电阻率异常体的区分能力。
[Abstract]:At present, the oil recovery in China is low, about 67% of the crude oil is buried in the form of remaining oil in the formation, and the cross-well is the main area where the remaining oil exists. It is of great significance to study the exploration theory and method of remaining oil production in oil and gas fields. In this paper, the research and exploration of cross-well electromagnetic detection and medium identification are carried out with the aid of the National Fund for Nature. In this paper, a method of cross-well electromagnetic detection based on line source is established. The casing of one well is used as the emission line source, and the receiving instrument is placed in the other well to realize the electromagnetic detection between wells. Taking advantage of the fact that the casing is a good conductor, the emission current is applied to the casing directly as the emission source. Compared with the mode of magnetic dipole emission in the well, the line source emitter can effectively eliminate the attenuation and shielding effect of the casing on the electromagnetic signal. Thus the remote detection is realized. Aiming at the transmission and receiving models of line source and magnetic dipole, the relationship between the electromagnetic emission parameters and the received signal is studied, and the emission frequency and emission current in the formation are analyzed. The influence of the parameters such as the length of the line source and the position of the receiving point on the magnetic field value in the receiving well is studied. The measures and methods to improve the detection distance are put forward. The resistivity of cross-well anomalous medium, the effect of dip angle and horizontal position of anomalous thin plate on the distribution of cross-well electric field line are studied, and the influence of different resistivity medium and horizontal position of abnormal body on the electric field of the interface is analyzed. It is concluded that the anomalous range of electric field distribution decreases gradually with the increase of inclination angle. According to the transient electromagnetic principle and the characteristics of the secondary field response signal, several factors affecting the waveform, the noise interference and the suppression method are considered, the appropriate electronic components are selected, and the relevant emission circuit and detection circuit are developed. The power supply circuit of the whole system is developed. The circuit is debugged, and the problems encountered in the circuit debugging are solved. The detection performance of wire source receiving and coil receiving is studied, and the influence of the position of the detection coil on the detection performance is tested. And the ability of detecting system to distinguish resistivity anomaly.
【学位授予单位】：西安石油大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE327

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