石油学报 ›› 2020, Vol. 41 ›› Issue (8): 960-968.DOI: 10.7623/syxb202008005

• 地质勘探 • 上一篇    下一篇

低电阻率地层基于凹陷电极对的油基泥浆电成像测井四参数计算方法

高建申, 宋阳, 刘彦萍, 朱凯然, 刘昕   

  1. 西安石油大学电子工程学院 陕西西安 710065
  • 收稿日期:2019-09-02 修回日期:2020-03-03 出版日期:2020-08-25 发布日期:2020-09-01
  • 通讯作者: 高建申,男,1987年生,2010年获中国石油大学(华东)学士学位,2017年获中国石油大学(华东)博士学位,现为西安石油大学讲师,主要从事电法测井方法与应用研究工作。Email:gjs1109@126.com
  • 作者简介:高建申,男,1987年生,2010年获中国石油大学(华东)学士学位,2017年获中国石油大学(华东)博士学位,现为西安石油大学讲师,主要从事电法测井方法与应用研究工作。Email:gjs1109@126.com
  • 基金资助:

    国家自然科学基金项目(No.41804115)、陕西省自然科学基金研究计划项目(2018JQ4008)和陕西省教育厅科研计划项目(19JK0665)资助。

A four-parameter calculation method of oil-based mud electric imaging logging based on concave electrode pairs in low-resistivity formation

Gao Jianshen, Song Yang, Liu Yanping, Zhu Kairan, Liu Xin   

  1. School of Electronic Engineering, Xi'an Shiyou University, Shaanxi Xi'an 710065, China
  • Received:2019-09-02 Revised:2020-03-03 Online:2020-08-25 Published:2020-09-01

摘要:

油基泥浆电成像测井是当前测井领域的研究热点之一。针对电成像测井在油基泥浆环境中存在的问题,提出了在低电阻率地层中基于凹陷电极对的油基泥浆电成像测井四参数计算方法,4个参数包括地层电阻率、泥饼厚度、油基泥浆电阻率和油基泥浆介电常数。基于凹陷电极对的极板结构、工作原理及四参数的计算方法分析了4个参数的影响因素,绘制了油基泥浆电阻率和相对介电常数的校正图版,并利用随机数据和层状地层模型验证了计算方法的准确性。结果表明,泥饼厚度是油基泥浆电成像测井四参数计算中的关键参数。参数的计算步骤为:首先计算出泥饼厚度,进而确定电极系数、计算地层电阻率;然后,根据电流频率、地层电阻率、泥饼厚度等参数对油基泥浆电阻率及其相对介电常数的数值计算结果进行校正。在低电阻率地层条件下,基于凹陷电极对的测量和计算能够准确地反映油基泥浆电阻率、油基泥浆相对介电常数、地层电阻率和泥饼厚度的变化,为油基泥浆电成像测井仪器设计和数据处理提供有利支持。

关键词: 油基泥浆, 电成像测井, 凹陷电极对, 低电阻率地层, 泥饼厚度

Abstract:

Oil-based mud (OBM) electric imaging logging is one of the research hotspots in the field of logging. Aiming at the problems of electric imaging logging in the OBM environment, this paper proposes a four-parameter calculation method of OBM electric imaging logging based on concave electrode pairs in low-resistivity formation. The four parameters include formation resistivity, mud cake thickness, OBM resistivity and OBM permittivity. Based on the electrode structure, working principle and the four-parameter calculation method of the concave electrode pairs, this paper analyzes the influencing factors of above four parameters, draws a correction chart for OBM resistivity and OBM relative permittivity, and verifies the accuracy of the calculation method using random data and a layered formation model. The results show that mud cake thickness is a key parameter to calculate the four parameters of OBM electric imaging logging. The calculation steps are as follows:(1) mud cake thickness is first calculated, and then the electrode coefficient and formation resistivity is determined and calculated, respectively; (2) according to the current frequency, formation resistivity, mud cake thickness and other parameters, the numerical calculation results of OBM resistivity and OBM relative permittivity are corrected. Under low-resistivity formation conditions, measurements and calculations based on concave electrode pairs can accurately reflect changes in OBM resistivity, OBM relative permittivity, formation resistivity, and mud cake thickness, providing favorable support for the instrument design and data processing of OBM electric imaging logging.

Key words: oil-based mud, electric imaging logging, concave electrode pair, low-resistivity formation, mud cake thickness

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