高温高压煤复电阻率各向异性实验研究

电阻率各向异性是影响煤储层电法勘探的重要因素，针对煤样复电阻率各向异性的参数评价，对焦作地区煤矿储层沿平行和垂直层理方向分别钻取了煤样，并在高温高压条件下测量得到了相应的复电阻率频谱。为了定量分析温度、压力对煤样复电阻率各向异性的影响，建立了煤样不同方向频散参数(界面极化频率、模值频散度、弛豫时间)与温度压力的对应关系，电阻率各向异性系数与温度、压力的对应关系。结果表明：平行层理方向频散参数均与温度、压力呈现良好的线性关系，垂直层理方向频散参数的线性关系不如平行层理方向好；任意方向煤样频散与温度、压力的响应关系都可以用弛豫时间来定量评价；随温度升高各向异性系数增大，随压力增大各向异性系数变化不明显。研究结果可为更精确地定量评价温度、压力对煤储层电各向异性的影响提供实验基础和理论参考。

Complex resistivity anisotropy of coal sample under high temperature and high pressure

[Abstract] The resistivity is an important factor affecting the electrical exploration of coal reservoirs, but the influence law of temperature and pressure on the complex resistivity anisotropy of coal samples is not clear. In this paper, coal samples were drilled along parallel and vertical bedding directions resistivity spectrum was measure conditions. In order to quantitatively analyze the effects of temperature and pressure on pressure on the complex resistivity anisotropy of coal samples, the corresponding relations between the dispersion parameters(interface polarization frequency, modulus dispersion, relaxation time)in different directions and temperature and pressure, and the corresponding relations between the resistivity anisotropy coefficient and temperature and pressure are established. The result show that the dispersion parameters in the direction of parallel bedding have a good linear relationship with temperature and pressure, and the linear relationship of the dispersion parameter in the direction of vertical bedding is wore than that in the direction of parallel bedding. The response of dispersion to temperature and pressure and pressure in any direction can be quantitatively evaluated by relaxation time. The anisotropy coefficient increasers wit the increase of temperature, but the anisotropy coefficient does not change significantly with the increase of pressure The research result in this paper make up for the shortage of complex resistivity dispersion data in coal resistivity anisotropy experiment under high temperature and high pressure conditions, and provide experimental basis and theoretical reference for more accurate quantitative evaluation of the influence of temperature and pressure on the electrical anisotropy of coal reservoir.