摘要
盆地导热系数是研究盆地深部热结构的重要参数,通常通过获取深部岩心测试获得,但这种传统方法经常会受到经费、取样条件等限制,并且对于地热井来说,因受温度压力条件的影响,室内测试结果也不能代表岩石原位导热系数。本研究获取了松科2井三开3 289m至4 536m岩心实测导热系数和测井参数,分析了砂岩、泥岩、流纹岩导热系数与测井参数之间的关系,结果显示砂岩的测井参数孔隙度、波速与导热系数之间具有明显的相关性,泥岩和流纹岩的相关性并不高。在此基础上,本研究分析了松辽盆地温度、压力对导热系数的影响,认为温度效应造成松辽盆地松科2井三开导热系数与室内实测值偏小约30%;压力效应使盆地三开段导热系数相对室内测试值偏大约10%。本研究成果可以为我国盆地深部导热系数以及大地热流值的获取提供新的思路,尤其是对于一些具有测井数据但无法获取深部岩心的废弃井具有更大的意义。
Thermal conductivity is an important parameter to study the deep thermal structure of the sedimentary basin. The traditional way to obtain the thermal conductivity by measurement of deep core test is limited by funding, sampling conditions and some other factors. Meanwhile, due to the reason that geothermal wells are affected by temperature and pressure conditions, indoor test results cannot represent the in-situ thermal conductivity of the rocks. In this study, the measured thermal conductivity and logging parameters of cores from3 289 to 4 536 meters in the third spudding of well Songke 2 are obtained, and the relationship between thermal conductivity of sandstone, mudstone and rhyolite and logging parameters was analyzed. The results show that correlation between porosity, wave velocity and thermal conductivity of sandstone logging parameters is obvious,but the correlation for mudstone and rhyolite is not high. On such a basis, the authors analyzed the influence of temperature and pressure on the thermal conductivity of the Songliao Basin. It is concluded that the thermal conductivity of the third spudding of well Songke 2 in Songliao Basin is reduced by about 30% due to temperature effect, and the thermal conductivity is increased by about 10% due to pressure effect compared with the measured values in laboratory. The results of this study can provide a new idea for the acquisition of deep thermal conductivity and geothermal flow value of basins in China, especially for some abandoned wells with logging dates but can not obtain deep cores.