松辽盆地南部海力锦铀矿床镭氡平衡系数计算方法研究

Study on Calculation Method of Radium Radon Equilibrium Coefficient of Hailijin Uranium Deposit in Southern Songliao Basin

镭氡平衡系数是地浸砂岩型铀矿勘查中重要的物探参数之一,能否正确计算镭氡平衡系数将直接影响铀矿床资源量估算结果的准确性。目前在实际工作中,镭氡平衡系数主要由物探参数孔观测法和伽马测井解释结果与取样分析结果对比法确定,而物探参数孔观测法又可分为平均值法和曲线拟合法。对松辽盆地南部海力锦地区姚家组下段地层的铀矿镭氡平衡系数进行了计算和研究,并对计算结果进行了对比与评价。两种方法在砂岩型铀矿镭氡平衡系数计算中都非常重要,可以相互验证。经过分析,物探参数孔观测法比伽马测井解释结果与取样分析结果对比法计算的镭氡平衡系数可信度更高。对于物探参数孔观测法的两种计算方法,曲线拟合法更接近氡气的恢复情况,可以避免观测值误差或氡气未达到平衡等因素导致计算结果不准确,结果更为合理。

Radium radon equilibrium coefficient is an important parameter for in-situ leachable sandstone type uranium resources estimation.Whether the radium radon equilibrium coefficient be calculated correctly or not will directly affects the accuracy of the estimation results of uranium deposit resources.At present exploration practice,the radium radon equilibrium coefficient is mainly determined by the comparison between the interpretation result of gamma logging,drilling geophysical parameter measurement and sample assay.The drilling geophysical parameter method can be divided into initial observation data ratio method and curve fitting method.In this paper,the radium radon equilibrium coefficients of uranium ore in different horizons of Yaojia formation in Hailijin area were studied.The equilibrium coefficients were calculated by the two method and the result was evaluated.The two methods were found very important in the calculation of radium radon equilibrium coefficient of sandstone type uranium deposit and can be verified each other.After analyzing the geophysical parameters,the result of radium radon equilibrium coefficient calculated by drilling geophysical parameter method was closer than that calculated by gamma logging interpretation to the sample analysis.For the two calculation methods of drilling geophysical parameter measurement,the result of curve fitting method is closer to the recovery rate of radon,which can avoid the inaccurate calculation results caused by observation value error or radon not reaching balance,so the results are more reasonable.