组合式γ测井探管研制OA

Total gamma logging is a commonly used geophysical method in uranium exploration,which can be used to determine the depth,thickness and grade of ore layers in boreholes,and collect detailed information on the variation of mineralization along the borehole direction.Due to its advantages of economy,speed and stability,total gamma logging has long been used as the standard logging method for estimating uranium resources.To meet the country's growing demand for uranium resources and to increase the speed of uranium exploration logging,an combined gamma logging instrument has been developed in this paper.This instrument builds an combined core detection unit with two groups of 38 mm diameter and 38 mm height cylindrical Cebr3 detectors,increasing the detection volume through the collaborative work of multiple detectors.It is equipped with a self-developed acquisition circuit and combined data fusion algorithm,achieving the goal of high-speed logging.Test results show that the uranium content sensitivity of the combined gamma logging instrument is 1231.79(0.01%eU·s)-1,with a stability of 2.3%,a dead time of 0.72 μs,and an indication error of 0.7%.Its performance meets the requirements of the Verification regulation for gamma ray logger:JJG(Military Industry)27-2012.Field logging application verification shows that the maximum logging speed of the combined gamma logging instrument in mineralized sections can reach 12 m·min-1,which is 6 times higher than the requirements of the gamma logging specification,not only shorten the logging time of a single borehole but also provide core technical equipment support for the construction of China's fourth-generation uranium exploration technology system.