摘要
关于第四纪埋藏沉积物成因类型的研究,常规的方法是利用钻井取芯资料进行综合分析和对比,所得结论往往是定性的。由于钻井取芯的费用十分昂贵,且第四纪松散沉积物的收获率一般比较低,所以这种方法的广泛应用受到了很大的限制。本文介绍了一种利用测井资料进行沉积相分析的思路和方法。由于地球物理测井具有快速、经济等特点,因此该方法在第四纪沉积的研究中具有较好的应用前景。另外,随着计算机的广泛使用,人工智能技术的迅速发展为测井相分析的定量化和自动化提供了实现的途径。
The identification of sedimentary facies for buried Quaternary strata remains to be a problem up to now. This paper illustrates the method of applying geophysical logging data tofacies analysis, making full use of the knowledge of both log-analysers and geologists. First, interpreted petrographic log details can be obtained by quantitatively assessing logging data. based upon which detailed facies study can be made through petrographic-log analysis combined with feature identification of logging curves. All the processes can be undertaken automatically by computer. Methodology 1. Petrographic-log Analysis The study of sedimentary facies by means of petrographic-log analysis is based on petrographic features and vertical variations which reflect the changes in hydrological conditions or provenances. So petrographic-log analysis can be used to reconstruct palaeo-environment. 1) Quantitative Identification of Petrograph Our research suggests that 'layer-by-layer hydrological identification' is an effective way to ensure petrographic division in detail without reducing coincidence rate. Different from traditional point-to-point definite identification method, the main ideas of our method are as follows: (1) Log curves sensitive to boundaries of strata are used first of all to divide the strata and, every curve is modified for each petrographic layer in order to eliminate the influence of environmental factors and obtain real logging value. In this way reliability of classification can be guaranteed; (2) Methods of pattern recognition are utilised, following a number of interpreting models to undertake detailed classification. Our results show that tree classifier can function satisfactorily. By means of this a complicated multiple differentiation problem can be transfered to several simpler classifications. The greatest advantage of this method is that sorting for each mid-way knot can be made by using the best assemblage of loggings most beneficial to the classification, while specific method can be used for
出处
《第四纪研究》
CAS
CSCD
1993年第3期240-249,共10页
Quaternary Sciences
