测井剖面定量地层对比新技术

根据岩性地层对比原理,本文提出一个测井剖面定量地层对比模式。该模式由三部份组成:1.利用“多变量最优分段方法”将两对比测井剖面的地层进行分段处理;2.利用“爬山法”计算分属不同测井剖面的任意两段地层之间的相似性指标;3.根据相似性指标,利用“动态规划”方法确定地层对比结果。本文还利用上述模式进行了定量地层对比的实例研究,其结果比较令人满意。

A NEW TECHNIQUE OF QUANTITATIVE STRATIGRAPHIC CORRELATION OF WELL LOGS

According to the principle of lithostratigraphic correlation, this paper puts forward a practical pattern about quantitative stratigraphic correlation of well logs using the methods of classical statistical correlation and dynamic programming. The pattern consists of three parts as follows: 1. Segmenting each of two correlated well logs into a few stratigraphic units. As the basis of correlating, segmenting using Multivariate Optimal Zonation Method seems comparatively successful. 2. Calculating the similarity index between each stratigraphic unit in one well log and each in the other. In consideration of both the similarity of lithologic character and the change of thickness of the same Stratigraphic unit in lateral direction, the local optimal error of energy calculated by Hill Climbing Method is thought to reflect the degree of similarity between two stratigraphic units exactly. 3. Determing the result of stratigraphic correlation. A one-to-one correspondence between the stratigraphic correlation programmes and the Slotting Sequences of stratigraphic units is built on condition that one stratigraphic unit in one well log can at most be correlated with one in the other and the order of stratigraphic units in each well log is preserved in each programme, the optimal programme of stratigraphic correlation is determined by the optimal slotting sequence constructed on the basis of the similarity indexes. The result of an application of the pattern to the Upper Dainan Forma tion of northern Jiangsu is very inspiring.