木里地区水合物及岩性测井识别方法  

Identification of hydrate and lithology based on well logs in Muli area

作　　者：覃瑞东 林振洲[1,2] 潘和平[1] 秦臻[1] 邓呈祥 纪扬[1] 徐伟[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,湖北武汉430074 [2]中国地质科学院地球物理地球化学勘查研究所,河北廊坊065000

出　　处：《物探与化探》2017年第6期1088-1098,共11页Geophysical and Geochemical Exploration

基　　金：国家127专项"天然气水合物资源勘查与试采工程"项目(GZHL20110324;GZH201400305);中国地质调查局地质调查项目(DD20160224)

摘　　要：木里地区由于断层、裂隙发育,以及多种岩性都存在天然气水合物,地质背景复杂,导致各种岩性的测井响应特征复杂,给天然气水合物及岩性识别带来一定的难度。本文通过分析多口井水合物及岩性的测井响应特征,利用直方图和交会图研究各种岩性在含天然气水合物或有水合物异常与不含天然气水合物时的测井响应的差异,找出对水合物反映敏感的测井参数,对该地区的水合物及岩性进行识别。然后综合利用对天然气水合物响应明显的自然伽马(GR)、电阻率(RT)、声波时差(AC)和补偿密度(DEN)等测井曲线,采用贝叶斯和BP神经网络两种方法识别岩性。识别结果与录井岩性吻合良好,准确识别出了含水合物地层的岩性,为木里地区寻找有利的天然气水合物储层提供了依据。The geological background in Mull area is very complex due to the well-developed faults, fractures and lithologic difference of gas hydrate-bearing formations,which makes it more difficult to identify the lithology with well logging data.Through the analysis of log- ging response characteristics, the differences between lithologic characters can be found so as to recognize the lithology that contains gas hydrate by utilizing histogram and cross-plot methods. According to natural gamma ray （ GR）, resistivity （ RT）, acoustic travel time AC）, and compensated density （ DEN）, which are sensitive to gas hydrate, the gas hydrate-bearing formation and lithology can he classified by using Bayesian discriminant and BP neural network.The identification results are consistent with the core data, the gas hydrate- bearing lithology is recognized accurately, which can provide some reference for the exploration of gas hydrate.

关 键 词：木里地区 天然气水合物 测井响应特征 岩性识别 

分 类 号：P631.4[天文地球—地质矿产勘探]