青海木里三露天天然气水合物储层测井识别与划分

三露天天然气水合物钻探结果揭示，水合物主要赋存于裂隙型和孔隙型储层中。基于钻探结果，在测井岩性识别的基础上，综合利用常规测井和超声波成像测井等资料，总结两类天然气水合物储层的测井响应特征，形成了基于测井资料的水合物储层识别方法，并对该区储层进行划分。结果表明：(1)裂隙型水合物储层比纯泥岩层段的裂隙发育；声波速度较高，范围为1.5~4.5 km/s ；电阻率最高可达90 Ω·m。孔隙型水合物储层比砂岩水层的声波速度高，范围为2.0~4.0 km/s；电阻率亦为高值，范围为90~180 Ω·m。(2)研究区14个钻孔共识别出裂隙型储层12层，孔 隙型储层15层，总厚度为217.2 m。钻遇水合物的厚层均能识别，但少量钻遇的薄层未能识别，原因可能为薄层水合物含量少，导致测井响应不明显。总体上，测井方法在三露天天然气水合 物储层识别方面应用效果良好。

Classification and Identification of Gas Hydrate Reservoirs from Well Log Data in Sanlutian,Muli Coalfield,Qinghai

In Sanlutian well field, the drilling results reveal that gas hydrate mainly occurs in the fractured and porous reservoirs. Based on the results of drilling and log lithology identification, by using conventional and ultrasonic imaging log data, this article summarizes the log response characteristics of the both kinds of reservoirs respectively, and establishes identification methods which use log data to divide gas hydrate reservoirs in this area. The results show that:(1)compared to shale section，the fracture is developed, and sonic velocity is relatively high(in the range of 1.5 to 4.5 km/s) and the resistivity is up to 90 Ω·m in fractured gas hydrate reservoirs; compared to the aqueous layer of sandstone, the acoustic velocity is of relatively high value in the range of 2.0-4.0 km/s, the resistivity is also of relatively high value in the range of 90-180 Ω·m in porous hydrate reservoirs. (2)12 layers of fractured reservoirs and 15 layers of porous reservoirs which have a total thickness of 217.2 m are identified in the 14 wells of the study area. All the thick drilling reservoirs can be identified except a small amount of thin ones，and the most possible reason is that log response is unobvious to less content of gas hydrate. Overall, the application effect of log methods is good at the identification of gas hydrate reservoirs in the Sanlutian well field.