凝析气与轻质油的气测识别方法及应用

Identification Method for Condensate Gas and Light Oil by Gas Logging and Its Application

渤海油田P7构造中深层轻质油气流富集,原油密度小,气油比高,流体普遍处于气液共存的交错相态,加之部分井眼条件差,测井资料不完善,造成油、气判别难度大。对已钻井的气测资料进行统计分析发现,凝析气和轻质油在岩屑录井时均可见荧光显示,气测录井组分均齐全,特征极其相似,常用图版法很难区分。3H曲线呈现一定的规律性,但与传统模型的出入较大,对3H解释模型进行优化,制订解释标准。提出气体组分星型图版,该图版选取5个特征参数对流体相进行分析,不同的流体相特征差异十分明显。2种方法相结合,对P7构造凝析气与轻质油进行气测识别,分析储层内部流体相态分界面,应用效果很好。该研究促进了P7构造油气分布格局和储量的落实,在其他钻遇轻质油气流的区块具有较大的应用推广价值。

The light oil and gas is enriched in middle-deep layers in the structure P7 of the Bohai Oilfield, with smaller crude oil density and high gas/oil ratio. Moreover, fluids are generally at cross phase of gas phase and liq- uid phase, and the well logging data is not complele, leading to high difficulty in identifying oil and gas. According to statislics and analysis of the gas logging data of the drilled wells, there are fluorescent displays fur condensate gas and light oil in cutting logging, with relatively complete gas logging components and much similar features, thus they are hard to be distinguished by the common plate method. The 3H curve has certain regularity, but it has big- ger difference frum the conventional model. We optimized the 3H interpretation model and formulated the interpreta- tion standard. We proposed a star-shape plate of gas components. This plate uses five characteristic parameters to analyze fluid phases, and finds that various fluid phases have very different features. By combining two methods, we conducted gas logging identification of condensate gas anti light oil in the structure PT, analyzed fluid phase inter- ta.ces inside the reservoir, and obtained good application result. This study promoted the confirmation of hydrocarbon distribution framework and reserves of the structure P7 ~ and has bigger application value in other blocks with light oil and gas flows.