页岩气的测井响应特征 翻译

2 页岩气的测井响应特征

2.1 页岩气的常规测井响应

页岩气的常规测井响应主要包括页岩储层的自然伽马、井径、声波时差、中子孔隙度、地层密度、岩性密度和深浅电阻率等。吴庆红等（2011）研究认为斯伦贝谢公司于2004年开展了页岩气测井解释，建立了页岩气测井系列，包括自然伽马、补偿中子、补偿密度、电阻率、声波扫描、电阻率成像(FMI)、伽马能谱(HNGS)和元素俘获能谱测井(ECS)等，其中声波扫描、电阻率成像、元素俘获能谱测井是页岩测井的关键技术[10]。潘仁芳（2009）研究总结了对页岩气储层有效的测井曲线及对应的响应关系[11]，见表3。

表3 页岩气测井曲线响应特征（文献[11]）

Tab.3 Response characteristics of shale gas well logging (data [11])

2.2 页岩气的常规测井系列

裸眼井测井常用三大测井系列、十一条测井曲线，可解决储层的岩性划分、物性评价和含油气性评价等。由于页岩气测井的特殊性，需要对常规测井系列进行方法组合优选。

笔者认为，页岩气测井的主要内容应包括：岩性定性识别和定量评价、含气层的划分与评价、储集空间和渗流空间物性评价。开展页岩气测井的关键问题是，那里是页岩层、源岩有机质含量如何、页岩含气性如何、裂缝等储渗空间发育程度怎样。页岩气测井评价中，岩性定性识别和定量评价的常规测井方法主要包括自然电位测井、自然伽马测井和井径测井；含气层划分与评价的主要测井方法包括深浅侧向或深中感应电阻率测井、声波时差测井、密度测井和中子测井；储集空间和渗流空间物性评价的主要测井方法是声波时差测井、密度测井和中子测井。

值得指出，页岩气常规测井系列从方法上似乎涵盖了现代测井全部方法，但页岩气测井方法组合和资料解释的侧重点却与石油测井有所不同。这与页岩气本身的特殊性密切相关。

测井新技术中的核磁双Tw测井，进行差谱分析后,可根据差谱识别油、气、水层,对双TE测井进行移谱分析,可以判断气层。时间推移测井,下套管后最佳时间测量的中子与固井后24h内测量的中子曲线重叠,利用其差值可以评价气层[2]。

2 Logging Response Characteristics of Shale Gas

2.1 Conventional Logging Response of Shale Gas

Conventional logging responses of shale gas mainly include natural gamma ray, well diameter, acoustic time, neutron porosity, formation density, lithology density and depth resistivity of shale reservoir. On the basis of the research in 2011, Wu Qinghong, etc think that Schlumberger Company has carried out the logging data interpretation of shale gas and has established logging suite of shale gas in 2004. This logging suite includes natural gamma ray, compensation neutrons, compensation density, resistivity, sound waves scanning, resistivity imaging (FMI), gamma ray spectrum (HNGS) and element captured spectrometry logging (ECS) and so on. And among these, the key technologies of shale logging are sound waves scanning, resistivity imaging and element captured spectrometry logging [10]. In 2009, Pan Renfang has summarized the logging curves that are effective to shale gas reservoir and their corresponding relationships as shown in Table 3.

2.2 Conventional Logging Suite of Scale Gas

Openhole logging usually uses three logging suites including eleven logging curves to solve the problem of lithology division, physical parameters evaluation and oiliness evaluation of the reservoir. Because of the particularity of shale gas logging, conventional log series need to be choosed and combined renewedly.

In the author’s opinion, the main content of shale gas logging should include the qualitative identification and quantitative evaluation of the lithology, the classification and evaluation of the aerationzone and the physical parameters evaluation of the reservoir space and seepage space. The important problems of scale gas logging are the situation of shale strata, organic matter content of source rock, gas content of shale and permeability space abundance of reservoir. In shale gas logging evaluation, the conventional logging methods of the qualitative identification and quantitative evaluation of the lithology mainly include natural potential logging, natural gamma ray logging and well diameter logging; the conventional logging methods of the classification and evaluation of aeration zone are mainly include depth lateral logging or depth-mid induction resistivity logging, acoustic time logging, density logging and neutron log; the conventional logging methods of physical parameters evaluation of reservoir space and seepage space mainly