松辽盆地北部深层火成岩储层自然电位形成机理

Mechanism of Forming Spontaneous Potential in Deep Igneous Rock Reservoir of Northern Songliao Basin

松辽盆地北部深层火成岩剖面的自然电位显示与砂泥岩剖面差别较大，测井资料无法按常规方法解释。利用自行研制的岩心自然电位室内测量装置，对松辽盆地北部深层火成岩储层的岩心进行系统的实验研究。结果表明，松辽盆地北部深层火成岩储层的自然电位主要是扩散吸附电位；其扩散吸附电位系数在2～39mV之间变化较大；火成岩的自然电位受岩性影响较大。搞清了该区火成岩储层自然电位形成机理，有助于火成岩储层自然电位测井解释方法研究。

In northern Songliao basin, the spontaneous potential in deep igneous profile differs greatly from that in more familiar sand-shale rock profile. Therefore, it is difficult to interpret the SP with conventional method. Proprietary lab equipment for core SP measurement is used on cores from deep igneous rock reservoir of northern Songliao basin. The result shows that the SP in deep igneous rock reservoir of northern Songliao basin is mainly the diffusion-absorption potential. The coefficient of diffusion-absorption potential has large dynamic range （2-39 mV）. I.ithology greatly affects the SP in igneous rock. Understanding the SP creation-mechanism helps the research on SP interpretation in igneous rock reservoir.