多矿物模型在复杂岩性地层中的应用

Application of Multi-mineral Analysis Model in Complex Lithology Formation

针对泥质重、含多种矿物组分的复杂岩性地层,适宜用多矿物分析进行处理解释。首先,对岩心资料进行分析,以交会图作为手段,选择合适的矿物和流体以及测井曲线来建立多矿物方程组。在一定的约束条件下,可求解地层中各组分的相对体积,计算孔隙度和含水饱和度等储层参数。应用多矿物模型,对南海西部油田的复杂岩性地层进行了处理,但初始的处理效果并不理想,怀疑在模型中缺少一种特殊矿物,它的密度大,钍含量高,钾含量低,且光电吸收截面较大。通过自然伽马能谱测井与交会图技术相结合;并参考薄片和重矿物分析资料,确定这种矿物是皓石,因此在多矿物模型中加入皓石,将处理结果与岩心资料中的岩石描述以及常规测井解释进行对比。结果显示,建立的多矿物解释模型能够有效地模拟真实地层,计算的储层参数与岩心资料吻合较好,其效果要优于传统测井解释模型,且比常规测井解释能提供更多的关于地层矿物和孔隙流体的信息。

In view of Complex Lithology Formation which contains many mineral composition and have a high shale content,the multi-minerals analysis is the most suitable for logging interpretation,in the first place.An analysis of core data,use the cross-plot as a means of research,and choosing the appropriate mineral,fluid and logging curves to build multi-minerals model is presented,Under certain conditions,the relative volume of the formation mineral composition,compute the reservoir parameter such as porosity,saturation and so on can be evaluated,Use the Multi-minerals Model to process Complex Lithology Formation in Western South China Sea oil field,but the initial treatment efficiency is not idealistic,so suspect there is a special mineral that is not included in the multi-mineral model,it have a high density,thorium content,photoelectric absorption cross section and have a low potassium content,combine spectral gamma-ray log with crossplot technique,refer to thin-section analysis and heavy mineral analysis.Finally the mineral is zircon,so add it into the multi-mineral model,compare the processing results with rock description and conventional logging interpretation.The results show that the multi-minerals model can simulate true formation effectively,the calculated reservoir parameters is found in good coincidence with core data.The processing result is better than conventional log interpretation model,and it can provide more information about mineral and pore fluid than conventional logging interpretation.