惠州凹陷古近系文昌组、恩平组录井解释方法研究

A DISCUSSION ON WELL LOGGING INTERPRETATION METHOD:A CASE FROM PALEOGENE WENGCHANG AND ENPING FORMATIONS IN THE HUIZHOU DEPRESSION

惠州凹陷古近系文昌组、恩平组暗色泥岩既为生油岩也为盖层,其气测组分齐全且含量高,异常幅度常明显高于相邻储层段,对油气水识别造成很大的困扰,常规解释方法适用性较差,无法准确区分储层流体性质。计算全烃-流体类型图版是在总结不同流体类型实时流体录井(Fluid Logging&Analysis In Real time,简称FLAIR)组分特征的基础上,结合取样、测试结论进行数理统计分析,建立起的区域性解释图版。考虑到该图版对油层与含油水层的区分具有一定的局限性,通过统计凹陷内7口探井93个样品的地化岩石热解气相色谱图,归纳总结出油层、含油水层及水干层岩石热解气相色谱图特征差异。两种不同载体录井资料解释方法相结合,能够准确的对储层流体性质做出评价,现场实际应用效果较好,录井综合解释符合率达到88.5%。

The Paleogene dark mudstone in the Wengchang and Enping Formations is not only a source rock,but also a cover layer for oil accumulation.It usually shows complete gas logging composition of higher content comparing to adjacent reservoirs,and always brings great trouble to the fluid evaluation.Conventional interpretation methods are not effective enough to distinguish the fluid properties.In this study,a regional interpretation chart for calculating total hydrocarbon-fluid types is built upon the characteristics of the FLAIR components for different fluid types,combined with sampling and testing data.There is certain limitation to distinguish oil from oil-bearing water.According to the gas chromatogram data for geochemical rock pyrolysis analysis for 93 samples from 7 wells in the depression,the characteristics are summarized in this paper for oil layers,oil-bearing water layers,water layers and dry layers respectively.To integrate the two logging interpretation methods based on different data carriers,reservoir fluid properties of the Paleogene can be accurately evaluated.The consistency of comprehensive logging interpretation method may reach 88.5%.