渤海A油田馆陶组低阻油层成因机理研究及流体性质识别新方法

Genesis Mechanism of Low Resistance Oil Formation and New Method of Fluid Property Identification in the Guantao Formation,Bohai A Oilfield

低阻油层作为一种非常规、隐蔽性强的特殊油层,勘探潜力巨大。研究区低阻油层的形成受多重因素的影响,测井响应特征在油水层的对比度较低,造成测井解释困难。为此,首先从宏观和微观两个方面深入分析低阻油层的成因机理;其次,将测井、气测录井以及生产开发资料相结合,针对研究区气测烃组分数据的特点,改进了含油气丰度计算方法用以定量识别低阻油层。结果表明:弱水动力环境和压实作用是低阻油层的宏观成因,孔隙结构复杂导致的高束缚水饱和度是普遍微观成因,天然淡水水淹成藏模式导致的油水层矿化度差异是主控成因。改进的含油气丰度能够有效定量的识别研究区低阻油层,解释符合率达到84.7%,可以为渤海A油田低阻油层的挖潜工作提供定量依据。

As an unconventional,hidden and special oil formation,the low-resistance oil layer has great exploration potential.The formation of low-resistance oil formation in the study area is influenced by multiple factors,and the contrast of logging response characteristics in the oil-water layer becomes low,which makes logging interpretation difficult.Firstly,the formation mechanism of low-resistance oil formations was analyzed from both macroscopic and microscopic aspects.Secondly,by combining logging,gas logging hydrocarbon components and production and development data,and considering the characteristics of gas logging data in the study area,an improved method for calculating oil and hydrocarbon abundance was proposed to quantitatively identify low-resistance oil formations.The results show that the weak hydrodynamic environment and compaction are the macroscopic causes of the low-resistance reservoir,the high saturation of bound water due to the complex pore structure is one of the microscopic causes,and the difference of formation water mineralization due to the natural freshwater flooding formation mode is another microscopic cause.The improved hydrocarbon-bearing abundance can effectively and quantitatively identify the low resistance oil reservoirs in the study area,and can provide a quantitative basis for the tapping of low resistance oil reservoirs in the Bohai A oil field.