松辽盆地白垩系营城组火山机构储层定量分析

根据火山岩形态和内部结构,将松辽盆地白垩系营城组火山机构划分为火山口—近火山口相带、近源相带和远源相带。基于304个钻井岩样的孔隙度、渗透率和压汞法毛细管压力曲线资料,对火山机构3个相带的储层特征分析结果表明,火山口—近火山口相带的储层具有大孔隙、宽长裂缝、孔喉半径大、孔喉分选好的特征,实测孔隙度为2%～25%,平均为7.74%,实测渗透率为(0.01～100)×10^-3μm²,平均为1.99×10^-3μm²,属于中孔高渗储层,局部为高孔高渗储层。近源相带的储层具有中等孔隙、窄小裂缝、孔喉半径较大、孔喉分选较好的特征,实测孔隙度为1%～15%,平均为7.47%,实测渗透率为(0.01～20)×10^-3μm²,平均为0.95×10^-3μm²,属于中孔中渗储层,局部为中孔高渗储层。远源相带的储层具有中小孔隙、宽长裂缝、孔喉半径小、孔喉分选差的特征,实测孔隙度为1%～10%,平均为6.95%,实测渗透率为(0.02～1)×10^-3μm²,平均为0.13×10^-3μm²,属于中低孔低渗储层。目前火山岩勘探的有利目标为火山口—近火山口相带。

Quantitative analysis on reservoirs in volcanic edifice of Early Cretaceous Yingcheng Formation in Songliao Basin

According to occurrence, lithological association of volcanic rocks and volcanic facies composition in the Early Cretaceous Yingcheng Formation of Songliao Basin, the volcanic edifice was classified into three kinds of cracter-near cracter facies belt, proximal facies belt and distal facies belt. The reservoirs characteristics in each facies belt of volcanic edifice were analyzed using the parameters of porosity, permeability and mercury-injection capillary pressure curve from 304 drilling samples. The reservoir in the crater-near crater facies belt is characterized by big pore, wide and long fracture, big pore-throat radius and pore-throat well-sorted. The measured porosity ranges from 2% to 25%, and the average value is 7.74%. The range of permeability is from 0.01×10^-3μm² to 100×10^-3μm², and the average value is 1.99×10^-3μm². In the crater-near crater facies belts, most reservoir is charaterized by middle porosity and high permeability, the local parts are the reservoir with high porosity and high permeability. The reservoir in the proximity facies belt is of the properties of middle pore, narrow and small crack, middle pore-throat radius and pore-throat slightly well-sorted. The range of porosity is from 1% to 15%, and the average value is 7.47 %. The range of permeability is from 0.01×10^-3μm² to 20×10^-3μm², and the average value is 0.95×10^-3μm². The proximal facies belt mostly is the reservoir with middle porosity and permeability. Some part of the belt is the reservoir with middle porosity and high permeability. The distal facies belt is the reservoir with middle-small pore, wide and long crack, small pore-throat radius and pore-throat bad-sorted. The range of porosity is from 1% to 10%, and the average value is 6.95%. The range of permeability is from 0.02×10^-3μm² to 1.0×10^-3μm², and the average value is 0.13×10^-3μm². The distal facies belt is the reservoir with middle-small porosity and low permeability. The crater-near crater facies belt is the preferable target for volcanic reservoir exploration.