松辽盆地长岭断陷层碎屑岩储层微观特征研究

在对长岭断陷层碎屑岩储层宏观沉积特征研究的基础上,通过岩心观察,结合测井资料、岩石薄片、铸体薄片、扫描电镜、物性、孔隙结构等分析化验资料研究表明:断陷层碎屑岩储层的岩石学类型主要为长石岩屑砂岩、长石砂岩、岩屑长石砂岩;储集空间类型主要为裂缝—孔隙型;储层物性差,主要为低孔低渗和特低孔特低渗储层;储层具有排驱压力及饱和度中值压力较高、孔喉半径小、孔隙结构参数总体较差的特征;强烈的压实—压溶作用是形成低孔低渗的主要原因之一;成岩阶段划分认为东岭地区断陷层主要处于晚成岩期的A阶段,腰英台地区断陷层(主要指登娄库组、营城组)主要处于晚成岩期的B、C阶段。通过以上分析并结合碎屑岩储层评价标准认为:长岭断陷层碎屑岩储层主要为Ⅲ类或Ⅲ—Ⅳ类储层;有利区主要发育于东岭和双深1井等地区,其次为腰英台地区。 

Study on reservoir micro-characteristics of clastic rocks in Changling Faulted Depression of the Songliao Basin

Based on macro-sedimentary characteristics of clastic rocks and observed by cored samples, several analysis methods such as logging data, rock thin section, casting slice, scanning electron microscope, physical properties and pore structure are used to study the clastic reservoir in Changling Faulted Depression. The result showed that the petrologic types of reservoir in the Changling Faulted Depression mainly include feldspathic lithic sandstone, feldspar sandstone and debris feldspar sandstone. The reservoirs are mainly fractured-porous reservoirs. The physical properties of clastic rocks reservoir is low porosity and permeability or extra low porosity and permeability. The reservoir in this area is characterized by higher drainage capillary pressure and saturation medium pressure value, small pore throat radium and worse pore texture parameters. The stronger compaction-pressolution is the main reasons for the formation of low porosity and permeability. According to the diagenesis stage division, the faulted depression in Dongling area is regarded as A stage of late diagenesis. However, the faulted depression in Yaoyingtai area is grouped into B and C stage of late diagenesis. Combined with evaluation standard of clastic rocks, it was generally considered that the calstic rocks reservoir in Changling Faulted Depression is regarded as Ⅲ or Ⅲ-Ⅳ, and the favorable exploration area is mainly developed in Dongling and Shuangshen Well 1 area, then in Yaoyingtai area.