满加尔凹陷东部志留系致密砂岩储层特征  

Reservoir characteristics of Silurian tight sandstone in the eastern Manjiaer sag

作　　者：李玲玲[1] 

机构地区：[1]中国石油大庆油田有限责任公司勘探开发研究院,黑龙江大庆163712

出　　处：《油气地质与采收率》2016年第2期47-51,75,共6页Petroleum Geology and Recovery Efficiency

基　　金：国家科技重大专项"大型油气田及煤层气开发"(2011ZX05001-001-004)

摘　　要：满加尔凹陷东部志留系厚层的致密砂岩具有广阔的天然气勘探前景,但是目前对于致密砂岩储层特征的研究较少。利用薄片鉴定、电子探针、扫描电镜、X衍射、压汞及物性分析等方法,对致密砂岩储层特征进行了研究。与满加尔凹陷东部常规砂岩储层相比,致密砂岩储层具有以下特征:1储层埋深较大;2砂岩成分、结构成熟度较低,岩屑和填隙物含量较高;3物性较差,孔隙度为5%~10%,渗透率为0.1×10^(-3)~1×10^(-3)μm^2;4以原生粒间孔、粒间溶孔、微孔隙等混合孔隙为主,孔隙结构总体较差;5粘土矿物组合以网状伊蒙混层和绿泥石、伊利石为主;6成岩作用较强,处于中成岩B期—晚成岩期。致密砂岩的储集物性受沉积、成岩及构造等多种因素的影响。研究区砂岩离物源近,较低的成分成熟度和结构成熟度、泥质杂基充填等因素不利于原始孔隙大量保存;压实作用是孔隙度降低的主要因素;方解石胶结、石英次生加大降低了孔隙度;局部溶解作用和少量构造裂缝改善了物性。Thick tight sandstones in the Silurian period in the eastern Manjiaer sag have broad prospects for natural gas exploration,but there are few studies on reservoir characteristics of the tight sandstone at present. Based on comprehensive utilization of thin-section identification,EPMA,SEM,X-ray diffraction,mercury injection and physical property analysis,the reservoir characteristics of the tight sandstones were studied. Compared with conventional sandstone reservoirs in the eastern Manjiaer sag,the tight sandstone reservoirs have the following characteristics:(1)great burial depth;(2)low compositional maturity,low textural maturity,high content of debris and interstitial material;(3)poor physical properties(porosity is 5%-10%,permeability is 0.1×10^(-3)-1×10^(-3)μm^2);(4)reservoir space types mainly include primary intergranular pore,intergranular dissolution pore and micropore,and the pore structure is poor in general;(5)clay mineral composition are dominated by reticular illite smectite mixed layer,chlorite and illite;(6)severe diagenesis and the diagenetic stage is from B substage of middle diagenetic stage to late diagenetic stage. The physical property of the reservoirs is influenced by various factors such as deposition,diagenesis and structure. The factors such as near source deposition,low compositional maturity,low textural maturity and argillaceous matrix filling are not favorable for the preservation of the most of primary pores. The compaction is the main factor resulting in the loss of porosity,and calcite cement and quartz secondary enlargement lead to porosity reduction. Partial dissolution and a few structural fractures improve the reservoir physical property.

关 键 词：致密砂岩 储层特征 成岩作用 控制因素 满加尔凹陷 

分 类 号：TE112.23[石油与天然气工程—油气勘探]