关键词: 头台油田, 孔隙结构, 矿物组成, 润湿性, 储层敏感性, 渗吸采油

Abstract:

The further understand of the reservoir characteristics of the peripheral low permeability blocks in Daqing oilfield provides the theoretical basis for the adjustment of the development measures. Taking the block Mao-503 in Toutai oilfield as an example, and by using the equipment of the mercury injection apparatus, the X-ray energy dispersion spectrometer, the scanning electron microscope and the displacement equipment, we provide the stimulation suggestions of the improving recovery ratio by the imbibition oil recovery, according to the imbibition test and field experiment effects and based on the characters of the pore structure, mineral composition, wettability and reservoir sensitivity. The reservoir physical properties test of the block Mao-503 in Toutai oilfield shows that the main clay minerals of the reservoir rock are the illite, montmorillonite and kaolinite, the main component elements are oxygen（O）, silicon（Si） and aluminium（Al）, and the minor elements are ferrum（Fe）, magnesium（Mg）, natrium（Na）, barium（Ba） and carbon（C）. The target reservoir with the porosity between 10 % and 17 % and the permeability range of （0.40~8.2）×10 ^-3μm ² belongs to the medium porosity and ultra-low permeability sandstone reservoir. The pore throat size of the rocks is relatively small, and the sorting and connectivity are poor. Furthermore, the rocks show weak hydrophilicity, and the capillary force can be used as power in the process of the production. Meanwhile, the rocks have strong velocity sensitivity, water sensitivity and alkaline sensitivity. The indoor experiment and mineral field experiment show that the similar physical block is suitable for the imbibition oil recovery, and adding the surfactant into the water solution is good for improving the imbibition recovery and enhancing the development effects.

Key words: Toutai oilfield, pore structure, mineral composition, wettability, reservoir sensitivity, imbibition oil recovery