| Based on geology of reservoir, adopting polarizing microscope and scanning electron microscope and so on optical instrument to observe; through the analysis of the depth, palaeogeothermal, degree of organic metamorphism and siallite of semideep reservoir in Gao Shang-pu area; link mercury intrusion experiment and image analysis of cast thin section, and found that the depth between 2000m and 2900m is in early diagenesis B, the depth below 2900m to 3500m is in late diagenesis A in Gaonan semideep strata, and there are two developmental zones of secondary pore. The semideep strata in Gaobei area is in late diagenesis A, and there exists one secondary pore developmental zone, formed by two phases of denudations. These secondary pores formed the main accumulative interspace of semideep reservoir. The throat shape is point and schistose. The types of combination between pore and throat are mainly mesopore leptothroat and fine pore-leptothroat. The poroperm characteristics have vicinity with pore throat diameter and throat mean. Based on these researches, analyze the affect of diagenesis to pore, and found that compaction is much more influencing than cementation on the loss, and the primary pore even vanished because of compaction. Denudation is the most important factor on the generation of secondary pore, and Feldspar is the object of corroding. Another nonresistance mineral-carbonate mineral, has little contribution on the forming of secondary pore. Finally, Based on the microscopic feature, analyze the sensitivity of minerals, found that the interstitial material in the throat have high water sensitivity, high rapid sensitivity, low acid sensitivity, low alkali sensitivity and multivariant salt sensitivity, and could use mud acid to acidify or use saline whose salinity is between 6527mg/L and 9000mg/L to inject the reservoir to exploit. In addition, To avoid the interstitial materials'sensitivity, propose to adopt fracturing technology to exploit.
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