Reservoir Sensitivity Research Of Some Basins

This paper is based on a great deal of on-the-spot data in some basins. Log coresfrom twenty wells are selected to perform clay mineral composition analysis, shapeand structure of slice core analysis, and sensitivity analysis.Through analyzing rock feature, pore structure feature and physical feature ofreservoir, it turns out that the oil and gas potential in most well intervals is badand only a few well intervals are good.Based on basic structure, connected with hydrous expansion, flocculate anddisintegration, the potential method by which clay mineral does damage toreservoir is analyzed theoretically. Through much clay mineral analysis, itschanging regularity is shown from shallow to deep vertically, i.e.: smectite-kaolinite combination (mainly smectite), kaolinite -smectite combination (mainlykaolinite), kaolinite - illite combination (mainly kaolinite), illite - kaolinitecombination (mainly illite ), illite-chlorite combination. So it is concluded that inthe shallow layer, clay mineral does damage to reservoir by means of expansion,in the middle layer by means of particulate transmit, in the deep layer by means ofparticulate transmit and acid sensitivity.The reservoir sensitivity test turns out that the velocity sensitivity of the basin isweak to medium, water sensitivity is strong in first sag and third sag and weak inthe second sag. Acid treatment indicates that several types of acid on the spot areunfit for acid stimulation in the basin and it is necessary to discover new acidtreatment method and prescription.The reservoir sensitivity test turns out that the whole basin is mainly watersensitivity and velocity sensitivity. So the research of reservoir sensitivity in this paper give some Solving Schemes as follows. Water sensitivity of the first sag is strong, especially hydrous expansion of clay mineral; velocity sensitivity of the second sag is strong, preventing particulate transmit; permeability of the third sag is bad, to do fracture treatment mainly.