| Unlike in permeability reservoirs due to fluid flow characteristics in the low and ultra low permeability reservoirs, the Ordos Basin as a whole basically belong to the low permeability, low permeable reservoir, making the research and understanding of the low permeability and low permeabilitythe microscopic flow of pore structure and fluid in the reservoir characteristics and the law is particularly important. This study, particle size analysis, pore image, cast thin section, the conventional pressure mercury, constant pressure of mercury, the oil-water relative permeability, methods and techniques of nuclear magnetic resonance and X-ray diffraction experiment, the study of the pore structure of the reservoir and the flow characteristics detailed study. And to explore the deposition and diagenesis of the pore structure of the study area, analyze the impact of different pore types and the occurrence of oil displacement efficiency and the residual oil.1、The Chang6reservoir has varying types of porosity types, pore combination types and throat types. Pore type intergranular pores, feldspar dissolution porosity, debris and dissolved pores, micro cracks; porosity combination of the main types of dissolved pore-intergranular pores, intergranular pores-microporous dissolved pore class, microporous class Lord; throat type to bend flakiness throat.2、The study area diagenesis and development:compaction, cementation, metasomatism and the dissolution of the classification and standards of the diagenetic stage of the study area the target layer reservoir in the early diagenetic stage late into the night early diagenetic stage. The strength of diagenesis, the composition of the interstitial material, the contact between the rock particles, pore type is an important factor to affect the pore structure of low permeability reservoirs. Diagenesis in the general case the influence of pore structure mainly constructive role and the devastating effects of two, in addition to the role of dissolved pore structure has a constructive role, mostly manifested as destructive role.3、Water displacing oil form mainly refers to the three types of shape, mesh and evenly shaped, which the network drive for the main, higher oil displacement efficiency of water flooding after the residual oil type is more widely distributed. The residual oil distribution of impact factors, is mainly affected by the influence of pore structure. Uniform type of drive for the residual oil film shape retention, and occasionally met with a solitary dot residual oil; flow around like residual oil remain in refers to the shape and mesh water flooding. The residual oil in the intergranular pores persist in film form, fewer residues; dissolved pores due to high clay mineral content, a greater impact on the efficiency of water flooding, the more residual.4、The different pore types can be retained on the water flooding process and the residual oil to produce a certain effect, in which particles Kong and feldspar dissolution porosity is a major oil storage space in the study area reservoirs, water flooding, major flooding when the channel. Different pore portfolio types can also be left a certain impact on the process of water displacing oil and residual oil. Which dissolved pore-intergranular holes and particles between the holes-oil displacement efficiency in porous relatively high residual oil content of less dissolved pore class, and microporous less oil displacement efficiency, and residual oil retained more, which is mainly given by the impact of different porosity and pore combination type properties.5、The size of the reservoir porosity and permeability of high and low and can not decide on the model of oil displacement efficiency, and joint decision but by the connectivity of reservoir properties and reservoir porosity reservoir model of oil displacement efficiency. |
PDF Full Text Request