巴彦油田超深储层孔隙结构特征及分类评价OA

The Xinghua block of Bayan Oilfield is characterized by deep burial,poor physical properties and strong heterogeneity.To clarify the pore structure characteristics of this ultra-deep reservoir and the distribution patterns of different types of reservoirs,the mi-croscopic pore structure characteristics of the reservoirs in the Xinghua 11 and 12 blocks of Bayan Oilfield was systematically analyzed by comprehensively utilizing various experimental testing methods such as X-ray diffraction,cast thin sections,nuclear magnetic reso-nance and high-pressure mercury injection.The analysis of the test results indicates that the lithological characteristics of the Xinghua 11 and 12 blocks are similar,but the microscopic pore structures exhibit significant differences.The porosity and permeability of the rock samples are1.1%～24.0%and(0.02～1 470)×10-3 μm2 respectively,and they present a certain linear relationship on the semi-logarithmic coordinate system.The predominant pore types are composite pores including intergranular pores,intergranular dissolu-tion pores and intragranular dissolution pores,and all pore throat radius less than 16 μm.The overall reservoir has a relatively strong storage capacity and good connectivity,and four types of pore throats,namely coarse,coarse-medium,medium-fine and fine-micro,are developed.Selecting the key parameters of lithology,physical properties and pore throat characteristics as evaluation indicators,the res-ervoirs are classified from good to poor into Class I,II,III and IV,and an evaluation standard is established,providing a basis for the de-termination of development technical policies such as production capacity evaluation,stratigraphic division and combination,and well pattern and well spacing optimization in Bayan Oilfield.