【摘要】 大庆外围已发现的 2 0个低渗透或分散小油田 ,储层品质差 ,在开发中易受伤害 ,伤害后难恢复。以储量相对较大的两个典型大庆外围油田为例 ,实验测定了油层岩心的岩相学特征和敏感性程度。龙西油田高台子油层岩性以含泥粉砂岩为主 ,泥质含量 7.2 %～ 38.7% ;粘土矿物组成复杂 ,以伊利石为主 (6 5 %～ 85 % ) ;最大孔隙半径 4.74μm2 ,中值半径 0 .0 0 4～ 0 .2 95 μm2 ,孔隙和喉道半径相差悬殊 ;渗透率特低 ,地层水测渗透率为 0 .0 13× 10 -3 ～ 13×10 -3 μm2 ;敏感性程度和相应敏感指数如下 :弱速敏 ,Iv=0 .0 4～ 0 .35 ;中等偏弱到强水敏 ,Iw=0 .31～ 0 .78;中等盐敏 ,Is=0 .39～ 0 .6 0 ,临界矿化度 2 2 5 0mg/L ;中等酸敏 ,Ia=0 .41～ 0 .47。葡萄花油田葡萄花油层岩性为细粒、粉粒砂岩 ,泥质含量 10 %～ 15 % ;不同深度上粘土含量不同 ,组成复杂 ,可能发生地层微粒运移 ;最大孔隙半径 13.7μm ,中值半径 1.9～ 5 .2 μm ,有厚约 8m的疏松岩层 ;地层水测渗透率 2 1× 10 -3 ～ 2 93× 10 -3 μm2 ;敏感性程度和相应敏感指数如下 :弱速敏 ,Iv=0 .0 6～ 0 .2 7;中等偏弱到中等偏强水敏 ,Iw=0 .31～ 0 .78;弱到中等盐敏 ,Is=9.5 9～5 7.0 6 ,临界矿化度 6 0 71mg/L ;中等酸敏 ,Ia=0 .31～ 0 .39。两更多还原

【Abstract】 On the peripheral regions of Daqing there are 20 low permeable or discrete low grade oil fields now. These reservoirs are easily damageable and the damages once created are difficult to be removed. The petrographical characteristics and sensitivities of reservoir cores are determined experimentally for two peripheral oil fields of relatively higher reserves as typial examples. Reservoir formations Gaotaizi of Longxi oil fields are mainly shaly siltstone with shale content 7.2-38.7%; clay minerals are complex in composition with illite being main constituent(65-85%); the maximal pore radium 4.74 μm and the median pore radii 0.004- 0.295 μm display large differences in sizes of pore and throat; reservoir permeability is extra-low, accounting 0.013×10 -3-13×10 -3 μm 2 to the formation water; the degrees and indexes of sensitivities are as follows: weak to flow rate and I v=0.04-0.35; medium(-) to strong to water and I w=0.31-0.78, medium to salts, I s=0.39-0.60, and critical TSD=2 250 mg/L; medium to acids and I a=0.41-0.47. Reservoir formations Putaohua of Putaohua oil fields are mainly siltstone with shale content 10-15%; clay content is different in different depth and its composition is complex which shows possibility of formation fine transfer; the maximal pore radium 13.7 μm, the median pore radii 1.9-5.2 μm and loose layer of ～8 m thickness encountered; permeability to the formation water 21×10 -3-293×10 -3 μm 2; the degrees and indexes of sensitivities are as follows: weak to flow rate and I v= 0.06-0.27; medium(-) to medium(+) to water and I w=0.31-0.78; weak to medium to salts, I s=9.59-57.06, and critical TSD=6 071 mg/L; medium to acids and I a=0.31-0.39. The two reservoirs are susceptible to the damages connected with water and acids sensitivities.更多还原