PI Formation oil layers in West Block Yuan-13 of Daqing Toutai Oilfield are low permeability reservoirs,and at present they are in the high-watercut development stage.In order to further enlarge the swept volume in the middle and low permeability layers by means of deep fluid diverting stimulation,taking the target reservoirs and fluids as the stimulated objects and the resistance coefficient,residual resistance coefficient and recovery as the evaluated indexes,the screening and oil incremental experimental effects of the deep fluid diverting agent were researched.The achievements show that the relative molecular mass of the corresponding polymer with the target reservoir should be less than 800× 104,the mass concentration of the polymer should be less than 900 mg/L,the mass concentration ρ (polymer):ρ (Cr3+) of the cross-linker ranges from (180-270 ）:1;under the same conditions of the relative molecular mass and concentration,comparing with the polymer solution,not only the resistance coefficient and residual resistance coefficient of Cr3+ polymer gel are larger,but also the residual resistance coefficient is greater than the resistance coefficient,and the gel shows wonderful fluid diverting and oil incremental effects;with the increase of the polymer gel slug size,the profile controlling and flooding recovery increase,but the growth decreases gradually,the suitable slug size is 0.1-0.15 PV.%大庆头台油田源13西块PI组油层为低渗油藏,目前已经处于高含水开发期.为进一步通过深部液流转向措施扩大中低渗透层波及体积,以目标油藏储层和流体为模拟对象,以阻力系数、残余阻力系数和采收率为评价指标,开展了深部液流转向剂筛选及其增油效果评价实验研究.结果表明:与目标油藏储层相适应的聚合物相对分子质量不大于800×104,聚合物质量浓度不大于900 mg/L,交联剂中聚合物与Cr”聚合物凝胶的质量浓度比为(180～270):1;在相对分子质量和质量浓度相同条件下,与聚合物溶液相比,Cr”聚合物凝胶不仅阻力系数和残余阻力系数较大,而且残余阻力系数大于阻力系数,表现出优良的液流转向增油效果;随着聚合物凝胶段塞尺寸增加,调驱采收率增大但增幅逐渐减小,适宜段塞尺寸为0.1～0.15 PV.
展开▼
