低渗透油藏液流转向剂传输运移能力与驱油效率

TRANSPORTING-MIGRATING CAPACITIES AND OIL DISPLACED EFFICIENCY FOR THE FLUID DIVERTING AGENT IN THE LOW-PERMEABILITY RESERVOIRS

大庆头台油田源13西块PI组油层为处于高含水开发期的低渗透油藏,亟待扩大低渗透层波及体积。以高分子材料学、物理化学和油藏工程等理论为指导,以化学分析、仪器检测和物理模拟等为技术手段,以多测压点长岩心各个区间的压差和驱油效率为评价指标,以目标油藏的储层和流体为模拟对象,开展了深部液流转向剂传输运移能力和驱油效率物理模拟实验。结果表明:在聚合物浓度相同条件下,与聚合物溶液相比较,Cr^(3+)聚合物凝胶在储层岩心内传输运移能力较差,但二者差异并不明显;随岩心渗透率减小,转向剂传输运移能力变差;当渗透率小于100×10^(-3)μm^2后,转向剂传输运移能力和驱油效率都明显减小;在聚合物相对分子质量和质量浓度相同条件下,与聚合物溶液比较,Cr^(3+)聚合物凝胶驱油效率较高,技术经济效果较好。

PI-Formation oil layers in West Block Yuan-13 of Daqing Toutai Oilfield in are low-permeability reservoirs at the stage of high watercut development,so it is urgent to expand the swept volume for the low-permeability layers. Guided by high-molecule material,physicochemical,reservoir engineering and other theories,taking chemical analysis,instrumental detection,physical simulationand so on as the technical means,regarding thepressure difference and oil displaced efficiency in each interval of multiple-piezometric-point and long cores as the evaluating indexes,and moreover considering the layers and fluids of the target reservoirs as the simulated objects,the physical simulating experimentsin the transporting-migrating capacities and oil displaced efficiency were conducted for the deep fluid diverting agent. The achievements show that under the same polymer concentration,comparing with the polymer solution,the capacities of the Cr^（3＋）polymer gel are rather poorer in the reservoir cores,but the differencebetween the two is not obvious; with the decrease of the core permeability,the abilities of the diverting agent get worse; when the permeability is less than 100 × 10^（-3）μm^2,both the capacities and oil displaced efficiency of the diverting agent decrease obviously; under the same conditions of the relative molecular mass and mass concentration of the polymer,comparing with the polymer solution,the displaced efficiency of the Cr^（3＋）polymer gel is pretty higher and furthermore the technical and economic effects are more favorable.