低渗透油藏液流转向剂传输运移能力与驱油效率

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。

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

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 Cr3+ polymer gel are rather poorer in the reservoir cores,but the difference between 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 μm2,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 Cr3+ polymer gel is pretty higher and furthermore the technical and economic effects are more favorable.