海上多元热流体吞吐提高采收率机理及油藏适应性研究

Research on the mechanism of multi-thermal fluids on enhanced oil recovery and reservoir adaptability

多元热流体吞吐热采作为海上稠油热采开发创新技术,已在渤海油田稠油开发中进行了先导性试验,但对其提高采收率机理及油藏适用范围的研究尚不够深入。通过理论分析、物理实验分析和数值模拟等方法,研究了热流体中各个组分的作用机理以及各组分之间的耦合作用,深入剖析了多元热流体提高采收率机理;同时,利用渤海油田稠油油藏的地层原油粘度、渗透率和非均质性等参数,对比研究了多元热流体吞吐和蒸汽吞吐的开发效果及各自的油藏适应条件。研究结果表明:多元热流体提高采收率机理与单纯蒸汽吞吐相比,增加了扩大热波及半径、提高地层能量及减少热损失等作用,但所携带热焓总量略有下降,因此,更适用于原油粘度相对不高、储层非均质性弱、油层较薄、天然能量较小的稠油油藏。

A new technology named multi-thermal fluids,as an innovative technology for offshore heavy oil,has been used in pilot test of Bohai oilfield,but the mechanism of multi-thermal fluids on enhanced oil recovery and reservoir adaptability has still not enough indepth research.Through theoretical analysis,numerical simulation and experiment analysis,the stimulation mechanism of components in multi-thermal fluids and the coupling of components was studied to discuss the mechanism of multi-thermal fluids on enhanced oil recovery;at the same time,based on crude oil viscosity,permeability,heterogeneity parameters and other data from heavy oil reservoirs in Bohai oilfield,the effect of multi-thermal fluids and the adapted reservoir conditions were compared with steam stimulation.The results show that:compared with steam stimulation,the multi-thermal fluid can enlarge heating volume,increase formation energy,reduce heat loss,and so on,but it carries less total enthalpy.As a result,multi-thermal fluids technology is more suitable for the heavy oil reservoirs which have relatively low oil viscosity,weak heterogeneity,thin oil layer and small natural energy.