烯酯类驱油剂在致密油藏驱替开发中的应用*

Study on Olefin Ester Oil Displacement Agents in the Development of Tight Oil Reservoirs

吴 凡 侯吉瑞

WU Fan HOU Jirui

致密油藏驱替过程中存在注入压力高，采出程度低的问题。本文提出将烯酯类驱油剂运用到致密油藏驱 替开发中，以9-癸烯酸甲酯为例通过致密岩心驱替实验，研究烯酯类驱替剂在致密岩心驱替过程中注入压力与 驱油效果相对常规驱油剂的优势。9-癸烯酸甲酯不溶于水，能够与乙醇、乙醚、乙酸等有机溶剂互溶，在驱替过 程中可以迅速传质扩散到岩心深处。研究结果表明：对于0.1×10-3μm2 级别的致密岩心，相对于常规驱油剂，9-癸 烯酸甲酯驱替压力极大降低，不到水驱压力的1/30，适用于致密油藏的驱替开发。同时驱替实验表明，先注入2 PV的9-癸烯酸甲酯再进行水驱，9-癸烯酸甲酯驱采出程度达到80%以上，综合采出程度达到90%以上。水驱后 注入0.3、1.5 PV的9-癸烯酸甲酯段塞，提高采收率分别达到20.61%、57.52%。烯酯类驱油剂在致密油藏驱替开 发应用中具有良好的注入适应性同时可以极大地提高采出程度，具有广阔的应用前景。

There are problems of high injection pressure and low recovery in the process of tight oil reservoir displacement. Olefin ester oil displacement agents was proposed to apply to the displacement development of tight oil reservoirs. Taking 9-decenoic acid methyl ester as an example，through tight core flooding experiments，the advantages of the injection pressure and oil displacement effect of olefin ester flooding agents over conventional oil flooding agents in the process of tight core flooding were studied. 9-decenoic acid methyl ester is insoluble in water and can be miscible with organic solvents such as ethanol，ether，acetic acid， etc.，and can rapidly transfer mass to the depth of the core during the displacement process. The research results showed that for the tight core with the permeability level of 0.1 × 10-3 μm2 ，the displacement pressure of 9-decenoic acid methyl ester was greatly reduced compared to conventional oil displacement agents，being of less than 1/30 of the water flooding pressure，which was suitable for the flooding of tight oil reservoirs. The flooding experiment showed that，by injecting 2 PV 9-decenoic acid methyl ester first and then water flooding，the oil recovery rate of 9-decenoic acid methyl ester flooding reached more than 80% ，and the comprehensive oil recovery rate reached more than 90%. After water flooding，0.3 PV and 1.5 PV 9-decenoic acid methyl ester slugs were injected to increase oil recovery to 20.61% and 57.52%，respectively. Ester oil-displacing agents had good injection adaptability in the development and application of tight oil reservoirs，and at the same time could greatly improve the degree of recovery，and have broad application prospects.

10.19346/j.cnki.1000-4092.2021.04.021