空气泡沫驱高稳定性起泡剂的合成及性能评价

Synthesis and performance evaluation of high stability foaming agent for air foam flooding

杨兴利 郭平 何敏侠

YANG Xingli GUO Ping HE Minxia

油气藏地质及开发工程国家重点实验室 ·西南石油大学 延长油田股份有限公司宝塔采油厂 中国石油大学（北京）石油天然气工程学院

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum Institute, Chengdu 610500, Sichuan, China Baota Oil Production Plant, Yanchang Oilfield Co., Ltd., Xi'an 716000, Shaanxi, China College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China

低渗油藏孔隙结构复杂，比表面积大，空气泡沫驱过程中起泡剂在储层中吸附损失严重，影响空气泡沫驱的应用效果。延长东部油田甘谷驿油区孔隙度平均为10.76%，渗透率平均为0.933 mD，属于低孔特低渗储层。为了减小起泡剂在地层中的吸附，同时提高泡沫液的稳定性，结合油藏实际地质特征，研制了一种基于脂肪醇聚氧乙烯醚-邻苯二甲酸酯钠盐的新型阴离子表面活性起泡剂，对新型起泡剂发泡能力、耐温耐盐性、吸附损失大小、耐油能力和界面张力等基本性能进行了系统评价。结果表明：在稳定性方面，当起泡剂含量大于2 000 mg/L时，发泡高度可超过180 mm，在2 000 mg/L、30 ℃时，新型起泡剂均优于SDS（十二烷基硫酸钠）和ABS（十二烷基苯磺酸钠）发泡性能；在遇油稳定性方面，加原油后起泡，原油加量为20%以内时对起泡结果仅有微弱干扰，起泡后加原油，当加入量为20%时，泡沫依然有较好的稳定性。新型起泡剂在遇油稳定性方面明显强于ABS和甘谷驿区块泡沫驱体系使用的BK6A起泡剂；在吸附损失方面，当油砂加量达到25 g时，起泡体积仅从620 mL降低至590 mL，吸附量少。新型起泡剂体系优越的发泡性能、稳泡性能和抗温抗盐性能，为泡沫驱油剂体系提供了重要的物质基础，不仅适合延长东部浅层特低渗油藏，同时也适应于延长西部中深层特低渗油藏。

The pores in low permeability reservoirs are structurally complex with large surface area, so the adsorption loss of foaming agent in reservoirs is serious in the process of air foam flooding and consequently the application effect of air foam flooding is impacted. The reservoirs in Ganguyi Block of eastern Yanchang Oilfield are of low porosity (average 10.76%) and extra low permeability (average 0.933 mD). In order to reduce the adsorption of foaming agent to the reservoirs and increase the stability of foam solution, a new kind of anionic surfactant foaming agent based on aliphatic alcohol polyoxyethylene ether-phthalic acid ester sodium salt was developed according to the actual geological characteristics of the oil reservoirs. Then, its basic performance was evaluated systematically, e.g., foamability, tolerance to high temperature and salt, adsorption loss, oil resistance, and interfacial tension. And the following research results were obtained. As for the stability, the foam height is over 180 mm when the concentration of foaming agent is more than 2 000 mg/L, and the foamability of the new foaming agent is superior to that of sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (ABS) in the case of 2 000 mg/L and 30 ℃. Speaking of the stability in presence of oil, the foaming is slightly interfered if foam occurs after the crude oil is added with the dosage less than 20%. If the crude oil is added after the foaming, the stability of the foam is still better when the dosage is 20%. It is revealed that the new foaming agent is much better than the ABS and the BK6A adopted in foam flooding system of Ganguyi Block in term of stability in presence of oil. As for the adsorption loss, the foaming volume decreases from 620 mL to 590 mL when 25 g oil sand is added. Obviously, the adsorption amount is small. The excellent foamability, foam stability and tolerance to high temperature and salt of new foaming system provide the important substantial basis for foam flooding agent system. It is not only suitable for the extra low permeability oil reservoirs in the shallow layers in eastern Yanchang, but also for the extra low permeability oil reservoirs in the middle and deep layers in western Yanchang.

10.13639/j.odpt.2018.02.017