蒸汽驱CO2地面混相泡沫增效技术研究与试验

Experimental Study on CO2 Surface Mixed Foam Profile Control and Flooding Technology for Super Heavy Oil

针对杜229块超稠油蒸汽驱开发“蒸汽突破”阶段,油井高温、高含水及产油量低等开发矛盾,从伴生气分离CO2回收处理、地面混相泡沫发生器研制、耐高温发泡剂室内实验评价等方面,研究应用CO2地面混相泡沫增效技术。结果表明:伴生气分离CO2回收处理可以从油井套管气分离出的CO2含量为66%,纯度高达94%;地面混相泡沫发生器可以实现将耐高温发泡剂与CO2在地面直接充分搅拌混合形成泡沫,密度可达到0.9g/cm^3;耐高温发泡剂在温度250℃以上时,泡沫体积仍可达到350mL,半衰期为110min,阻力因子大于20以上。现场试验井组提高油层纵向动用程度50%,井温平均下降6.7℃,含水降低7%,增油969t,对维持油田长期稳产具有重要的意义。

In view of the“steam breakthrough”stage in the development of super heavy oil steam flooding in Du 229 block,the contradiction between high temperature,high water cut and low oil production was studied.The CO 2 surface miscible foam synergistic technology was studied from the aspects of separation and recovery of associated gas CO 2,the development of surface miscible foam generator,and the laboratory evaluation of high temperature foaming agent.The results show that the separation of CO 2 from the oil well casing gas by the separation of the associated gas can result in a CO 2 content of 66%and a purity of 94%.The surface miscible foam generator can directly mix the high temperature foaming agent and CO 2 directly on the ground to form a foam,and the density can reach 0.9 g/cm^3.When the high temperature foaming agent is above 250 CO 2,the foam volume can still reach 350 mL and the half-life is 110.For min,the resistance factor is more than 20.Field test wells increase the vertical productivity of reservoirs by 50%,average well temperature decreases by 6.7 C,water cut decreases by 7%,and increase oil production by 969 t,which is of great significance for maintaining long-term stable production of oilfields.