低渗稠油油藏热化学复合驱油体系实验

EXPERIMENT ON THE THERMOCHEMICAL COMPLEX FLOODING SYSTEM FOR LOW-PERMEABILITY HEAVY OIL RESERVOIRS

叙利亚O油田Sh-B油藏为典型的低渗稠油油藏,具有埋藏深、渗透率低、原油黏度大等特点,蒸汽吞吐注汽难,注汽质量差。针对这些问题,开展了低渗稠油热化学复合体系室内研究,筛选、复配了适合该油藏稠油的油溶性降黏剂、高温驱油剂,并评价了伴注CO2、高温驱油剂和油溶性降黏剂在低渗稠油开发中的效果及其可行性。结果表明,添加降黏剂能使降黏率达到78%以上,高温驱油剂显著降低界面张力,注入CO2能够明显改善O油田稠油开采效果,150℃条件下热化学复合体系最终驱替效率达到91.65%。热化学复合体系能够显著改善低渗稠油油藏开发效果,提高油藏采收率,为国内外低渗稠油油藏开发提供借鉴。

Reservoir Sh-B in Syria Oilfield O is one of the typical low-permeability heavy oil reservoirs characterized by deep buried depth, low permeability, high viscosity and so on, so it is difficult to inject the steam for huff and puff, thus the injected steam quality is rather poorer. In the light of the problems stated above, the indoor stud- ies on the thermochemical complex system of the low-permeability heavy oil were conducted, the oil-solvent viscosi- ty-reducer and high-temperature oil displacing agent for the kind of the oil were screened and prepared, and moreo- ver the effects and feasibilities were evaluated for the associated CO2 injection, two kinds of the agents stated above in the development of the low- permeability heavy oil. The achievements show that the viscosity-reducer agent can reduce the viscosity by more than 78% and the oil displacing agent can apparently decrease the interfacial tension, the injected CO2 can obviously improve the produced effects of the heavy oil in Oilfield O, the UEOR of the system can be up to 91.65% under the condition of 150℃. The system can significantly improve the developed effects of the low- permeability heavy oil and enhance the oil recovery of the oil reservoirs, thus these achievements can pro- vide a certain references for the development of the low-permeability heavy oil reservoir at home and abroad.