伴注烟道气改善蒸汽辅助重力泄油开发效果的实验研究

Experimental study on the development effect of flue gas-associated SAGD

赵庆辉

ZHAO Qinghui

中国石油辽河油田分公司勘探开发研究院 国家能源稠(重)油开采研发中心

Exploration and Development Research Institute, PetroChina Liaohe Oilfield Company, Panjin 124010, Liaohe, China R & D Center of Viscous (Heavy) Oil Production, National Energy Administration, Panjin 124010, Liaohe, China

蒸汽辅助重力泄油(即SAGD)是开发厚层超稠油油藏的有效技术，但在开发中后期存在注入蒸汽超覆严重、热损失大、油汽比低等问题，影响了开发效果。为此，在室内利用高压物性分析仪、比例物理模拟系统等装置，开展了烟道气对地层原油性质的影响，以及伴注烟道气后蒸汽向上覆地层热损失、蒸汽腔变化规律和生产特征等实验研究。结果表明，注入的烟道气可以有效降低地层原油黏度，提高原油渗流能力，增大体积系数，增加弹性能量；与常规SAGD方式相比，烟道气辅助SAGD方式蒸汽腔横向扩展速度加快，纵向扩展速度减缓，蒸汽超覆现象得到有效抑制；伴注的烟道气在蒸汽腔上方聚集，形成隔热层，减少了蒸汽向上覆盖层的热损失，提高了热量利用效率；在常规SAGD过程中伴注烟道气，可以一定程度减少蒸汽注入量，提高油汽比，改善开发效果。综合分析认为，伴注烟道气方式是改善SAGD开发中后期开发效果的可行途径。

Steam assisted gravity drainage (SAGD) is an effective technology to develop thick super heavy oil reservoirs, but there are serious steam overlay, great heat loss, low oil/steam ratio and other problems in the middle and late stages of the development, which impact the development effect. In this paper, the influences of flue gas on in-place oil properties and the heat loss of steam in the overlying strata, change laws of steam chamber and production characteristics after the injection of steam with flue gas were experimentally studied in the laboratory by using PVT analyzer and proportional physical simulation system. It is indicated that the injected flue gas can effectively reduce the in-place oil viscosity, improve the flow capacity of crude oil and increase the volume coefficient and the elastic energy. Compared with conventional SAGD, the flue gas-assisted SAGD speeds up the transverse expansion of steam chamber and slows down the longitudinal expansion, so as to effectively inhibit the phenomenon of steam overlay. The flue gas injected together with steam accumulates above the steam chamber to form a heat insulation layer, which reduces the heat loss of steam in the overlying cover, so as to improve the heat utilization efficiency. Steam injection with flue gas in the process of conventional SAGD can reduce the amount of steam injection to a certain degree, increase the oil/steam ratio and improve the development effect.

10.13639/j.odpt.2021.03.016