泡沫辅助SAGD开发特征

应用数值模拟及Surfer制图软件绘制蒸汽辅助重力泄油(SAGD)和泡沫辅助SAGD(FA-SAGD)在均质和非均质油藏中温度场分布图,对不同开发方式下蒸汽腔扩展过程进行直观、形象地描述,并对比两种开发方式的开发效果。结果表明:FA-SAGD蒸汽腔横向扩展速度大于SAGD,垂向扩展速度小于SAGD,FA-SAGD蒸汽腔主要作用于油层中部,蒸汽腔与盖层接触面积较小,盖层热损失较小;非均质储层SAGD开发过程中,蒸汽易沿高渗透层窜流,蒸汽腔在水平井筒方向不均匀扩展,FA-SAGD开发过程中,由于泡沫对蒸汽沿高渗层窜流的调控作用,蒸汽腔在地层内的扩展更为均匀,可以减小产出能量和盖层热损失,提高生产油汽比和采收率。

Characterization of foam assisted SAGD process

Steam assisted gravity drainage (SAGD) and foam assisted SAGD (FA-SAGD) are effective processes for heavy oil recovery. The temperature distributions in these processes were studied for both homogeneous and heterogeneous reservoirs using a numerical simulation method in order to reveal the expansion of the steam chambers and compare the effectiveness of the two production methods. The results show that, in the FA-SAGD production process, the lateral expansion of the steam chamber is faster than that in the SAGD process, and the vertical expansion is slower than that in the SAGD. The steam chamber of the FA-SAGD is mainly developed in the middle part of the reservoir, and its contact area with cap rocks is small, which can reduce the heat loss of the cap rock. When the SAGD process is applied in a heterogeneous reservoir, steam tends to flow through mainly in high permeable layers, and the expansion of the steam chamber along the horizontal well bore is not uniform. While in the FA-SAGD process, the expansion of the steam chamber in the reservoir is uniform due to the blocking effect of foam in high permeable layers, which can increase the sweeping efficiency of foam and reduce heat loss. Subsequently, the application of the FA-SAGD can improve the ratio of oil to steam and increase oil recovery.