Abstract

CO₂ injection and water-alternating-gas injection are EOR methods for improving oil recovery. This paper shows Water alternating gas (WAG) and continuous gas injection experiments with CO₂ in secondary recovery. Experiments were performed in sand-packed-model. The continuous gas injection experiments were conducted at 3800, 4200, 4600 and 5000 psi, then two WAG experiments was completed at 3800 psi. Also temperature was 190 °F (the reservoir temperature) in all experiments. Six tests were conducted to investigate continuous CO₂ and WAG injection under the reservoir condition. In the first test, 1.2 PV (pore volume) of CO₂ was injected into sand-packed-model at pressure of 3800 psi and temperature of 190 °F. Amount 1.2 PV of CO₂ was injected into sand-packed-model at 4200 psi in the test 2. In third one, 1.2 PV of CO₂ was injected at 4600 psi and 1.2 of PV CO₂ was injected at 5000 psi in forth one. Water alternating gas injection experiments with CO₂ were including two tests. In the first one, 0.3 PV of CO₂ and 0.9 PV of brine were injected consecutively into model. In the second one, 0.3 PV of CO₂ and 0.3 PV of brine were injected respectively into model and this test was completed in two cycles. The results indicate that increase of injection pressure enhances oil recovery in continuous CO₂ injection and increase of injected CO₂ increases oil recovery in WAG process. Also WAG injection increases oil recovery more than CO₂ continuous injection.

摘要

CO ₂注入和水交替气注入是提高采油率的EOR方法。本文显示了水交替气（WAG）和在二次回收中使用CO ₂进行连续注气的实验。实验是在沙堆模型中进行的。连续气体注入实验在3800、4200、4600和5000 psi下进行，然后在3800 psi下完成了两次WAG实验。在所有实验中，温度均为190°F（储层温度）。进行了六个测试，以调查在储层条件下连续注入CO ₂和WAG的情况。在第一个测试中，在3800 psi的压力和190°F的温度下，将1.2 PV（孔体积）的CO ₂注入到填沙模型中。一氧化碳量1.2 PV₂是在4200 psi的在测试2中第三个注入填砂模型，CO 1.2 PV ₂在4600 psi的注入和PV CO 1.2 ₂是在5000psi在所述一个喷射。用CO ₂进行的水交替气体注入实验包括两个测试。在第一个模型中，将0.3 PV的CO ₂和0.9 PV的盐水连续注入模型中。在第二个模型中，分别将0.3 PV的CO ₂和0.3 PV的盐水注入模型中，并且该测试在两个周期中完成。结果表明，增加注入压力可提高连续CO ₂注入中的采油量，并增加注入的CO _2。提高WAG工艺中的石油采收率。同样，与连续注入CO ₂相比，WAG注入还可以提高采油率。