﻿ 高含水水平井注CO2酸岩反应数学模型 Mathematical Model of Acid Rock Reaction in the Process of CO2 Huff and Puff Stimulation of Horizontal Wells in High Water Cut

Journal of Oil and Gas Technology
Vol.38 No.03(2016), Article ID:18661,10 pages
10.12677/JOGT.2016.383026

Mathematical Model of Acid Rock Reaction in the Process of CO2 Huff and Puff Stimulation of Horizontal Wells in High Water Cut

Sen Lin

School of Petroleum Engineering, Yangtze University, Wuhan Hubei

Received: Dec. 1st, 2015; accepted: Jan. 18th, 2016; published: Sep. 15th, 2016

ABSTRACT

Mathematical model of corrosion of CO2 on the wellbore radial in the process of CO2 huff and puff of horizontal wells in high water cut is established to study the effect CO2 stimulation to the reservoir and the effect of injection rate, injection, soaking time, time of huff and puff, pressure of reservoir and temperature of reservoir to corrosion. Simulation results show that the effective distance of acid is short, which is less than 0.2 m; with the increase of injection rate, acid range increases, the degree of reservoir reconstruction decreases; as the injection, formation temperature and formation pressure increase, modification extent increase; soak time will have little impact on the reservoir reconstruction; with the increase of throughput times, the degree of reservoir reconstruction become greater, but the degree of each stage and reformation decreases.

Keywords:High Water Cut, Horizontal Wells, CO2 Huff and Puff, Mathematical Model, Reservoir Reconstruction, Impact Parameters

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1. 引言

2. 数学模型的建立

Figure 1. Diagram of CO2 huff and puff

2.1. 注酸阶段数学模型

H2CO3质量浓度方程为：

2.2. 焖井阶段反应的数学模型

H2CO3质量浓度方程：

2.3. 数学模型的离散

H2CO3质量浓度差分方程：

2.4. 求解方法

3. 计算实例

3.1. 注气速度的影响

3.2. 注气量的影响

Figure 2. The influence of gas injection rate on the porosity

Table 1. The parameters of mineral and process of injecting H2CO3

Figure 3. The influence of gas injection rate on the carbonate minerals

110℃，地层压力50.18 MPa。由酸液质量浓度计算得，计算结果如图4图5所示。结果表明，随着注气量的增加，储层改造的程度越大。

3.3. 焖井时间的影响

3.4. CO2吞吐次数的影响

3.5. 地层温度

3.6. 地层压力

4. 结论

1) 酸岩反应在很多方面具有共通性，在具体研究时可以相互借鉴，并且具有很强的指导意义。以“两酸三矿物”砂岩酸化模型为借鉴，建立了实际现场高含水水平井CO2吞吐时，形成的酸液沿井筒径向流

Figure 4. The influence of injection volume on the porosity

Figure 5. The influence of injection volume on carbonate minerals

Figure 6. The influence of soak time on the porosity

Figure 7. The influence of soak time on the carbonate minerals

Figure 8. The influence of CO2 huff and puff times on the porosity

Figure 9. The influence of CO2 huff and puff times on the carbonate minerals

Figure 10. The influence of formation temperature on the porosity

Figure 11. The influence of formation temperature on the carbonate minerals

Figure 12. The influence of formation press on the porosity

Figure 13. The influence of formation press on the carbonate minerals

2) 在实际塔河油田的参数下，碳酸溶液的作用距离很短，只能有效地作用于距井壁0.2 m范围内的储层。而且酸液主要消耗在距井壁0.1 m的范围内。

3) CO2吞吐对储层有很好的解堵作用，建议在施工过程中增加注气速度和注气量，增加改造范围和改造程度，更有利于吐阶段的反向流动。

4) 地层温度越高，酸液消耗速度越快，酸液作用距离越短，在具体施工中，可以适当增加注气速度，增加酸化穿透深度，以便更好地解堵。

Mathematical Model of Acid Rock Reaction in the Process of CO2 Huff and Puff Stimulation of Horizontal Wells in High Water Cut[J]. 石油天然气学报, 2016, 38(03): 57-66. http://dx.doi.org/10.12677/JOGT.2016.383026

1. 1. da Motta, E.P., Plavnlk, B., Schechter, R.S., et al. (1993) Accounting for Silica Precipitation in the Design of Sandstone Acidizing. SPE-23802-PA, Society of Petroleum Engineers.

2. 2. 李松岩, 李兆敏, 李宾飞. 砂岩基质酸化中酸岩反应数学模型[J]. 中国矿业大学学报, 2012, 41(2): 236-241.

3. 3. 李松岩, 李兆敏, 林日亿, 等. 泡沫分流酸化数学模型的建立及应用[J]. 中国石油大学学报(自然科学版), 2008, 32(5): 77-82.

4. 4. 范泓澈, 黄志龙, 袁剑, 等. 高温高压条件下甲烷和二氧化碳溶解度试验[J]. 中国石油大学学报(自然科学版), 2011, 35(2): 6-11.

5. 5. 周琳淞. CO2驱水–气–岩反应对疏松砂岩储层物性影响的研究[D]: [硕士学位论文]. 成都: 西南石油大学, 2014.

6. 6. 张超, 李兆敏, 张东. 超临界CO2驱对储层物性影响的实验研究[J]. 西南石油大学学报(自然科学版), 2013, 35(5): 94-98.