﻿ 气层厚度对井底压力的影响分析 Analyzing the Effect of Gas Layer Thickness on Bottom Hole Pressure

Journal of Oil and Gas Technology
Vol.38 No.02(2016), Article ID:17824,7 pages
10.12677/JOGT.2016.382016

Analyzing the Effect of Gas Layer Thickness on Bottom Hole Pressure

Ruidong Tao1, Liang Zhu2, Guibin Li1, Yaoquan Liu1, Jingguo Xu1

1No.3 Drilling Company, CNPC Bohai Drilling Engineering Company Limited, Tianjin

2School of Petroleum Engineering, Yangtze University, Wuhan Hubei

Received: Dec. 10th, 2015; accepted: Feb. 28th, 2016; published: Jun. 15th, 2016

ABSTRACT

In the process of drilling of gas wells, the change of bottom hole pressure has great influence on well control. However, the influence of gas layer thickness on the bottom hole pressure was not considered currently in analyzing the factors influencing the changes of bottom hole pressure. Based on mass conservation and principle of conservation of momentum, the mathematical model of bottom pressure after invading was established. And then based on the engineering case, combined with the phase separation equations, the finite difference method is used to discuss the influential rules of gas layer thickness on the bottom hole pressure. The result shows that the bottom hole differential pressure and the stable value of B.H.P. increases while the thickness of drilling gas formation is large, which can increase the difficulty of well control. The suggestion is that rational measurement is used for early control of gas invasion to reduce the gas invasion and safe well control. The study is the completion to the understanding of gas invasion and regulation of the changes of bottom hole pressure, it provides guidance for setting up the strategy of well control.

Keywords:Bottom Hole Pressure, Drilling Thickness of Gas Formation, Well Control, Stable Value

1中石油渤海钻探工程有限公司第三钻井工程公司，天津

2长江大学石油工程学院，湖北 武汉

1. 引言

2. 气侵后井底压力计算模型

2.1. 气相和液相控制方程

M点的流入质量为；ds段内地层产气质量为；M'点的流出质量为；ds段内累积质量为

(1)

(2)

(3)

2.2. 气、液两相混合运动方程

(4)

(5)

2.3. 求解方法

Figure 1. A physical model of body mass conservation element

3. 工程实例

3.1. 基本参数计算

A井是一口水平井，在6492~7300.29 m进行欠平衡钻进，施工过程中在6492 m和6512 m发生了溢流，井身结构参数如表1所示。计算分析过程中需要的参数如表2表3所示。

3.2. 气层厚度对井底压力变化的影响

Figure 2. Relationship between gas invasion time and bottom hole pressure under different well depth and gas layer thickness

Table 1. The parameters of well structure

Table 2. The basic calculation parameters of Well A

Table 3. The relevant parameters of the well section

4. 结论与认识

1) 在讨论影响气侵后井底压力变化规律时，气层厚度是值得考虑的一个因素，对于现场制定井控安全控制策略具有指导意义。

2) 气层厚度对应的井底压力稳定值受气侵时间与钻开气层厚度的影响，而且随着气侵时间的推移和气层厚度的增加，井底压力稳定值减小，导致井底压差增大，最终加大井控难度。

3) 如果采取相应的手段及早发现气侵并且采取井控措施，能够减少地层气体的侵入量，达到安全井控的目的。

Analyzing the Effect of Gas Layer Thickness on Bottom Hole Pressure[J]. 石油天然气学报, 2016, 38(02): 59-65. http://dx.doi.org/10.12677/JOGT.2016.382016

1. 1. Ansari, A.M., Sylveste, N.D., Shoham, O., et al. (1990) A Comprehensive Mechanistic Model for Upward Two-Phase Flow in Wellbores. SPE Production & Facilities, 9, SPE-20630-PA.

2. 2. Hasan, A.R. and Kablr, C.S. (1988) Predicting Multiphase Flow Behavior in a Deviated Well. SPE Production Engineering, 3, SPE-15449-PA.

3. 3. Lage, C.V.M., Rommetveit, R. and Time, R.W. (2000) An Experimental and Theoretical Study of Two-Phase Flow in Horizontal or Slightly Deviated Fully Eccentric Annuli. IADC/SPE Asia Pacific Drilling Technology, Kuala Lumpur, 11-13 September 2000, SPE-62793-MS.

4. 4. Nickens, H.V. (1987) A Dynamic Computer Model of a Kicking Well. SPE Drilling Engineering, 2, 159-173. http://dx.doi.org/10.2118/14183-PA

5. 5. Santos, O.L.A. (1991) Well-Control Operations in Horizontal Wells. SPE Drilling Engineering, 6, SPE-21105-PA.

6. 6. Choe, J. (2001) Advanced Two-Phase Well Control Analysis. Journal of Canadian Petroleum Technology, 40, 39-47. http://dx.doi.org/10.2118/01-05-02

7. 7. 李相方, 庄湘琦, 隋秀香, 等. 气侵期间环空气液两相流动研究[J]. 工程热物理学报, 2004, 25(1): 73-76.

8. 8. 周照明. 欠平衡随钻气侵规律及运移模型研究[D]: [博士学位论文]. 大庆: 大庆石油学院, 2010.

9. 9. 谢明英. 作业井井侵期间气液流动规律研究[D]: [硕士学位论文]. 山东: 中国石油大学(华东), 2007.

10. 10. 王凯. 水平井井筒压力计算研究[D]: [硕士学位论文]. 北京: 中国石油大学, 2008.

11. 11. 范军, 施太和. 气井动态井控模型及计算机仿真[J]. 天然气工业, 1998, 18(4): 71-74.

12. 12. 徐朝阳, 孟英峰, 魏纳, 等. 气侵过程井筒压力演变规律实验和模型[J]. 石油学报, 2015, 36(1): 120-126.

13. 13. 王志远, 孙宝江, 程海清. 深水井控过程中天然气水合物生成区域预测[J]. 应用力学学报, 2009, 26(2): 224-229.

14. 14. 王利田. 大牛地气田低孔低渗气藏储层评价及含气性预测[D]: [博士学位论文]. 北京: 中国地质大学(北京), 2009.

15. 15. 杜新江, 任春玲. 利用“同相轴下拉”地震反射特征预测苏里格气田气层[J]. 石油天然气学报(江汉石油学院学报), 2008, 30(2): 466-467, 655.

16. 16. 张光荣, 卢晓敏, 孔令霞, 等. 川中潼南地区须二气藏多参数储层预测[J]. 石油钻采工艺, 2010, 32(S1): 12-15.