﻿ 碳酸盐岩油藏生产过程中的动态应力场变化规律——以塔河地区TP326CH井为例 The Variation Law of Dynamic Stress Field in the Production of Carbonate Reservoirs——By Taking Well TP326CH in Tahe Area as an Example

Journal of Oil and Gas Technology
Vol.40 No.04(2018), Article ID:26389,6 pages
10.12677/JOGT.2018.404089

The Variation Law of Dynamic Stress Field in the Production of Carbonate Reservoirs

——By Taking Well TP326CH in Tahe Area as an Example

Junjiang Zhang, Hailin Ying

Research Institute of Engineering and Technology, Northwest Petroleum Company, SINOPEC, Urumqi Xinjiang

Received: Feb. 5th, 2018; accepted: Jun. 7th, 2018; published: Aug. 15th, 2018

ABSTRACT

In the production process, the in-situ stress distribution affected the distribution of “dessert area” in secondary stimulation and the breakdown pressure changes in peripheral well region, which was for guiding the implementation of stimulation in the late period. By using a pore elastic mechanics theory, a random coupling model of natural fracture and acid fracturing is established, and the finite element method is used for obtaining the change of stress field in the production process. By comparing the production data from model calculation and the actual well production, it proves that the model is consistent with the actual situation.

Keywords:Carbonate Rock, Dynamic Stress Field, Random Fracture, Repeated Fracturing

——以塔河地区TP326CH井为例

Copyright © 2018 by authors, Yangtze University and Hans Publishers Inc.

1. 引言

2. 仿真建模

Table 1. The statistical characteristics of natural fractures (replacing wells)

Table 2. The data list for modeling

Figure 1. The production in Well TP326CH

3. 动态应力场的变化规律

3.1. 孔隙压力的变化规律

Figure 2. The pore pressure distribution after 1d production

3.2. 垂直裂缝方向正应力变化规律

X轴方向正应力，即垂直裂缝方向正应力。由图3可知，垂直裂缝方向正应力的扩展规律与孔隙压力相同，其最大值区域始终分布在酸压裂缝周围。随着时间推移，酸压裂缝根部的垂直裂缝方向正应力渐渐减小，最大值区域向酸压裂缝前端集中，最终酸压裂缝周围没有明显的极值区域。

Figure 3. The normal stress distribution in vertical fracturing direction during the production process

3.3. 沿裂缝方向正应力的变化规律

Y轴方向正应力，即沿裂缝方向的正应力。由图4可知，沿裂缝方向正应力有2个较为明显的分界面，分别为水平井筒附近和包裹两级酸压裂缝的扇形区域。在生产初期，水平井筒和酸压裂缝周围的沿裂缝方向正应力最先开始增大；随生产进行，区域慢慢扩大，但纵向上始终在酸压裂缝尖端附近，纵向上远离酸压裂缝的区域，油气储量会有所增加，也是实施二次增产措施的有利区域。

Figure 4. The normal stress distribution in vertical fracturing direction after production for 60 d

4. 模型验证

Figure 5. The production simulation results

5. 结论

1) 人工裂缝前端的闭合应力始终最大，也最先发生裂缝闭合。

2) 随着生产进行，远离酸压裂缝区域的垂直裂缝方向正应力减小，油气储量会有所增加，是实施二次增产措施的有利区域。

3) 纵向上远离酸压裂缝的区域，油气储量也会有所增加，同样也是实施二次增产措施的有利区域。

[1] 刘洪林, 王勃, 王烽, 等. 沁水盆地南部地应力特征及高产区带预测[J]. 天然气地球科学, 2007, 18(6): 885-890.

[2] 李春林, 郭鹏, 任德生. 大民屯凹陷构造应力场及其与油气运聚关系[J]. 油气地质与采收率, 2012, 19(6): 47-49+114.

[3] 郭鹏, 李春林, 哈文雷, 等. 构造应力场与油气运聚规律探讨——以鄂尔多斯盆地苏10区块为例[J]. 特种油气藏, 2011, 18(5): 64-66+138.

[4] 曾顺鹏, 张国强, 韩家新, 等. 多裂缝应力阴影效应模型及水平井分段压裂优化设计[J]. 天然气工业, 2015, 35(3): 55-59.

[5] 才博, 唐邦忠, 丁云宏, 等. 应力阴影效应对水平井压裂的影响[J]. 天然气工业, 2014, 34(7): 55-59.

[6] 李大奇, 康毅力, 游利军. 碳酸盐岩储层渗透率应力敏感性实验研究[J]. 天然气地球科学, 2014, 25(3): 409-413.

[7] 杨枝, 孙金声, 张洁, 等. 裂缝性碳酸盐岩储层应力敏感性实验研究[J]. 钻井液与完井液, 2009, 26(6): 5-6+9+91.

[8] 李宁, 张清秀. 裂缝型碳酸盐岩应力敏感性评价室内实验方法研究[J]. 天然气工业, 2000, 20(3): 30-33+8.

[9] Yang, X. and Yan, J. (2017) Poroelastodynamic Response of a Borehole in a Non-hydrostatic Stress Field. International Journal of Rock Mechanics & Mining Sciences, 93, 82-93. https://doi.org/10.1016/j.ijrmms.2017.01.008

[编辑] 邓磊