Study on Flushing Efficiency of Drilling Fluid Filter Cake in Oval Wellbore
-
摘要: 目前固井工程中钻井液滤饼冲洗效率的研究多针对于圆形井眼套管居中条件下的冲洗情况,而针对井眼形状和套管偏心等因素对钻井液滤饼冲洗效率影响的研究较少。使用钻井液滤饼冲洗模拟实验装置测试了椭圆井眼中偏心度和冲洗流量对钻井液滤饼冲洗效率的影响,并基于计算流体力学(CFD)方法分析了冲洗液在环空中的流场,计算了冲洗液的水力剪切力,阐明了滤饼冲洗效率变化的机理。研究结果表明:椭圆井眼环空中的短轴方向偏心时,钻井液滤饼冲洗效率在环空长轴方向最大,宽短轴方向次之,窄短轴方向最小;增加环空短轴偏心度,钻井液滤饼冲洗效率在长轴方向略微减小,宽短轴方向增加,窄短轴方向大幅降低;增加环空冲洗流量,环空中钻井液滤饼总体冲洗效率明显增加,但环空中长轴方向滤饼冲洗效率的增幅最大,宽短轴次之,窄短轴最小。Abstract: At present, the research on the flushing efficiency of drilling fluid filter cake in cementing engineering mainly focuses on the flushing condition of the circular hole casing in the middle, while the research on the influence of the hole shape and casing eccentricity on the flushing efficiency of drilling fluid filter cake is less. This study uses the drilling fluid filter cake flushing simulation experimental device to test the influence of eccentricity and flushing flow rate in the elliptical hole on the drilling fluid filter cake flushing efficiency, and analyzes the flow field of the flushing fluid in the annulus based on the computational fluid dynamics (CFD) method, calculates the hydraulic shear force of the flushing fluid, and clarifies the mechanism of the change of the filter cake flushing efficiency. The results show that when the short axis direction in the annulus of the elliptical hole is eccentric, the flushing efficiency of the drilling fluid filter cake is the largest in the long axis direction of the annulus, followed by the wide and short axis direction, and the narrow and short axis direction is the smallest; By increasing the eccentricity of the short axis in the annulus, the flushing efficiency of the drilling fluid filter cake decreases slightly in the long axis direction, increases in the wide and short axis direction, and decreases significantly in the narrow and short axis direction; With the increase of annulus flushing flow, the overall flushing efficiency of annulus drilling fluid filter cake is significantly increased, but the increase of filter cake flushing efficiency in the long axis direction of the annulus is the largest, followed by the wide and short axis, and the narrow and short axis is the smallest.
-
Key words:
- Oval wellbore /
- Filter cake /
- Flushing fluid /
- Eccentricity /
- Flushing flow rate /
- Flushing efficiency
-
表 1 椭圆井眼滤饼冲洗实验方案
滤饼压制 t冲洗间隔/
minK
pa·snn 冲洗流量/
L·s−1偏心度(e) P/MPa t/min 1.5 30 5 2.119 0.516 0.31 0 0.61 0.2 0.92 0.4 1.22 0.6 1.53 -
[1] NELSON E B. 现代固井技术[M]. 刘大为, 田锡君, 廖润康, 译. 沈阳: 辽宁科学技术出版社, 1994.NELSON E B. Well cementing[M]. translated by LIU Dawei, TIAN Xijun, LIAO Runkang. Shenyang: Liaoning Science and Technology Publishing House, 1994. [2] 胡永宏,高锦屏,郭东荣,等. 钻井液滤饼强度实验方法的建立[J]. 石油大学学报,1993,17(6):45-49.HU Yonghong, GAO Jingping, GUO Dongrong, et al. Development of the experiment method for measuring strength of drilling fluid filter cakes[J]. Journal of China University of Petroleum, 1993, 17(6):45-49. [3] 王松,魏霞,喻霞,等. 钻井液泥饼强度评价研究[J]. 钻井液与完井液,2011,28(1):11-13.WANG Song, WEI Xia, YU Xia, et al. Research on evaluation of mud cake intensive[J]. Drilling Fluid & Completion Fluid, 2011, 28(1):11-13. [4] 黄锐,靳荣博,青帅,等. 聚磺钻井液泥饼厚度及致密性研究[J]. 西部探矿工程,2012,24(7):79-82. doi: 10.3969/j.issn.1004-5716.2012.07.027HUANG Rui, JIN Rongbo, QING Shuai, et al. Study on filter cake thickness and compactness of polysulfonate drilling fluid[J]. West-China Exploration Engineering, 2012, 24(7):79-82. doi: 10.3969/j.issn.1004-5716.2012.07.027 [5] 王广雷,吴迪,姜增东,等. 固井冲洗效率评价方法探讨[J]. 石油钻探技术,2011,39(2):77-80.WANG Guanglei, WU Di, JIANG Zengdong, et al. Discussion on evaluation method of cementing flushing efficiency[J]. Petroleum Drilling Techniques, 2011, 39(2):77-80. [6] 赵敏,李云鹃. 泥饼抗冲刷能力强弱的机理研究[J]. 西南石油学院学报(自然科学版),1995(3):76-84.ZHAO Ming, LI Yunjuan. The mechanism of shear resistance for mud cake[J]. Journal of Southwest Petroleum University(Science & Technology Edition) , 1995(3):76-84. [7] 周风山,王世虎,李继勇,等. 泥饼结构物理模型与数学模型研究[J]. 钻井液与完井液,2003,20(3):4-8. doi: 10.3969/j.issn.1001-5620.2003.03.002ZHOU Fengshan, WANG Shihu, LI Jiyong, et al. Mathematical & physical models for drilling fluid filter cake[J]. Drilling Fluid & Completion Fluid, 2003, 20(3):4-8. doi: 10.3969/j.issn.1001-5620.2003.03.002 [8] 崔茂荣,马勇. 评价钻井液滤饼对固井二界面胶结质量影响的新方法[J]. 天然气工业,2006,26(12):92-93. doi: 10.3321/j.issn:1000-0976.2006.12.023CUI Maorong, MA Yong. A new method for evaluating the influence of drilling fluid filter cake on the quality of cementing secondary interface[J]. Natural Gas Industry, 2006, 26(12):92-93. doi: 10.3321/j.issn:1000-0976.2006.12.023 [9] 朱江林,石礼岗,冯克满,等. 一种物理模拟冲洗液冲洗效率的评价方法[J]. 钻井液与完井液,2012,29(1):69-70. doi: 10.3969/j.issn.1001-5620.2012.01.020ZHU Jianglin, SHI Ligang, FENG Keman, et al. An physical simulating evaluation method of flushing efficiency of flushing fluid[J]. Drilling Fluid & Completion Fluid, 2012, 29(1):69-70. doi: 10.3969/j.issn.1001-5620.2012.01.020 [10] 胡兴. 泥饼性能对冲洗效率的影响研究[D].成都:西南石油大学, 2016.HU Xing. Effect of filter cake properties on flushing efficiency[D].Chengdu:Southwest Petroleum University, 2016. [11] 郭小阳, 张夏雨, 李宁, 等. 固井注水泥钻井液滤饼冲洗效率评价装置及方法: CN201910871419.7[P].2019-12-27.GUO Xiaoyang, ZHANG Xiayu, LI Ning, et al. Device and method for evaluating flushing efficiency of drilling fluid filter cake: CN201910871419.7[P]. 2019-12-27. [12] 梅超, 张贵仪, 濮洪, 等.一种钻井液滤饼压制及清洗效率一体化评价装置及方法:CN201910515022.4[P].2019-08-09.MEI Chao, ZHANG Guiyi, PU Hong, et al. An integrated device for drilling fluid filter cake generating and flushing: CN201910515022.4[P]. 2019-08-09. [13] 刘勇. 提高界面顶替效率的冲洗液体系及相关理论研究[D]. 成都: 西南石油大学, 2016.LIU Yong. Study on flushing fluid system and theory for improving cementing displacement interface efficiency[D]. Southwest Petroleum University, 2016. [14] 张鑫. 南苏丹Palouge油田滤饼清除技术[J]. 石油钻探技术,2018,46(5):46-51. doi: 10.11911/syztjs.2018083ZHANG Xin. Filter cake removal technology in the Palouge oilfield in South Sudan[J]. Petroleum Drilling Techniques, 2018, 46(5):46-51. doi: 10.11911/syztjs.2018083 [15] 李蕾. 油基钻井液滤饼清洗液室内研究[J]. 承德石油高等专科学校学报,2020,22(3):10-14. doi: 10.3969/j.issn.1008-9446.2020.03.004LI Lei. Laboratory research of filter cake removal fluid of oil-based drilling fluid[J]. Journal of Chengde Petroleum College, 2020, 22(3):10-14. doi: 10.3969/j.issn.1008-9446.2020.03.004