| 煤层气水平井钻井工程因素对煤粉产出影响的数值模拟——以柳林区块为例 |
| |
| 作者姓名： | 魏迎春 王亚东 张劲 王安民 孟涛 |
| |
| 作者单位： | 1.中国矿业大学(北京)地球科学与测绘工程学院，北京 100083 |
| |
| 基金项目： | 国家自然科学基金41972174中央高校基本科研业务费专项资金2022YJSDC10 |
| |
| 摘 要： | 煤粉产出是制约煤层气开发的关键因素。影响煤粉产出的因素包括静态和动态因素，钻井工程是动态因素中影响煤粉产出的重要因素之一。以柳林煤层气区块为例，从井壁稳定性角度出发，运用ANSYS软件建立了二维、三维模型，分别模拟了不同钻井方位、钻井液密度、井眼半径、井斜情况下井壁的受力和变形，分析了煤层气水平井钻井工程因素对煤粉产出的影响。研究表明，井眼大小和井斜对煤粉产出的影响较大，而井眼方位和钻井液密度对煤粉产出的影响较小；井眼方位沿最大水平地应力方向时，井周等效应力差值最大，应力集中最明显；钻井液密度过大会导致井壁拉伸破坏；水平井钻进过程中，井眼半径越大、井斜越大，越易产生煤粉。为了减少钻井因素导致的煤粉产生，建议研究区水平井钻进时，井眼方位选择沿最小水平地应力方向，水平段选用清水钻进，水平段井眼倾角尽量与煤层倾角保持一致。研究成果为煤粉管控措施提供参考。
|
| 关 键 词： | 煤层气水平井 钻井工程 煤粉 井壁稳定 数值模拟 |
| 收稿时间： | 2021-12-07 |
Numerical simulation on the effect of drilling engineering factors on coal fines output in coalbed methane horizontal wells: a case study of Liulin block |
| |
| Affiliation: | 1.College of Geosciences and Surveying Engineering, China University of Mining and Technology-Beijing, Beijing 100083, China2.State Key Laboratory of Coal Resources and Safe Mining, Beijing 100083, China |
| |
| Abstract: | The coal fines output is the key factor restricting the development of coalbed methane.Factors affecting coal fines output include static factors and dynamic factors.Drilling engineering is one of the important dynamic factors affecting coal fines output.Taking Liulin coalbed methane block as an example, this study established 2D and 3D models by ANSYS software from the perspective of the wellbore stability, and simulated the force and deformation of the borehole wall under different drilling orientations, drilling fluid density, wellbore size, and wellbore inclination.The influence of factors in drilling engineering on the coal fines production was analyzed for the coalbed methane horizontal well.Results show that borehole size and inclination on coal fines production exert greater effect than borehole orientation and drilling fluid density.When the borehole orientation is along the direction of the maximum horizontal in-situ stress, it demonstrates the biggest difference in the equivalent stress around the borehole, and the most obvious stress concentration.Excessive density drilling fluid will lead to tensile failure of the wellbore.In the process of horizontal well drilling, the larger the radius of the wellbore and the larger the inclination of the well, the easier it is to generate coal fines.In order to reduce the generation of coal fines caused by drilling factors, it is suggested that when drilling horizontal wells in the study area, the borehole orientation should be along the direction of the minimum horizontal in-situ stress, the horizontal section should be drilled with clear water, and the inclination of the horizontal section should be consistent with the inclination of the coal seam.The research results provide a theoretical basis for the control measures of coal fines. |
| |
| Keywords: | |
|
| 点击此处可从《》浏览原始摘要信息 |
|
点击此处可从《》下载全文 |
|
