Optimization of Perforation in CBM Horizontal Wells in Southern Qinshui Basin

doi:10.7657/XJPG20240510

Abstract

Abstract:

To enhance the fracturing performance of coalbed methane (CBM) horizontal wells in the Qinshui basin, by analyzing the data of distributed optical fiber monitoring of water and gas production profiles, mud log, and well logging, the key factors influencing the fracturing performance were identified. These factors include coal quality, coal structure, drilling position, and perforation method. The middle to upper part of coal seam No. 3 in the Qinshui basin, characterized by low GR values, high coal quality, and intact coal structure, is identified as the optimal interval for fracturing stimulation. Based on the double GR curves, the drilling position of horizontal wellbore trajectory in the coal seam can be accurately determined, aiding in the selection of optimal fracturing interval and perforation method. When the drilling position is located in the middle part of the coal seam, conventional perforation method can be efficient. When the drilling position approaches the roof or is beyond the seam, downward directional perforation is preferred to effectively stimulate the high-quality upper part of the coal seam. When the drilling position is near the lower dirt band, upward directional perforation is advisable to target the high-quality middle part of the coal seam. Field application to 46 horizontal wells demonstrated that the single well production exceeded 2.5×10⁴ m³/d and was stabilized at 2×10⁴ m³/d, and the reservoir fracturing efficiency increased by 10% to 50%, recording a satisfactory development effect of the horizontal wells.

Key words: Qinshui basin, CBM, horizontal well, coal structure, perforation interval optimization, perforation method

CLC Number:

TE377

LI Kexin, ZHANG Cong, LI Jun, LIU Chunchun, YANG Ruiqiang, ZHANG Wuchang, LI Shaonan, REN Zhijian. Optimization of Perforation in CBM Horizontal Wells in Southern Qinshui Basin[J]. Xinjiang Petroleum Geology, 2024, 45(5): 581-589.

Figures/Tables 10

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Table 1.

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Table 2.

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Fig. 7.

Table 3.

References 27

[1]	周加佳. 水平井分段压裂技术在煤层气开发中的应用实践[J]. 中国煤炭地质, 2019, 31(8):27-30.
	ZHOU Jiajia. Application practice of horizontal well segmental fracturing technology in CBM exploitation[J]. Coal Geology of China, 2019, 31(8):27-30.
[2]	张群, 降文萍, 姜在炳, 等. 我国煤矿区煤层气地面开发现状及技术研究进展[J]. 煤田地质与勘探, 2023, 51(1):139-158.
	ZHANG Qun, JIANG Wenping, JIANG Zaibing, et al. Present situation and technical research progress of coalbed methane surface development in coal mining areas of China[J]. Coal Geology & Exploration, 2023, 51(1):139-158.
[3]	龚杰立, 李国富, 李德慧, 等. 山西省煤成气勘查开发现状及探索[J]. 煤田地质与勘探, 2022, 50(2):39-47.
	GONG Jieli, LI Guofu, LI Dehui, et al. Present situation and prospects of coal-derived gas exploration and development in Shanxi province[J]. Coal Geology & Exploration, 2022, 50(2):39-47.
[4]	张鹏, 曾星航, 郑力会, 等. 煤层气井两层合采气水同产井底流压计算方法[J]. 新疆石油地质, 2023, 44(4):497-508.
	ZHANG Peng, ZENG Xinghang, ZHENG Lihui, et al. A calculation method of bottomhole flowing pressure in coalbed methane wells with double-layer commingled production in gas-water co-production stage[J]. Xinjiang Petroloeum Geology, 2023, 44(4):497-508.
[5]	姜在炳, 李浩哲, 许耀波, 等. 煤层顶板分段压裂水平井地质适应性分析与施工参数优化[J]. 煤田地质与勘探, 2022, 50(3):183-192.
	JIANG Zaibing, LI Haozhe, XU Yaobo, et al. Geological adaptability analysis and operational parameter optimization for staged fracturing horizontal wells in coal seam roof[J]. Coal Geology & Exploration, 2022, 50(3):183-192.
[6]	张稳, 张雷, 黄力, 等. 低勘探程度区煤系致密气水平井地质导向技术及应用:以DJ-P37井区为例[J]. 煤田地质与勘探, 2022, 50(9):171-180.
	ZHANG Wen, ZHANG Lei, HUANG Li, et al. Geosteering technology and application in horizontal wells for coal measure tight gas reservoirs in the areas of low exploration degree:Taking DJ-P37 bore field as an example[J]. Coal Geology & Exploration, 2022, 50(9):171-180.
[7]	苏建政. 水平井压裂选层技术探讨[J]. 断块油气田, 2010, 17(4):455-457.
	SU Jianzheng. Research on selection of well and formation for horizontal well fracturing[J]. Fault-Block Oil & Gas Field, 2010, 17(4):455-457.
[8]	刘川庆, 朱卫平, 夏飞, 等. 鄂尔多斯盆地大宁—吉县区块煤层气水平井分段压裂实践[J]. 天然气工业, 2018, 38(增刊1):112-117.
	LIU Chuanqing, ZHU Weiping, XIA Fei, et al. Segmented fracturing practice of coalbed methane horizontal wells in Daning-Jixian block,Ordos basin[J]. Natural Gas Industry, 2018,38 (Supp.1):112-117.
[9]	许耀波, 郭盛强. 软硬煤复合的煤层气水平井分段压裂技术及应用[J]. 煤炭学报, 2019, 44(4):1169-1177.
	XU Yaobo, GUO Shengqiang. Technology and application of staged fracturing in coalbed methane horizontal well of soft and hard coal composite coal seam[J]. Journal of China Coal Society, 2019, 44(4):1169-1177.
[10]	李宗源, 倪小明, 石延霞, 等. 马必东区块水力喷射分段压裂工艺优化与应用[J]. 煤矿安全, 2021, 52(12):78-83.
	LI Zongyuan, NI Xiaoming, SHI Yanxia, et al. Optimization and application of hydrqulic injection segmental fracturing process in Mabidong block[J]. Safety in Coal Mines, 2021, 52(12):78-83.
[11]	胡秋嘉, 李梦溪, 乔茂坡, 等. 沁水盆地南部高阶煤煤层气井压裂效果关键地质因素分析[J]. 煤炭学报, 2017, 42(6):1506-1516.
	HU Qiujia, LI Mengxi, QIAO Maopo, et al. Analysis of key geologic factors of fracturing effect of CBM wells for high-rank coal in Southern Qinshui basin[J]. Journal of China Coal Society, 2017, 42(6):1506-1516.
[12]	黄中伟, 李志军, 李根生, 等. 煤层气水平井定向喷射防砂压裂技术及应用[J]. 煤炭学报, 2022, 47(7):2687-2697.
	HUANG Zhongwei, LI Zhijun, LI Gensheng, et al. Oriented and sand control hydro-jet fracturing in coalbed methane and horizontal wells and field application[J]. Journal of China Coal Society, 2022, 47(7):2687-2697.
[13]	李明宅. 沁水盆地煤层气勘探及地质分析[J]. 天然气工业, 2000, 20(4):24-26.
	LI Mingzhai. Coal-bed gas exploration in Qinshui basin and its geological analysis[J]. Natural Gas Industry, 2000, 20(4):24-26.
[14]	朱庆忠, 刘立军, 陈必武, 等. 高煤阶煤层气开发工程技术的不适应性及解决思路[J]. 石油钻采工艺, 2017, 39(1):92-96.
	ZHU Qingzhong, LIU Lijun, CHEN Biwu, et al. Inadaptability of high-rank CBM development engineering and its solution idea[J]. Oil Drilling & Production Technology, 2017, 39(1):92-96.
[15]	姚艳斌, 王辉, 杨延辉, 等. 煤层气储层可改造性评价:以郑庄区块为例[J]. 煤田地质与勘探, 2021, 49(1):119-129.
	YAO Yanbin, WANG Hui, YANG Yanhui, et al. Evaluation of the hydro-fracturing potential for coalbed methane reservoir:A case study of Zhengzhuang CBM field[J]. Coal Geology & Exploration, 2021, 49(1):119-129.
[16]	胡奇, 王生维, 张晨, 等. 沁南地区煤体结构对煤层气开发的影响[J]. 煤炭科学技术, 2014, 42(8):65-68.
	HU Qi, WANG Shengwei, ZHANG Chen, et al. Coal structure affected to coalbed methane development in Qinnan region[J]. Coal Science and Technology, 2014, 42(8):65-68.
[17]	贾慧敏, 胡秋嘉, 樊彬, 等. 沁水盆地郑庄区块北部煤层气直井低产原因及高效开发技术[J]. 煤田地质与勘探, 2021, 49(2):34-42.
	JIA Huimin, HU Qiujia, FAN Bin, et al. Causes for low CBM production of vertical wells and efficient development technology in northern Zhengzhuang block in Qinshui basin[J]. Coal Geology & Exploration, 2021, 49(2):34-42.
[18]	谢楠, 姚艳斌, 杨延辉, 等. 郑庄区块煤层气评价井压裂效果影响因素分析[J]. 煤炭科学技术, 2016, 44(增刊):180-185.
	XIE Nan, YAO Yanbin, YANG Yanhui, et al. Fracturing effect factors analysis of CBM appraisal wells in Zhengzhuang block[J]. Coal Science and Technology, 2016,44(Supp.):180-185.
[19]	李存磊, 杨兆彪, 孙晗森, 等. 多煤层区煤体结构测井解释模型构建[J]. 煤炭学报, 2020, 45(2):721-730.
	LI Cunlei, YANG Zhaobiao, SUN Hansen, et al. Construction of a logging interpretation model for coal structure from multi-coal seams area[J]. Journal of China Coal Society, 2020, 45(2):721-730.
[20]	陈博, 汤达祯, 张玉攀, 等. 韩城矿区H3井组煤体结构测井反演及三维地质建模[J]. 煤炭科学技术, 2019, 47(7):88-94.
	CHEN Bo, TANG Dazhen, ZHANG Yupan, et al. Logging inversion and three-dimensional geological modeling of coal structure in Hancheng H3 well group[J]. Coal Science and Technology, 2019, 47(7):88-94.
[21]	鲁秀芹, 汪关妹, 杨延辉, 等. 基于叠前AVO数据的波形指示反演预测煤体结构[J]. 石油地球物理勘探, 2022, 57(增刊1):117-121.
	LU Xiuqin, WANG Guanmei, YANG Yanhui, et al. Prediction of coal body structure by waveform indication inversion based on prestack AVO data[J]. Oil Geophysical Prospecting, 2022, 57(Supp.1):117-121.
[22]	彭刘亚, 崔若飞, 任川, 等. 利用岩性地震反演信息划分煤体结构[J]. 煤炭学报, 2013, 38 (增刊2):410-415.
	PENG Liuya, CUI Ruofei, REN Chuan, et al. Classification of coal body structure using seismic liythology inversion information[J]. Journal of China Coal Society, 2013, 38(Supp.2):410-415.
[23]	王瑞杰, 马彦良. 构造煤地震识别方法研究[J]. 中国煤炭地质, 2017, 29(12):78-81.
	WANG Ruijie, MA Yanliang. Tectonoclastic coal seismic identification[J]. Coal Geology of China, 2017, 29(12):78-81.
[24]	王创业, 方惠军, 詹顺, 等. 连续管定向喷砂射孔拖动压裂技术在煤层气水平井中的应用[J]. 天然气工业, 2018, 38(增刊1):143-147.
	WANG Chuangye, FANG Huijun, ZHAN Shun, et al. Application of continuous tube directional sand blasting perforation driving fracturing technology in coalbed methane horizontal wells[J]. Natural Gas Industry, 2018, 38(Supp.1):143-147.
[25]	杜承强, 陈帅, 吴英新. 水平井定向射孔分段压裂在煤层气井中的应用[J]. 油气井测试, 2017, 26(4):66-69.
	DU Chengqiang, CHEN Shuai, WU Yingxin. Application of horizontal well’s directional perforation fracturing tech in coal bed gas methane well[J]. Well Testing, 2017, 26(4):66-69.
[26]	许露露. 沁水盆地南部郑庄区煤储层水力裂缝扩展规律研究[D]. 北京: 中国地质大学(北京), 2015.
	XU Lulu. Mechanism of hydraulic fracture propagation of the coal reservoir in the Zhengzhuang,southern Qinshui basin,China[D]. Beijing: China University of Geosciences(Beijing), 2015.
[27]	高向东, 孙昊, 王延斌, 等. 临兴地区深部煤储层地应力场及其对压裂缝形态的控制[J]. 煤炭科学技术, 2022, 50(8):140-150.
	GAO Xiangdong, SUN Hao, WANG Yanbin, et al. In-situ stress field of deep coal reservoir in Linxing area and its control on fracturing crack[J]. Coal Science and Technology, 2022, 50(8):140-150.

序号	射孔深度/m	自然伽马/ API	射孔点位置	全烃含量/%	煤体结构	实测日产气量/m³
1	1 810.61	30.25	下煤层	51.77	碎粒结构	281
2	1 740.25	20.45	下煤层	56.76	碎粒结构	110
3	1 670.34	19.29	中煤层	76.84	原生结构	899
4	1 602.84	38.22	中煤层	68.13	原生结构	529
5	1 520.65	25.00	中煤层	50.17	原生结构	2 224
6	1 447.86	10.70	中煤层	52.56	原生结构	1 271
7	1 389.79	45.07	下夹矸层附近	57.33	碎裂结构	629
8	1 311.07	19.75	下夹矸层附近	61.14	碎裂结构	550
9	1 184.02	14.91	中煤层	45.65	原生结构	916
10	1 099.79	24.25	中煤层中部	37.79	原生结构	599
11	1 034.29	11.32	下煤层下部	47.13	碎粒结构	231
12	952.18	10.32	下煤层下部	57.84	原生结构	356
13	886.85	9.61	下夹矸层附近	49.93	碎裂结构	405

压裂点级别	优选标准				分类理由
压裂点级别	自然伽马/API	全烃含量/%	煤体结构指数	井眼轨迹位置	分类理由
Ⅰ类压裂点	<20	>50	>8	中煤层	含气量高，易压裂
Ⅱ类压裂点	20~40	30~50	7~8	上煤层或顶板	含气量中等，易压裂
非压裂点	>40	<30	<7	下煤层或底板	煤体破碎，压裂效果差

压裂点	自然伽马/API	全烃含量/%	煤体结构指数	井眼轨迹位置	射孔方式	施工曲线类型
1	14.0	60.4	7.84	煤层中部	常规射孔	缓慢上升—稳定型
2	21.5	64.9	8.39	煤层上部	水平斜向下30°射孔	缓慢下降型
3	25.5	69.6	8.15	煤层上部	水平斜向下60°射孔	平稳型
4	14.0	70.4	8.42	煤层上部	水平斜向下60°射孔	平稳型
5	17.0	68.8	7.81	煤层上部	水平斜向下60°射孔	平稳型
6	27.0	68.7	8.12	煤层中部	常规射孔	平稳型
7	17.0	64.9	8.71	煤层中部	常规射孔	平稳型
8	16.5	72.0	8.77	煤层上部	常规射孔	平稳型
9	36.0	62.6	7.02	下夹矸层顶	水平斜向上30°射孔	平稳型
10	19.5	68.2	7.56	煤层中部	常规射孔	缓慢下降型