四川盆地威远区块典型平台页岩气水平井动态特征及开发建议
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摘要
位于四川盆地长宁—威远国家级页岩气示范区范围内的威远页岩气田(以下简称威远区块),同一平台上气井的生产动态特征存在着较大的差异,目前对于其页岩气井产气量的主控因素和开发工艺措施的有效性认识尚不明确。为此,以威远区块PT2平台的6口水平井为例,针对气井生产动态存在的差异,从钻遇优质页岩段的长度、水平段轨迹倾向、压裂段长度、改造段数、加砂量及井底积液等方面进行分析,明确了影响威远区块页岩气水平井产气量的主要因素,进而提出了有针对性的开发措施建议。研究结果表明:(1)优质页岩段钻遇长度是气井高产的物质地质保障,水平压裂段长度、改造段数/簇数和加砂量是主要的工程因素;(2)页岩气井生产早期均为带液生产且水气比较大,当产气量低于临界携液流量时,井底积液对产气量和井口压力的影响不容忽视;(3)建议低产井应采用小油管生产(油管内径小于等于62 mm),对于上半支低产井,应及早采取橇装式排水采气工具和措施以释放气井产能,而对于下半支低产井,则应放压生产,防止井底过早积液。
The Weiyuan Shale Gas Field(hereinafter, "Weiyuan Block" for short) is located in the Changning–Weiyuan National Shale Gas Demonstration Region, Sichuan Basin. In the Weiyuan Block, gas wells even on the same platform are quite different in production performance. And so far, the main factors controlling the gas production rate of shale gas wells in this block and the effectiveness of their development technologies and measures have not been understood clearly. In this paper, 6 horizontal wells on PT2 platform in the Weiyuan Block were taken as the research objects. Aiming at the differences of production performance between these gas wells, this paper analyzes the high-quality shale drilling length, dip direction of horizontal section, length of fracturing interval, number of fracturing stages, sand volume and bottom-hole liquid loading to figure out the main factors affecting the gas production rate of shale-gas horizontal wells. Then, it proposes the targeted development measures and suggestions. And the following research results were obtained. First, high-quality shale drilling length is the material and geological guarantee for the high yield of gas wells, and length of horizontal fracturing interval, number of fracturing stages/clusters and sand volume are the main engineering factors. Second, in the early production stage of shale gas wells, the produced gas contains liquid with higher water–gas ratios. When gas production rate is lower than the critical liquid-carrying flow rate, the effect of bottom-hole liquid loading on gas production rate and wellhead pressure cannot be ignored. Third, it is recommended that small tubing(ID≤62 mm) be applied to low-yield wells. When the upward inclined well has low production, skid-mounted drainage gas recovery tools and measures shall be adopted as early as possible to release gas well productivity. And when the downward inclined well has low production, the production method of decreasing tubing pressure shall be adopted to prevent the early bottom-hole liquid loading.
The Weiyuan Shale Gas Field(hereinafter, "Weiyuan Block" for short) is located in the Changning–Weiyuan National Shale Gas Demonstration Region, Sichuan Basin. In the Weiyuan Block, gas wells even on the same platform are quite different in production performance. And so far, the main factors controlling the gas production rate of shale gas wells in this block and the effectiveness of their development technologies and measures have not been understood clearly. In this paper, 6 horizontal wells on PT2 platform in the Weiyuan Block were taken as the research objects. Aiming at the differences of production performance between these gas wells, this paper analyzes the high-quality shale drilling length, dip direction of horizontal section, length of fracturing interval, number of fracturing stages, sand volume and bottom-hole liquid loading to figure out the main factors affecting the gas production rate of shale-gas horizontal wells. Then, it proposes the targeted development measures and suggestions. And the following research results were obtained. First, high-quality shale drilling length is the material and geological guarantee for the high yield of gas wells, and length of horizontal fracturing interval, number of fracturing stages/clusters and sand volume are the main engineering factors. Second, in the early production stage of shale gas wells, the produced gas contains liquid with higher water–gas ratios. When gas production rate is lower than the critical liquid-carrying flow rate, the effect of bottom-hole liquid loading on gas production rate and wellhead pressure cannot be ignored. Third, it is recommended that small tubing(ID≤62 mm) be applied to low-yield wells. When the upward inclined well has low production, skid-mounted drainage gas recovery tools and measures shall be adopted as early as possible to release gas well productivity. And when the downward inclined well has low production, the production method of decreasing tubing pressure shall be adopted to prevent the early bottom-hole liquid loading.
引文
[1]邹才能,董大忠,王玉满,李新景,黄金亮,王淑芳,等.中国页岩气特征、挑战及前景(二)[J].石油勘探与开发,2016,43(2):1-13.Zou Caineng,Dong Dazhong,Wang Yuman,Li Xinjing,Huang Jinliang,Wang Shufang,et al.Shale gas in China:Characteristics,challenges and prospects(Ⅱ)[J].Petroleum Exploration and Development,2016,43(2):1-13.
[2]王红岩,刘玉章,董大忠,赵群,杜东.中国南方海相页岩气高效开发的科学问题[J].石油勘探与开发,2013,40(5):574-579.Wang Hongyan,Liu Yuzhang,Dong Dazhong,Zhao Qun&Du Dong.Scientific issues on effective development of marine shale gas in southern China[J].Petroleum Exploration and Development,2013,40(5):574-579.
[3]李文阳,邹洪岚,吴纯忠,王永辉.从工程技术角度浅析页岩气的开采[J].石油学报,2013,34(6):1218-1224.Li Wenyang,Zou Honglan,Wu Chunzhong&Wang Yonghui.An analysis of shale gas development in view of engineering technologies[J].Acta Petrolei Sinica,2013,34(6):1218-1224.
[4]王玉满,董大忠,李建忠,王社教,李新景,王黎,等.川南下志留统龙马溪组页岩气储层特征[J].石油学报,2012,33(4):551-561.Wang Yuman,Dong Dazhong,Li Jianzhong,Wang Shejiao,Li Xinjing,Wang Li,et al.Reservoir characteristics of shale gas in Longmaxi Formation of the Lower Silurian,southern Sichuan[J].Acta Petrolei Sinica,2012,33(4):551-561.
[5]贾爱林,位云生,金亦秋.中国海相页岩气开发评价关键技术进展[J].石油勘探与开发,2016,43(6):949-955.Jia Ailin,Wei Yunsheng&Jin Yiqiu.Progress in key technologies for evaluating marine shale gas development in China[J].Petroleum Exploration and Development,2016,43(6):949-955.
[6]Wang Junlei&Jia Ailin.A general productivity model for optimization of multiple fractures with heterogeneous properties[J].Journal of Natural Gas Science and Engineering,2014,21(2):608-624.
[7]王军磊,贾爱林,位云生,赵文琪.有限导流压裂水平气井拟稳态产能计算及优化[J].中国石油大学学报(自然科学版),2016,40(1):100-107.Wang Junlei,Jia Ailin,Wei Yunsheng&Zhao Wenqi.Pseudo steady productivity evaluation and optimization for horizontal well with multiple finite conductivity fractures in gas reservoirs[J].Journal of China University of Petroleum(Edition of Natural Science),2016,40(1):100-107.
[8]Wang Junlei,Yan Cunzhang,Jia Ailin,He Dongbo,Wei Yunsheng&Qi Yadong.Rate decline analysis of multiple fractured horizontal well in shale reservoirs with triple continuum[J].Journal of Central South University,2014,21(11):4320-4329.
[9]王军磊,贾爱林,何东博,位云生,齐亚东.致密气藏分段压裂水平井产量递减规律及影响因素[J].天然气地球科学,2014,25(2):278-285.Wang Junlei,Jia Ailin,He Dongbo,Wei Yunsheng&Qi Yadong.Rate decline of multiple fractured horizontal well and influence factors on productivity in tight gas reservoirs[J].Natural Gas Geoscience,2014,25(2):278-285.
[10]王晓泉,张守良,吴奇,刘玉章,雷群,丁云宏.水平井分段压裂多段裂缝产能影响因素分析[J].石油钻采工艺,2009,31(1):73-76.Wang Xiaoquan,Zhang Shouliang,Wu Qi,Liu Yuzhang,Lei Qun&Ding Yunhong.Factors affecting the productivity of multi-section fractures in subsection fracturing of horizontal wells[J].Oil Drilling&Production Technology,2009,31(1):73-76.
[11]廖开贵,李颍川,杨志,钟海全.产水气藏气液两相管流动态规律研究[J].石油学报,2009,3(4):607-612.Liao Kaigui,Li Yingchuan,Yang Zhi&Zhong Haiquan.Study on pressure drop models of gas-liquid two-phase pipe flow in gas reservoir[J].Acta Petrolei Sinica,2009,3(4):607-612.
[12]李闽,郭平,谭光天.气井携液新观点[J].石油勘探与开发,2001,28(5):105-106.Li Min,Guo Ping&Tan Guangtian.New look on removing liquids from gas wells[J].Petroleum Exploration and Development,2001,28(5):105-106.
[13]李闽,孙雷,李士伦.一个新的气井连续排液模型[J].天然气工业,2001,21(5):61-63.Li Min,Sun Lei&Li Shilun.A new gas well liquid continuous withdrawal model[J].Natural Gas Industry,2001,21(5):61-63.
[14]李闽,郭平,张茂林,梅海燕,刘武,李士伦.气井连续携液模型比较研究[J].西南石油学院学报,2002,24(4):30-32.Li Min,Guo Ping,Zhang Maolin,Mei Haiyan,Liu Wu&Li Shilun.Comparative study of two models for continuous removal of liquids from gas wells[J].Journal of Southwest Petroleum Institute,2002,24(4):30-32.
[15]谢军,赵圣贤,石学文,张鉴.四川盆地页岩气水平井高产的地质主控因素[J],天然气工业,2017,37(7):1-12.Xie Jun,Zhao Shengxian,Shi Xuewen&Zhang Jian.Main geological factors controlling high production of horizontal shale gas wells in the Sichuan Basin[J].Natural Gas Industry,2017,37(7):1-12.
[16]张晓明,石万忠,徐清海,王任,徐壮,王健,等.四川盆地焦石坝地区页岩气储层特征及控制因素[J].石油学报,2015,36(8):926-939.Zhang Xiaoming,Shi Wanzhong,Xu Qinghai,Wang Ren,Xu Zhuang,Wang Jian,et al.Reservoir characteristics and controlling factors of shale gas on Jiaoshiba area,Sichuan Basin[J].Acta Petrolei Sinica,2015,36(8):926-939.
[17]郭彤楼,张汉荣.四川盆地焦石坝页岩气田形成与富集高产模式[J].石油勘探与开发,2014,41(1):28-36.Guo Tonglou&Zhang Hanrong.Formation and enrichment mode of Jiaoshiba shale gas field,Sichuan Basin[J].Petroleum Exploration and Development,2014,41(1):28-36.
[18]李庆辉,陈勉,Wang FP,金衍,李志猛.工程因素对页岩气产量的影响--以北美Haynesville页岩气藏为例[J].天然气工业,2012,32(4):54-59.Li Qinghui,Chen Mian,Wang FP,Jin Yan&Li Zhimeng.Influences of engineering factors on shale gas productivity:A case study from the Haynesville shale gas reservoir in North America[J].Natural Gas Industry,2012,32(4):54-59.
[19]贾成业,贾爱林,何东博,位云生,齐亚东,王军磊.页岩气水平井产量影响因素分析[J].天然气工业,2017,37(4):80-88.Jia Chengye,Jia Ailin,He Dongbo,Wei Yunsheng,Qi Yadong&Wang Junlei.Key factors influencing shale gas horizontal well production[J].Natural Gas Industry,2017,37(4):80-88.
[20]雷征东,覃斌,刘双双,蔚涛.页岩气藏水力压裂渗吸机理数值模拟研究[J].西南石油大学学报(自然科学版),2017,39(2):118-124.Lei Zhengdong,Qin Bin,Liu Shuangshuang&Wei Tao.Imbibition mechanism of hydraulic fracturing in shale gas reservoir[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(2):118-124.
[21]张书平,吴革生,白晓弘,程小莉,李耀德.橇装式小直径管排水采气工艺技术[J].天然气工业,2008,28(8):92-94.Zhang Shuping,Wu Gesheng,Bai Xiaohong,Cheng Xiaoli&Li Yaode.Technology of gas production by dewatering through skid-mounted and small-diameter pipes[J].Natural Gas Industry,2008,28(8):92-94.
[22]叶长青,熊杰,康琳洁,彭杨,陈家晓.川渝气区排水采气工具研制新进展[J].天然气工业,2015,35(2):54-58.Ye Changqing,Xiong Jie,Kang Linjie,Peng Yang&Chen Jiaxiao.New progress in the R&D of water drainage gas recovery tools in Sichuan and Chongqing gas zones[J].Natural Gas Industry,2015,35(2):54-58.
[2]王红岩,刘玉章,董大忠,赵群,杜东.中国南方海相页岩气高效开发的科学问题[J].石油勘探与开发,2013,40(5):574-579.Wang Hongyan,Liu Yuzhang,Dong Dazhong,Zhao Qun&Du Dong.Scientific issues on effective development of marine shale gas in southern China[J].Petroleum Exploration and Development,2013,40(5):574-579.
[3]李文阳,邹洪岚,吴纯忠,王永辉.从工程技术角度浅析页岩气的开采[J].石油学报,2013,34(6):1218-1224.Li Wenyang,Zou Honglan,Wu Chunzhong&Wang Yonghui.An analysis of shale gas development in view of engineering technologies[J].Acta Petrolei Sinica,2013,34(6):1218-1224.
[4]王玉满,董大忠,李建忠,王社教,李新景,王黎,等.川南下志留统龙马溪组页岩气储层特征[J].石油学报,2012,33(4):551-561.Wang Yuman,Dong Dazhong,Li Jianzhong,Wang Shejiao,Li Xinjing,Wang Li,et al.Reservoir characteristics of shale gas in Longmaxi Formation of the Lower Silurian,southern Sichuan[J].Acta Petrolei Sinica,2012,33(4):551-561.
[5]贾爱林,位云生,金亦秋.中国海相页岩气开发评价关键技术进展[J].石油勘探与开发,2016,43(6):949-955.Jia Ailin,Wei Yunsheng&Jin Yiqiu.Progress in key technologies for evaluating marine shale gas development in China[J].Petroleum Exploration and Development,2016,43(6):949-955.
[6]Wang Junlei&Jia Ailin.A general productivity model for optimization of multiple fractures with heterogeneous properties[J].Journal of Natural Gas Science and Engineering,2014,21(2):608-624.
[7]王军磊,贾爱林,位云生,赵文琪.有限导流压裂水平气井拟稳态产能计算及优化[J].中国石油大学学报(自然科学版),2016,40(1):100-107.Wang Junlei,Jia Ailin,Wei Yunsheng&Zhao Wenqi.Pseudo steady productivity evaluation and optimization for horizontal well with multiple finite conductivity fractures in gas reservoirs[J].Journal of China University of Petroleum(Edition of Natural Science),2016,40(1):100-107.
[8]Wang Junlei,Yan Cunzhang,Jia Ailin,He Dongbo,Wei Yunsheng&Qi Yadong.Rate decline analysis of multiple fractured horizontal well in shale reservoirs with triple continuum[J].Journal of Central South University,2014,21(11):4320-4329.
[9]王军磊,贾爱林,何东博,位云生,齐亚东.致密气藏分段压裂水平井产量递减规律及影响因素[J].天然气地球科学,2014,25(2):278-285.Wang Junlei,Jia Ailin,He Dongbo,Wei Yunsheng&Qi Yadong.Rate decline of multiple fractured horizontal well and influence factors on productivity in tight gas reservoirs[J].Natural Gas Geoscience,2014,25(2):278-285.
[10]王晓泉,张守良,吴奇,刘玉章,雷群,丁云宏.水平井分段压裂多段裂缝产能影响因素分析[J].石油钻采工艺,2009,31(1):73-76.Wang Xiaoquan,Zhang Shouliang,Wu Qi,Liu Yuzhang,Lei Qun&Ding Yunhong.Factors affecting the productivity of multi-section fractures in subsection fracturing of horizontal wells[J].Oil Drilling&Production Technology,2009,31(1):73-76.
[11]廖开贵,李颍川,杨志,钟海全.产水气藏气液两相管流动态规律研究[J].石油学报,2009,3(4):607-612.Liao Kaigui,Li Yingchuan,Yang Zhi&Zhong Haiquan.Study on pressure drop models of gas-liquid two-phase pipe flow in gas reservoir[J].Acta Petrolei Sinica,2009,3(4):607-612.
[12]李闽,郭平,谭光天.气井携液新观点[J].石油勘探与开发,2001,28(5):105-106.Li Min,Guo Ping&Tan Guangtian.New look on removing liquids from gas wells[J].Petroleum Exploration and Development,2001,28(5):105-106.
[13]李闽,孙雷,李士伦.一个新的气井连续排液模型[J].天然气工业,2001,21(5):61-63.Li Min,Sun Lei&Li Shilun.A new gas well liquid continuous withdrawal model[J].Natural Gas Industry,2001,21(5):61-63.
[14]李闽,郭平,张茂林,梅海燕,刘武,李士伦.气井连续携液模型比较研究[J].西南石油学院学报,2002,24(4):30-32.Li Min,Guo Ping,Zhang Maolin,Mei Haiyan,Liu Wu&Li Shilun.Comparative study of two models for continuous removal of liquids from gas wells[J].Journal of Southwest Petroleum Institute,2002,24(4):30-32.
[15]谢军,赵圣贤,石学文,张鉴.四川盆地页岩气水平井高产的地质主控因素[J],天然气工业,2017,37(7):1-12.Xie Jun,Zhao Shengxian,Shi Xuewen&Zhang Jian.Main geological factors controlling high production of horizontal shale gas wells in the Sichuan Basin[J].Natural Gas Industry,2017,37(7):1-12.
[16]张晓明,石万忠,徐清海,王任,徐壮,王健,等.四川盆地焦石坝地区页岩气储层特征及控制因素[J].石油学报,2015,36(8):926-939.Zhang Xiaoming,Shi Wanzhong,Xu Qinghai,Wang Ren,Xu Zhuang,Wang Jian,et al.Reservoir characteristics and controlling factors of shale gas on Jiaoshiba area,Sichuan Basin[J].Acta Petrolei Sinica,2015,36(8):926-939.
[17]郭彤楼,张汉荣.四川盆地焦石坝页岩气田形成与富集高产模式[J].石油勘探与开发,2014,41(1):28-36.Guo Tonglou&Zhang Hanrong.Formation and enrichment mode of Jiaoshiba shale gas field,Sichuan Basin[J].Petroleum Exploration and Development,2014,41(1):28-36.
[18]李庆辉,陈勉,Wang FP,金衍,李志猛.工程因素对页岩气产量的影响--以北美Haynesville页岩气藏为例[J].天然气工业,2012,32(4):54-59.Li Qinghui,Chen Mian,Wang FP,Jin Yan&Li Zhimeng.Influences of engineering factors on shale gas productivity:A case study from the Haynesville shale gas reservoir in North America[J].Natural Gas Industry,2012,32(4):54-59.
[19]贾成业,贾爱林,何东博,位云生,齐亚东,王军磊.页岩气水平井产量影响因素分析[J].天然气工业,2017,37(4):80-88.Jia Chengye,Jia Ailin,He Dongbo,Wei Yunsheng,Qi Yadong&Wang Junlei.Key factors influencing shale gas horizontal well production[J].Natural Gas Industry,2017,37(4):80-88.
[20]雷征东,覃斌,刘双双,蔚涛.页岩气藏水力压裂渗吸机理数值模拟研究[J].西南石油大学学报(自然科学版),2017,39(2):118-124.Lei Zhengdong,Qin Bin,Liu Shuangshuang&Wei Tao.Imbibition mechanism of hydraulic fracturing in shale gas reservoir[J].Journal of Southwest Petroleum University(Science&Technology Edition),2017,39(2):118-124.
[21]张书平,吴革生,白晓弘,程小莉,李耀德.橇装式小直径管排水采气工艺技术[J].天然气工业,2008,28(8):92-94.Zhang Shuping,Wu Gesheng,Bai Xiaohong,Cheng Xiaoli&Li Yaode.Technology of gas production by dewatering through skid-mounted and small-diameter pipes[J].Natural Gas Industry,2008,28(8):92-94.
[22]叶长青,熊杰,康琳洁,彭杨,陈家晓.川渝气区排水采气工具研制新进展[J].天然气工业,2015,35(2):54-58.Ye Changqing,Xiong Jie,Kang Linjie,Peng Yang&Chen Jiaxiao.New progress in the R&D of water drainage gas recovery tools in Sichuan and Chongqing gas zones[J].Natural Gas Industry,2015,35(2):54-58.