深层页岩油藏具有高闭合压力、高地层温度、高弹性模量的特点,通过压裂获得高导流能力裂缝的难度较大。为实现对深层页岩气藏压裂缝的有效支撑与维持,以四川威远区块深层页岩为例,基于自主改进的API裂缝导流能力测试平台,研究了高闭合压力(82.8 MPa)和高地层温度(160 ℃)对支撑裂缝导流能力的影响规律,对比了不同支撑剂类型和组合方式下导流能力的差异,分析了自支撑裂缝在深层页岩条件下的适应性。研究表明:高闭合压力是支撑裂缝导流能力降低的主控因素,在82.8 MPa的高闭合压力下,增加铺砂浓度对导流能力的正向效果已不再明显;高温环境会增大支撑剂的破碎与嵌入程度,温度越高,导流能力越低;40/70目陶粒支撑剂的裂缝导流能力明显大于70/140目石英砂和微纳米支撑剂的导流能力;石英砂与陶粒(质量比为1∶1)分段铺置比全域混合铺置的导流能力高,更具有经济性;自支撑裂缝壁面的凸起点在高闭合压力下易被压碎,导流能力呈现较强的应力敏感,不利于生产后期导流能力的维持。该研究结果可为深层页岩气藏压裂参数的设计和导流能力的优化提供理论支撑。
Deep shale reservoirs are characterized by high closure pressure,high formation temperature,and high elastic modulus,making it challenging to achieve high conductivity fractures through fracturing.To effectively support and maintain pressure fractures in deep shale gas reservoirs,taking the deep shale of the Weiyuan Block in Sichuan as an example,based on an self-developed testing platform of API fracture conductivity,this study investigated the impact of high closure pressure (82.8 MPa) and high formation temperature (160 ℃) on the conductivity of supported fractures.The differences in conductivity under different types and combinations of proppants are compared,and the adaptability of self-supported fractures under deep shale conditions is analyzed.The results indicates that the high closure pressure is the main controlling factor for the decrease of fracture conductivity.Under the high closure pressure of 82.8 MPa,the positive effect of increasing sand concentration on conductivity is no longer evident;the high-temperature environment increases the degree of proppant breakage and embedment,with higher temperatures resulting in lower conductivity;the fracture conductivity of 40/70 mesh ceramsite proppant is significantly greater than that of 70/140 mesh quartz sand and micro-nano proppants;the conductivity of quartz sand and ceramsite (mass ratio of 1∶1) placed in sections is more economical and has higher conductivity than the whole mixed placement;the convex points on the wall of self-supported fractures are easily crushed under high closure pressure,showing strong stress sensitivity in conductivity,which is not conducive to maintaining conductivity in the later stages of production.The results of this study provide theoretical support for the design of fracturing parameters and optimization of conductivity in deep shale gas reservoirs.
[1] 谢军.长宁-威远国家级页岩气示范区建设实践与成效[J].天然气工业,2018,38(2):1-7.
XIE Jun.Practices and achievements of the Changning-Weiyuan shale gas national demonstration project construction[J].Natural Gas Industry,2018,38(2):1-7.
[2] 刘红磊,周林波,陈作,等.中国石化页岩气电动压裂技术现状及发展建议[J].石油钻探技术,2023,51(1):62-68.
LIU Honglei,ZHOU Linbo,CHEN Zuo,et al.The up-to-date electric shale gas fracturing technologies of Sinopec and suggestions for further improvements[J].Petroleum Drilling Techniques,2023,51(1):62-68.
[3] 马新华.天然气与能源革命——以川渝地区为例[J].天然气工业,2017,37(1):1-8.
MA Xinhua.Natural gas and energy revolution:a case study of Sichuan-Chongqing gas province[J].Natural Gas Industry,2017,37(1):1-8.
[4] 郭建春,赵峰,詹立,等.四川盆地页岩气储层暂堵转向压裂技术进展及发展建议[J].石油钻探技术,2023,51(4):170-183.
GUO Jianchun,ZHAO Feng,ZHAN Li,et al.Recent advances and development suggestions of temporary plugging and diverting fracturing technology for shale gas reservoirs in the Sichuan Basin[J].Petroleum Drilling Techniques,2023,51(4):170-183.
[5] 舒红林,刘臣,李志强,等.昭通浅层页岩气压裂复杂裂缝扩展数值模拟研究[J].石油钻探技术,2023,51(6):77-84.
SHU Honglin,LIU Chen,LI Zhiqiang,et al.Numerical simulation of complex fracture propagation in shallow shale gas fracturing in Zhaotong[J].Petroleum Drilling Techniques,2023,51(6):77-84.
[6] MIDDLETON R S,GUPTA R,HYMAN J D,et al.The shale gas revolution:barriers,sustainability,and emerging opportunities[J].Applied Energy,2017,199(1):88-95.
[7] 龙胜祥,冯动军,李凤霞,等.四川盆地南部深层海相页岩气勘探开发前景[J].天然气地球科学,2018,29(4):443-451.
LONG Shengxiang,FENG Dongjun,LI Fengxia,et al.Prospect of the deep marine shale gas exploration and development in the Sichuan Basin[J].Natural Gas Geoscience,2018,29(4):443-451.
[8] 龚月,高和群,李小越,等.四川盆地及周缘页岩气赋存方式展布特征研究[J].非常规油气,2023,10(2):49-56.
GONG Yue,GAO Hequn,LI Xiaoyue,et al.Study on the distribution characteristics of occurrence modes of shale gas in the Sichuan Basin and its periphery[J].Unconventional Oil & Gas,2023,10(2):49-56.
[9] 谭宾.四川盆地南部地区深层页岩气工程关键技术与展望[J].天然气工业,2022,42(8):212-219.
TAN Bin.Key technologies and prospects of deep shale gas engineering in the southern Sichuan Basin[J].Natural Gas Industry,2022,42(8):212-219.
[10] 赵振峰,王文雄,徐晓晨,等.鄂尔多斯盆地海相深层页岩气压裂技术[J].石油钻探技术,2023,51(5):23-32.
ZHAO Zhenfeng,WANG Wenxiong,XU Xiaochen,et al.Hydraulic fracturing technology for deep marine shale gas in Ordos Basin[J].Petroleum Drilling Techniques,2023,51(5):23-32.
[11] 马新华,谢军,雍锐,等.四川盆地南部龙马溪组页岩气储集层地质特征及高产控制因素[J].石油勘探与开发,2020,47(5):841-855.
MA Xinhua,XIE Jun,YONG Rui,et al.Geological characteristics and high production control factors of shale gas reservoirs in Silurian Longmaxi Formation,southern Sichuan Basin,SW China[J].Petroleum Exploration and Development,2020,47(5):841-855.
[12] 曾义金,陈作,卞晓冰.川东南深层页岩气分段压裂技术的突破与认识[J].天然气工业,2016,36(1):61-67.
ZENG Yijin,CHEN Zuo,BIAN Xiaobing.Breakthrough in staged fracturing technology for deep shale gas reservoirs in SE Sichuan Basin and its implications[J].Natural Gas Industry,2016,36(1):61-67.
[13] 梁天成,才博,蒙传幼,等.水力压裂支撑剂性能对导流能力的影响[J].断块油气田,2021,28(3):403-407.
LIANG Tiancheng,CAI Bo,MENG Chuanyou,et al.The effect of proppant performance of hydraulic fracturing on conductivity[J].Fault-Block Oil & Gas Field,2021,28(3):403-407.
[14] 赵越哲.变温环境下多尺度支撑剂对裂缝导流能力影响研究[D].常州:常州大学,2021.
ZHAO Yuezhe.Study on the influence of multi-scale proppant on fracture conductivity under variable temperature environment[D].Changzhou:Changzhou University,2021.
[15] 陈迟.页岩气藏清水压裂自支撑裂缝导流能力研究[D].成都:西南石油大学,2014.
CHEN Chi.Study on flow conductivity of self-supporting fracture in water fracturing of shale gas reservoir[D].Chengdu:SouthWest Petroleum University,2014.
[16] 何治亮,聂海宽,胡东风,等.深层页岩气有效开发中的地质问题——以四川盆地及其周缘五峰组—龙马溪组为例[J].石油学报,2020,41(4):379-391.
HE Zhiliang,NIE Haikuan,HU Dongfeng,et al.Geological problems in the effective development of deep shale gas:a case study of Upper Ordovician Wufeng-Lower Silurian Longmaxi Formations in Sichuan Basin and its periphery[J].Acta Petrolei Sinica,2020,41(4):379-391.
[17] 毕文韬.页岩储层支撑裂缝导流能力影响因素研究[D].东营:中国石油大学(华东),2016.
BI Wentao.Study on influencing factors of fracture conductivity of shale reservoir support[D].Dongying:China University of Petroleum (East China),2016.
[18] FREEMAN E R,ANSCHUTZ D A,RICKARDS A R,et al.Modified API/ISO crush tests with a liquid-saturated proppant under pressure incorporating temperature,time,and cyclic loading:what does it tell us?[C].SPE118929-MS,2009:1-7.
辽公网安备 21110002000031号 辽ICP备18011648号-1
