Productivity Assessment of Tight Gas Wells after Fracturing based on Unstable Pressure Well Test Analysis

doi:10.3969/j.issn.1006-6535.2023.04.015

Abstract

Abstract: To solve the problem of difficultly predicting the productivity for tight gas reservoirs after fracturing, based on the seepage mechanism and considering the stress sensitivity of the formation and the effect of formation improvement after fracturing, a linear heterogeneous composite zone fractured well model applicable to the inversion of fracture pump-stop is established, the fracture parameters and formation parameters are determined by using the established model and numerical well tests, and the relationship between productivity and fracture scale before and after fracturing is established by applying SPSS regression method, to obtain the The relationship between productivity and fracture scale before and after fracturing was established by applying SPSS regression method, to obtain the productivity prediction method for tight gas reservoirs after fracturing. The study shows that the double logarithmic characteristic curves of shut-in pressure change after hydraulic fracture pump-stop can be divided into fracture linear flow stage, transition stage, interfacial flow stage, outer zone linear flow stage and boundary effect stage; the newly established productivity prediction method is applied to Well Block X in Yulin Gas Field, with the average error of productivity prediction of 16.1% and good applicability; the effects of different fracturing parameters on productivity are, in descending order, discharge volume, sand addition volume, and fracturing fluid volume, with the optimal fracturing discharge volume of 3.36-4.83 m³/min, the optimal sand addition volume of 56.95-77.66 m³, and the optimal fracturing fluid volume of 167.09-259.91 m³.The study results have certain guidance for optimizing the fracturing design and post-fracturing productivity prediction of tight gas reservoirs.

Key words: tight gas reservoir, pump-stop inversion, analytical model, numerical well test, production evaluation

CLC Number:

TE319

Wang Tao, Yu Haiyang, Zhao Pengfei, Li Jingsong, Liu Rumin, Kou Shuangyan, Wang Jing, Liao Shuang. Productivity Assessment of Tight Gas Wells after Fracturing based on Unstable Pressure Well Test Analysis[J]. Special Oil & Gas Reservoirs, 2023, 30(4): 122-130.

References

[1] 刘洪平,赵彦超,孟俊,等.压裂水平井产能预测方法研究综述[J].地质科技情报,2015,34(1):131-139.
LIU Hongping,ZHAO Yanchao,MENG Jun,et al.A methodologies of predicting the fractured horizontal well production[J].Geological Science and Technology Information,2015,34(1):131-139.
[2] 陈浩,杨明洋,王宇,等.大庆油田M2区块致密油藏缝网压裂直井初期产能预测[J].中国海上油气,2021,33(5):107-114.
CHEN Hao,YANG Mingyang,WANG Yu,et al.Initial productivity prediction of network fracturing vertical well in tight reservoir of M2 Block,Daqing Oilfield[J].China Offshore Oil and Gas,2021,33(5):107-114.
[3] 莫雯波.低渗透油藏分段压裂水平井产能评价研究[D].北京:中国石油大学(北京),2020.
MO Wenbo.Research on productivity evaluation of multistage fractured horizontal well in low permeability reservoirs[D].Beijing:China University of Petroleum(Beijing),2020.
[4] 季岭,刘钰铭,郭小龙,等.枣园油田孔缝型油藏单井产能地质控制因素研究[J].石油科学通报,2021,6(4):566-575.
JI Ling,LIU Yuming,GUO Xiaolong,et al.Geological controlling factors of single well productivity in perforated and fractured reservoir in Zaoyuan Oilfield[J].Petroleum Science Bulletin,2021,6(4):566-575.
[5] 胡晓东,涂志勇,罗英浩,等.拟合函数-神经网络协同的页岩气井产能预测模型[J].石油科学通报,2022,7(3):394-405.
HU Xiaodong,TU Zhiyong,LUO Yinghao,et al.Shale gas well productivity prediction model with fitted function-neural network cooperation[J].Petroleum Science Bulletin,2022,7(3):394-405.
[6] 窦宏恩.预测水平井产能的一种新方法[J].石油钻采工艺,1996,18(1):76-81,108.
DOU Hongen.A new method to predict the productivity of horizontal wells[J].Oil Drilling & Production Technology,1996,18(1):76-81,108.
[7] 宁正福,韩树刚,程林松,等.低渗透油气藏压裂水平井产能计算方法[J].石油学报,2002,23(2):68-71.
NING Zhengfu,HAN Shugang,CHENG Linsong,et al.Calculation method of productivity of fractured horizontal well in low permeability reservoir[J].Acta Petrolei Sinica,2002,23(2):68-71.
[8] 韩树刚,程林松,宁正福.气藏压裂水平井产能预测新方法[J].石油大学学报(自然科学版),2002,26(4):36-39.
HAN Shugang,CHENG Linsong,NING Zhengfu.A new method for predicting productivity of fractured horizontal wells in gas reservoir[J].Journal of China University of Petroleum(Edition of Natural Science),2002,26(4):36-39.
[9] 于国栋.水平井产能分析理论与方法研究[D].北京:中国地质大学(北京),2006.
YU Guodong.Research on theory and method of horizontal well productivity analysis[D].Beijing:China University of Geosciences(Beijing),2006.
[10] 王金鹤.压裂水平井产能评价[J].化学工程与装备,2022,47(2):78-79.
WANG Jinhe.Productivity evaluation of fractured horizontal wells[J].Chemical Engineering & Equipment,2022,47(2):78-79.
[11] 王忠利,张一军,顾学峰.利用测试资料预测压裂后最低产量的一种方法[J].油气井测试,2003,12(6):7-9,71.
WANG Zhongli,ZHANG Yijun,GU Xuefeng.A method of prediction the minimum production after fracturing from test data[J].Well Testing,2003,12(6):7-9,71.
[12] 何云.大牛地气田水平井动态产能预测方法[J].石油化工应用,2018,37(3):15-19,24.
HE Yun.Prediction method for dynamic productivity of horizontal wells in Daniudi Gasfield[J].Petrochemical Industry Application,2018,37(3):15-19,24.
[13] SHI J T,WU J Y,SUN Z,et al.Methods for simultaneously evaluating reserve and permeability of undersaturated coalbed methane reservoirs using production data during the dewatering stage[J].Petroleum Science,2020,17(4):1067-1086.
[14] 牛丽娟,徐健,于书新,等.致密油藏水平井压后产能评价技术及其应用[J].大庆石油地质与开发,2014,33(5):245-248.
NIU Lijuan,XU Jian,YU Shuxin,et al.Productivity evaluating technique and its application for the horizontal well after fractured in the tight oil reservoirs[J].Petroleum Geology & Oilfield Development in Daqing,2014,33(5):245-248.
[15] 周文武.低渗透油藏压裂水平井产能模拟研究[D].成都:西南石油大学,2018.
ZHOU Wenwu.Research on productivity simulation of fractured horizontal well in low permeability reservoir[D].Chengdu:Southwest Petroleum University,2018.
[16] 丰妍.低渗透致密砂岩气藏压裂水平井产能研究[D].成都:西南石油大学,2018.
FENG Yan.Research on productivity of fractured horizontal well in tight sandstone gas reservoir with low permeability[D].Chengdu:Southwest Petroleum University,2018.
[17] 徐建春.多级压裂水平井产能分析及数值模拟方法研究[D].青岛:中国石油大学(华东),2017.
XU Jianchun.Research on productivity analysis and numerical simulation method of multi-stage fractured horizontal well[D].Qingdao:China University of Petroleum(East China),2017.
[18] 李庆远.考虑天然裂缝影响的火山岩气藏压裂水平井产能研究[D].大庆:东北石油大学,2022.
LI Qingyuan.Research on productivity of fractured horizontal wells in volcanic gas reservoirs considering the influence of natural fractures[D].Daqing:Northeast Petroleum University,2022.
[19] XUE L,GU S H,JIANG X E,et al.Ensemble-based optimization of hydraulically fractured horizontal well placement in shale gas reservoir through Hough transform parameterization[J].Petroleum Science,2021,18(3):839-851.
[20] 何佑伟,程时清,胡利民,等.多段压裂水平井不均匀产油试井模型[J].中国石油大学学报(自然科学版),2017,41(4):116-123.
HE Youwei,CHENG Shiqing,HU Limin,et al.A pressure transient analysis model of multi-fractured horizontal well in consideration of unequal production of each fracture[J].Journal of China University of Petroleum(Edition of Natural Sciences),2017,41(4):116-123.
[21] 严谨,何佑伟,史云清,等.致密气藏水平井压裂缝不均匀产气试井分析[J].天然气地球科学,2017,28(6):839-845.
YAN Jin,HE Youwei,SHI Yunqing,et al.Well testing analysis of multi-fractured horizontal well with unequal gas production of fractures in tight gas reservoir[J].Natural Gas Geoscience,2017,28(6):839-845.
[22] 秦佳正,程时清,何佑伟,等.压裂水平井裂缝和水平井筒不规则产油试井分析[J].大庆石油地质与开发,2018,37(2):88-95.
QIN Jiazheng,CHENG Shiqing,HE Youwei,et al.Well test analyses of the non-uniform oil production from the fractured horizontal well fractures and its wellbore[J].Petroleum Geology & Oilfield Development in Daqing,2018,37(2):88-95.
[23] 齐松超,于海洋,杨海烽,等.致密砂岩逆向渗吸作用距离实验研究[J].力学学报,2021,53(9):2603-2611.
QI Songchao,YU Haiyang,YANG Haifeng,et al.Experimental research on quantification of countercurrent imbibition distance for tight sandstone[J].Chinese Journal of Theoretical and Applied Mechanics,2021,53(9):2603-2611.
[24] 陈志明,陈昊枢,廖新维,等.基于试井分析的新疆吉木萨尔页岩油藏人工缝网参数反演研究[J].石油科学通报,2019,4(3):263-272.
CHEN Zhiming,CHEN Haoshu,LIAO Xinwei,et al.A well-test based study for parameter estimations of artificial fracture networks in the Jimsar shale reservoir in Xinjiang[J].Petroleum Science Bulletin,2019,4(3):263-272.
[25] PEDROSA O A J.Pressure transient response in stress-sensitive formations[C].SPE15115-MS,1986:110-125.
[26] EKATERINA S,LOUIS M.Analytical model for unconventional multifractured composite systems[C].SPE162516-PA,2013:246-256.
[27] 陈志明,王佳楠,廖新维,等.海陆过渡相页岩气藏不稳定渗流数学模型[J].力学学报,2021,53(8):2257-2266.
CHEN Zhiming,WANG Jianan,LIAO Xinwei,et al.An unstable porous flow model of marine-continental transitional shale gas reservoir[J].Chinese Journal of Theoretical and Applied Mechanics,2021,53(8):2257-2266.
[28] 傅建斌.考虑多因素影响的致密气藏压裂井产能预测方法[J].断块油气田,2021,28(2):156-161.
FU Jianbin.Productivity prediction method of fractured wells in tight gas reservoir considering multi factors[J].Fault-Block Oil & Gas Field,2021,28(2):156-161.
[29] 李宪文, 王历历, 王文雄, 等.基于小井眼完井的压裂关键技术创新与高效开发实践——以苏里格气田致密气藏为例[J].天然气工业, 2022, 42(9):76-83.
LI Xianwen, WANG Lili, WANG Wenxiong, et al.Innovation and efficient development practice of key fracturing technologies based on slim-hole completion: a case study of tight gas reservoir in Sulige Gasfield[J].Natural Gas Industry, 2022, 42(9):76-83.