Production Decline Analysis of Vertical Well with Multi⁃Layer Network Fracturing in Tight Oil Reservoir

doi:10.3969/j.issn.1006-396X.2021.05.008

Abstract

Abstract:

For improving reservoir permeability and increasing oil well production, fracture network fracturing is often chosen for tight oil reservoirs with longitudinal direction multi?layer development. A transient flow model for multi?layer fracture network fracturing in vertical wells is established. After fracturing, each layer is divided into artificial fracture area, stimulated reservoir volume (SRV) area and unstimulated reservoir volume area. The Blasingame production decline curves are drawn and analyzed. The curve is divided into 7 flow stages. When the total fracture length is fixed, the fluid seepage of the half?length fracture firstly reaches the unstimulated reservoir volume area. The fluid seepage resistance is large, and the Blasingame curve is in lower region. When the total stimulated reservoir volume is fixed during the simulation, the larger the difference of each layer exist in the stimulated reservoir volume of the reconstruction, the lower the Blasingame curve stay. The established model is used to interpret the measured production data and the relevant formation parameters, such as the fracture half?length of each layer and the permeability of the stimulated reservoir volume area, are obtained. This model has directive significance for the production analysis of vertical wells with multi?layer fracture network fracturing.

Key words: Tight oil reservoir, Network fracturing, Type curves, Production decline

摘要：

垂向多层发育的致密油藏常采用缝网压裂进行开采，从而改善储层渗透率，提高油井产量。为此建立直井多层缝网压裂不稳定渗流数学模型，压裂后各层划分为人工裂缝区、改造区和未改造区。绘制分析Blasingame产量递减典型曲线，曲线分为7个流动阶段，总裂缝长度一定时，裂缝半长短的储层流体渗流率先到达未改造区，流体渗流阻力大，Blasingame曲线靠下；总改造体积一定时，各层改造体积差异越大，Blasingame曲线越靠下。用所建立的模型，对实测生产资料进行解释，获得各层裂缝半长、改造区渗透率等相关地层参数，该模型对进行多层缝网压裂直井产量分析具有指导意义。

关键词: 致密油藏, 缝网压裂, 典型曲线, 产量递减

CLC Number:

TE357

Li Dai, Hongjun Yin, Hongfei Yuan, Fansong Meng. Production Decline Analysis of Vertical Well with Multi⁃Layer Network Fracturing in Tight Oil Reservoir[J]. Journal of Petrochemical Universities, 2021, 34(5): 50-55.

代立, 尹洪军, 袁鸿飞, 孟凡嵩. 致密油藏直井多层缝网压裂产量递减分析[J]. 石油化工高等学校学报, 2021, 34(5): 50-55.

Figures/Tables 11

Fig.1 Schematic diagram of physical model of multi-layer fracture network fracturing in vertical well

Fig.2 Blasingame production decline type curves

Fig.3 Fracture half-length analysis

Fig.4 Fracture conductivity analysis

Fig.5 Permeability ratio of SRV area analysis

Fig.6 Stimulate reservoir volume analysis

Table 1 Basic parameters

层位	有效厚度/m	有效孔隙度	黏度/(mPa·s)	综合压缩系数/(MPa^-1)
FⅢ3⁃1	1.3	0.121	2.53	0.015 35
FⅡ3⁃3	2.9	0.100	2.53	0.015 35
FⅡ3⁃2	0.7	0.121	2.53	0.015 35
FⅠ7	1.4	0.121	2.53	0.015 35

Fig.7 Production transient curve of well A

Fig.8 Blasingame matching curve

Fig.9 Production history matching curve

Table 2 Permeability and conductivity

层位	裂缝半长/m	改造区渗透率/(10^-3μm²)	裂缝导流能力/(μm²·cm)
FⅢ3⁃1	184.97	6.56	40.71
FⅡ3⁃3	178.72	8.01	48.03
FⅡ3⁃2	188.40	4.04	25.34
FⅠ7	190.37	4.15	25.67

References 16

1	邹才能，张国生，杨智，等.非常规油气概念、特征、潜力及技术——兼论非常规油气地质学［J］.石油勘探与开发，2013，40（4）：385⁃399.
	Zou C N，Zhang G S，Yang Z，et al.Geological concepts，characteristics，resource potential and key techniques of unconventional hydrocarbon：On unconventional petroleum geology［J］.Petroleum Exploration and Development，2013，40（4）：385⁃399.
2	翁定为，雷群，胥云，等.缝网压裂技术及其现场应用［J］.石油学报，2011，32（2）：280⁃284.
	Weng D W，Lei Q，Xu Y，et al.Network fracturing techniques and its application in the field［J］.Acta Petrolei Sinica，2011，32（2）：280⁃284.
3	李准,吴晓东,韩国庆,等.考虑储层应力敏感效应的体积压裂水平井瞬态压力分析［J］.东北石油大学学报,2018,42（3）： 92⁃101.
	Li Z,Wu X D,Han G Q,et al.Transient pressure analysis of volume⁃fractured horizontal well with consideration of stress⁃sensitivity［J］.Journal of Northeast Petroleum University,2018,42（3）：92⁃101.
4	慕立俊,吴顺林,徐创朝,等.基于缝网扩展模拟的致密储层体积压裂水平井产能贡献分析［J］.特种油气藏,2021,28（2）： 126⁃132.
	Mu L J,Wu S L,Xu C C,et al.Analysis on contribution to productivity of SRV⁃fractured horizontal wells in tight reservoirs based on simulation of fracture network propagation［J］.Special Oil & Gas Reservoirs,2021,28（2）：126⁃132.
5	侯冰,付卫能,谭鹏,等.页岩暂堵转向压裂水力裂缝扩展物模试验研究［J］.辽宁石油化工大学学报,2020,40（4）：98⁃104.
	Hou B,Fu W N,Tan P,et al.Experimental study on the hydraulic fracture propagation for shale temporary plugging and diverting fracturing［J］.Journal of Liaoning Shihua University,2020,40（4）：98⁃104.
6	蒋廷学，单文文，杨艳丽.垂直裂缝井稳态产能的计算［J］.石油勘探与开发，2001，28（2）：61⁃63.
	Jiang Y X，Shan W W，Yang Y L.The calculation of stable production capability of vertically fractured well［J］.Petroleum Exploration and Development，2001，28（2）：61⁃63.
7	赵海洋，贾永禄，王东权.双重-均质复合油藏产量递减模型研究［J］.新疆石油地质，2010，31（1）：63⁃65.
	Zhao H Y，Jia Y L，Wang D Q.Study of production decline model for dual porosity⁃homogeneous composite reservoir［J］.Xinjiang Petroleum Geology，2010，31（1）：63⁃65.
8	严谨，程时清，郑荣臣，等.确定压裂裂缝部分闭合的现代产量递减分析方法及应用［J］.石油钻采工艺，2018，40（6）：787⁃793.
	Yan J，Cheng S Q，Zheng R C，et al.Development and application of the modern production decline analysis method in consideration of partial closure of hydraulic fracture［J］.Oil Drilling & Production Technology，2018，40（6）：787⁃793.
9	刘雄，王磊，王方，等.致密油藏水平井体积压裂产能影响因素分析［J］.特种油气藏，2016，23（2）：85⁃88.
	Liu X，Wang L，Wang F，et al.Sensitivity analysis of volume⁃fractured horizontal well productivity in tight reservoir［J］.Special Oil Gas Reservoirs，2016，23（2）：85⁃88.
10	Archer R A.New semi⁃analytical solutions for multilayer reservoirs［C］.Calgary：[s.n.]，2008.
11	Osman M E.Transient pressure analysis for wells in multilayered reservoir with finite conductivity fracture［C］.Bahrain：[s.n.]，1993.
12	尹洪军，袁鸿飞，付春权，等.致密油藏体积压裂水平井Blasingame产量递减分析［J］.水动力学研究与进展，2020，35（2）：194⁃200.
	Yin H J，Yuan H F，Fu C Q，et al.Blasingame production decline analysis for a multi⁃fractured horizontal well in tight reservoirs［J］.Chinese Journal of Hydrodynamics，2020，35（2）：194⁃200.
13	Lu T，Li Z P，Lai F P，et al.Blasingame decline analysis for variable rate/variable pressure drop：A multiple fractured horizontal well case in shale gas reservoirs［J］.Journal of Petroleum Science and Engineering，2019，178：193⁃204.
14	姜瑞忠，何吉祥，姜宇，等.页岩气藏压裂水平井Blasingame产量递减分析方法建立与应用［J］.石油学报，2019，40（12）：1503⁃1510.
	Jiang R Z，He J X，Jiang Y，et al.Establishment and application of Blasingame production decline analysis method for fractured horizontal well in shale gas reservoirs［J］.Acta Petrolei Sinca，2019，40（12）：1503⁃1510.
15	Stalgorova K，Matter L.Analytical model for unconventional multifractured composite systems［J］.SPE Reservoir Evaluation & Engineering，2013，16（3）：246⁃256.
16	尹洪军，李兴科，赵二猛，等.体积压裂水平井不稳定试井解释研究［J］.特种油气藏，2017，24（5）：85⁃90.
	Yin H J，Li X K，Zhao E M，et al.Interpretation of transient well test data in horizontal wells with volumetric fracturing［J］.Special oil and Gas Reservoir，2017，24（5）：85⁃90.

[1]	Jianping Yang. Production Decline Analysis Method of Heavy Oil Thermal Recovery Based on Steam Soaking [J]. Journal of Petrochemical Universities, 2022, 35(3): 70-74.
[2]	Wang Wei. Analysis on Influential Factors for Initial Productivity of the Network Fracturing Vertical Well in Tight Oil Reservoir [J]. Journal of Petrochemical Universities, 2020, 33(6): 37-42.
[3]	Ma Quanzheng, Yang Shenglai, Wang Junru, Huang Yu. Non⁃Linear Seepage Model of Tight Reservoir Based on Threshold Pressure Gradient [J]. Journal of Petrochemical Universities, 2020, 33(1): 36-41.
[4]	Zhou Sibin. Feasibility Study of CO₂ Flooding in Honghe Tight Oil Reservoir [J]. Journal of Petrochemical Universities, 2019, 32(1): 41-46.
[5]	PuYu,WangXiuyu,YangShenglai. Research on Spontaneous Imbibition Mechanism of Tight Oil Reservoirs Using NMRI Method [J]. , 2017, 30(1): 45-48.