Study on Flowrate Distribution of Fracturing Fluid in Multi-Stage Fractures
-
摘要: 当前,以页岩油气为主的非常规油气藏开发力度日益加大,水力压裂是开发该类储层的核心技术。在该类储层的开发过程中,往往采用多级复杂裂缝压裂技术,但目前针对压裂过程中各级裂缝内流量分布规律研究甚少,而该规律对认识裂缝、指导压裂方案至关重要。为了研究压裂过程中多级裂缝内的流量分布规律,自主研制了多级裂缝系统有效输砂模拟实验装置,在模拟多级裂缝情况下,开展了不同压裂液黏度、支撑剂粒径、注入排量、砂比等因素对各级裂缝内流量的影响规律实验研究。研究结果表明,各级裂缝中流量占比逐级减小,主裂缝占比平均为64.63%,一级分支缝平均为22.14%,二级分支缝平均为13.23%;各级裂缝中流量分布比例主要受总流量大小影响,流量越大,主裂缝中流量占比越高,分支缝中流量占比越低,其次依次为支撑剂粒径、压裂液黏度和砂比。通过研究形成了一套多级裂缝内流量分布规律评价方法,揭示了各级裂缝内流量分布规律,为认识裂缝、优化压裂设计方案提供了依据。Abstract: Hydraulic fracturing is the core technology for the more and more prevailing development of unconventional hydrocarbon such as shale gas. Multistage fracturing has always been used in the development of unconventional hydrocarbon reservoirs. Study on the flowrate distribution in each level of fractures during fracturing has seldom conducted, although the understanding of the flowrate distribution is very important to the understanding of fractures and to the design of fracturing program. An apparatus for experimenting effective sand transport in multistage fractures was developed to study the flowrate distribution in multistage fractures. Using this apparatus, several factors, such as viscosity of fracturing fluid, particle size of proppant, injection rate, sand concentration etc., were studied for their effects om the flowrate distribution of fracturing fluid in multistage fractures. It was found in the study that flow rate was decreasing along the fractures in different descending stages. 64.63% of the flow rate is in the master facture, 22.14% in the first level fractures, and the rest in the second level fractures. The distribution of flowrate in different levels of fractures is also affected by the total flowrate; the higher the total flowrate, the higher the flowrate distributed in the master fracture and the lower the flowrate in the sub-fractures. Other factors, according to their level of importance, are the particle size of proppant, viscosity of fracturing fluid and sand concentration. The study gives birth to a method of evaluating the pattern of flowrate distribution in multistage fractures and reveals the pattern of flow rate distribution in each level of fracture, providing a basis on which the properties of fractures can be understood and fracturing program can be optimized.
-
Key words:
- Fracturing fluid /
- Multi-stage fracture /
- Flowrate distribution /
- Physical simulation
-
[1] DEKEE D.Transport processes in bubbles, drops and particles[M].New York, Taylor & Francis, 2002. [2] MICHAELIDES E E. Hydrodynamic force and heat/mass transfer from particles, bubbles, and drops-the freeman scholar lecture[J].Journal of Fluids Engineering, 2003, 125(2):209-238. [3] MALHOTRA S, SHARMA M M. Settling of spherical particles in unbounded and confined surfactant-based shear thinning viscoelastic fluids:An experimental study[J]. Chemical Engineering Science, 2012, 84:646-655. [4] 郭大立, 纪禄军, 赵金洲. 支撑剂在三维裂缝中的运移分布计算[J]. 河南石油, 2001, 15(2):32-34.GUO Dali, JI Lujun, ZHAO Jinzhou. Calculation of migration and distribution of proppant in three-dimensional fractures[J].Henan Petroleum, 2001, 15(2):32-34. [5] 刘磊, 廖红伟, 周芳德. 砂粒与复杂流体压裂液在裂缝中的流动特性研究[J]. 工程热物理学报, 2008,(1):102-104. LIU Lei, LIAO Hongwei, ZHOU Fangde. Study on flow rate characteristics of sand and complex fluid fracturing fluid in fractures[J]. Journal of Engineering Thermophysics, 2008, (1):102-104. [6] 张鹏. 煤层气井压裂液流动和支撑剂分布规律研究[D]. 青岛:中国石油大学, 2011. ZHANG Peng. Study on fracture fluid flow rate and proppant distribution in coalbed methane wells[D]. Qingdao:China University of petroleum, 2011. [7] 温庆志, 翟恒立, 罗明良, 等. 页岩气藏压裂支撑剂沉降及运移规律实验研究[J]. 油气地质与采收率, 2012, 19(6):104-107.WEN Qingzhi, ZHAI Hengli, LUO Mingliang, et al. Experimental study on the subsidence and migration of fracturing proppant in shale gas reservoir[J]. Oil and Gas Geology and Recovery, 2012, 19(6):104-107. [8] 温庆志, 刘欣佳, 黄波, 等. 水力压裂可视裂缝模拟系统的研制与应用[J]. 特种油气藏, 2016, 23(2):136-139.WEN Qingzhi, LIU Xinjia, HUANG Bo, et al. Development and application of visual fracture simulation system for hydraulic fracturing[J].Special Oil and Gas Reservoir, 2016, 23(2):136-139. [9] 温庆志, 段晓飞, 战永平, 等. 支撑剂在复杂缝网中的沉降运移规律研究[J]. 西安石油大学学报(自然科学版), 2016, 31(1):79-84. WEN Qingzhi, DUAN Xiaofei, ZHAN Yongping, et al. Study on the settlement and migration of proppant in complex fracture network[J]. Journal of Xi'an University of Petroleum(NATURAL SCIENCE EDITION), 2016, 31(1):79-84. [10] KAMGA L N, JENNIFER L M, HAZIM H A, et al. Experimental study of proppant transport in horizontal wellbore using fresh water[C].SPE Hydraulic Fracturing Technology Conference and Exhibition, 2017. [11] 梁莹, 罗斌, 黄霞. 水力压裂低密度支撑剂铺置规律研究及应用[J]. 钻井液与完井液,2018,35(3):110-113.LIANG Ying, LUO Bin, HUANG Xia. Study and application of low density proppant placement in hydraulic fracturing[J].Drilling Fluid & Completion Fluid, 2018, 35(3):110-113. -

计量
- 文章访问数: 815
- HTML全文浏览量: 227
- PDF下载量: 98
- 被引次数: 0