The Study on Fractal Damage of Rock under Hydraulic Fracturing Basing on Conversation of Energy

2010 ◽  
Vol 29-32 ◽  
pp. 1363-1368 ◽  
Author(s):  
Wan Chun Zhao ◽  
Ting Ting Wang ◽  
Guo Shuai Ju ◽  
Da Chun Zheng
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Field ◽  
Damage Variable ◽  
Rock Damage ◽  
Porosity Evolution ◽  
Variable Porosity ◽  
Fracturing Process ◽  
Fractal Characteristics ◽  
Damage Theory ◽  
Energy Conservation Principle

The fractal characteristics is Considered in rock porosity structure, and rock damage variable is defined by reduced amount pore number whose radius is greater than R during arbitrary fracturing stage. Assuming that the micro-fracturing process of evolution cracks meets Logistic bifurcation standard model, according to energy conservation principle, the model of hydraulic fracturing of rock damage and infiltration of evolution is established based on the porosity fractal damage theory. And then the hydraulic fracturing rock evolution model is built. Taking one well of any oil field as the example, rock damage variable, porosity evolution during fracturing process are calculated, which shows that the results are reasonable and accurate.

scholarly journals Implementation of Hydraulic Fracturing Operation for a Reservoir in KRG

2019 ◽  
Vol 3 (2) ◽  
pp. 10-21
Author(s):  
Akram Humoodi ◽  
Maha Hamoudi ◽  
Rasan Sarbast
Keyword(s):  
Hydraulic Fracturing ◽  
Design Procedure ◽  
Oil Field ◽  
Fracture Conductivity ◽  
Fracture Width ◽  
Fracturing Process ◽  
Before And After ◽  
Fracture Height ◽  
Well Data ◽  
Field Formation

This study focuses on procedures to enhance permeability and flow rate for a low permeability formation by creating a conductive path using the hydraulic fracturing model. Well data are collected from the Qamchuqa KRG oil field formation. A Fracpro simulator is used for modelling the hydraulic fracturing process in an effective way. The study focuses on an effective hydraulic fracturing design procedure and the parameters affecting the fracture design. Optimum design of fracturing is achieved by selecting the proper fracturing fluid with a suitable proppant carried in a slurry, determining the formation fracturing pressure, selection of a fracture propagation fluid, and also a good proppant injection schedule, using a high pump rate and good viscosity. Permeability and conductivity are calculated before and after applying the hydraulic fracturing. Fracture height, length, and width are calculated from the Fracpro software, among other parameters, and the production rate changes. From the results, it is observed that by using hydraulic fracturing technology, production will increase and permeability will be much higher. The original formation permeability is 2.55 md, and after treatment, the average fracture conductivity has significantly increased to 1742.3 md-ft. The results showed that average fracture width is 0.187 inch. The proppant used in this treatment has a permeability of 122581 md. The suitable fluid choice is hyper with an apparent viscosity of 227.95 cp, and the proper proppant type is Brady sand with a conductivity of 2173.41 md-ft. Fracture orientation from the Khurmala oil field in Kurdistan is vertical fractures produced at a depth of 1868 m. Fracture half-length, total fracture height, and average fracture width are 220 ft, 42 ft, and 0.47 inch, respectively. After fracturing, the maximum and average area of fracture are 33.748 and 17.248 ft2, respectively. The recommended pump hydraulic horse power is 3200 HHP, and the total required fluid is 1076.3 bbl. In this study, hydraulic fracture is designed, and then, it has been analyzed after that production is optimized.

Optimal design of cumulative shale gas hydraulic fracturing process based on rock fatigue damage theory

2019 ◽  
Vol 200 (1) ◽  
pp. 99-107
Author(s):  
Dongjin Xu ◽  
Xu Yuan ◽  
Jiangping Wu ◽  
Lili Fan ◽  
Xue Yang ◽  
...  
Keyword(s):  
Optimal Design ◽  
Hydraulic Fracturing ◽  
Fatigue Damage ◽  
Shale Gas ◽  
Rock Fatigue ◽  
Fracturing Process ◽  
Damage Theory

The Damage Theory Model on Fluid-Solid-Heat Coupling of Reservoir under Process Injection

2010 ◽  
Vol 29-32 ◽  
pp. 2053-2058 ◽  
Author(s):  
Wan Chun Zhao ◽  
Chi Ai ◽  
Da Chun Zheng
Keyword(s):  
Injection Pressure ◽  
Theory Model ◽  
Oil Field ◽  
Damage Variable ◽  
New Model ◽  
Finite Element Software ◽  
Variable Porosity ◽  
Distribution Rule ◽  
Set Up ◽  
New Research

Based on the study of double porous medium, the paper provides a new model of cylinder volume element plastic yielding, which assumes that the rock mass is compressible and obeys the D-P formula, and deformation, nucleation and growing of pores and fractures are induced by stress of injection pressure and temperature. The damage variable is defined by strain porosity, and then constitutional equation of double pore medium saturated liquid-solid is set up. Taking one well of Jilin Oil Field in China as a case, the damage variable, porosity and induced stress change laws of rock strain coupling with temperature-injection are studied. The results are acquired from numerical simulation of finite element software, including induced stresses of thermal field, water flood pressure, rock stress distribution rule, together with evolving regulations of stress, damage variable and strain porosity. The numerical computation results match well with the practical situation, which shows that there is obvious elastic and plastic damage characteristic during mass water flood recovery. The new model provides a new research method and theoretical base for changes of reservoir pores and fractures during water flood exploration.

The Use of Tracer Technologies for Well Monitoring with Multi-Stage Hydraulic Fracturing on Bolshetirskoye Oil Field

2021 ◽  
Author(s):  
Ivan Krasnov ◽  
Oleg Butorin ◽  
Igor Sabanchin ◽  
Vasiliy Kim ◽  
Sergey Zimin ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Oil Recovery ◽  
Hydraulic Fracture ◽  
Horizontal Wells ◽  
Pilot Project ◽  
Oil Field ◽  
Well Completion ◽  
Construction Design ◽  
Multi Stage ◽  
Urgent Task

Abstract With the development of drilling and well completion technologies, multi-staged hydraulic fracturing (MSF) in horizontal wells has established itself as one of the most effective methods for stimulating production in fields with low permeability properties. In Eastern Siberia, this technology is at the pilot project stage. For example, at the Bolshetirskoye field, these works are being carried out to enhance the productivity of horizontal wells by increasing the connectivity of productive layers in a low- and medium- permeable porous-cavernous reservoir. However, different challenges like high permeability heterogeneity and the presence of H2S corrosive gases setting a bar higher for the requirement of the well construction design and well monitoring to achieve the maximum oil recovery factor. At the same time, well and reservoir surveillance of different parameters, which may impact on the efficiency of multi-stage hydraulic fracturing and oil contribution from each hydraulic fracture, remains a challenging and urgent task today. This article discusses the experience of using tracer technology for well monitoring with multi-stage hydraulic fracturing to obtain information on the productivity of each hydraulic fracture separately.

Optimized Clay Control Fracturing Fluid Used in a Highly Water-Sensitive Tight Oil Reservoir Hydraulic Fracturing Application in Xinjiang Oil Field: Case Study

2021 ◽  
Author(s):  
Xinjun Mao ◽  
Chaofeng Chen ◽  
Renzhong Gan ◽  
Shubo Zhou ◽  
Zichao Wang ◽  
...  
Keyword(s):  
Hydraulic Fracturing ◽  
Recovery Rate ◽  
Oil Field ◽  
National Standard ◽  
Working Fluid ◽  
Tight Oil ◽  
Fracturing Fluid ◽  
Core Flow ◽  
Velocity Sensitivity ◽  
Highly Sensitive

Abstract The candidate wells are tight oil wells and most of the wells in the area have a low recovery rate of fracturing fluid after fracturing treatment. The lithology is glutenite with weak cementation and a high sensitivity tendency. This paper presents the process of sensitivity evaluation and fracturing fluid evaluation. Also, this paper introduces a customized and optimized clay control fracturing fluid wells in a highly sensitive reservoir. Per local national standard, traditional methods of swelling test (ST) and x-ray diffraction (XRD) were employed for qualitative formation cutting analysis. An innovative trial was then developed to evaluate cores quantitatively by water sensitivity. A clay stabilizer was then chosen to be used for the highly sensitive cores and regain permeability testing of the broken fracturing fluid was performed. Based on the analysis and evaluation, a customized treatment design was initiated for the hydraulic fracturing treatment. The qualitative evaluation showed the rock is highly water sensitive and the cores easily collapse because of weak cementation. No flow could be established during traditional core flow tests with brine. The newly developed method used kerosene as the working fluid to prevent the cores from contact with water or brine. The core flow tests resulted in a velocity sensitivity damage rate of 92%, which is considered as highly velocity sensitive. Accordingly, a special clay stabilizer was chosen to be used in the fracturing fluid and the permeability damage of the broken fracturing fluid is only 26.9%(Table 16). Field results have shown that the fracturing fluid recovery rate in treated wells is higher than the area average level and treated wells have significant oil production increase. The innovative clay control fracturing fluid and its field application reduces the influence of water and velocity sensitivity. The customized treatment with special clay stabilizer helps increase the recovery rate of fracturing fluid in reservoirs with severe clay stability and weak cementation issues.

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