Effect of injection flow rate on fracture toughness during hydraulic fracturing of hot dry rock (HDR)

ABSTRACT Venturi injectors are commonly employed for fertigation purposes in agriculture, in which they draw fertilizer from a tank into the irrigation pipeline. The knowledge of the amount of liquid injected by this device is used to ensure an adequate fertigation operation and management. The objectives of this research were (1) to carry out functional tests of Venturi injectors following requirements stated by ISO 15873; and (2) to model the injection rate using dimensional analysis by the Buckingham Pi theorem. Four models of Venturi injectors were submitted to functional tests using clean water as motive and injected fluid. A general model for predicting injection flow rate was proposed and validated. In this model, the injection flow rate depends on the fluid properties, operating hydraulic conditions and geometrical characteristics of the Venturi injector. Another model for estimating motive flow rate as a function of inlet pressure and differential pressure was adjusted and validated for each size of Venturi injector. Finally, an example of an application was presented. The Venturi injector size was selected to fulfill the requirements of the application and the operating conditions were estimated using the proposed models.

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Influence of mineralization and injection flow rate on flow patterns in three-dimensional porous media

Physical Chemistry Chemical Physics ◽

10.1039/c9cp01382b ◽

2019 ◽

Vol 21 (27) ◽

pp. 14605-14611 ◽

Cited By ~ 2

Author(s):

R. Moosavi ◽

A. Kumar ◽

A. De Wit ◽

M. Schröter

Keyword(s):

Porous Media ◽

Flow Field ◽

Flow Rate ◽

Three Dimensional ◽

Flow Patterns ◽

Low Flow ◽

Flow Rates ◽

Injection Flow Rate ◽

Injection Flow

At low flow rates, the precipitate forming at the miscible interface between two reactive solutions guides the evolution of the flow field.

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The Coupling Model of Wellbore Conduit Flow, Throttled Flow and Formation Seepage in Water Injection Wells

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.2486 ◽

2012 ◽

Vol 594-597 ◽

pp. 2486-2489

Author(s):

Bao Jun Liu ◽

Hai Xia Shi ◽

Yun Sheng Cai

Keyword(s):

Flow Rate ◽

Water Injection ◽

Coupling Model ◽

Water Flooding ◽

Finite Radius ◽

Injection Wells ◽

Conduit Flow ◽

Injection Flow Rate ◽

Injection Flow ◽

Low Efficiency

Separate layer water flooding is adopted in most oilfields in China and the injection flow rate is controlled by the diameter of water nozzle of each layer. In order to ensure the effect of water injection, applicable water nozzles need to be adjusted to meet the requirements of injection flow rate. The adjustment is commonly realized according to experience, which leads to long adjustment time and low efficiency. To solve this problem, the coupling model of wellbore conduit flow, throttled flow and formation seepage was established based on theoretical analysis, which could provide theoretical basis for water nozzles adjustment. In the model, the Bernoulli Equation was adopted to analyze wellbore conduit flow; indoor experiments were done to research throttled flow; the research object of the seepage was finite radius well in homogeneous infinite formation.

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Experimental Analysis of CO2 Injection on Permeability of Vuggy Carbonate Aquifers

Journal of Energy Resources Technology ◽

10.1115/1.4007799 ◽

2012 ◽

Vol 135 (1) ◽

Cited By ~ 22

Author(s):

Ibrahim M. Mohamed ◽

Jia He ◽

Hisham A. Nasr-El-Din

Keyword(s):

Flow Rate ◽

Initial Permeability ◽

Co2 Injection ◽

Reaction Products ◽

The Core ◽

Injection Flow Rate ◽

Injection Flow ◽

Injection Scheme ◽

Core Permeability ◽

Permeability Alteration

Reactions of CO2 with formation rock may lead to an enhancement in the permeability due to rock dissolution, or damage (reduction in the core permeability) because of the precipitation of reaction products. The reaction is affected by aquifer conditions (pressure, temperature, initial porosity, and permeability), and the injection scheme (injection flow rate, CO2:brine volumetric ratio, and the injection time). The effects of temperature, injection flow rate, and injection scheme on the permeability alteration due to CO2 injection into heterogeneous dolomite rock is addressed experimentally in this paper. Twenty coreflood tests were conducted using Silurian dolomite cores. Thirty pore volumes of CO2 and brine were injected in water alternating gas (WAG) scheme under supercritical conditions at temperatures ranging from 21 to 121 °C, and injection rates of 2.0–5.0 cm3/min. Concentrations of Ca++, Mg++, and Na+ were measured in the core effluent samples. Permeability alteration was evaluated by measuring the permeability of the cores before and after the experiment. Two sources of damage in permeability were noted in this study: (1) due to precipitation of calcium carbonate, and (2) due to migration of clay minerals present in the core. Temperature and injection scheme don't have a clear impact on the core permeability. A good correlation between the initial and final core permeability was noted, and the ratio of final permeability to the initial permeability is lower for low permeability cores.

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Seismic Response to Injection Well Stimulation in a High-Temperature, High-Permeability Reservoir

10.26686/wgtn.13792676.v1 ◽

2021 ◽

Author(s):

C Hopp ◽

Steven Sewell ◽

S Mroczek ◽

Martha Savage ◽

John Townend

Keyword(s):

High Temperature ◽

Compressive Stress ◽

Flow Rate ◽

Matched Filter ◽

Taupo Volcanic Zone ◽

Valuable Insight ◽

High Permeability ◽

Injection Flow Rate ◽

Well Stimulation ◽

Injection Flow

©2019. American Geophysical Union. All Rights Reserved. Fluid injection into the Earth's crust can induce seismic events that cause damage to local infrastructure but also offer valuable insight into seismogenesis. The factors that influence the magnitude, location, and number of induced events remain poorly understood but include injection flow rate and pressure as well as reservoir temperature and permeability. The relationship between injection parameters and injection-induced seismicity in high-temperature, high-permeability reservoirs has not been extensively studied. Here we focus on the Ngatamariki geothermal field in the central Taupō Volcanic Zone, New Zealand, where three stimulation/injection tests have occurred since 2012. We present a catalog of seismicity from 2012 to 2015 created using a matched-filter detection technique. We analyze the stress state in the reservoir during the injection tests from first motion-derived focal mechanisms, yielding an average direction of maximum horizontal compressive stress (SHmax) consistent with the regional NE-SW trend. However, there is significant variation in the direction of maximum compressive stress (σ1), which may reflect geological differences between wells. We use the ratio of injection flow rate to overpressure, referred to as injectivity index, as a proxy for near-well permeability and compare changes in injectivity index to spatiotemporal characteristics of seismicity accompanying each test. Observed increases in injectivity index are generally poorly correlated with seismicity, suggesting that the locations of microearthquakes are not coincident with the zone of stimulation (i.e., increased permeability). Our findings augment a growing body of work suggesting that aseismic opening or slip, rather than seismic shear, is the active process driving well stimulation in many environments.

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Effect of the Pumping-injection flow rate on Heat Transfer Characteristic of Borehole Heat Exchangers for Coupling Ground-Source Heat Pump System

10.21203/rs.3.rs-23773/v2 ◽

2020 ◽

Author(s):

Jiuchen Ma ◽

Qian Jiang ◽

Qiuli Zhang ◽

Yacheng Xie ◽

Yahui Wang ◽

...

Keyword(s):

Heat Transfer ◽

Flow Rate ◽

Heat Exchangers ◽

Transfer Characteristic ◽

Ground Source Heat Pump ◽

Pump System ◽

Heat Pump System ◽

Injection Flow Rate ◽

Injection Flow ◽

Ground Source

Abstract A coupling ground source heat pump system (CGSHP) is established in areas where groundwater is shallow but the seepage velocity is weak, which sets up pumping and injection wells on both sides of borehole heat exchangers (BHEs). A convection-dispersion analytical model of excess temperature in aquifer that considers groundwater forced seepage and axial effects and thermal dispersion effects is proposed. A controllable forced seepage sandbox is built by equation analysis method and similarity criteria. Through indoor test and the proposed analytical model, the correctness and accuracy of the numerical simulation software FEFLOW7.1 is verified. The influence of different pumping-injection flow rate on the heat transfer characteristic of BHEs is studied by numerical simulation. The results show that the average heat efficiency coefficient of BHEs increases and the heat influence range of downstream BHEs expands with the increasing of pumping-injection flow rate. The relation curve between Pe and the increment of heat transfer rate per unit depth of BHEs (Δ`q) is distributed as Gaussian function. The pumping-injection flow rate that makes Darcy velocity reaches 0.6×10-6~1.4×10-6 m∙s-1 in the aquifer is the best reference range for CGSHP system，so 400~600 m3∙d-1 is taken as the best pumping-injection flow rate in this paper.

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Numerical Analysis of Safety Injection System’s Flow Rate

18th International Conference on Nuclear Engineering: Volume 4, Parts A and B ◽

10.1115/icone18-29303 ◽

2010 ◽

Author(s):

Dengke Sun ◽

Xiaojiang Wang ◽

Jun Li ◽

Jiang Liu ◽

Changyue Li

Keyword(s):

Flow Rate ◽

Optimization Design ◽

Direct Injection ◽

Injection System ◽

Primary Circuit ◽

Accident Analysis ◽

Fluid Temperature ◽

Injection Flow Rate ◽

Injection Flow ◽

Injection Pump

In this paper, a hydraulic model for Safety Injection System (SIS) of M310 reactor is extended. The model is checked and calibrated by test results under test conditions. Based on commissioning test criteria, the system’s maximum and minimum pressure drop coefficients are calibrated according to anti-extrapolation method. Considering modifications of various projects, analysis of 41 flow rate curves under different conditions has been performed using this model. These flow rate curves indicate the relationship between injection flow rates and primary circuit pressures. Accident analysis has taken these curves as input data. Also, the strategy for dealing with accident is established based on these curves. Results of accident analysis show that the design of SIS system can satisfy the safety requirements of M310 reactor. The sensitivity analysis of typical conditions illustrates that injection flow rate will increase as the primary circuit pressure decreases. With the same configuration, the injection flow rate during recirculation phase will be smaller than that during direct injection phase, which is mainly caused by the decrement of suction elevation and the increment of fluid temperature. When low head safety injection pump (LHSI PO) is boosting high head safety injection pump (HHSI PO), if the pressure is relatively high, the injection flow rate will not be improved apparently. If the pressure is relatively low, the boosting is necessary. These conclusions can be the basis for the later optimization design.

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Remazol Brilliant Blue Degradation Using Contact Glow Discharge Electrolysis Reactor with Air Injection and NaCl Solution

E3S Web of Conferences ◽

10.1051/e3sconf/20186704043 ◽

2018 ◽

Vol 67 ◽

pp. 04043

Author(s):

Fikri Averous ◽

Dwiputra Muhammad Zairin ◽

Nelson Saksono

Keyword(s):

Glow Discharge ◽

Flow Rate ◽

Dye Degradation ◽

Liquid Waste ◽

Air Injection ◽

Brilliant Blue ◽

Nacl Solution ◽

Injection Flow Rate ◽

Contact Glow Discharge Electrolysis ◽

Injection Flow

Remazol Brilliant Blue dye waste is one of the liquid waste produced from the textile industry and harmful to the environment. Contact Glow Discharge Electrolysis (CGDE) method is an effective method to degrade dye waste by producing OH radicals which will be used in liquid waste degradation process. This study aims to determine the effect of anode depth, temperature, and flow rate of air injection on the production of hydroxyl radicals and dye degradation of Remazol Brilliant Blue. This research was conducted in batch reactor with electrolyte NaCl 0,03 M. Variation which done is anode depth which is 0,5 cm; 2 cm; 4 cm, temperature of 40°C; 50°C; 60°C, and air injection flow rate of 0 lpm and 2.5 lpm. The research was conducted by voltage - current characteristic test, hydroxyl radical production test, and dye degradation test. Remazol Brilliant Blue degradation reached 96.15% within 30 minutes where the tension was 750 V, 0.03 M NaCl solution concentration, Fe2+ 40 ppm, 2 cm anode depth, 50°C temperature, and 2.5 lpm air injection flow rate.

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