Flow Rate-Dependent Skin in Water Disposal Injection Well

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Ibrahim M. Mohamed ◽  
Gareth I. Block ◽  
Omar A. Abou-Sayed ◽  
Salaheldin M. Elkatatny ◽  
Ahmed S. Abou-Sayed

Reinjection is one of the most important methods to dispose fluid associated with oil and natural gas production. Disposed fluids include produced water, hydraulic fracture flow back fluids, and drilling mud fluids. Several formation damage mechanisms are associated with the injection including damage due to filter cake formed at the formation face, bacteria activity, fluid incompatibility, free gas content, and clay activation. Fractured injection is typically preferred over matrix injection because a hydraulic fracture will enhance the well injectivity and extend the well life. In a given formation, the fracture dimensions change with different injection flow rates due to the change in injection pressures. Also, for a given flow rate, the skin factor varies with time due to the fracture propagation. In this study, well test and injection history data of a class II disposal well in south Texas were used to develop an equation that correlates the skin factor to the injection flow rate and injection time. The results show that the skin factor decreases with time logarithmically as the fracture propagates. At higher injection flow rates, the skin factor achieved is lower due to the larger fracture dimensions that are developed at higher injection flow rates. The equations developed in this study can be applied for any water injector after calibrating the required coefficients using injection step rate test (SRT) data.

2021 ◽  
Vol 1 ◽  
pp. 67-74
Author(s):  
Iwan Febrianto ◽  
Nelson Saksono

The Gas Gathering Station (GGS) in field X processes gas from 16 (sixteen) wells before being sent as selling gas to consumers. The sixteen wells have decreased in good pressure since 2011, thus affecting the performance of the Acid Gas Removal Unit (AGRU). The GGS consists of 4 (four) main units, namely the Manifold Production/ Test, the Separation Unit, the Acid Gas Removal Unit (AGRU), the Dehydration Unit (DHU). The AGRU facility in field X is designed to reduce the acid gas content of CO2 by 21 mol% with a feed gas capacity of 85 MMSCFD. A decrease in reservoir pressure caused an increase in the feed gas temperature and an increase in the water content of the well. Based on the reconstruction of the design conditions into the simulation model, the amine composition consisting of MDEA 0.3618 and MEA 0.088 wt fraction to obtain the percentage of CO2 in the 5% mol sales gas. The increase in feed gas temperature up to 146 F caused foaming due to condensation of heavy hydrocarbon fraction, so it was necessary to modify it by adding a chiller to cool the feed gas to become 60 F. Based on the simulation, the flow rate of gas entering AGRU could reach 83.7 MMSCFD. There was an increase in gas production of 38.1 MMSCFD and condensate of 1,376 BPD. Economically, the addition of a chiller modification project was feasible with the economical parameters of NPV US$ 132,000,000, IRR 348.19%, POT 0.31 year and PV ratio 19.06.


2019 ◽  
Vol 21 (27) ◽  
pp. 14605-14611 ◽  
Author(s):  
R. Moosavi ◽  
A. Kumar ◽  
A. De Wit ◽  
M. Schröter

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


2018 ◽  
Vol 849 ◽  
pp. 163-191 ◽  
Author(s):  
Draga Pihler-Puzović ◽  
Gunnar G. Peng ◽  
John R. Lister ◽  
Matthias Heil ◽  
Anne Juel

We study the viscous-fingering instability in a radial Hele-Shaw cell in which the top boundary has been replaced by a thin elastic sheet. The introduction of wall elasticity delays the onset of the fingering instability to much larger values of the injection flow rate. Furthermore, when the instability develops, the fingers that form on the expanding air–liquid interface are short and stubby, in contrast with the highly branched patterns observed in rigid-walled cells (Pihler-Puzović et al., Phys. Rev. Lett., vol. 108, 2012, 074502). We report the outcome of a comprehensive experimental study of this problem and compare the experimental observations to the predictions from a theoretical model that is based on the solution of the Reynolds lubrication equations, coupled to the Föppl–von-Kármán equations which describe the deformation of the elastic sheet. We perform a linear stability analysis to study the evolution of small-amplitude non-axisymmetric perturbations to the time-evolving base flow. We then derive a simplified model by exploiting the observations (i) that the non-axisymmetric perturbations to the sheet are very small and (ii) that perturbations to the flow occur predominantly in a small wedge-shaped region ahead of the air–liquid interface. This allows us to identify the various physical mechanisms by which viscous fingering is weakened (or even suppressed) by the presence of wall elasticity. We show that the theoretical predictions for the growth rate of small-amplitude perturbations are in good agreement with experimental observations for injection flow rates that are slightly larger than the critical flow rate required for the onset of the instability. We also characterize the large-amplitude fingering patterns that develop at larger injection flow rates. We show that the wavenumber of these patterns is still well predicted by the linear stability analysis, and that the length of the fingers is set by the local geometry of the compliant cell.


1996 ◽  
Vol 79 (2) ◽  
pp. 571-578 ◽  
Author(s):  
Philip Wylie ◽  
Katsura Uchiyama

Abstract Gas chromatographic (GC) analysis of 6 organo-phosphorus pesticides (methamidophos, acephate, omethoate, diazinon, dimethoate, and chlorpyrifos) was performed with cool on-column, splitless, and pulsed splitless injections and with nitrogen–phos phorus or mass-selective detection. The pulsed splitless technique uses a high column flow rate during injection to sweep the sample out of the inlet rapidly, reducing analyte loss due to adsorption or thermal decomposition. After injection, the column flow rate is automatically reduced to normal values for chromatographic analysis. Pesticide recoveries for splitless and pulsed splitless injections were determined by comparison of GC peak areas with those obtained with cool on-column injection. With conventional splitless injection at a column flow rate of 5 mL/min, recoveries of acephate, omethoate, and methamidophos were only 57, 63, and 71 %, respectively. Pulsed splitless methods with very fast injection flow rates dramatically improved recoveries, with all 6 pesticides falling in the 97–102% range. Because column flow rates are much less for GC with mass spectral detection (GC/MS), recoveries with splitless injection were lower and improvements with pulsed splitless injection were less dramatic for GC/MS. When splitless injection was used, recoveries of the 6 pesticides spiked into a green bean matrix were better than those of pesticides dissolved in pure solvent, presumably because matrix compounds compete with pesticides for active sites in the inlet. By using pulsed splitless injection of solvent standards with very fast initial column flow rates, systematic analyte losses in the inlet were eliminated, making recoveries of pesticides from solvent and green bean matrix very similar.


2018 ◽  
Vol 34 (3) ◽  
pp. 545-553 ◽  
Author(s):  
Pan Tang ◽  
Hong Li ◽  
Zakaria Issaka ◽  
Chao Chen

Abstract. The proportional injector is commonly used in agricultural chemigation due to its relatively high injection ratio. A major challenge with the proportional injector is related to its dependence on differential pressure, which is significantly influenced by changes in the viscosity, and setting injection ratio. A series of experiments were conducted to investigate the influence of differential pressures, solution viscosities, and setting injection ratios on the inlet and injection flow rates of a D25RE2 proportional injector. A mathematical model was developed to represent the hydraulic performance of this proportional injector. Finally, the mathematical model was verified using four different kinds of chemicals (humic acid, urea ammonium nitrate 32% N, fosthiazate, and colza oil). The inlet flow rate increased significantly with increasing differential pressure and decreased with increasing setting injection ratio. Results showed that the highest operating differential pressure should not be greater than 0.15 MPa for the D25RE2 proportional injector. The inlet flow rate gradually decreased with increasing viscosity, and a quadratic function relationship was derived between the inlet flow rate and the viscosity. The injection flow rate decreased with increasing viscosity. However, the viscosity had a slight influence on the injection flow rate when it was lower than 20 mPa·s. Mathematical models for calculating the inlet and injection flow rates with the influence of viscosity were developed, respectively. The coefficient of determination and the root mean square error (RMSE) for inlet flow rate calculation model were 0.8316 and 143.36 kg h-1, respectively. The coefficient of determination and the RMSE for the injection flow rate calculation model were 0.9706 and 0.9520 kg h-1, respectively. The calculating formula of inlet flow rate had a satisfactory accuracy under low differential pressure and high setting injection ratio. The calculating formula of the injection flow rate had a good accuracy, which is useful for calculating the injection flow rate when injected with different kinds of solutions. The average deviations between calculated and experimental injection flow rates with injection ratios of 0.2%, 1.2%, and 2% were obtained as 4.96%, 4.66%, and 4.1% respectively, which indicated that the average deviations decreased with increasing setting injection ratio. Results from this study are useful for both designers and users to effectively manage agricultural chemigation system with the proportional injector. Keywords: Agriculture, Chemigation, Proportional injector, Hydraulic performance.


2009 ◽  
Vol 49 (1) ◽  
pp. 433
Author(s):  
Shakil Ahmed ◽  
Mohamed Nabil Noui-Mehidi ◽  
Jamal Naser's ◽  
Gerardo Sanchez Soto ◽  
Edson Nakagawa

This paper describes the computational fluid dynamics (CFD) modelling of a laboratory scale gas-liquid separator designed for high gas content. The separator consists of two concentric pipes with swirl tube in the annular space between the pipes. The gas-liquid mixture comes tangentially from the side inlet and the system works with a combination of gravity and centrifugal forces to achieve a high-efficient gas-liquid separation. Three dimensional transient multi-phase fluid flows were solved to predict the velocity and volume fraction of each phase. The standard k- turbulence model was used for turbulence closure. The performance of the gas-liquid separator was visually established for a range of gas flow rates (271–495 L/min), with volume fraction (VF) =0.874–0.985 by observing the liquid carry over (LCO) regime where liquid was carried out in the gas stream. The liquid and gas flow rates at which the LCO was observed defines the upper operational range of the separator. Air-water mixture was used in the numerical simulations to keep consistent with the experiments. The pressure between the inlet and exit was validated against the experiments for different air-water flow rate combinations. The values were matched reasonably well for high air flow rate (495 L/min, VF=0.985) but were under-predicted for low air flow rate (271 L/min, VF=0.874). The air and water were mixed upstream of the inlet in the experiments and the pressure was measured at the start of the inlet. In case of numerical simulation the air and water were mixed at the inlet. This might cause the deviation of pressure when the air flow rate was low.


1999 ◽  
Vol 1999 (1) ◽  
pp. 757-764
Author(s):  
Kendal L. Keyes ◽  
Joanna B. Mott ◽  
Steven S. Barnes ◽  
David A. Jensen

ABSTRACT The ability of some halophytes to accumulate salts may make them helpful in remediating soil contaminated with produced water and drilling mud from oil and gas exploration and production. Three inland halophytes, Atriplex acanthocarpa (two accessions) and A. canescens, were grown in pot culture in salt-contaminated soil, soil contaminated with salt and hydrocarbons, and uncontaminated soil collected from a Webb Co., Texas, gas production site. Electrical conductivity and soluble sodium of the soil extract were determined prior to planting and re-analyzed following harvest. Total sodium content in mature leaves was determined following harvest. Mature plant survival for all species in all soils ranged from 90–100%. In the salt-contaminated soil, post-harvest electrical conductivity and soluble sodium were significantly lower in the planted soils than in the unplanted soil. For each accession, biomass and plant mortality were greatest in the salt-contaminated soil. In both contaminated soils, the local ecotype of A. acanthocarpa had the highest concentration of tissue sodium and produced the greatest decrease in both electrical conductivity and soluble sodium. Field studies are necessary to determine the effectiveness of in situ application.


Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 765 ◽  
Author(s):  
Jin-yuan Qian ◽  
Min-rui Chen ◽  
Zan Wu ◽  
Zhi-jiang Jin ◽  
Bengt Sunden

The injection flow rates of two liquid phases play a decisive role in the slug generation of the liquid-liquid slug flow. However, most injection flow rates so far have been constant. In order to investigate the effects of dynamic injection flow rates on the slug generation, including the slug size, separation distance and slug generation cycle time, a transient numerical model of a cross-junction square microchannel is established. The Volume of Fluid method is adopted to simulate the interface between two phases, i.e., butanol and water. The model is validated by experiments at a constant injection flow rate. Three different types of dynamic injection flow rates are applied for butanol, which are triangle, rectangular and sine wave flow rates. The dynamic injection flow rate cycles, which are related to the constant slug generation cycle time t0, are investigated. Results show that when the cycle of the disperse phase flow rate is larger than t0, the slug generation changes periodically, and the period is influenced by the cycle of the disperse phase flow rate. Among the three kinds of dynamic disperse flow rate, the rectangular wave influences the slug size most significantly, while the triangle wave influences the separation distance and the slug generation time more prominently.


2021 ◽  
Vol 13 (3) ◽  
pp. 1543
Author(s):  
Gu Sun Jeong ◽  
Seil Ki ◽  
Dae Sung Lee ◽  
Ilsik Jang

The relative permeabilities of CO2 and brine are important parameters that account for two-phase flow behavior, CO2 saturation distribution, and injectivity. CO2/brine relative permeability curves from the literature show low endpoint CO2 permeability values and high residual brine saturation values. These are the most distinguishing aspects of the CO2/brine relative permeability from oil/water and gas/oil. In this study, this aspect is investigated experimentally by employing a wide range of CO2 injection flow rates. As a result, all the measurements align with previous studies, having low endpoint relative permeability and high residual brine saturation values. They have obvious relationships with the changes in CO2 flow rates. As the CO2 flow rate increases, the endpoint relative permeability increases, the residual brine saturation decreases, and they converge to specific values. These imply that a high CO2 injection flow rate results in high displacement efficiency, but the improvement in efficiency decreases as the flow rate increases. The reasons are identified with the concept of the viscous and capillary forces, and their significance in the CO2 injection into a reservoir is analyzed.


1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.


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