Injection Pressure Drop Research Articles

Experimental study of Cryogenic jet injection using centrifugal nozzles at supercritical pressure

The new generation of large-thrust rockets commonly employ cryogenic liquids such as liquid hydrogen (LH2), liquid oxygen (LOX), and methane as propellants. Conventional analytical methods established under subcritical (specifically, low-pressure) conditions are inadequate for addressing the atomization issues under trans-critical and supercritical conditions. Therefore, conducting experimental research on atomization of cryogenic fluids under supercritical conditions holds significant practical value. This paper employs liquid nitrogen (LN2) as the working fluid and focuses on conducting injection atomization experiments on LN2 under supercritical pressure conditions. The research involves the design and construction of an experimental system for supercritical cryogenic fluid injection, with the aim of measuring and studying the spray characteristics of centrifugal nozzles under various conditions. Three major categories of experiments were designed for low-temperature LN2 injection: subcritical nitrogen into subcritical environment (BB), subcritical nitrogen into supercritical environment (BP), and supercritical nitrogen into supercritical environment (PP). The experimental results ultimately reveal that for jets in BB, both the spray cone angle and the breakup length increase with higher injection pressure drop. In the case of BP, the spray cone angle decreases while the penetration distance increases with higher pressure drop. As for the jets in PP, the spray cone angle increases and the penetration distance decreases with higher injection pressure drop. Across different geometric parameters of the centrifugal nozzle, it was observed that with an increase in the geometric parameter, the rate of decrease in the spray cone angle with respect to pressure drop amplifies, and the penetration distance exhibits an increasing trend as the geometric parameter grows.

A Numerical Simulation Approach for Superheated Steam Flow during Multipoint Steam Injection in Horizontal Well

Superheated steam flow during multipoint steam injection technology has a good effect on improving the steam absorption profile of heavy oil thermal recovery wells, enhancing the production degree of horizontal section of thermal recovery wells, and enhancing oil recovery. Based on the structure of multipoint steam injection horizontal string, considering the characteristics of variable mass flow, pressure drop of steam-liquid two-phase flow, and throttling pressure difference of steam injection valve in the process of steam injection, this paper establishes the calculation model of various parameters of multipoint steam injection horizontal wellbore and calculates the distribution of steam injection rate, temperature, pressure gradient, and dryness along the section of multipoint steam injection in horizontal wellbore. The results show that the temperature and pressure decrease gradually from heel to toe, and the steam dryness decreases gradually. Considering the influence of throttle pressure difference of steam injection valve and pressure drop of gas-liquid two-phase flow in the wellbore, the traditional calculation model of steam injection thermodynamic parameters is optimized, and the optimization of wellbore structure and steam injection parameters is an effective method to achieve uniform steam injection in horizontal wells. The steam injection uniformity of horizontal wells can be effectively improved by adjusting the steam injection valve spacing and steam injection parameters. When the steam injection volume is 200 m3/d and the steam injection valve spacing is 20 m, a more stable steam injection effect can be obtained. The findings of this study can help for better understanding of improving the uniformity of steam injection and enhancing the recovery factor.

Continuous Injector Geometry Variation to Augment Rotating Detonation Combustor Operation and Performance

Sensitivity of rotating detonation combustor operation and performance to oxidizer injector pressure drop was characterized using continuous variation of the injector area during combustor operation. As the oxidizer injector area was both increased and decreased, the sensitivity of the combustion process to varying injector pressure drop was characterized using high-frequency measurements of pressure and chemiluminescence intensity. Detonation wave strength and coherence were characterized using peak-to-peak intensity and power fraction calculated from point-chemiluminescence measurements. Propulsive performance of the combustor was evaluated using thrust and equivalent available pressure, relating them back to reactant supply pressures for assessment of combustor pressure gain. Pressure gain increased during a test as the oxidizer injector area was increased and the corresponding manifold pressure was decreased. At larger injector areas, pressure gain decreased as the operating mode of the combustor transitioned from detonation to deflagration, concomitant with a reduction of gross thrust. Modeling of injector recovery time revealed that the injector operated in both choked and unchoked regimes, which was used to explain detonation wave number transitions in the experiment. A broadened range of detonative operability enabled by active variation of combustor geometry resulted in higher performance with a lower injector pressure drop.

Influence of operating parameters on hydrogen DISI engine at injection pressure-drop by experimental investigation and Taguchi method

Hydrogen, as a low-density, zero-carbon energy source, often faces injection pressure drop when used as an alternative fuel for multi-parameter regulation in direct injection spark ignition (DISI) engines. In this paper, the effects of operating parameters including torque, excess air coefficient (λ), ignition timing, and injection timing on combustion, emissions, and energy distribution of a hydrogen DISI engine were first investigated at injection pressures of 100 bar and 30 bar, respectively, followed by Taguchi methodology and analysis of variance (ANOVA) to determine the optimal parameter combinations and their contribution to typical indicators of engine performance. The results showed that injection pressure-drop deteriorated the coefficient of variation (COVIMEP), nitrogen oxides (NOx) emissions, and brake specific fuel consumption (BSFC) in the set of cases. And the deteriorating BSFC is mainly due to the increase in heat loss power (PHL) or the exhaust power (PEx). Taguchi method and ANOVA showed that injection pressure drop changed COVIMEP and BSFC regarding optimal ignition timing selection and PEx regarding optimal injection timing selection and it also increased the torque contribution to COVIMEP by 26.54 %. PHL and PEx should be simultaneously considered because their choice of optimal operating parameters is a “Trade-off” relationship in most cases.

Throttling simulation and control of liquid oxygen/liquid methane rocket engine pressurized by the electric pump

This article presented simulation and control of a liquid oxygen/liquid methane variable thrust rocket engine pressurized by the electric pump in the throttling process. To get a proper injection pressure drop, the variation of the injection area was investigated and determined. In the control scheme, the combustion pressure and mixture ratio were the targets. To simplify the control scheme, the pressure and mixture ratio were correlated to the oxygen mass flow rate and methane mass flow rate, respectively. By controlling the propellant mass flow rate, the target engine thrust was reached. In addition, the influence of mass flow rate measurement points on the control effect was analyzed. The simulation results showed that the designed controller can reduce the overshoot of the critical engine parameters. Therefore, the maximum temperature of the thrust chamber wall after the regenerative cooling was decreased. Consequently, the thrust control errors were within 3% except for the points where the thrust changed suddenly, which can meet the mission requirements.

Characterization of pintle engine performance for GO2/kerosene propellants

Liquid rocket engine with a wide range of thrust variations has drawn much attention in recent years. A GO2/kerosene deep-throttling variable thrust engine using a liquid–gas pintle injector is presented and tested with aim of characterizing engine performance, regulating capability, and heat flux distribution. Three-dimensional numerical simulations are conducted to investigate the flame appearance and spray characteristics of the engine. The SST k-omega model is used for modeling turbulence, the Wave model is used for modeling the secondary breakup, and a multi-step quasi-global combustion mechanism and eddy dissipation concept model are used for modeling combustion. The GO2/kerosene pintle engine achieves stable combustion at 0.18 ∼ 4.35 MPa with a thrust of 21.30 ∼ 864.70 N. The thrust ratio of the pintle engine is 40.6:1 indicating a deep-throttling variable thrust capability. The thrust regulation of the pintle engine using the closed-loop control has high accuracy and response speed, as well as high disturbance suppression capability. The effects of combustor pressure, spray characteristics, and reactants concentration distribution on flame appearance and heat flux distribution of the engine are studied in detail. The engine equipped with a liquid–gas pintle injector could ensure a good atomization effect and high combustion efficiency by actively adjusting the propellant injection pressure drop coefficient. This work will provide a reference for the design of the pintle injector and thermal protection system of deep-throttling variable thrust rocket engines.

Multi-objective optimization of fuel injection performance of a common rail injector

The improvement of injector performance is important for the operation of common rail (CR) fuel systems. In this study, the optimization work has been carried out on a large-flow common rail injector. First, to simulate the injection process, a one-dimensional (1-D) model was developed and validated against the experimental data. The mathematical approximation model was also established to correlate the injection performance with the factors. Then, a multi-objective model by taking three design objectives into account was established and solved. Finally, Pareto front was obtained and the final optimization solution was determined. Furthermore, an extensive validation and analysis for the optimized results under various operating conditions was also carried out. Results shows that the three objectives, total response time, injection pressure fluctuation and injection pressure drop respectively, are improved by 11.75%, 39.12%, and 10.03% under the typical condition. And the proposed multi-objective optimization program based on design of experiment (DOE) technique, response surface methodology (RSM) and Elitist Non-dominated sorting genetic algorithm (NSGA-II) in present work can exhibit a good capability to optimize the problem of the injection performance in a CR fuel system.

Effects of Injector Pressure Drop on the Performance of a Monopropellant Hydrazine Thruster

نتایج مطالعه روی رفتار یک رانشگر تک‌پیشرانه هیدرازینی هنگام استفاده از انژکتورهایی با ابعاد مختلف ارائه می‌شود. انژکتورهای استفاده شده در این رانشگرها از نوع اریفیس هستند. هرچند الگوی جریان سیال در این انژکتورها ممکن است ساده به نظر برسد، رفتار رانشگر -که ناشی از اندرکنش دینامیک انژکتور با محفظه است- ویژگی‌های جالب توجهی را نشان می‌دهد. افت فشار انژکتور، در محدوده مورد مطالعه، تاثیری بر سرعت مشخصه و تاخیر اشتعال نداشت. با این حال زمان پاسخ 90% فشار و نوسان فشار محفظه به شدت تحت اثر افت فشار انژکتور هستند؛ با افزایش افت فشار، زمان پاسخ افزایش می‌یابد اما نوسان فشار کم می‌شود. نتایج ارائه شده ثابت می‌کند که آزمون سرد انژکتور برای ارزیابی و صحه‌گذاری طراحی آن کافی نبوده و اهمیت تست گرم رانشگر را نشان می‌دهد. بحث‌های این مقاله همچنین برای طراحان هر سامانه‌ای که از اریفیس برای کنترل دبی استفاده می‌کنند و به دنبال تحلیل رفتار گذرای آن سامانه‌ها هستند، قابل توجه خواهد بود.

EXPERIMENTAL STUDY OF ELEMENTARY ACTS OF HYDRODYNAMICS AND HEAT TRANSFER DURING THE INTERACTION BETWEEN WATER DROPS AND FILM AND CASTING ROLLER SURFACE

Experimental studies of the boundary conditions of heat transfer for the thermally stressed state of casting rollers while are spraying with flat-jet nozzles in a thermal preconditioning unit have been carried out.
 It is shown that the hydrodynamic conditions on the sprinkling surface are formed as a result of both the influx of "primary" dispersed water from the flat jet nozzle, and the "secondary" liquid coming from neighboring areas in the form of reflected drops and films.
 The heat transfer effecting individual factors that form the hydrodynamic conditions on the sprinkling surface was studied separately.
 The heat transfer intensity was studied depending on the spraying density, the injection-pressure drop and the temperature of the cooled surface when the "primary" drop flow runs in the heat exchange surface. The local sprinkling density of droplets on the surface under the flat-jet nozzle spray were measured using a sampling tube moved by a coordinator. At the same time, the ingress of “secondary” liquid into it was excluded.
 The specific heat flux and heat transfer coefficient were determined using a heat meter made of a nichrome tape heated by direct current. In this case, the isothermality of the surface of the measuring section was ensured. Thermocouples measured the temperature of the lower surface of the tape, and then the stationary temperature of the upper surface of the heat meter sprinkled with drops is calculated.
 As a result of the multivariate analysis of the experimental data, the correlation dependence of the heat transfer coefficient in dependance on the local spraying conditions of the heat meter surface was obtained.
 Also, studies of the heat transfer during water film flow over the heat meter surface were carried out. A similar situation takes place when water spreads between the adjacent nozzles sprinkling zones of the roller surface.
 The correlation dependence between the heat transfer coefficient, the water film speed and the cooled surface temperature was obtained.
 Studies of heat transfer during combined influence of moving water film and a flat-jet nozzle drop flow on the heat exchange surface showed that the heat transfer rate is approximately 80–90 % of the arithmetic sum of the coefficients obtained by separate cooling the heat meter with drops and a water film.

Effect of Local Momentum Ratio on Spray Windward Distribution of a Gas–Liquid Pintle Injector Element

The variable-area pintle injector has unique geometry and spray characteristics compared to traditional coaxial injectors, and is advantageous for weight lightening and deep throttling of liquid rocket engines. To obtain an accurate prediction of the spray windward distribution of a gas–liquid pintle injector with discrete radial orifices, a pintle injector element using air and water as simulants was designed for spray experiments in the atmospheric environment. The air-film injection pressure drop and water-jet injection orifice diameter were both adjusted for a wide variance range from 0.19 to 2.85 for the local momentum ratio. Backlight imaging was adopted for shooting the frozen spray pattern from one side, and a new dimensionless parameter, i.e., the spray fraction, was defined to quantitatively analyze the time-averaged windward boundary band. The dimensionless spray windward boundary band model for a circular-orifice jet and the corresponding derivative formula of the spray half angle were summarized through parameter study. The predicted results of empirical models were in good agreement with the experimental results. It was found that when the local momentum ratio was about 1, the spray distribution range basically overlapped with the coverage scope of gas film with uniform liquid mist.

Injection Properties According to the Inner Shape of Metal Additive Layer Manufactured Coaxial Injectors

The application of three-dimensional (3D) printing technology in rocket engine development has numerous benefits considering cost and time. Among the various techniques of 3D printing, the selective laser melting method has the advantage of being able to manufacture complex structures and process multiple materials. In this study, five types of coaxial injectors with different internal configurations were manufactured using metal 3D printing. To confirm the atomization and mixing performance according to the structure of each injector's oxidizer and fuel post, a cold flow test using water and air was performed under a wide range of experimental conditions. As a result of analyzing the injection pressure drop, discharge coefficient, spray pattern, breakup length, and spray angle, the shape of the oxidizer post had a significant influence on the performance of the injector. In comparison, the effect of the fuel post structure was relatively small; however, there was a meaningful difference in the breakup length and spray angle depending on the direction of rotation.

Experimental investigation of a flow-oriented throttleable injector designed for throttleable hybrid rocket motor

Easily achieving thrust throttling is a significant advantage of hybrid rocket motor. To achieve more stable combustion and reduce the pressure of the upstream feed system during the thrust throttling, it is necessary to control the injection conditions while controlling the oxidizer mass flow rate. In view of this, a flow-oriented throttleable injector that can control the injection pressure drop during the thrust throttling was designed, fabricated and tested. In order to verify the feasibility and obtain the injection pressure drop characteristics, cold flow tests of the flow-oriented throttleable injector were performed, including static injection pressure drop tests with/without back pressure and dynamic injection pressure drop tests with/without back pressure. Then, the steady-state hot test and thrust throttling hot tests of the throttleable hybrid rocket motor with the flow-oriented throttleable injector were conducted, in which the 98%H2O2/PE were adopted as the propellant combination and the controllable cavitating venturi was used to control oxidizer mass flow rate. In thrust throttling tests, the achieved maximum of the thrust throttling ratio was 8.65 under the condition that the change ratio of oxidizer mass flow rate was 7.19. During the thrust throttling, the motor worked stably, and the combustion chamber pressure, thrust and injector pressure drop varied approximately linearly with the linear variation of the oxidizer mas flow rate. The variation of injection pressure drop of the flow-oriented throttleable injector was much less than that of the conventional fixed structure injector, of which the injection pressure drop is proportional to the square of the oxidizer mas flow rate.

Experimental study on the injection of polysilicon nanomaterials in natural gas pipeline

China is a big oil country, and its oil production and storage are in the forefront of the world. However, China's oil resources are mainly low-permeability reservoirs. It is characterized by small porosity, which leads to the increase of injection pressure and seriously affects the production rate. The main solution is to use polysilicon nano injection enhancer. Polysilicon nano materials can solve the problem of high injection pressure from the micro level. At present, there are many researches on polysilicon nano injection technology at home and abroad, but the research on the application of polysilicon nano materials in natural gas pipeline materials is still blank. In order to solve this problem, this paper will further study the injection enhancement effect of polysilicon nano materials in natural gas pipeline materials. First of all, through theoretical research and analysis, this paper believes that polysilicon nano injection technology has good application, good effect in oilfield injection pressure drop, and obvious advantages over other traditional injection additives. In order to further analyze the injection enhancement effect of polysilicon nanomaterials, the corresponding experimental model is established. The experiment is divided into two parts, one is the preparation of reagents and solvents. In this paper, nano polysilicon solution and corrosion inhibitor are re optimized. The other part is the specific test steps. In order to ensure the quality and verifiability of the test, this paper explains and records the test principle and steps in detail. After sampling and analysis of many core factors such as adsorption time and permeability, it can be seen from the analysis data that when polysilicon nanomaterials are injected, when the injection volume is about 1pv, the effect of depressurization is the best, and the comprehensive effect of depressurization is good. This study has achieved ideal results, which is of great significance to the related research of oil field.

Rotating Detonation Wave Direction and the Influence of Nozzle Guide Vane Inclination

This study describes a rotating detonation combustor (RDC) equipped with a set of nozzle guide vanes (NGVs) of variable number and inclination angle. Different instrumented guide vanes were manufactured and integrated for in situ measurements of static and stagnation pressure. It is shown that the mode progression and stagnation pressure gain of the device are not negatively affected by addition of the NGV stage. The positive effects of increasing mass flux, increasing NGV throat restriction, and decreasing air injector pressure drop are observed; however, no positive pressure gain is ultimately measured. A large number () of individual runs with a single detonation wave mode is statistically analyzed. In this analysis, the wave direction is automatically determined using a cross-correlation method, and binomial hypothesis testing is subsequently applied to the dataset. It is demonstrated that changing the vane inclination influences the preferential detonation wave direction such that the oblique shock is oriented at a less acute angle with respect to the vane’s axial chord. This results in less energy reflected back to the detonation wave and increases the ability of the vane stage to ingest the high-enthalpy flow, which also impacts a number of performance metrics. The combination of wave direction and vane inclination is categorized as either “aligned” or “misaligned” based on these observations. For the aligned configuration, the flow acceleration across the vane stage is larger, as is the static pressure difference between pressure and suction sides. The average flow Mach number at the NGV leading and trailing edges and the static pressure distribution in the converging–diverging vane section are shown to agree well with predicted values from isentropic relations. Pressure fluctuations are attenuated by some 80% across the NGV stage. The study demonstrates that for RDCs integrated into larger systems, it is imperative to know and control the wave direction, and that NGVs may be a useful tool to achieve this goal. It further underlines that a careful integration of turbomachinery with RDCs is key to harnessing the full potential of this promising technology.

Blowout characteristics of the partially premixed flame during the condition transition in a supersonic combustor

The blowout characteristics of partially premixed flame during the condition transition in a cavity-stabilized scramjet combustor are investigated by the experimental method. More attention is placed on the unsteady evolution of the turbulent jet flame, as well as its dynamic response with the initial reactive flow states. The Mach number of flow at the entrance of the combustor is 2.52, the total pressure and the stagnation temperature of which are 1.6 MPa and 1486 K. The cavity-stabilized jet flame is blown out once the injection pressure drop reaches a critical value. During the flame blowout process, the most strongly reactive region gradually transits from vicinity of the cavity shear layer to downstream. Accompanied the sharply decrease of combustion intensity, the light intensity drops rapidly until the flame is completely extinguished. The experimental results indicate that the dynamic process of flame blowout depends on the initial reactive flowfields. The jet flame lasts longer and more intermediate products with high temperature reside within the combustor, which is beneficial to ignite the combustible fuel mixed in the air. As the increase of initial combustion intensity, the flame can be maintained in the combustor at a lower limit of global equivalence ratio after the condition transition. The results on the flame blowout limits are of great significance for the design of the condition transition in a scramjet.

Combustion Modes and Unsteady Characteristics during the Condition Transition of a Scramjet Combustor

To investigate the combustion modes and unsteady characteristics during the condition transition of a scramjet combustor, a series of experiments were carried out under the condition of Mach 2.52 supersonic incoming flow, the corresponding stagnation pressure and temperature of which were 1.6 MPa and 1486 K, respectively. A fuel supply system that could dynamically adjust the injection pressure was adopted to simulate the condition transition stage of a scramjet. Based on the advanced combustion diagnosis technique, the transient chemiluminescence image and the wall pressure were recorded during the whole combustion process. Three typical modes of turbulent combustion occurred when the injection pressure drop gradually increased. The jet flame was stable after the condition transition when the injection pressure drop was relatively low. An unstable combustion phenomenon accompanied by intermittent local extinction and reignition could be found near the blowout limits. With a further increase in the injection pressure drop, the flame was blown out quickly during the transition process. In addition, the flame development characteristics during condition transition under stable combustion mode and the effect of injection pressure drop were studied in detail. During the process of switching between the two conditions, the area and light intensity of the flame decreased over time, and the wall pressure was accordingly reduced. As the increase in injection pressure dropped, the intensity of chemical reactions deceased obviously and the transition time became longer.

Characteristics of Modern Geostress and Removability of No. 15 Coal Reservoir, Yangquan Mining Area, China

Based on injection pressure drop test data and acoustic emission test data of 13 records for samples from the Wenjiazhuang and Sijiazhuang mines in the Yangquan mining area, the vertical distribution characteristics of modern in situ stress and its influence on permeability in the Yangquan mining area were analyzed, and the exploitation of the No. 15 coal reservoir was studied. The results show that the Yangquan mining area is a low-stress area within burial depths of 400–760 m, moderate-stress area within 760–950 m, and high-stress area within 950–1300 m. The Yangquan mining area hosts a strike–slip fault stress field within burial depths of 400–900 m and a normal fault stress field within burial depths of 900–1300 m, and the permeability showed a “decrease–increase–decrease” trend with an increase in burial depth. The pressure coefficient K of the modern in situ stress field in the Yangquan mining area decreased with increasing burial depth, and its relationship formula with burial depth was 68.25/H + 0.2846 ≤ K ≤ 397.63/H + 0.6061. The permeability of No. 15 coal seam had a strong logarithmic relationship with horizontal principal stress, a strong exponential relationship with horizontal principal stress difference, and a strong power function relationship with effective stress. With an increase in stress and in stress difference, permeability decreased rapidly. The results of the acoustic emission tests of the No. 15 coal were analyzed. The in situ stress type of the Sijiazhuang mine and Wenjiazhuang mine is the normal fault stress field type, which is consistent with the well test analysis results. The high ring counts in the horizontal direction of coal seam 15 lasted for a long time, which was conducive to the generation of several network-forming fractures in the process of fracturing. The No. 15 coal reservoir is located in strike–slip fault stress field and normal fault stress field areas, and the fractures generated by hydraulic fracturing expanded along the vertical direction and the maximum horizontal principal stress direction, which was favorable for the fracturing transformation of coal reservoirs and the production and development of coalbed methane.

Experimental study on the fuel heating at the nozzle of the high pressure common-rail injector

In this study, an experimental and theoretical investigation of the fuel temperature increase at the nozzle of a common rail injector was conducted. The results showed that the temperature of the fuel at the nozzle began to increase rapidly with an increase in the injector working time and then stabilized. In the steady state, the temperature increase of the fuel at the nozzle holes only depended on the injection pressure drop rather than the discharge coefficient for the nozzle holes. The temperature increase of the fuel at the nozzle was not only related to the pressure drop but was also affected by the duty cycle of the injection pulse, which reflected the relative injection duration. The existing thermogenesis model for continuous flow is not suitable for the calculation of the temperature increase in the pulse injection mode of the common rail injector. A correction formula for the Joule–Thomson coefficient that considered the injection pulse and injection duration was proposed. The calculation results were in good agreement with the experimental data, which proved the accuracy of the model. These results and the mathematical model could be used to determine the thermodynamic boundary conditions inside a nozzle when using a three-dimensional method to calculate the thermodynamic state of the injector.

Role of Precombustion Chamber Design in Feed-System Coupled Instabilities of Hybrid Rockets

Oxidizer feed-system coupled instabilities have been observed in several liquid and hybrid propellant rocket engines, although they are not likely to be catastrophic for the latter. However, severe pressure oscillation in hybrid rocket may result in a significant reduction in the performance of the propulsion system restricting the application of the technology. In this research, feed-system coupled instabilities were studied theoretically and experimentally for hybrid rocket engines. Two test campaigns were performed to investigate the effects of the precombustion chamber and oxidizer injector configurations on engine pressure oscillation. Then, an extended mathematical formulation (including the injector pressure drop, the precombustion chamber residence time, the gas residence time, and the combustion time lag) has been proposed. The investigation was based on a transfer function using the stability limit analysis and the root locus method. It has been found that the configuration of the precombustion chamber plays an important role in the nature of the feed-system coupled instabilities, and a correlation was proposed to predict the fundamental frequency based on the oxidizer precombustion chamber residence time. The work has shown that the precombustion chamber length and the oxidizer injection velocity are key parameters that affect the period of the pressure oscillations in hybrid engines subjected to feed-system coupled instabilities.

The Effect of Carbon Steel Pipeline Deterioration to Water Injection Quality and Pressure Drop in Tanjung Waterflood Injection Plant.

In Tanjung, South Kalimantan, PT Pertamina EP (PEP) use secondary recovery (waterflood injection) for its technique for oil lifting. Low permeability reservoir condition make quality of water injection must be comply with low permeability reservoir requirement and the pressure injection must be around 1400 psig. In the common PEP injection plant, carbon steel pipeline is still used. Flakes accumulation and trapped oil could occur along with the deterioration of carbon steel pipeline. This matter can make the quality of requirements of injection water become worst. There were four data were analyzed; Oil content, TSS (Total Suspended Solid), Turbidity and Total Iron. The sample was taken at discharge pump and one of the injections well during 6 months. Averagely the result of value of total iron, turbidity and oil content in injection well are bigger than discharge pump while TSS has little fluctuation. In conclusion, deterioration carbon steel pipeline has effect to reduce quality water injection become worst and effect of roughness of pipeline due to carbon steel deterioration can make the pressure drop is higher in accordance with the length.