Product Flow Rate Research Articles

Critical sand deposition velocity for gas-liquid stratified flow in horizontal pipes

Sand is frequently produced along with production fluids from a reservoir with low formation strength. Sand deposition in pipeline causes problems such as equipment failure, pipeline erosion, excessive pressure drop, and production decline. Operating above critical sand deposition velocity, which is the velocity that keeps particles moving all the time at the pipe bottom, is the best strategy to manage sand deposition and simultaneously optimizing production flow rates. In this paper, a comprehensive study of sand flow regimes in air – PAC (Polyanionic Cellulose) water stratified flow in horizontal pipelines for various sand concentrations upto 10,000 ppm is presented. Six sand flow regimes are observed, namely, fully dispersed solid flow, dilute solids at wall, concentrated solids at wall, moving dunes, stationary dunes and stationary bed. Critical sand deposition velocities are determined based on the transition between moving (concentrated solids at wall/moving dunes, as appropriate) and stationary (stationary dunes/bed, as appropriate) sand particles. The viscosity of water is increased to 5 cp by using PAC to investigate the effect of viscous sublayer. The experimental data for tested conditions show that for concentrations above 4000 ppm, stationary beds are observed at the pipe bottom, and bigger particle size has higher critical sand deposition velocities, while for concentrations less than 4000 ppm, stationary dune and stationary bed are observed, and the critical sand deposition velocity depends on which sand flow regime occurs at the pipe bottom.

Difluorocarbene Addition to Alkenes and Alkynes in Continuous Flow.

The first in-flow difluorocarbene generation and addition to alkenes and alkynes is reported. The application of continuous flow technology allowed for the controlled generation of difluorocarbene from TMSCF3 and a catalytic quantity of NaI. The in situ generated electrophilic carbene reacts smoothly with a broad range of alkenes and alkynes, allowing the synthesis of the corresponding difluorocyclopropanes and difluorocyclopropenes. The reaction is complete within a 10 min residence time at high reaction concentrations. With a production flow rate of 1 mmol/min, continuous flow chemistry enables scale up of this process in a green, atom-economic, and safe manner.

Oil spill cleanup by atmospheric distillation

ABSTRACTOil spills impose major environmental challenges by leakage of oil in its surrounding areas. In this study, the collected oil spill from water surface was sent to the distillation column for fractionation processing. It was observed that the distillation column converts the oil spill to a useful form of petroleum products; however, energy consumption of the distillation column increases. In addition, increasing the oil spill flow rate to the distillation column increases its influence on energy consumption and flow rates of products, so the optimal rate of oil spill injection is computed.

Hydrogen production from alcohol solution by microwave discharge in liquid

Hydrogen, as an attractive energy carrier, is regarded as one of the best environmentally-friendly energy sources in the future. In the paper, it was reported that hydrogen was produced by 2.45 GHz microwave discharge in low carbon alcohol (methanol and ethanol) solution. The effects of microwave input power and concentration of alcohol solution on hydrogen production were studied. All results corresponded to the non-equilibrium plasma at reduced pressure (3000Ра). The gaseous products of microwave discharge in alcohol solution mainly included hydrogen, carbon monoxide, acetylene and carbon dioxide. The flow rates of total gaseous products and hydrogen increased with the increasing of power, while that increased firstly and then decreased with the increasing of concentration of alcohol solution. The percentage concentrations of hydrogen and carbon monoxide increased with the increasing of power, and when the concentration of alcohol solution was 8% v/v, the percentage concentrations of hydrogen and carbon monoxide reached a maximum value. As the power increased, the energy efficiency of hydrogen production improved significantly, and the energy efficiency of hydrogen produced from ethanol solution was higher than that from methanol solution with the same power. The energy efficiency of hydrogen production increased firstly and then decreased with the increasing of concentration of alcohol solution. In the paper, the best results of flow rate of hydrogen, percentage concentration of hydrogen and energy efficiency were 401.00 mL/min, 64.55% and 137.63 NL/kWh, respectively.

Evaluation of gas condensate reservoir behavior using velocity dependent relative permeability during the numerical well test analysis

Abstract Gas condensate is one of the most different fluids in reservoir simulation due to retrograde condensation in case of pressure reduction. In this kind of fluids, two phenomena named negative inertia and positive coupling, become significant in the high velocity zone around the wellbore. In this study, a modified black oil simulator is developed that take into account the velocity dependent relative permeability. Against the industrial simulator that assumes linear variation of transmissibilities by pressure, modified black oil nonlinear equations are solved directly without linearization. The developed code is validated by ECLIPSE simulator. The behavior of two real gas condensate fluids, a lean and a rich one, are compared with each other. For each fluid, simulations of PVT experiments are carried out to calculate black oil property applying Coats approach for gas condensate fluids. For both fluids, the proposed models for gas condensate velocity dependent relative permeability show different influence of velocity on relative permeability in the same conditions. Moreover, it is observed that higher flow rate of gas production leads to more condensate production during constant rate well testing.

Hot dry rock geothermal potential of the Xujiaweizi area in Songliao Basin, northeastern China

A series of studies was conducted to determine a suitable site for enhanced geothermal systems (EGSs) in mainland China. First, the Xujiaweizi (XJWZ) area in the Songliao Basin in northeastern China was identified to possess several features indicating a huge potential for hot dry rock (HDR) resource development from the aspects of tectonics, geology, geophysics, and geothermics. Then, a hydraulic fracturing model based on the real geological and logging data of well YS-2 and field fracturing experience in this region was established, and the geometric dimension and flow conductivity of the induced fracture were imported into a 3D hydrothermal coupled model established using TOUGH2-EOS1. The electricity generation potential of the fractured reservoir using three horizontal well production patterns is evaluated. Finally, three enhanced methods are proposed and discussed based on the simulation results. Results indicate that HDR resources in the XJWZ area demonstrate a significant potential for development from the aspect of geology. The Yingcheng Formation is selected as the potential target formation. The gel-proppant fracturing method is adopted in consideration of the undeveloped natural fractures in the target formation. The generalized EGS reservoir region possessed a considerable length of 600 m. The maximum production flow rate is determined to be 1 kg/s. The water flow impedance is relatively high during the heat production process for economic exploitation. Such an EGS reservoir has poor electricity generation capacity. A naturally fractured reservoir with a higher temperature should be targeted for electricity generation.

Transesterification of cotton seed oil using cosolvent in a tubular reactor

ABSTRACTMost commercial processes for making biodiesel use batch processes. Typical reaction time ranges from 20 minutes to more than an hour. However, batch reactors are generally not suitable in the production of large-capacity chemicals. Production of biodiesel using a cosolvent such as tetrahydrofuran (THF) requires a rather short reaction time. The result is a fast reaction, in the order of 5–10 minutes. In this work, the production of cotton seed oil methyl ester (CSOME) was carried out in a tubular reactor using THF as cosolvent, while potassium hydroxide (KOH) served as catalyst. The feed was pre-mixed in a feed tank and pumped into the reactor using fuel pump at various flow rates. The yield of CSOME increased from 93.3% for a residence time of six minutes to 99.5% for a residence time of 14 minutes. The reaction was carried out at room temperature with methanol/oil ratio of 6:1 and methanol/THF volume ratio 1:1. The variance of product flow rate, kinematic viscosity and specific gravity was determined to ensure biodiesel quality consistency. Fuel properties such as flash point, cetane number, and kinematic viscosity were determined and compared with ASTM standards.

Continuous manufacturing of carboxyamidotriazoleencapsulated nanoemulsions using adaptive focused acoustics: Potential green technology for the pharmaceutical industry

Nanoemulsions containing hydrophobic drugs have a great potential in the pharmaceutical industries to improve thebioavailability of the drug. However, currently there is no cost-effective way of producing nanoemulsions in large scale.The need of subjecting emulsions to an extreme pressure of 50 MPa demands a large excess of energy for themanufacturing process, while low-energy method requires large amount of solvents. Here, nanoemulsions containing awell-characterized hydrophobic drug, carboxyamidotriazole (CAI), are produced in both batch and continuous modes todemonstrate the scalability of nanoemulsion production using Covaris’ Adaptive Focused Acoustics™ (AFA) technology.To move from batch scale to continuous flow, the acoustic and thermal energy inputs can be manipulated to adjust particlesize, while the composition and temperature of starting materials can be altered to achieve complete dissolution ofhydrophobic drugs, thus providing 100% encapsulation efficiency. Furthermore, using two AFA systems in series candrastically enhance the production flow rates, making AFA a competitive means for producing nanoemulsions in thepharmaceutical industry.

Optimization of the reaction parameters of heavy naphtha reforming process using Pt-Re/Al2O3 catalyst system

One of the most significant procedures in oil refineries is naphtha catalytic reforming unit in which high octane gasoline is gained. Normally, in oil refineries, flow instability in the composition of feedstock can affect the product quality. The aim of the present work was focused on modifications of the final product flow rate and product’s octane number with respect to the modifications of the feedstock composition. The main three reforming reactions investigated, namely; dehydrogenation, dehydrocyclization, and hydrocracking were conducted employing silica supported bimetallic (Pt-Re) patented catalyst. Optimization of the catalytic process reaction conditions, i.e.; temperature, hydrogen pressure and liquid hourly space velocity (LHSV) was carried out with regard to conversion and selectivity. The optimization results indicated that heavy naphtha component conversion (paraffin’s and naphthenes) increases with an increasing in reaction temperature and pressure while decreases with an increase in LHSV. The kinetic study of catalytic reforming reactions reported helped establishing the reaction model explicitly.

Simultaneous Workload Allocation and Capacity Dimensioning for Distributed Production Control

Capacity dimensioning in production systems is an important task within strategic and tactical production planning which impacts system cost and performance. Traditionally capacity demand at each worksystem is determined from standard operating processes and estimated production flow rates, accounting for a desired level of utilization or required throughput times. However, for distributed production control systems, the flows across multiple possible production paths are not known a priori. In this contribution, we use methods from algorithmic game-theory and traffic-modeling to predict the flows, and hence capacity demand across worksystems, based on the available production paths and desired output rates, assuming non-cooperative agents with global information. We propose an iterative algorithm that converges simultaneously to a feasible capacity distribution and a flow distribution over multiple paths that satisfies Wardrop's first principle. We demonstrate our method on models of real-world production networks.

Cardioprotective effect of aqueous extract of Chichorium intybus on ischemia-reperfusion injury in isolated rat heart.

Several studies have shown that Chichorium intybus (C. intybus) which possesses flavonoid compounds has an effective role in treatment of cardiovascular diseases. Contractile dysfunction mostly occurs after acute myocardial infarction, cardiac bypass surgery, heart transplantation and coronary angioplasty. The aim of the present study was to investigate the effect of aqueous extract of C. intybus on ischemia- reperfusion injury in isolated rat heart. The animals were divided into four groups (Sham, Control, 1 mg/ml and 3 mg/ml of extract) of 8 rats. The aorta was cannulated, and then the heart was mounted on a Langendorff apparatus. Next, a balloon was inserted into the left ventricle (LV) and peak positive value of time derivate of LV pressure (+dp/dt), coronary flow (CF), and left ventricular systolic pressure (LVSP) in pre-ischemia and reperfusion period were calculated by a Power Lab system. All groups underwent a 30-minute global ischemia followed by a 60-minute reperfusion. The results showed that heart rate (HR), coronary flow, and left ventricular developed pressure (LVDP) and rate of pressure product (RPP) significantly decreased in the control group during reperfusion, while these values in the groups receiving the extract (3mg/ml) improved significantly during reperfusion (p<0.001). It seems that flavonoid compounds of aqueous extract of C. intybus reduce ischemia - reperfusion injuries, suggesting its protective effect on heart function after ischemia.

Technical feasibility comparison of off-grid PV-EDR and PV-RO desalination systems via their energy consumption

To explore the techno-economic feasibility of powering remote, rural desalination systems with renewable energies, this study conducted pilot-scale experimental work and software modeling to identify the energy consumptions of two common brackish water desalination technologies – electrodialysis reversal (EDR) and reverse osmosis (RO) – when operated with different water salinities, flow rates, and temperatures. The pilot-scale experiments were conducted in parallel at the Brackish Groundwater National Desalination Research Facility in Alamogordo, New Mexico; for the software modeling, WATSYS software was used for EDR, and WinFlows software was used for RO. The experimental results showed that product flow rate and the salinity of feed water significantly affected the specific energy consumptions (SECs) of EDR and RO. The SEC of EDR is more sensitive to feed water salinity variations, as compared to the SEC of RO. The SEC sensitivities of EDR and RO to product flow rate were slightly different. The SEC of EDR was not significantly influenced by temperature variations, while the SEC of RO was affected significantly by temperature variations. With the energy requirements for these systems identified under a range of operating conditions, HOMER software was used to identify optimal renewable energy systems for powering the desalination technologies under each combination of operating conditions. Lastly, the total net present cost of each renewable energy system was calculated, and the most economical systems were identified. As determined by measured energy consumption and modeled energy production, solar energy can feasibly power off-grid ED/EDR and RO systems in regions with meteorological conditions similar to Alamogordo, New Mexico. For low-salinity water with solar power, EDR was far more efficient than solar-powered RO, with a total net present cost difference of 48–159%, if the blending is not an option for RO. For higher-salinity water, solar-powered RO was more efficient than solar-powered EDR, with a lower total net present cost.

CO2 Capture from a Binary CO2/N2 and a Ternary CO2/N2/H2 Mixture by PSA: Experiments and Predictions

The results of pressure-swing adsorption experiments performed in a two-column setup are presented, as a way of validating a model developed to design and optimize cyclic adsorption processes. The experiments were conducted using a commercial activated carbon as the sorbent and an adsorption pressure of 20 bar. Two feed mixture compositions were studied: a binary CO2/N2 mixture representative of a flue gas and a ternary CO2/N2/H2 mixture representative of the product stream of air-blown autothermal reformers. During the experiments, the temperature was measured at five locations along the center of each column, along with the pressure, feed flow rate, product composition, and high-pressure product flow rate. A one-dimensional, nonisothermal, nonequilibrium model was used to simulate the experiments in a fully predictive manner. This model was previously validated in breakthrough experiments as well as PSA experiments using a binary CO2/H2 mixture. A thorough analysis of the experimental results and comparison with the simulation results showed that the model is fully capable of handling rather different feed compositions while still predicting satisfactorily the temperatures within the column, the product composition, and the overall process performance for a variety of process configurations and operating conditions.

Digital Reamer Enhances Drilling Efficiency, Economics, and Safety

Technology Update Expandable reamers were developed to improve efficiencies and reduce risk while drilling through problematic formations in deep water and other offshore wells, where wellbore stability is a major challenge. Lean-profile well designs have been implemented to enable operators to drill faster and more efficiently, with better well control and less material, within a narrow pressure window between formation fracture and shale collapse. Using this concept, the well is drilled using the smallest possible hole sections and minimum clearances between casing strings. This allows access to the reservoir with a larger-diameter hole to increase production flow rate or access to additional reserves that otherwise would be unreachable because of their extreme depth. Lean-profile wells require rotary steerable systems to create smooth wellbores, and expandable reamers to manage equivalent circulating densities (ECDs) and maintain wellbore stability while enlarging the hole under the casing sufficiently to allow reliable cementing. The first concentric expandable reamers were ball-activated. Once expanded, they could not be closed without stopping circulation. The second iteration was modified so that the reamer could be deactivated to allow circulation after reaming for better hole cleaning. The advantages of the concentric expandable reamer over its mechanical-arm predecessors included the attainment of a larger borehole size that could accommodate larger bottomhole assembly (BHA) components, flexibility in pilot bit selection, higher flow rates, and the ability to ream a previously drilled hole or to back ream a hole after drilling. The advances in underreaming technology expanded its application to the point at which it is now used on a high percentage of development wells. The most common application is shoe-to-shoe underreaming to enlarge the clearance for easier tripping and casing running. However, there are drawbacks to traditional expandable underreaming systems. Activation cannot be confirmed. Additionally, the placement of the reamer at 100 to 300 ft above the bit means that the equivalent portion of the hole, known as a rathole, cannot be enlarged without a dedicated trip that typically requires 1 to 2 days of rig time at a daily cost ranging from USD 1 million to USD 2 million.

A novel method for predicting gas/oil flow rate from temperature log data

Abstract Gas/oil flow rate of production well is an important parameter for evaluating oilfield production. This study presents an effective inversion method for estimating the flow rate from temperature log data, and the proposed method is based on the temperature-flow rate model of production well. Therefore, a novel heat transfer model for production well with consideration of wellbore heat capacity is built first to obtain the temperature-flow rate model. Then sensitivity analysis is applied to investigation of the correlation between the flow rate and fluid temperature for the inversion method. Lastly, the inversion method is used to estimate the flow rate as well as thermal conductivity of three production wells with study on the difference between the entire-wellbore and single-point inversion method. Analyses of results show that the entire-wellbore method tends to be more accurate to estimate flow rate with relative error less than 10%, while the single-point method shows lower error at the middle-points of wellbore for flow rate estimation. Furthermore, the estimated fluid temperature also agrees well with the temperature log data.

Optimization of Heat-Integrated Crude Oil Distillation Systems. Part I: The Distillation Model

This work presents a methodology for optimizing heat-integrated crude oil distillation systems. Part I of this three-part series presents a modeling strategy where artificial neural networks are used to represent the distillation process. Part II presents a new methodology to retrofit heat exchanger networks (HENs) and Part III presents the application of this distillation model to perform operational optimization of the crude oil distillation unit while proposing retrofit modifications to the associated HEN. Independent variables of the distillation model include flow rates of products, stripping steam, pump-around specifications, and furnace exit temperature. Dependent variables include those related to product quality, and temperatures, duties, and heat capacities of process streams involved in heat integration. The resulting neural network model is able to overcome convergence problems presented by rigorous or simplified models. Simulation time is significantly improved using neural networks, compared to rigorous models, with practically no detriment to model accuracy.

Overcoming challenges in the classification of deep geothermal potential

&lt;p&gt;&lt;strong&gt;Abstract.&lt;/strong&gt; The geothermal community lacks a universal definition of deep geothermal systems. A minimum depth of 400 m is often assumed, with a further sub-classification into middle-deep geothermal systems for reservoirs found between 400 and 1000 m. Yet, the simplistic use of a depth cut-off is insufficient to uniquely determine the type of resource and its associated potential. Different definitions and criteria have been proposed in the past to frame deep geothermal systems. However, although they have valid assumptions, these frameworks lack systematic integration of correlated factors. To further complicate matters, new definitions such as hot dry rock (HDR), enhanced or engineered geothermal systems (EGSs) or deep heat mining have been introduced over the years. A clear and transparent approach is needed to estimate the potential of deep geothermal systems and be capable of distinguishing between resources of a different nature. In order to overcome the ambiguity associated with some past definitions such as EGS, this paper proposes the return to a more rigorous petrothermal versus hydrothermal classification. This would be superimposed with numerical criteria for the following: depth and temperature; predominance of conduction, convection or advection; formation type; rock properties; heat source type; requirement for formation stimulation and corresponding efficiency; requirement to provide the carrier fluid; well productivity (or injectivity); production (or circulation) flow rate; and heat recharge mode. Using the results from data mining of past and present deep geothermal projects worldwide, a classification of the same, according to the aforementioned criteria is proposed.&lt;/p&gt;

Effects of operating conditions on ion removal from brackish water using a pilot-scale electrodialysis reversal system

Understanding the effects of operating factors on ion removal in the electrodialysis/electrodialysis reversal (ED/EDR) process can significantly benefit industrial applications, enabling process optimization through different combinations of operational factors. Several studies have shown the effects of specific operating factors on ion removal, and it has been established that superficial velocity influences ion removal. However, previous studies have yielded mixed results on whether increases in superficial velocity increase or decrease ion removal; also, since previous studies are based on laboratory-scale ED systems, the results may not be fully applicable to full-scale desalination due to differences in system characteristics such as membrane area, flow path, and degree of superficial velocity’s effect on ion removal. Therefore, this experimental study employs a pilot-scale EDR system that is very similar to a full-scale system in order to explore the effects of applied voltage, superficial velocity, and feed water temperature on ion removal. Additionally, a conceptual explanation is developed to explain the inconclusive results from previous research. The findings of this experiment confirmed that increases in superficial velocity decreased ion removal, and this result can help predict and optimize full-scale operations. In the investigated ranges, increasing voltage and temperature resulted in increased ion removal, while increasing superficial velocity resulted in decreased ion removal. The experiments were conducted at the Brackish Groundwater National Desalination Research Facility in Alamogordo, NM, USA on a General Electric Company pilot-scale EDR system with a maximum product flow rate of 45 L/min, using brackish water with a conductivity of 1,700 μS/cm.

Determination of the temperature distribution of ESP motors under variable conditions of flow rate and loading

Abstract A model to predict the motor temperature of an electrical submersible pump (ESP), under variable conditions of flow rate and loading, has been developed. This model takes into account the coupled behavior between motor, pump and production system. Thus, given a defined frequency in the variable speed drive, the motor temperature was determined as a result of the equilibrium between the heat generation, calculated from the power that the pump demands from the motor, and the heat extraction resistance, calculated from the production flow rate around the motor. Furthermore, in real field operations, the measurement of the motor temperature is made at the lower end of the stator winding, which is not exactly the maximum temperature point. In order to predict the maximum motor temperature value, the model developed in this work determines the motor temperature distribution. A convective heat transfer study has also been made comparing models based on fully developed temperature profile to models that consider the development of the thermal boundary layer. A case study has been made with several oil viscosities and water cut. The results showed a fact commonly observed in ESP field operations, that is, the motor temperature rises when the motor speed is continuously increased. It was also shown that neglecting the effect of the thermal boundary layer development may result in an overheated motor prediction where actually, the motor maximum temperature is much lower than its upper limit. Thus, it was observed that fully developed temperature profile models suffer from inaccuracy when used in viscous oil applications, because of their great thermal entry length.

Evaluation of developing an enhanced geothermal heating system in northeast China: Field hydraulic stimulation and heat production forecast

In this work, the feasibility of using enhanced geothermal system correlation techniques (hydraulic fracturing and heat extraction) to develop medium–low temperature geothermal resources for heating purposes in northeast China is investigated. A detailed experiment on field hydraulic fracturing stimulation is conducted. Combining with numerical simulation approaches, heat production potential of this system is forecasted. Field hydraulic stimulation results indicate that the matrix acidizing treatment significantly limits near wellbore friction loss. For network fracturing treatment, however, the formation of branching fractures and its enhancing effects on reservoir flow conductivity needs to be verified by production tests in the future. The geometric dimension and flow conductivity of the induced fracture are determined by numerical simulation of hydraulic fracturing process. The accuracy of the numerical model is verified through matching well head pressure curve. Parameters including production flow rate, flow impedance, production temperature, heat extraction rate and energy efficiency are determined through the simulation results of heat production forecast. The results indicate that thermal energy production from the stimulated reservoir is satisfactory for heating purpose. However, water flow impedance maintains at a relative high level during production period.