Flow Rate Of Crude Oil Research Articles

Prediction of Separation Length of Turbulent Multiphase Flow Using Radiotracer and Computational Fluid Dynamics Simulation

Multiphase flow modeling presents great challenges due to its extreme importance in various industrial and environmental applications. In the present study, prediction of separation length of multiphase flow is examined experimentally by injection of two kinds of iodine-based radiotracer solutions into a hydrocarbon transport pipeline (HCT) having an inner diameter of 24 in (60,96 m). The main components of fluids in the pipeline are water 95%, crude oil 3% and gas 2%. A radiotracing experiment was carried out at the segment of pipe which is located far from branch points with assumptions that stratified flows in such segment were achieved. Two radiation detectors located at 80 and 100 m from injection point were used to generate residence time distribution (RTD) curve resulting from injection of radiotracer solutions. Multiphase computational fluid dynamics (CFD) simulations using Eulerian-Eulerian control volume and commercial CFD package Fluent 6.2 were employed to simulate separation length of multiphase flow. The results of study shows that the flow velocity of water is higher than the flow rate of crude oil in water-dominated system despite the higher density of water than the density of the crude oil. The separation length in multiphase flow predicted by Fluent mixture model is approximately 20 m, measured from injection point. This result confirms that the placement of the first radiation detector at the distance 80 m from the injection point was correct. Received: 04 December 2012; Revised: 29 January 2013; Accepted: 09 March 2013

An experimental design approach for investigating the effects of operating factors on the wax deposition in pipelines

An experimental study is conducted to determine the wax deposition potential of three waxy crude oils during laminar flow in a pipeline system. The Taguchi experimental design approach is used to evaluate the influence of important operating factors such as inlet crude oil temperature, temperature difference between the oil and the pipe wall (ΔT), the flow rate of crude oil, wax content and time on wax deposition phenomena. It is found that the parameter ΔT and flow rate have maximum and minimum percentage of contribution on the amount of deposited wax, respectively. The results demonstrate that a waxy crude oil with higher wax content could lead the more deposited solid wax in transportation lines. The differential scanning calorimetry (DSC) analysis showed that wax appearance temperature (WAT) and solid content of the deposit were increased as deposition time increased.

Electrorheology Improves Transportation of Crude Oil

A system to simulate crude oil flow in pipeline is established in the authors’ lab. The system measures the crude oil flow rate with and without the electric field treatment. With this system, it is demonstrated that the crude oil flow rate is increased by about 20% after an electric field of 12,000 V/cm is applied in the direction parallel to the flow direction. The electric energy for this electric field treatment is very small and oil temperature is almost unchanged. The electrorheology-induced thinning effect will have significant application in crude oil pipeline transportation.

A multi-level simulation approach for the crude oil loading/unloading scheduling problem

An integrated approach for refinery production scheduling and unit operation optimization problems is presented. Each problem is at a different decision making layer and has an independent objective function and model. The objective function at the operational level is an on-line maximization of the difference between the product revenue and the energy and environmental costs of the main refinery units. It is modeled as an NLP and is constrained by ranges on the unit's operating condition as well as product quality constraints. The production scheduling layer is modeled as an MILP with the objective of minimizing the logistical costs of unloading the crude oil over a day-to-week time horizon. The objective function is a linear sum of the unloading, sea waiting, inventory, and setup costs. The nonlinear simulation model for the process units is used to find optimized refining costs and revenue for a blend of two crudes. Multiple linear regression of the individual crude oil flow rates within the crude oil percentage range allowed by the facility is then used to derive linear refining cost and revenue functions. Along with logistics costs, the refining costs or revenue are considered in the MILP scheduling objective function. Results show that this integrated approach can lead to a decrease of production and logistics costs or increased profit, provide a more intelligent crude schedule, and identify production level scheduling decisions which have a tradeoff benefit with the operational mode of the refinery.

Fuzzy logic controller for crude oil levels at Escravos Tank Farm

Fuzzy logic controller (FLC) for crude oil flow rates and tank levels was designed for monitoring flow and tank level management at Escravos Tank Farm in Nigeria. The fuzzy control system incorporated essence of expert knowledge required to handle the tasks. Proportional Integral Derivative (PID) control of crude flow rates and levels was also investigated, and the performance compared with the FLC and hybrid FLC/PID control by using rise time and settling time as system parameters. The FLC provided the best system management when compar-ed with PID and FLC/PID controls.

Formation Damage Caused by Simultaneous Sulfur and Asphaltene Deposition

Summary Although many oil reservoirs are producing crude oils of different sulfur and asphaltene contents, deposition problems of sulfur and asphaltene components in porous media are investigated separately. The major objectives of this laboratory study are to investigate the simultaneous deposition of sulfur and asphaltene in porous media. To achieve these objectives, the influences of the following on the permeability damage of the reservoir rock were experimentally investigated:crude-oil flow rate,permeability of reservoir rock through which crude oil flows, andconcentrations of sulfur and asphaltene in the crude oil. A base run was conducted using the crude oil after removing sulfur and asphlatene. Ten dynamic flow experiments were carried out using different crude oils of different sulfur and asphaltene concentrations and under different flow rates. The crude oil was flooded through different rock permeabilities of 2.34, 6.23, 16.58, and 21.48 md and under different flow rates of 0.5, 1.0, 2.0, and 3.0 cc/min, respectively. No permeability reduction or pore plugging was measured for the base experiment. The results indicated that the increase of flow rate increases the formation damage because of simultaneous deposition of sulfur and asphaltene in the reservoir rock. Core samples of lower permeability showed more severe permeability damage than those of higher permeability for the same applied flow rate and the same sulfur and asphaltene content of the crude oil. Furthermore, the increase of asphaltene and/or sulfur content of the crude oil increases the rock damage. The attained results of this study highlighted the important role of formation damage of carbonate oil reservoirs containing oils with a considerable amount of sulfur and asphaltene. In addition, the study provides two empirical correlations capable of predicting the permeability damage rate as a function of flow rate or initial rock permeability. These correlations represent useful tools for semianalytical and simulation studies. Introduction and Review Almost all deep sour-gas reservoirs contain elemental sulfur as a dissolved species. Reduction in pressure and temperature induced sulfur precipitation by a reduction in the solubility of the sulfur in the gas and/or oil phase beyond its thermodynamic saturation point. These changes occur during production operations and can result in sulfur deposition in the reservoir, wellbore, and surface facilities. Deposition of elemental sulfur in the near-wellbore area may significantly reduce the inflow performance of sour-gas wells. In addition, oil reservoirs all over the world suffer from simultaneous sulfur and asphaltene deposition problems in porous media, which cause problems in production facilities. Investigation of sulfur deposition in porous media receives little attention, while asphaltene nature and deposition in porous media have been covered extensively. Furthermore, the investigation of simultaneous sulfur and asphaltene deposition has not been studied in spite of the expected problems of formation damage and facility corrosion.

Oilfield control system

Real-time control techniques for measuring parameters in crude oil storage tanks are described. The techniques enable the height of the oil/water layer in the storage tanks to be measured. By using this measuring technique for the oil-water interface, with the height of the interface in the tanks, coupled with the measurements of the water/oil content ratio, the density and flow rate of crude oil and the net oil quantity can be calculated. Therefore, automatic online computation of crude oil reserves and gross output quantity of net oil can be accurately predicted. The proposed method solves a difficult oil field problem that enables control of oil and gas production volumes to be maintained, particularly in low temperature environments where conventional instrumentation has proved ineffective. The control techniques enable the oil production process to function safely and reliably.

Preparation and characterization of a water-soluble fraction of crude oil by a Karr reciprocating-plate countercurrent extraction column

A 1.8 m×2.5 cm reciprocating-plate countercurrent extraction column was evaluated for the preparation of WSF (water-soluble fractions) from Flotta North Sea light crude oil. The energy input from the plate reciprocation speeds was found to be the main factor affecting the characteristics of the extracted WSF, and the throughputs of the stock solution or the ratio of seawater to crude oil had little effect on the concentration and composition of the extracted WSF. A combination of a reciprocation speed of 170 strokes/min, a seawater flow rate of 220 ml/min, and a crude oil flow rate of 2.9 ml/min produced a WSF stock solution with a total hydrocarbon concentration of 13.5±0.30 mg/kg (n=6) which was more reproducible than that made by a previously used large-scale batch extraction method. A settlement time of 5 h or less for the stock solution allowed a full separation of any dispersed droplets of crude oil from the aqueous phase under the above conditions, but further increases in reciprocation speeds caused difficulties in the final separation of this crude oil. The column extraction method was highly reproducible and gave a more concentrated WSF containing a higher proportion of alkanes than a WSF made by the batch extraction method. Low-boiling aromatics were the main components of the total extracted hydrocarbons of the WSF.

Drag reduction in turbulent crude oil pipelines using a new chemical solvent

Pilot-scale experiments have been conducted to reduce drag in pipelines carrying crude oil using a new chemical additive. The effects of pipe diameter and crude oil flow rate on drag reduction rate have been studied in 1″, 2″, 3″, and 4″ pipes. The effect of additive concentration on drag reduction was also investigated, and it was found that a 9-ppm concentration of the chemical solvent is optimum for the studied system. A maximum drag reduction of 63% has been achieved when 9 ppm of the solvent was added to the 4″ pipe.

Influence of ultrasonics upon liquid flow through porous media

This investigation was primarily a study of the effects of acoustic energy upon the flow rate of crude oil through porous sandstone. However, the effect of water flow through a porous stainless steel filter was also investigated. When acoustic energy of 20kHz was introduced, there was a substantial increase in the rate of liquid flow through all the porous media tested. An optimum ultrasonic intensity level was noted which gave the greatest rate of oil flow through the sandstone. This optimum intensity remained approximately the same regardless of the thickness of the sandstone. A study of the acoustic action by means of motion pictures revealed a possible explanation for the results obtained.