Oil Pumping Stations Research Articles

Interfacial Contamination Between Batches of Crude Oil Due to Dead-Legs in Pump Station Piping

Some oil pump station design layouts may contain multiple dead-legs. During the transportation of heavy crude through the pump station, these dead-legs will be filled with this crude. When a light crude batch is introduced next into the pipeline, following the heavy crude ahead, two phenomena will occur. First, contamination between batches at the interface of the two crudes will occur due to axial turbulent diffusion along the length of the pipeline itself. Second, as the light crude flows through the pump station and passes by each dead-leg containing still heavy crude from the preceding batch, the heavy crude trapped in these dead-legs will start to drain out into the passing light crude in the main run. This causes further contamination and spreading of the mixing zone between the two batches. These two different sources of contamination are addressed in this paper with the objective of accurately quantifying the extent of the contamination, with particular emphasis on the second phenomenon which could cause appreciable contamination particularly for large size and number of these dead-legs. A computational fluid dynamics (CFD) model has been developed to quantify the drainage rate of the contaminating crude into the main stream and its impact on widening the mixed zone (contamination spread) between the two batches. Two drainage mechanisms of the heavy crude in the dead-legs into the main stream of the light crude have been identified and quantified. The initial phase is a gravity-current-induced outflow of the initially stagnant fluid in the dead-leg, followed by a subsequent draining mechanism primarily induced by turbulent mixing and diffusion at the mouth of the dead-leg penetrating slightly into the dead-leg. It was found that the second mechanism takes a much longer time to drain the first, and that the break point in time where drainage switches from a predominantly gravity current to a turbulent diffusion appears to be at a specific time normalized with respect to the length of the dead-leg and the gravity current speed. The results show a consistent trend with actual interface contamination data obtained from the Keystone 2982 km pipeline from Hardisty (Canada) to the Patoka Terminal (U.S.A.).

A Novel Bearing Condition Monitoring Method in Induction Motors Based on Instantaneous Frequency of Motor Voltage

Bearing failures are the most frequent faults in induction motors. By utilizing an efficient bearing condition monitoring (BCM) method, unscheduled breakdowns and unnecessary costs caused by bearing failures can be eliminated. The methods proposed in the literature for this purpose are mainly based on measuring and analyzing vibration and current. This paper proposes a novel BCM method based on “instantaneous frequency of motor voltage.” Simulation and experimental results show that defective bearings cause to increase the amount of non-Gaussianity in this signal. In this paper, it is shown the global kurtosis of the proposed signal is able to detect bearing defects at an early stage. In contrast, for both vibration and current signals, it is preferable to applying the kurtosis locally in different frequency bands. The electrical signals are acquired from the motor terminals and motor control center of an oil pump station. Results approve the merits and effectiveness of the proposed method for industrial applications.

DISADVANTAGES OF LOCK UNDERVOLTAGE PROTECTION AT OIL PUMPING STATIONS

This article examines the effectiveness of the blocking action for the undervoltage protection from the overcurrent protection in electric mains pump stations and analyzes the impact of non-selective action of the undervoltage protection on the technological process of pumping. The process of pumping oil through main pipelines is continuous. However, when power failure, the motors of the main pumps lose power, that can disrupt the continuity of the technological process of pumping. The protection from power loss are used to detect power failure and taking measures to preserve the continuity of the technological process at oil pumping stations. Undervoltage protection is the main power loss protection when asynchronous drives of the main pumps are used on oil pumping stations. The undervoltage protection must not operate when short circuits in the distribution network of the enterprise to ensure the selectivity of the action. Disable entire section tires switchgear may take place if non-selective trigger occur. It can lead to the stop of the main pumping units and to the total breakdown of the process of pumping oil through the pipeline. Therefore, the protection of the minimum voltage should be blocked when the short circuits in the electrical network of the enterprise. Lock protection minimum voltage at the booster stations is performed from an overcurrent protection input. It isshown that depending on the mode of the supply network lock maximum current input protection may not be effective and undervoltage protection may work selectively. Found resistance range electric supply the range of distances to the fault location at which the failure of MTW and non-selective tripping MNH, at PS, the Investigated transients in the pipeline in the non-selective protection of the minimum voltage. It is shown that depending on the mode of the supply network the blocking may be not effective and undervoltage protection may work incorrect. Found resistance range of electric supply network and the range of distances to the fault location at which an overcurrent protection is not work but undervoltage protection works. Investigated transient processes in the pipeline when protection of the minimum voltage acts not selective.

The Influence of Main Pump with High-Voltage Variable Frequency Drives on Electric Motors Periodic Repair

The main objective of the work - to investigate the effect on the wear of high voltage electric motors of main pump units periodic switching on and off in cyclical pumping. Frequent starts motors in a cyclic pumping lead to accelerated wear of the mechanical parts of the motor due to the impact of dynamic loads at start-up, as well as winding insulation due to high inrush currents flow. As a result of accelerated depreciation may decrease residual life, overhaul period and service life of electric motors. The main factor affecting the service life of insulation motors are winding temperature, and as a consequence, the thermal aging of the insulation. The use of variable frequency drive can significantly reduce the cyclic transfer modes, or even eliminate them. The authors obtained analytical expressions for the evaluation of insulation deterioration at the start of the motor, which allow us to study the impact of the following factors: insulation class, the start time, break time at work, initial and nominal temperature, the temperature rise of the windings over the ambient temperature. The effect on the deterioration of the insulation cold start and hot conditions, as well as the percentage of the hottest start-ups in the total number of starts. Obtained expressions for the depreciation of isolation to determine the change timing of overhauls of high voltage electric main pump units. The developed method was approved by the example of the use of a variable frequency drive on the oil pumping stations construction section Leninsk-Nurlino trunk pipeline Nizhnevartovsk - Kurgan - Kuibyshev. The analysis showed that the installation of a variable frequency drive motors on three main pump units technological area of the number of starts to decline by 14%. The results can be used for pipeline transport of oil companies when planning the timing and costs of the current and capital repairs of high voltage electric motors main pump units.

The effect of fast changes in voltage unbalance on vibration characteristics of asynchronous motors

The effect of voltage unbalance in electrical networks that supply electrified traction loads on the operating regimes of large asynchronous motors (AMs) is considered. Based on the method of symmetrical components and analysis of hodographs of magnetic fields of AMs with a short squirrel-cage rotor, the influence of various types of voltage unbalance (continuous and intermittent) on its vibration characteristics is studied. It is shown that an increase in magnetic induction in the air gap of an AM causes an increase in radial vibration generating forces in the case of voltage unbalance. The obtained results indicate that alternating voltage unbalance can be riskier for AM operation than is constant voltage unbalance, in addition to having increased levels of AM vibrations. It is concluded that the use of new parameters of electric-energy quality allowing determination of instantaneous values of unbalance amplitude and the angle between symmetrical components of voltage of positive and negative phase-sequence is reasonable. The relevance of this research is confirmed by typical cases of AM shutoff at an oil-pumping station due to tripping of vibration-protection sensors.

To define the head at diagrams kilometers between pumping stations at the set productivity transfer

Solving problems calculations pumping modes (appointment setting regulatory pressure, the choice of optimum pumping mode, etc.) due to the technological constraints checking at each point on the linear part of the pipeline. By technological limitations include allowable working pressure of pipe sections of the pipeline and minimum pressure, providing complete oil pumping section. On average, 100 km pipeline reaches the number of such points 40·103 for the highlands and 18·103 - the plains. Multivariate decision tasks (eg, optimization ) provides check these restrictions for each analyzed variant that increases the calculations of 4-5. To reduce the volume and the computation time for solving multivariate problems advisable to carry out pre- test technological limitations before deciding the basic problem. Reduce the duration of the calculations due to the exclusion of inspections analyzed options in the calculation of the optimum mode is possible due to a lineout diagrams pressures for a given performance ( the area in which all modes set performance will be realizable and safe ). To do this , you must first determine the setting of automatic pressure regulation (ACS) on oil pumping stations (OPS) so that the actual diagrams pressures have not crossed epure pressures corresponding to the maximum working pressure of the pipeline sections (upper limit of the corridor ) and epure extending above the profile with some margin (the lower limit of the corridor). In this paper we describe an algorithm for constructing diagrams head technology corridor area , taking into account technological restrictions imposed by the linear part of the OPS and technology ( minimum operating pressure input OPS ) , and determine the appropriate setting ranges ACS pressure on the OPS . A mathematical formulation of the problem and methods for its solution.

Information measuring subsystem oil pumping station “Parabel”

Information-measurement subsystem oil pumping station (OPS) Parabel, located on the site of the main pipeline Alexandrov-Anzhero (OJSC AK Transneft ). Developed on the basis of a modern microprocessor equipment, automation, as well as high-speed digital data channels. The simple solution to meet the requirements set out in the guidance document Automation and remote control of trunk pipelines. «General provisions» (RD-35.240.0000-KTN-207-08).

Structure of microprocessor-based automation system of oil pumping station “Alexndrovskaya”

Structure of microprocessed-based automation system (MBAS) of oil pumping station (OPS) «Alexandrovskaya», located on the territory of Tomsk region and forming part of the Oil Transporting Joint Stock Company «Transneft», developed in accordance with the requirements of the guidance document «Complex of the typical design choices automation of OPSs and crude storages on the basis of modern standard solutions and components».

Distribution of total petroleum hydrocarbons in Dezful aquifer, Southwest of Iran

Determination of total petroleum hydrocarbon distribution (TPH) in groundwater of Dezful aquifer was the main purpose of this study. The study area, which is located between latitudes 32°00′ and 32°35′ N and longitudes 48°10′ and 49°35′ E, covers about 1,920 km2 in the north of Khuzestan Province, Iran. Hydrocarbon pollutants in the area were being released into the aquifer, from a variety of sources. An oil pipe crash accident, which occurred on 19 Feb. 2009 in the vicinity of the northern part of the study area, released about 6,000 barrels of crude oil to the Karkhe River. Other possible sources of TPH in the region are asphalt factories, gas stations, and the Sabzab oil pump station. Since the main source of drinking water in the Dezful area is groundwater reservoirs, this study would be very crucial, especially when there is considerable agricultural activity in the area as well. In order to determine the presence of TPH and heavy metals in the groundwater, samples were taken from wells with different usage within two periods, i.e., in Nov. 2008 and May 2009. The second sampling operation was carried out to determine the effect of the accident in the water resources. In situ groundwater parameter measurements including pH, dissolved oxygen, temperature, and electrical conductivity were also carried out in the field. Based on the results, there are four zones in the study area which were contaminated with TPH from different origins: (1) southeast of Dezful City, which was contaminated by Shokati gas station; (2) southeast of Shush City, which was contaminated by an asphalt factory; (3) southwest of Dezful City, which was contaminated by Sabzab oil pump station; and (4) the shores of Karkhe River which were contaminated due to the pipeline crash accident. This could be a serious threat to the environment and human health because TPH concentration was higher than the EPA standard in the study area. Heavy metals were not distributed in a uniform pattern in the aquifer. The concentrations were lower than the contamination level based on the EPA drinking standard, and there was no meaningful relation between concentrations of TPH and the heavy metals. It was recommended that a monitoring network should be designed to monitor oil contaminants in the ground and surface water monthly because of importance of the water resources and presence of potential oil contaminant sources.

Selection of optimum parameters of pumping equipment at trunk pipeline oil pumping stations

Selection of the number of functioning (normal) and standby pumps at trunk pipeline oil pumping stations (OPS) based on the cost of the life cycle of the pump as well as on the theory of discrete continuous-time Markovian processes and the graph theory is examined. The efficiency maintenance factor (reliability factor), which is equal to the ratio of the mean efficiency (throughput) of the operating (productive) section of the trunk oil pipeline (TOP) having a length of 500 km to the rated, was taken as the criterion of selection of the number of standby pumps at the OPS. For the parameters representing the degree of perfection of pump design, a graphical relationship of the reliability factor of the OPS with the degree of its redundancy has been derived, which helps determine, based on this assigned normative factor, the required degree of redundancy of pumps at the OPS and then the optimum head of the full-flow pump.

Iraq goes to polls, China seeks more oil and UK worries about petrol

This section summarizes downstream developments of the previous month. Exploration & Production are covered in 'Upstream Review'. Following a month in which US and British forces suffered their heaviest daily casualties, the Iraqi people voted in large numbers for a new national assembly (see 'Focus'). Violence, however, continued after the election and oil installations were reported damaged, including a pipeline linking the Kirkuk oil field to the Baiji refinery and a further line between Baiji and the refinery at Daurah. The export line connecting Kirkuk to the Turkish Mediterranean port of Ceyhan was also hit. Sabotage to electricity installations affected oil pumping stations in the south of the country cutting production and forcing the Iraqis to announce a 10% cut in contract volumes of Basrah Light until the middle of the year. An official investigation into the UN‐administered Oil‐for‐Food Programme concluded that the man in charge, Benon Sevan "repeatedly solicited" oil for a company called Africa Middle East Petroleum. A further report into other allegations of corruption in connection with the programme, which supervised export sales of Iraqi petroleum from 1993 to 2003, is due later this year. Relief at the apparent success of the Iraqi election caused crude oil prices to fall by about $3 a barrel. OPEC ministers did their bit for oil prices by agreeing not to cut output at their meeting on 30th January. Quotas remain unchanged at 27 mn bpd. The organization's target price band of $22‐28 a barrel, however, has been suspended. A new one will be discussed in March. Kuwait announced it was to increase security at its oil installations following an attack by armed men in an area close to the emirate's largest refinery, at Mina al‐Ahmadi.

Reliable and Safe Operation of Electric Drives of Pumps at Oil Pumping Stations

Reliable and Safe Operation of Electric Drives of Pumps at Oil Pumping Stations

The Use of Treatment Wetlands for Petroleum Industry Effluents

Although the use of treatment wetlands is well established for wastewater categories such as municipal waste, stormwater, and acid mine drainage water, their use in treating a variety of industrial and agricultural wastewaters is less well developed. Several large-scale wetland projects currently exist at oil refineries, and numerous pilot studies of constructed treatment wetlands have been conducted at terminals, gas and oil extraction and pumping stations, and refineries. This paper reviews treatment wetland performance for chemical oxygen demand, biochemical oxygen demand, trace organics, metals, toxicity, total suspended solids, nitrogen, and phosphorus. All of these contaminants can be reliably removed from wastewater by treatment wetlands. Pollutant removal is highly dependent on hydraulic loading and influent concentration and to a lesser extent on internal plant communities, water depth, and hydraulic efficiency. In most cases, data from petroleum industry wetland studies indicate that treatment wetlands are equally or more effective at removing pollutants from petroleum industry wastewaters than from other types of wastewater. Until industry-specific data are more complete, this finding can be used along with published rate constants from other wastewater categories to provide conservative estimates for sizing petroleum industry treatment wetlands.